enGene (ENGN) 10-K29 Jan 242023 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Oct. 31, 2023	Jan. 25, 2024
Entity Listings [Line Items]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Oct. 31, 2023
Document Fiscal Year Focus	2023
Entity File Number	001-41854
Entity Registrant Name	enGene Holdings Inc.
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	false
Entity Filer Category	Non-accelerated Filer
Current Fiscal Year End Date	--10-31
Document Fiscal Period Focus	FY
Entity Incorporation, State or Country Code	A1
Entity Central Index Key	0001980845
Entity Tax Identification Number	00-0000000
Document Financial Statement Error Correction [Flag]	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	false
Entity Address, Address Line One	4868 Rue Levy, Suite 220
Entity Address, City or Town	Saint-Laurent
Entity Address, State or Province	QC
Entity Address, Country	CA
Entity Address, Postal Zip Code	H4R 2P1
City Area Code	514
Local Phone Number	332-4888
Entity Ex Transition Period	true
Entity Public Float		$ 43,848,040
Entity Common Stock, Shares Outstanding		23,197,976
Auditor Name	KPMG LLP
Auditor Location	Montreal, Canada
Auditor Firm ID	85
Common Shares
Entity Listings [Line Items]
Trading Symbol	ENGN
Title of 12(b) Security	Common Shares
Security Exchange Name	NASDAQ
Warrants, each exercisable for one Common share, at an exercise price of $11.50 per share
Entity Listings [Line Items]
Trading Symbol	ENGNW
Title of 12(b) Security	Warrants, each exercisable for one Common Share, at an exercise price of $11.50 per share
Security Exchange Name	NASDAQ

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Oct. 31, 2023	Oct. 31, 2022
Current assets:
Cash and cash equivalents	$ 81,521	$ 20,434
Restricted investments	76	74
Investment tax credits receivable	2,343	1,336
Prepaid and other current assets	1,500	739
Assets, Current, Total	85,440	22,583
Property, Plant and Equipment, Net	589	387
Other assets	930	939
Total assets	86,959	23,909
Current liabilities:
Accounts payable	1,156	723
Accrued expenses and other current liabilities	3,539	3,116
Current portion of notes payable	562	1,265
Total current liabilities	5,257	5,104
Note payable, net of current portion	9,216	9,649
Convertible debentures		17,405
Convertible debenture embedded derivative liabilities		3,791
Warrant liabilities		11,456
Liabilities, Total	14,473	47,405
Shareholder's deficit:
Preferred shares, no par value; unlimited shares authorized, zero shares issued and outstanding as of October 31, 2023, and 2022.
Common shares, no par value; unlimited shares authorized, 23,197,976 and 665,767 (restated to reflect Reverse Recapitalization - see Notes 1 and 3) shares issued and outstanding as of October 31, 2023 and 2022, respectively.	259,373	16,390
Additional paid-in capital	13,717	7,683
Accumulated other comprehensive loss	(1,016)	(1,016)
Accumulated deficit	(199,588)	(99,671)
Total shareholder's equity (deficit)	72,486	(76,614)
Total liabilities, redeemable convertible preferred shares and shareholder's equity	$ 86,959	23,909
Class A Redeemable Convertible Preferred Shares
Current liabilities:
Redeemable convertible preferred shares value		1,899
Class B Redeemable Convertible Preferred Shares
Current liabilities:
Redeemable convertible preferred shares value		1,554
Class C Redeemable Convertible Preferred Shares
Current liabilities:
Redeemable convertible preferred shares value		$ 49,665

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Preferred stock no par value
Preferred stock shares authorized unlimited	Unlimited	Unlimited
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common stock no par value
Common stock shares authorized unlimited	Unlimited	Unlimited
Common stock shares issued	23,197,976	665,767
Common stock shares outstanding	23,197,976	665,767
Class A Redeemable Convertible Preferred Shares
Temporary equity no par value
Temporary equity shares authorized	0
Temporary equity shares authorized unlimited		unlimited
Temporary equity shares issued	0	266,696
Temporary equity shares outstanding	0	266,696
Temporary equity aggregate amount of redemption requirement	$ 0	$ 3,634
Class B Redeemable Convertible Preferred Shares
Temporary equity no par value
Temporary equity shares authorized	0
Temporary equity shares authorized unlimited		unlimited
Temporary equity shares issued	0	156,036
Temporary equity shares outstanding	0	156,036
Temporary equity aggregate amount of redemption requirement	$ 0	$ 1,533
Class C Redeemable Convertible Preferred Shares
Temporary equity no par value
Temporary equity shares authorized	0
Temporary equity shares authorized unlimited		unlimited
Temporary equity shares issued	0	5,560,607
Temporary equity shares outstanding	0	5,560,607
Temporary equity aggregate amount of redemption requirement	$ 0	$ 107,462

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Operating expenses:
Research and development	$ 16,458	$ 15,467
General and administrative	9,602	3,960
Total operating expenses	26,060	19,427
Loss from operations	26,060	19,427
Other (income) expense, net:
Change in fair value of convertible debentures embedded derivative liabilities	21,421	(269)
Change in fair value of warrant liabilities	(10,849)	3,326
Change in fair value of convertible debentures	56,212
Interest income	(1,117)	(129)
Interest Expense	4,953	1,423
Loss on extinguishment of convertible debentures	3,091
Other expense, net	129	662
Total other (income) expense, net	73,840	5,013
Net loss before provision for income taxes	99,900	24,440
Provision for income taxes	17	22
Net loss	99,917	24,462
Deemed dividend attributable to redeemable convertibleb preferred shareholders	4,822	4,562
Net loss attributable to common shareholders, basic	104,739	29,024
Net loss attributable to common shareholders, diluted	104,739	29,024
Other comprehensive loss (gain):
Foreign currency translation adjustment		(1,167)
Total comprehensive loss	$ 99,917	$ 23,295
Net loss per share of common shares, basic	$ 151.22	$ 44.30
Net loss per share of common shares, diluted	$ 151.22	$ 44.30
Weighted-average common shares outstanding, basic	692,609	655,153
Weighted-average common shares outstanding, diluted	692,609	655,153

CONSOLIDATED STATEMENTS OF REDE

CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED SHARES AND SHAREHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Shares	Additional Paid in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Class A Redeemable Convertible Preferred Shares	Class B Redeemable Convertible Preferred Shares	Class C Redeemable Convertible Preferred Shares
Beginning balance (in shares) at Oct. 31, 2021						266,696	156,036	5,560,607
Beginning balance at Oct. 31, 2021						$ 1,899	$ 1,554	$ 49,665
Beginning balance (in shares) at Oct. 31, 2021		650,858
Beginning balance at Oct. 31, 2021	$ (53,442)	$ 16,363	$ 7,587	$ (2,183)	$ (75,209)
Exercise of stock options (in shares)		14,909
Exercise of stock options	7	$ 27	(20)
Share-based compensation expense	116		116
Foreign currency translation adjustment	1,167			1,167
Net loss	24,462				(24,462)
Ending balance (in shares) at Oct. 31, 2022						266,696	156,036	5,560,607
Ending balance at Oct. 31, 2022						$ 1,899	$ 1,554	$ 49,665
Ending balance (in shares) at Oct. 31, 2022		665,767
Ending balance at Oct. 31, 2022	$ (76,614)	$ 16,390	7,683	(1,016)	(99,671)
Exercise of stock options (in shares)	84,072	47,186
Exercise of stock options	$ 44	$ 79	(35)
Issuance of common shares upon cashless exercise of options (in shares)		15,494
Issuance of common shares upon cashless exercise of options		$ 11	(11)
Conversion and exchange of Old enGene convertible debentures and common share warrants into enGene Holdings common shares and common share warrants in connection with the Reverse Recapitalization (in shares)		6,379,822
Conversion and exchange of Old enGene convertible debentures and common share warrants into enGene Holdings common shares and common share warrants in connection with the Reverse Recapitalization	140,393	$ 138,410	1,983
Conversion and exchange of redeemable convertible preferred shares into common shares in connection with the Reverse Recapitalization (in shares)						(266,696)	(156,036)	(5,560,607)
Conversion and exchange of redeemable convertible preferred shares into common shares in connection with the Reverse Recapitalization						$ (1,899)	$ (1,554)	$ (49,665)
Conversion and exchange of redeemable convertible preferred stock into common shares in connection with the Reverse Recapitalization (in shares)		5,983,339
Conversion and exchange of redeemable convertible preferred stock into common shares in connection with the Reverse Recapitalization	53,118	$ 53,118
Common shares and common share warrants issued upon Reverse Recapitalization and PIPE Financing, net of issuance costs of $11.1 million (in shares)		10,106,368
Common shares and common share warrants issued upon Reverse Recapitalization and PIPE Financing, net of issuance costs of $11.1 million	52,012	$ 51,365	647
Share-based compensation expense	3,450		3,450
Net loss	99,917				(99,917)
Ending balance (in shares) at Oct. 31, 2023						0	0	0
Ending balance (in shares) at Oct. 31, 2023		23,197,976
Ending balance at Oct. 31, 2023	$ 72,486	$ 259,373	$ 13,717	$ (1,016)	$ (199,588)

CONSOLIDATED STATEMENTS OF RE_2

CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED SHARES AND SHAREHOLDERS' EQUITY (DEFICIT) (Parenthetical) $ in Millions	12 Months Ended
	Oct. 31, 2023 USD ($)
Issuance costs	$ 11.1

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Cash Flows from operating activities:
Net loss	$ (99,917)	$ (24,462)
Adjustments to reconcile net loss to net cash used in operating activities
Non-cash interest expense	778	644
Loss on extinguishment of convertible debentures	3,091
Change in fair value of warrant liabilities	(10,849)	3,326
Change in fair value of convertible debenture embedded derivative liabilities	21,421	(269)
Change in fair value of convertible debentures	56,212
Debt issuance costs expensed upon issuance of convertible debentures recorded using the fair value option	924
Non-cash lease expense		(5)
Foreign currency adjustments	489	646
Share-based compensation expense	3,450	116
Depreciation of property and equipment	175	238
Changes in operating assets and liabilities:
Investment tax credit receivable	(1,007)	143
Prepaid expenses and other assets	(751)	(113)
Accounts payable	373	(197)
Accrued expenses and other liabilities	868	2,341
Net cash used in operating activities	(24,743)	(17,592)
Cash flows from investing activities
Purchases of property and equipment	(318)	(153)
Net cash used in investing activities	(318)	(153)
Cash flows from financing activities
Proceeds from PIPE financing	56,892
Proceeds from FEAC trust account in connection with Reverse Recapitalization	7,363
Payment of transaction costs in connection with the Reverse Recapitalization and PIPE Financing	(10,497)
Proceeds from issuance of convertible notes	38,000	18,400
Payment of issuance costs associated with convertible debentures	(924)	(44)
Repayment of convertible debentures	(3,176)
Proceeds from issuance of common shares upon the exercise of stock options	44	12
Repayments of term loan principal	(1,555)
Proceeds from issuance of term loan		11,000
Payments of debt issuance costs associated with the term loan		(391)
Repayment of debt		(1,010)
Net cash provided by financing activities	86,147	27,967
Effect of exchange rate changes on cash	1	(805)
Net increase in cash and cash equivalents	61,087	9,417
Cash and cash equivalents at beginning of period	20,434	11,017
Cash and cash equivalents at end of period	81,521	20,434
Supplemental cash flow information:
Cash paid for interest	1,398	615
Supplemental disclosure of non-cash investing and financing activities
Reverse Recapitalization and PIPE financing transaction costs included within accrued expenses and accounts payable	613
Conversion of Preferred Shares upon Reverse Recapitalization	53,118
Derivative liability recognized upon issuance and modification of convertible debentures		3,531
Conversion of Convertible Debentures upon Reverse Recapitalization	113,627
Reclassification of warrant liability to equity upon Reverse Recapitalization	1,983
Liabilities assumed upon Reverse Recapitalization	1,130
Warrant liability recognized upon issuance of term loan	1,420	$ 90
Settlement of derivative liability upon repayment and conversion of convertible debentures	25,217
Fixed assets included in accrued expenses and accounts payable	58
Settlement of April 2023 Notes through the issuance of May 2023 Notes and warrants	$ 8,000

Description of Business

Description of Business	12 Months Ended
Description of Business	Oct. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	1 . Description of Business enGene Holdings Inc. (together with its consolidated subsidiaries “enGene” or the “Company”) formed in connection with the Merger Agreement (as defined below) was incorporated as 14963148 Canada Inc. under the federal laws of Canada on April 24, 2023 and changed its name to enGene Holdings Inc. on May 9, 2023. enGene Inc., its wholly owned subsidiary since October 31, 2023 (now known as “enGene Inc.” or “Old enGene”) , is a biopharmaceutical company located in Montreal, Quebec, Canada, and incorporated pursuant to the Canada Business Corporations Act on November 9, 1999. a Cayman Island exempted company on August 9, 2021 . The Company is a clinical-stage biotechnology company focused on developing gene therapies to improve the lives of patients with its head office located in Montreal, Quebec, Canada. The Company is developing non-viral gene therapies based on its novel and proprietary dually derived chitosan, or “DDX”, gene delivery platform, which allows localized delivery of multiple gene cargos directly to mucosal tissues and other organs. Merger with Forbion European Acquisition Corp. Forbion European Acquisition Corporation (“FEAC”) was a Special Purpose Acquisition Company (“SPAC”), incorporate as a Cayman Island exempted company on August 9, 2021 and formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more business or entities. On October 31, 2023 (the “Closing Date”), the Company, FEAC, enGene Inc., consummated the merger (the "Reverse Recapitalization”) pursuant to a business combination agreement, dated as of May 16, 2023 (the “Merger Agreement”). The transaction was accounted for as a “reverse recapitalization” in accordance with accounting principles generally accepted in the United States (“GAAP”). Under this method of accounting, FEAC was treated as the “acquired” company for financial reporting purposes. This determination is primarily based on the fact that subsequent to the Reverse Recapitalization, senior management of Old enGene continues as senior management of the combined company; Old enGene identifies a majority of the members of the board of directors of the combined company; the name of the combined company is enGene Holdings Inc. and it utilizes Old enGene’s current headquarters, and Old enGene’s operations comprise the ongoing operations of the combined company. Accordingly, for accounting purposes, the Company is considered to be a continuation of Old enGene, with the net identifiable assets of FEAC deemed to have been acquired by Old enGene in exchange for Old enGene common shares accompanied by a recapitalization, with no goodwill or intangible assets recorded. The number of redeemable convertible preferred shares, number of common shares, net loss per common share, the number of warrants to purchase common shares, and the number of stock options and the related exercise prices of the stock options issued and outstanding prior to the Reverse Recapitalization, have been retrospectively restated to reflect an exchange ratio of approximately 0.18048 (the “Exchange Ratio”) established in the Merger Agreement. Operations prior to the Reverse Recapitalization are those of Old enGene. The Reverse Recapitalization was effected in the following steps: (i) two entities were incorporated to effect the transaction, Can Merger Sub, a Canadian corporation and a wholly owned subsidiary of FEAC and Cayman Merger Sub, a Cayman Islands exempt company and a direct wholly owned subsidiary of the Company; (ii) immediately prior to the Closing Date, Cayman Merger Sub was merged with and into FEAC with FEAC as the surviving entity, resulting in FEAC becoming a wholly owned subsidiary of the Company (the “Cayman Merger”); (iii) on the Closing Date, Can Merger Sub and Old enGene amalgamated pursuant to a plan of arrangement (the “Amalgamation”), resulting in Old enGene becoming a wholly owned subsidiary of the Company. As a result of the Reverse Recapitalization, the Company became a publicly traded company, and listed its ordinary shares and warrants on the Nasdaq Global Market under the symbols “ENGN” and “ENGNW,” respectively, commencing trading on November 1, 2023, with Old enGene, a subsidiary of the Company continuing the existing business operations. Upon the consummation of the Reverse Recapitalization, each FEAC Class A share and FEAC Class B share (collectively, the “FEAC Shares”) issued and outstanding immediately prior to the effective time of the Cayman Merger (including Forbion Growth Sponsor FEAC I B.V.’s, the (“FEAC Sponsor”) shares but excluding any dissenting FEAC Shares), was transferred to the Company and (i) for each FEAC Share, the Company issued to each shareholder one validly issued share of the Company’s common share; (ii) each warrant to purchase one FEAC share was assumed by the Company and converted into a warrant to purchase one share of the Company’s common share at an exercise price of $ 11.50 per share, with all fractional shares rounded down to the nearest whole share. Concurrently with the Cayman Merger, the Company redeemed its 10 Class B common shares held by its sole shareholder for $ 1 CAD per share, which was equal to the amount of capital that the sole shareholder of the Company contributed. As a result of the Reverse Recapitalization, all outstanding FEAC Shares of 3,670,927 held by FEAC Sponsor and shareholders were converted into the same number of the Company’s common shares and outstanding FEAC warrants of 5,029,444 held by FEAC warrant holders were converted into the same number of warrants to purchase one share of the Company’s common shares. On the Closing Date, each share of Old enGene common shares was cancelled and in exchange the holders thereof received approximately 0.18048 newly issued shares of the Company’s common share. In addition, each share of Old enGene’s redeemable convertible preferred shares outstanding immediately prior to the close of the Reverse Recapitalization was exchanged for shares of the Company’s common shares based on the same Exchange Ratio, with no dividends or distributions being declared or paid on Old enGene’s redeemable convertible preferred shares. Further, certain of Old enGene’s existing convertible notes outstanding immediately prior to the close of the Reverse Recapitalization were converted to Old enGene common shares at the conversion ratio in place at the time of conversion. In addition, all of Old enGene’s existing outstanding Class C warrants outstanding at the time of the Reverse Recapitalization were terminated and all outstanding warrants exercisable for common shares in Old enGene were exchanged for warrants exercisable for the Company’s common shares at the Exchange Ratio. No other terms and conditions underlying the warrant changed. At the closing of the Reverse Recapitalization, each share option of Old enGene common share was cancelled, and the holders thereof received in exchange newly issued share options of the Company’s common share based on the same Exchange Ratio. The modification of the share options did not result in any incremental compensation expense upon closing of the Reverse Recapitalization. Upon the close of the Reverse Recapitalization, 13,091,608 common shares of the Company were issued to the Old enGene’s equity and convertible note holders, 2,679,432 common share warrants of the Company were issued to Old enGene’s warrant holders (which are inclusive of the shares and warrants issued to the FEAC Sponsor), and 2,706,941 common share options of the Company were issued to Old enGene’s share option holders. As part of the Reverse Recapitalization, the Company received net proceeds of $ 7.4 million from the FEAC trust account, net of the redemption payment to FEAC’s public shareholders and FEAC expenses. PIPE Financing In connection with the Merger Agreement, FEAC, the Company, and certain investors (the “PIPE Investors”) entered into subscription agreements (the “Subscription Agreements”) pursuant to which, the PIPE Investors agreed to purchase FEAC Class A Shares and FEAC Warrants (or the Company’s shares and warrants when such obligation was assumed (the “Assumption”) by the Company after the completion of the Cayman Merger and prior to the consummation of the PIPE Financing), for an aggregate commitment amount of $ 56.9 million. Concurrent with the execution of the Merger Agreement, FEAC, the FEAC Sponsor, Forbion Growth Opportunities Fund I Cooperatief U.A. and the other holders of FEAC Class B Shares, Old enGene, the Company and the other parties named therein entered into the sponsor and insiders letter agreements (the “Side Letter Agreements”), pursuant to which the FEAC Sponsor agreed to surrender and in effect issue to PIPE Investors, 1,789,004 FEAC Class B shares and 5,463,381 FEAC private placement warrants, immediately prior to the closing of the Reverse Recapitalization. Pursuant to the Subscription Agreements and Side Letter Agreements, the Company issued 6,435,441 shares of the Company’s common share and 2,702,791 warrants to purchase the Company’s common share for an aggregate purchase price equal to $ 56.9 million. Convertible Bridge Financing Prior to the execution and delivery of the Reverse Recapitalization Agreement, Old enGene agreed to certain modifications of existing convertible indebtedness in an aggregate principal amount of $ 18.4 million (the “2022 Convertible Notes” and, together with the Old enGene warrants to be issued by Old enGene as consideration for such modifications, the “Amended 2022 Financing”). Concurrently with the execution of the Merger Agreement, Old enGene also entered into agreements pursuant to which it issued new convertible indebtedness and warrants (i) for cash in an aggregate principal amount of $ 30.0 million and (ii) in settlement of the April 2023 Notes in an aggregate principal amount of $ 8.0 million (collectively, the “May 2023 Notes” and, together with the warrants purchased concurrently, the “2023 Financing”; the 2023 Financing together with the Amended 2022 Financing, the “Convertible Bridge Financing”). In connection with the Reverse Recapitalization, the Convertible Bridge Financing indebtedness was converted into 35,349,238 of Old enGene common at the conversion ratio in place at the time of conversion, which was exchanged to 6,379,822 of the Company’s common shares based on the aforementioned exchange ratio (see Note 9 for further detail). In relation to the Amended 2022 Financing, the holders of the 2022 Convertible Notes received warrants to purchase Old enGene common shares and the holders of the 2023 Convertible Notes were issued warrants in connection with the issuance of the 2023 Convertible Notes. On the closing of the Reverse Recapitalization, these warrants converted through the transaction to 2,679,432 warrants to purchase common shares of the Company based on the aforementioned exchange ratio. Immediately after giving effect to the Reverse Recapitalization and the PIPE Financing, the Company has 23,197,976 common shares and 10,411,641 warrants outstanding. Liquidity and Going Concern In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, the Company has evaluated whether there are any conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date these consolidated financial statements are issued. The Company’s consolidated financial statements have been prepared assuming the Company will continue as a going concern, which presumes the Company will continue in operation for the foreseeable future and will be able to realize its assets and discharge its liabilities and commitments in the ordinary course of business. As an emerging growth entity, the Company has devoted substantially all of its resources since inception to organizing and staffing the Company, raising capital, establishing its intellectual property portfolio, acquiring or discovering product candidates, research and development activities for developing non-viral gene therapies and other compounds, establishing arrangements with third parties for the manufacture of its product candidates and component materials, and providing general and administrative support for these operations. As a result, the Company has incurred significant operating losses and negative cash flows from operations since its inception and anticipates such losses and negative cash flows will continue for the foreseeable future. The Company has not yet commercialized any product candidates and does not expect to generate revenue from sales of any product candidates or from other sources for several years, if at all. The Company has incurred a net loss of $ 99.9 million and negative cash flows from operating activities of $ 24.7 million for year ended October 31, 2023, and, as of that date, has an accumulated deficit of $ 199.6 million. To date, the Company has not generated any revenues and has financed its liquidity needs primarily through the Reverse Recapitalization, PIPE Financing, debt and convertible debentures, and issuance of redeemable convertible Preferred Shares and warrants. The Company’s ability to continue as a going concern depends on its ability to successfully develop and commercialize its products, achieve and maintain profitable operations, as well as the adherence to conditions of outstanding loans (see note 18). The Company will require additional financing in order to fund its future expected negative cash flows and Management’s plans are to raise additional financing. While the Company has historically been successful in securing financing, raising additional funds is dependent on a number of factors outside of the Company’s control, and as such there is no assurance that it will be able to do so in the future. These conditions indicate the existence of a material uncertainty that raise substantial doubt about the Company’s ability to continue as a going concern and, therefore, that it may be unable to realize its assets and discharge its liabilities in the normal course of business. These consolidated financial statements do not include any adjustments to the amounts and classification of assets and liabilities that results from the outcome of this uncertainty. Such adjustments could be material.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Oct. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates (“ASU’s”) of the Financial Accounting Standards Board (“FASB”). The consolidated financial statements are expressed in US dollars. The consolidated financial statements have been prepared on a historical cost basis, except for items that are required to be accounted for at fair value. As the merger with FEAC has been accounted for as a reverse recapitalization, the historical operations of the Company represent that of Old enGene which is the accounting predecessor. The number of common shares, net loss per common share, the number of warrants to purchase common shares, and the number of stock options and the related exercise prices of the stock options issued and outstanding prior to the Reverse Recapitalization have been retrospectively restated to reflect the Exchange Ratio of approximately 0.18048 established in the Merger Agreement. For additional information on the Reverse Recapitalization, please refer to Note 3. Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include but are not limited to the accrual of research and development expenses, the recoverability of investment tax credits receivable and the valuations of common shares, redeemable convertible preferred shares, warrants to purchase redeemable convertible preferred shares, convertible debentures, embedded derivatives on convertible debt and share-based compensation. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. Actual results could differ from those estimates and such differences may be material to the consolidated financial statements. Segment Information Operating segments are defined as components of an entity about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company operates as a single business segment focused on research, discovery, and clinical development of human gene therapy products. The majority of the Company’s tangible assets are held in Canada. Functional Currency Change Prior to November 1, 2022, Old enGene’s functional currency was the Canadian dollar (“CAD”), and its reporting currency was the U.S. dollar (“USD”). During the period, Old enGene reassessed its functional currency and determined that its functional currency changed from the Canadian dollar to the USD based on management’s analysis as a result of evaluating criteria within ASC 830 . The change in functional currency is accounted for prospectively from November 1, 2022, and prior year financial statements have not been restated for the change in functional currency. All assets and liabilities were reported using the same USD values as previously reported under the USD reporting currency described above. As a result, the cumulative translation adjustment balance as of October 31, 2022, is carried forward and will remain unchanged. The Company reported net realized and unrealized foreign currency transaction losses of $ 0.1 million and $ 0.7 million for the years ended October 31, 2023 and 2022, respectively. These gains and losses are reflected within other expense (income), net in the Company’s consolidated statements of operations and comprehensive loss. Risk of Concentrations of Credit and Off-Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash. The Company regularly maintains deposits in accredited financial institutions in excess of federally insured limits. As of October 31, 2023, the Company held cash deposits at Silicon Valley Bank, or SVB, in excess of Federal Deposit Insurance Corporation (FDIC) insured limits. On March 10, 2023, SVB was closed by the California Department of Financial Protection and Innovation, and the FDIC, was appointed as receiver. No losses were incurred by the Company on deposits that were held at SVB. Management believes that the Company is not currently exposed to significant credit risk as the Company’s deposits were held in custody at third-party financial institutions. The Company is dependent on third-party Contract Development and Manufacturing Organization (“CDMOs”) and Contract Research Organization (“CRO”) with whom it does business. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements of active pharmaceutical ingredients and formulated drugs in order to perform research and development activities in its programs. The Company also relies on a limited number of third-party CROs to perform research and development activities on its behalf. These programs could be adversely affected by significant interruption from these providers. Cash and Cash Equivalents The Company considers all short-term, highly liquid investments purchased with an original maturity of three months or less at the date of purchase to be cash equivalents. The Company’s cash and cash equivalents include bank balances, demand deposits and other short-term, highly liquid investments. Cash and cash equivalents have been measured at amortized cost. The Company had no cash equivalents as of the years ended October 31, 2023 and 2022. Restricted Investments Restricted investments consist of temporary holdings of highly liquid Canadian guaranteed investment certificates held with a bank and is used as a guarantee of the Company’s short term borrowings and security deposits for it's lease agreements. As of October 31, 2023, the Company classified $ 70 thousand of restricted investments within other assets on the Consolidated Balance Sheet associated with its lease agreement that has a term longer than twelve months. Property and Equipment Property and equipment are comprised mainly of research and development equipment, computer hardware and software, office furniture and equipment, and leasehold improvements. Property and equipment are stated at cost less accumulated depreciation and accumulated impairment losses, if applicable. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset, as follows: Estimated Useful Life Lab equipment 5 years Computer equipment 3 years Computer software 5 years Office furniture 5 years Leasehold improvements Shorter of remaining lease term or useful life Estimated useful lives are periodically assessed to determine if changes are appropriate. Maintenance and repairs are charged to expense as incurred. When assets are retired or otherwise disposed of, the cost of these assets and related accumulated depreciation or amortization are eliminated from the consolidated balance sheet and any resulting gains or losses are included in the consolidated statements of operations and comprehensive loss in the period of disposal. The Company reviews long-lived assets, such as property and equipment, for impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. If indicators of impairment are present, the assets are tested for recoverability by comparing the carrying amount of the assets to the related estimated future undiscounted cash flows that the assets are expected to generate. If the expected undiscounted cash flows are less than the carrying value of the assets, then the assets are considered to be impaired and its carrying value is written down to fair value, based on the related estimated discounted future cash flows. To date, no such impairment losses have been recorded. Leases The Company adopted FASB ASC 842 with an effective date of November 1, 2019, using the modified retrospective transition approach which uses the effective date as the date of initial application. In accordance with ASC 842, the Company determines whether an arrangement is or contains a lease at inception. A contract is or contains a lease if the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. The Company classifies leases at the lease commencement date, when control of the underlying asset is transferred from the lessor to the lessee, as operating or finance leases and records a right-of-use (“ROU”) asset and a lease liability on the consolidated balance sheet for all leases with an initial lease term of greater than 12 months. The Company has elected to not recognize leases with a lease term of 12 months or less on the balance sheet. The Company enters into contracts that contain both lease and non-lease components. Non-lease components may include maintenance, utilities, and other operating costs. For leases of real estate, the Company combines the lease and associated non-lease components in its lease arrangements as a single lease component. Variable costs, such as utilities or maintenance costs, are not included in the measurement of right-of-use assets and lease liabilities, but rather are expensed when the event determining the amount of variable consideration to be paid occurs. Lease assets and liabilities are recognized at the lease commencement date based on the present value of the lease payments over the lease term using the discount rate implicit in the lease if readily determinable. If the rate implicit is not readily determinable, the Company utilizes an estimate of its incremental borrowing rate based upon the available information at the lease commencement date. ROU assets are further adjusted for initial direct costs, prepaid rent, or incentives received. Operating lease payments are expensed using the straight-line method as an operating expense over the lease term. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Fair Value Measurements of Financial Instruments Certain assets and liabilities of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: o Level 1—Quoted prices in active markets for identical assets or liabilities. o Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. o Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s convertible debentures embedded derivative, certain of its convertible debentures and warrant liabilities were carried at fair value, and were determined according to Level 3 inputs in the fair value hierarchy described above. Fair Value Option The Company elected the fair value option of accounting of ASC 825 for all convertible debentures issued in fiscal 2023 from their issuance date in order to not have to bifurcate any embedded derivatives in accordance with ASC 815. The notes for which the fair value option of accounting is elected are recorded at fair value upon the date of issuance and subsequently remeasured to fair value at each reporting period. Changes in the fair value of the notes accounted for at fair value, which include accrued interest, if any, are recorded as a component of other expense (income), net in the consolidated statement of operations and comprehensive loss. The Company has not elected to present interest expense separately from changes in fair value and therefore will not present interest expense associated with the notes. Any changes in fair value caused by instrument-specific credit risk are presented separately in other comprehensive income. During the year ended October 31, 2023, the Company did not record any changes in fair value related to instrument-specific credit risk. All costs associated with the issuance of the convertible debentures accounted for using the fair value option were expensed upon issuance. Debt Issuance Costs The Company capitalizes certain legal, accounting, and other third-party fees that are directly associated with the issuance of debt not accounted for using the fair value option as debt issuance costs. Debt issuance costs are recorded as a direct reduction of the carrying amount of the associated debt on the Company’s consolidated balance sheets and amortized as interest expense on the Company’s consolidated statements of operations and comprehensive loss using the effective interest method. Convertible Debenture Embedded Derivative Liabilities The Company’s convertible debentures contained certain features that meet the definition of embedded derivatives requiring b ifurcation from the convertible debenture instrument, for which the fair value option was not elected, as a separate compound derivative. The convertible debenture embedded derivative liabilities are initially measured at fair value on issuance and is subject to remeasurement at each reporting period with changes in fair value recognized in the change in fair value of derivative liabilities, net in the consolidated statements of operations and comprehensive loss. Common Share and Preferred Share Warrants The Company accounts for its common share warrants and redeemable convertible preferred shares warrants issued in connection with its various financing transactions based upon the characteristics and provisions of the instrument. Warrants that have been determined to be classified as liabilities are recorded on the consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value at each reporting period, with the changes in fair value recognized in the change in fair value of warrant liabilities, net in the consolidated statements of operations and comprehensive loss. The Company adjusted the liability for changes in the fair value of these warrants until the earlier of the exercise of the warrants, the expiration of the warrants, or until such time as the warrants were no longer considered liability. Convertible Debentures The Company’s 2022 Notes (as defined in Note 9) are convertible debentures that consist of a debt instrument, a minimum interest obligation, and a share conversion feature. Certain of the convertible debentures issued by the Company also included warrants to purchase redeemable convertible preferred shares, which were classified as liabilities. The Company identified embedded derivatives related to certain share conversion and repayment features within the convertible notes that required bifurcation as a single compound derivative instrument. At inception, the Company utilized the residual method to determine the value of the debt instrument based on the difference between gross proceeds and the estimated fair value of the embedded derivative and any warrants that were issued. The debt instrument is accounted for using the amortized cost method. The discounts on debt resulting from any issuance costs, embedded derivatives and warrants are amortized over the life of the debt using the effective interest method. The issuance costs allocated to the embedded derivatives and warrants are expensed at inception. Research and Development Expenses Research and development expenses are comprised primarily of costs incurred for our drug discovery efforts and development of our product candidates. These expenses include salaries, employee benefits, and share-based compensation expense for our research and development personnel, materials, supplies, depreciation on and maintenance of research equipment, the cost of services provided by outside CROs and consultants to conduct research and development activities including costs of clinical trials and manufacturing, and the allocable portions of facility costs, such as rent, utilities, and general support services. All costs associated with research and development are expensed as incurred. Management estimates the Company’s accrued research and development expenses as of each balance sheet date in the Company’s financial statements based on facts and circumstances known to the Company at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Nonrefundable advance payments for goods and services are deferred and recognized as expense in the period that the related goods are consumed or services are performed. Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications such as direct application fees, and legal and consulting expenses are expensed as incurred due to the uncertainty about the recovery of the expenditure. Patent-related costs are classified as general and administrative expenses within the Company’s consolidated statements of operations. Share-Based Compensation The Company has an incentive equity plan (the “2023 Incentive Equity Plan” or the “2023 Plan”), whereby employees render services as consideration for equity instruments. The Plan was adopted on October 31, 2023 upon the completion of the Reverse Recapitalization and superseded Old enGene’s employee stock option plan (the “ESOP”) and equity incentive plan (the “EIP”) (collectively, the “Old Plans”). The Company measures all share-based awards granted to employees, officers, directors and non-employees based on their fair value on the date of the grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award. The Company accounts for forfeitures of its share-based awards as they occur. The Company issues share-based awards with service-based vesting conditions and awards with both performance and service-based vesting conditions. For share-based awards with service-based vesting conditions, the Company records the expense using the straight-line method including when such awards have graded vesting. For share-based awards with both performance and service-based vesting conditions, the Company records the expense using an accelerated attribution method, once the performance conditions are considered probable of being achieved, using management’s best estimate. The fair value of each stock option is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the fair value of the Company’s common shares, expected share price volatility, the expected term of the award, the risk-free interest rate for a period that approximates the expected term of the option, and the Company’s expected dividend yield. The Company determines the volatility for awards granted based on an analysis of reported data for a group of guideline companies that have issued options with substantially similar terms. The expected volatility has been determined using a weighted average of the historical volatility measures of this group of guideline companies. The expected option term was calculated based on the simplified method for awards with only service based vesting conditions, which uses the midpoint between the vesting date and the contractual term, as the Company does not have sufficient historical data to develop an estimate based on participant behavior. For awards with both performance and service based vesting conditions, the expected term has been determined using management’s best estimate considering the characteristics of the award, contractual life, the timing of the expected achievement of the performance conditions, the remaining time-based vesting period, if any, and comparison to expected terms used by peers. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company has not paid, and does not anticipate paying, cash dividends on its common shares; therefore, the expected dividend yield is assumed to be zero. Prior to the consummation of the Reverse Recapitalization, because there was no public market for the Company’s common shares, the Board of Directors has determined the fair value of the Company’s common stock based on third-party valuations of the Company’s common shares. Initially, the estimated enterprise equity value of the Company was determined using a market approach and/or cost approach by considering the weighting of scenarios estimated using a back-solve method based on recent financing transactions of the Company. This value was then allocated towards the Company’s various securities of its capital structure using an option pricing method, or OPM, and a waterfall approach based on the order of the superiority of the rights and preferences of the various securities relative to one another. Significant assumptions used in the OPM to determine the fair value of common shares include volatility, discount for lack of marketability, and the expected timing of a future liquidity event such as an initial public offering (“IPO”), or sale of the Company in light of prevailing market conditions. This valuation process creates a range of equity values both between and within scenarios. In addition, the Company’s Board of Directors considered various objective and subjective factors to determine the fair value of the Company’s common shares as of each grant date, including the prices at which Old enGene sold shares of redeemable convertible preferred shares and the superior rights and preferences of the redeemable convertible preferred shares relative to its common shares at the time of each grant, external market conditions, the progress of the Company’s research and development programs, the Company’s financial position, including cash on hand, and its historical and forecasted performance and operating results, and the lack of an active public market for the Company’s common shares and redeemable convertible preferred shares, among other factors. The assumptions underlying these valuations represented management’s best estimate, which involved inherent uncertainties and the application of management’s judgment and these valuations are sensitive to changes in the unobservable inputs. As a result, if the Company had used different assumptions or estimates or if there are changes to the unobservable inputs, the fair value of its common shares and share-based compensation expense could have been materially different. Subsequent to becoming a publicly traded Company upon the consummation of the Reverse Recapitalization, the fair value of common stock underlying equity awards is based on the market price of the Company’s common stock at the date of the grant. The Company’s share-based compensation expense is recorded in general and administrative and research and development expenses in the Company’s consolidated statements of operations and comprehensive loss. Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the Company’s consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on differences between the consolidated financial statement carrying amounts and the tax basis of the assets and liabilities using the enacted tax rates in effect in the years in which the differences are expected to reverse. A valuation allowance against deferred tax assets is recorded if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of benefit that may be recognized is the largest amount that has a greater than 50 % likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. Comprehensive Loss Comprehensive loss includes net loss as well as other changes in shareholders’ deficit that result from transactions and economic events other than those with shareholders. The Company’s comprehensive loss includes foreign currency translation. Net Loss Per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common shares. Net loss per share attributable to common shareholders is calculated using the two-class method, which is an earnings allocation formula that determines net loss per share for the holders of the Company’s common shares and participating securities. Net loss attributable to common shareholders is allocated first based on dividend rights and then to common and preferred shareholders based on ownership interests on an as-converted basis as if all the earnings for the period had been distributed. When considering the impact of the convertible equity instruments, diluted net loss per share is computed using the more dilutive of (a) the two-class method or (b) the if-converted method. The Company allocates earnings first to preferred shareholders and warrant holders based on dividend rights and then to common and preferred shareholders and warrant holders based on ownership interests. The weighted-average number of common shares included in the computation of diluted net loss gives effect to all potentially dilutive common equivalent shares, including outstanding stock options, warrants, and the potential issuance of common shares upon the conversion of the convertible notes. Common stock equivalent shares are excluded from the computation of diluted net loss per share if their effect is antidilutive. In periods in which the Company reports a net loss attributable to common shareholders, diluted net loss per share attributable to common shareholders is generally the same as basic net loss per share attributable to common shareholders because dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. See Note 13, Net Loss per Share, for further detail. Deferred Transaction Costs The Company capitalized certain legal, professional accounting and other third-party fees that were directly associated with the Reverse Recapitalization and PIPE Financing as deferred transaction costs until such transaction was consummated. After the consummation of such transaction, these costs were recorded within equity as a reduction of the common share and warrants value within additional paid in capital, for both instruments issued and assumed to shareholders of FEAC and to PIPE financing investors, were allocated to each on a relative fair value basis. The Company incurred a total of $ 11.3 million of transaction costs as part of the Reverse Recapitalization and PIPE Financing. The Company did no t have any deferred transaction costs recorded on the balance sheet as of October 31, 2023 and 2022. In addition, transaction costs of $ 0.8 million related to the issuance of the April 2023 Notes and the May 2023 Notes for which the fair value option of accounting was elected and those allocated to the liability classified warrants issued as part of the 2023 Financing are not deferred and are included in general and administrative expenses in the Company’s consolidated statements of operations and comprehensive loss. Government Assistance Programs for Research and Development Expenditures The Company was eligible to claim Canadian federal and provincial tax credits as a Canadian controlled private corporation (“CCPC”) on eligible research and development expenditures through September 2023, at which time the Company lost its status as a CCPC. In addition, effective for fiscal 2023, the Company’s maximum refundable tax credits were reduced due to the Company’s taxable capital, as defined by the tax authorities, which reduction in credits has been recorded in the fourth quarter. The Canadian federal government offers a tax incentive to companies performing research and development activities in Canada and this tax incentive can be refunded or used to reduce federal income taxes in Canada otherwise payable. Such credits, if not refunded or used in the year earned, can be carried forward for a period of twenty years. The Quebec provincial government offers a similar refundable incentive. The investment tax credits recorded are based on management’s estimates of amounts expected to be recovered and are subject to audit by the taxation authorities, the resulting adjustments of which could be significant. Following the loss of CCPC status, the Company’s eligible research and development expenditures tax credits will be earned at a lower rate and some will no longer be refundable. Amounts received or receivable resulting from government assistance programs, including investment tax credits for research and development, are recognized when there is reasonable assurance that the amount will be received, and all attached conditions will be complied with. Reimbursements of eligible research and development expenditures pursuant to government assistance programs are received in cash. The amounts receivable are recorded as reductions of research and development costs when the related costs have been incurred and there is reasonable assurance regarding collection of the claim. During the years ended October 31, 2023 and 2022, the Company recorded $ 1.1 million and $ 1.4 million, respectively, as a reduction of research and development expense associated with research and development investment tax credits. Recently Adopted Accounting Pronouncements In December

Reverse Recapitalization

Reverse Recapitalization	12 Months Ended
Reverse Recapitalization	Oct. 31, 2023
Stockholders' Equity Note [Abstract]
Reverse Recapitalization	3. Reverse Recapitalization On October 31, 2023 (the "Closing Date”), FEAC, Old enGene, and the Company consummated the merger pursuant to the Merger Agreement, dated as of May 16, 2023 . As a result of the Reverse Recapitalization, the Company became a publicly traded company, with old enGene, a subsidiary of the Company, continuing the existing business operations. At the effective time of the Reverse Recapitalization: • each outstanding share of Old enGene common stock was exchanged for shares of the Company’s common stock at the Exchange Ratio; • each share of Old enGene’s redeemable convertible preferred shares outstanding immediately prior to the close of the Reverse Recapitalization was exchanged for shares of the Company’s common shares based on the same Exchange Ratio, with no dividends or distributions being declared or paid on Old enGene’s redeemable convertible preferred shares; • the 2022 Notes and May 2023 Notes (each as defined in Note 9) of Old enGene’s existing convertible notes outstanding immediately prior to the close of the Reverse Recapitalization were converted to Old enGene common shares at the conversion ratio in place at the time of conversion and were exchanged for shares of the Company at the Exchange Ratio; and • each outstanding option to purchase old enGene common stock became fully vested and converted into an option to purchase a number of shares of the Company’s common stock equal to the number of shares of old enGene common stock subject to such option multiplied by the Exchange Ratio, rounded down to the nearest whole share, at an exercise price per share equal to the current exercise price per share for such option divided by the Exchange Ratio, rounded up to the nearest whole cent; • all of Old enGene’s outstanding warrants exercisable for common shares in Old enGene were exchanged for warrants exercisable for the Company’s common shares using the Exchange Ratio, with the warrants maintaining the same terms and conditions; • all of Old enGene’s existing outstanding Class C warrants outstanding at the time of the Reverse Recapitalization were terminated; and • all outstanding FEAC Shares of 3,670,927 held by FEAC Sponsor and shareholders were converted into the same number of the Company’s common shares, and outstanding FEAC warrants of 5,029,444 held by FEAC warrant holders were converted into the same number of warrants to purchase one share of the Company’s common shares. Upon the close of the Reverse Recapitalization, 13,091,608 common shares of the Company were issued to the Old enGene’s equity and convertible note holders, 2,679,432 common share warrants of the Company were issued to Old enGene’s warrant holders, and 2,706,941 common share options of the Company were issued to Old enGene’s share option holders. In connection with the Merger Agreement, FEAC, the Company, and PIPE Investors entered into Subscription Agreements pursuant to which, the PIPE Investors have agreed to purchase the Company’s shares and warrants for an aggregate commitment amount of $ 56.9 million. As part of the PIPE Financing, the Company issued 6,435,441 shares of the Company’s common shares and 2,702,791 warrants to purchase the Company’s common shares for an aggregate purchase price equal to $ 56.9 million on October 31, 2023. The common shares and warrants issued as part of the PIPE Financing were determined to be equity classified. The proceeds were allocated between the common shares and warrants on a relative fair value basis, taking into consideration the quoted market price of the FEAC common shares and warrants on the close of the market on October 31, 2023, resulting in $ 56.1 million being allocated to the common shares and $ 0.8 million being allocated to the warrants. In connection with the Merger Agreement, FEAC, the FEAC Sponsor, Forbion Growth Opportunities Fund I Cooperatief U.A. and the other holders of FEAC Class B Shares, Old enGene, the Company and the other parties named therein entered into the Side Letter Agreements, pursuant to which the FEAC Sponsor agreed to surrender and in effect issue to PIPE Investors FEAC Class B shares and FEAC private placement warrants, immediately prior to the closing of the Reverse Recapitalization. Immediately following the Reverse Recapitalization and the PIPE Financing, the Company has 23,197,976 common shares and 10,411,641 warrants outstanding. On October 31, 2023, as part of the close of Reverse Recapitalization, the Company received proceeds of $ 7.4 million, from the FEAC trust account, net of the redemption payment to FEAC’s public shareholders and cash paid from the trust for FEAC expenses. Additionally, the Company received proceeds of approximately $ 56.9 million from the PIPE Financing. Upon the closing of the Reverse Recapitalization and PIPE Financing, the Company incurred $ 6.0 million in transaction costs, which was withheld from the proceeds received. The Company incurred a total of $ 11.1 million of transaction costs associated with the Reverse Recapitalization and PIPE Financing, of which $ 5.1 million was previously deferred by the Company and netted against the proceeds upon close. The transaction costs were allocated to the common shares and warrants on a relative fair value basis and netted against the proceeds upon close. The following table summarizes the elements of the net proceeds from the Reverse Recapitalization and PIPE Financing transaction as of October 31, 2023: Recapitalization Cash – FEAC’s Trust Account and Cash (net of redemptions $ 7,363 Cash – PIPE Financing 56,892 Less transaction costs withheld from cash proceeds on Closing ( 6,024 ) Cash proceeds received from the Reverse Recapitalization and $ 58,231 Less transaction costs previously deferred and netted against ( 5,086 ) Net cash proceeds from the Reverse Recapitalization and PIPE 53,145 The total transaction costs of $ 11.1 million were related to third-party legal, accounting services and other professional services to consummate the Reverse Recapitalization and the PIPE Financing incurred by Old enGene. These transaction costs are allocated between common shares and additional paid-in capital, based on the relative fair value of the common shares and warrants issued upon the close of the Reverse Recapitalization, on the Company’s consolidated balance sheet as the Company’s common shares have no par value. The following table summarizes the number of shares of common stock outstanding immediately following the consummation of the Reverse Recapitalization and PIPE Financing transaction: Number of Shares Old enGene Shareholders (Excluding Convertible Notes) 6,711,786 FEAC Shareholders, including sponsor's and shareholder with 3,670,927 Convertible Notes - Common Shares Issued 6,379,822 Common shares issued to PIPE Investors 6,435,441 Total common shares outstanding immediately after the 23,197,976

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Oct. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The Company did no t have any financial assets or liabilities that required fair value measurement on a recurring basis as of October 31, 2023. The following table presents the Company's fair value hierarchy for financial liabilities measured at fair value as of October 31, 2022: October 31, 2022 Description Total Quoted Prices in Significant Other Significant Other Liabilities Convertible debenture embedded derivative liabilities $ 3,791 $ — $ — $ 3,791 Warrant liabilities 11,456 — — 11,456 Total financial liabilities $ 15,247 $ — $ — $ 15,247 As of October 31, 2022, the Company had no financial assets that required fair value measurement on a recurring basis. As of October 31, 2022, the Company had Level 3 financial liabilities that were measured at fair value on a recurring basis. The Company’s convertible debenture embedded derivative liabilities and warrant liabilities were carried at fair value determined using Level 3 inputs in the fair value hierarchy. The assumptions underlying these valuations represented management’s best estimate, which involved inherent uncertainties and the application of management’s judgment, and these valuations are sensitive to changes in the unobservable inputs. As a result, if the Company had used different assumptions or estimates, or if there are changes to the unobservable inputs, the fair value of the warrants could have been materially different. During the year ended October 31, 2023 and 2022, there were no transfers or reclassifications between fair value measure levels of liabilities. The carrying values of all financial current assets, accounts payable and accrued expenses approximate their fair values due to the short-term nature of these assets and liabilities. Convertible Debentures Embedded Derivative Liabilities The Company’s convertible debentures contained equity conversion options, and certain repayment features, that have been identified as a single compound embedded derivative requiring bifurcation from the host contract for the convertible debentures for which the fair value has not been elected. The Company estimated the fair value of the convertible debenture embedded derivative liabilities on issuance using a probability weighted scenario expected return model. The estimated probability and timing of underlying events triggering the conversion and liquidity repayment features and probability of exercise of the extension features within the convertible debentures as well as discount rates, volatility and share prices are inputs used to determine the estimated fair value of the embedded derivative. The assumptions ranges that the Company used to determine the fair value of the convertible debentures embedded derivative liabilities for the 2022 Notes and BDC Notes that were outstanding as of each respective period (refer to Note 9 for description of notes) were as follows: Immediately prior to settlement on October 31, As of October 31, 2022 Probability of qualified financing* 100 % 60 % Volatility n/a 85 % Class C Preferred Share price (CAD) n/a $ 2.20 Liquidity price at conversion of listing event* $ 8.84 n/a Fair value of common share at conversion of listing $ 21.70 $ n/a Discount rate** 18.4 % 10.4 - 18.4 % Expected time to respective scenarios 0.0 years 0.4 years * The probability represents the cumulated probabilities of conversion at various dates before maturity. The probability includes the probability of a SPAC transaction (which corresponds to a listing event for the 2022 Notes and to a liquidity event for the BDC Notes). Volatility and Class C Preferred share price is not applicable and expected time to scenario is 0.0 years as of October 31, 2023 as the 2022 Notes converted to shares upon the Reverse Recapitalization and the BDC Notes were repaid in full. * The liquidity price at the conversion of a listing event represents the conversion price of the 2022 Notes upon the merger with FEAC, and the fair value per common share at conversion of a listing event represents the quoted market price of the FEAC common shares on the close of the market on October 31, 2023, immediately prior to the settlement upon the completion of the Reverse Recapitalization. **** Discount rate includes credit risk, discount for lack of marketability and other factors considered in the model. Upon the close of the Reverse Recapitalization the 2022 Notes were converted and exchanged for common shares of the Company, resulting in an extinguishment of the 2022 Notes and related embedded derivative liability. Further the BDC Note was repaid in full and the related embedded derivative liability was extinguished. Refer to Note 3 and Note 9. Immediately prior to the conversion and exchange of the 2022 Notes as part of the Reverse Recapitalization, the embedded derivative was measured to a fair value of $ 24.8 million. Further immediately prior to the repayment of the BDC Note, the embedded derivative liability was measured to a fair value of $ 0.4 million. The following table provides a summary of the change in the estimated fair value of the Company’s convertible debentures embedded derivative liabilities for the year ended October 31, 2023, and 2022. Total Balance as of October 31, 2021 $ 602 Fair value of convertible debenture embedded derivative 3,500 Change in fair value of convertible debenture embedded ( 269 ) Foreign exchange rate translation adjustment ( 42 ) Balance as of October 31, 2022 3,791 Change in fair value of convertible debenture embedded 21,421 Foreign exchange rate translation adjustment 5 Settlement of derivative liability in accordance with ( 25,217 ) Balance as of October 31, 2023 $ — April 2023 Notes The Company elected the fair value option of accounting for the April 2023 Notes. The Company recorded the April 2023 Notes at fair value upon the date of issuance, which was determined to be the total cash proceeds received of $ 8.0 million and was considered a Level 3 measurement within the fair value hierarchy . The April 2023 Notes were repaid through the issuance of $ 8.0 million in aggregate amount of convertible notes and warrants issued as part of the 2023 Financing. No change in fair value was recorded on the April 2023 Notes during the year ended October 31, 2023, given the close proximity between the issuance date of the notes and the repayment date. As of October 31, 2023, the April 2023 Notes are no longer outstanding. May 2023 Notes The Company elected the fair value option of accounting for the May 2023 Notes. At issuance and for periods prior to the settlement of the May 2023 Notes, t he Company estimated the fair value of the May 2023 Notes using a probability weighted scenario expected return model and was considered a Level 3 measurement per the fair value hierarchy . As part of the issuance of the May 2023 Notes, the Company also issued warrants which were determined to be freestanding, liability classified and measured at fair value. Refer below. The Company recorded both the May 2023 Notes and warrants issued as part of the 2023 Financing at fair value upon issuance, which totaled the amount of proceeds received on an aggregate basis, and subsequently remeasured the financial instruments to fair value at each reporting date. The assumptions that the Company used to determine the fair value of the May 2023 Notes as of the issuance date are as follows: As of Issuance Date Probability of qualified financing* 60 % Volatility 85 % Class C Preferred Share Price (CAD) $ 2.074 Liquidity price at conversion of listing event $ 8.42 Fair value of common share at conversion of listing event $ 10.25 Discount rate*** 40.8 % Expected time to respective scenarios 0.3 years * The probability represents the cumulated probabilities of conversion at various dates before maturity. The probability includes the probability of a SPAC transaction (which corresponds to a listing event for the 2023 Notes). The liquidity price at the conversion of a listing event represents the conversion price of the 2023 Notes upon the merger with FEAC, and the fair value per common share at conversion of a listing event represents the price per share of the Newco upon the merger with FEAC, as set forth in the Business Combination Agreement. * Discount rate includes credit risk, discount for lack of marketability and other factors considered in the model. Immediately prior to the conversion and exchange of the May 2023 Notes as part of the Reverse Recapitalization, the notes were remeasured to a fair value of $ 93.3 million. The fair value immediately prior to the settlement was determined using the quoted market price of $ 21.70 per share for the FEAC common shares on the close of business on October 31, 2023, which was determined to be fair value of the common share on settlement, and considering the 4,298,463 shares of the Company issued to the holders of the May 2023 Notes upon the consummation of the Reverse Recapitalization. T he following table provides a summary of the change in the estimated fair value of the Company’s 2023 Notes for the year ended October 31, 2023. Upon the close of the Reverse Recapitalization the 2023 Notes were exchanged for common shares of the Company, resulting in an extinguishment of the 2023 Notes. Refer to Note 3 and Note 9. Total Balance as of October 31, 2022 $ — Issuance of May 2023 Notes 37,043 Change in fair value of May 2023 Notes 56,212 Settlement of 2023 Notes upon the consummation of the Reverse ( 93,255 ) Balance as of October 31, 2023 $ — Warrant Liabilities Prior to the consummation of the Reverse Recapitalization, Old enGene issued warrants to purchase redeemable convertible preferred shares as part of the issuance of certain redeemable convertible preferred shares, convertible debentures, and term loan (the “Preferred Share Warrants”). Upon the close of the Reverse Recapitalization, the Preferred Share Warrants were surrendered for no consideration and the fair value was determined to be zero. The Company estimated the fair value of its Preferred Share Warrant liabilities using a Modified Black-Scholes option-pricing model, which included assumptions that are based on the individual characteristics of the Preferred Share Warrants on the valuation date, and assumptions related to the fair value of the underlying redeemable convertible preferred shares, expected volatility, expected life, dividends, risk-free interest rate and discount for lack of marketability (“DLOM”). Due to the nature of these inputs, the Preferred Share Warrants are considered a Level 3 liability. The weighted average expected life of the Preferred Share Warrants was estimated based on the weighting of scenarios considering the probability of different terms up to the contractual term of 10 years in light of the expected timing of a future exit event, which includes a SPAC transaction. The Company determines the expected volatility based on an analysis of reported data for a group of guideline companies that have issued instruments with substantially similar terms. The expected volatility has been determined using a weighted average of the historical volatility measures of this group of guideline companies. The risk-free interest rate is determined by reference to the Canadian treasury yield curve in effect at the time of measurement of the warrant liabilities for time periods approximately equal to the weighted average expected life of the warrants. The Company has not paid, and did not anticipate paying, cash dividends on its redeemable convertible preferred shares; therefore, the expected dividend yield is assumed to be zero. Because there was no public market for the underlying redeemable convertible preferred shares, the Company determined their fair value based on third-party valuations. Initially, the estimated enterprise equity value of the Company was determined using a market approach and/or cost approach by considering the weighting of scenarios estimated using a back-solve method based on recent financing transactions of the Company. This value was then allocated towards the Company’s various securities of its capital structure using an option pricing method, or OPM, and a waterfall approach based on the order of the superiority of the rights and preferences of the various securities relative to one another. Significant assumptions used in the OPM to determine the fair value of redeemable convertible preferred shares include volatility, DLOM, and the expected timing of a future liquidity event such as an IPO, SPAC transaction or sale of the Company, in light of prevailing market conditions. This valuation process creates a range of equity values both between and within scenarios. In addition to considering the results of these valuations, the Company considered various objective and subjective factors to determine the fair value of the Company's preferred shares as of each valuation date, including the prices at which the Company sold redeemable convertible preferred in the most recent transactions, external market conditions, the progress of the Company's research and development programs, the Company's financial position, including cash on hand, and its historical and forecasted performance and operating results, and the lack of an active public market for the Company's redeemable convertible preferred shares, among other factors. The assumptions that the Company used to determine the fair value of the Preferred Share Warrant liabilities as of October 31, 2022 were as follows: As of October 31, 2022 Weighted average expected life (in years) 3.0 Expected volatility 78.0 % Risk-free interest rate 3.92 % Expected dividend yield — Preferred share price – Class C (CAD) $ 2.20 Exercise price – Class C (CAD) $ 2.632 The warrants issued by Old enGene as part of the 2023 Financing (the “2023 Warrants”) were concluded to be freestanding, liability classified instruments upon issuance, which were subsequently reclassified to equity upon the consummation of the Reverse Recapitalization. See Note 9. The Company estimated the fair value of the 2023 Warrants based on the underlying quoted market price of the FEAC public warrants, prior to the close of the Reverse Recapitalization. The 2023 Warrants were classified as a Level 2 measurement given they are substantially similar to FEAC public warrants. The price used to value the 2023 Warrants as of the issuance date and immediately prior to the consummation of the Reverse Recapitalization was $ 0.53 and $ 0.74 , per warrant, respectively, which represented the quoted market price of the FEAC public warrants on each date. The following table provides a summary of the change in the estimated fair value of the Company’s warrant liabilities for the year ended October 31, 2023: Total Balance as of October 31, 2021 $ 9,088 Warrant liabilities recognized upon issuance of term loan 90 Change in fair value of warrant liabilities 3,326 Foreign exchange rate translation adjustment ( 1,048 ) Balance as of October 31, 2022 11,456 Warrant liability recognized upon issuance of May 2023 Notes 1,420 Change in fair value of warrant liabilities ( 10,849 ) Foreign exchange rate translation adjustment ( 44 ) Reclassification of 2023 Warrants to equity upon consummation ( 1,983 ) Balance as of October 31, 2023 $ —

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
Property and Equipment, Net	Oct. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	5. Property and Equipment, Net As of October 31, 2023, and 2022, property and equipment, consisted of the following: October 31, October 31, 2023 2022 Lab equipment $ 1,779 $ 1,472 Computer equipment 269 221 Computer software 70 70 Office furniture 69 55 Leasehold improvements 129 122 Property and equipment 2,316 1,940 Less: Accumulated depreciation and amortization 1,727 1,553 Property and equipment, net $ 589 $ 387 Depreciation and amortization expense related to property and equipment was $ 0.2 million and $ 0.2 million for the year ended October 31, 2023 and 2022, respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
Accrued Expenses and Other Current Liabilities	Oct. 31, 2023
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	6. Accrued Expenses and Other Current Liabilities As of October 31, 2023 and 2022, accrued expenses and other current liabilities consisted of the following: October 31, October 31, 2023 2022 Accrued research and development expenses $ 759 $ 1,845 Professional fees 1,708 573 Employee compensation and related benefits 814 676 Accrued income tax payable 39 22 Other 219 — Total accrued expenses and other current liabilities $ 3,539 $ 3,116

License Agreement and Clinical

License Agreement and Clinical Research Organization	12 Months Ended
License Agreement and Clinical Research Organization	Oct. 31, 2023
License Agreement and Clinical Research Organization [Abstract]
License Agreement and Clinical Research Organization	7. License Agreement and Clinical Research Organization License Agreement – Nature Technology Corporation On April 10, 2020, the Company entered into a Non-Exclusive License Agreement (the “License Agreement”) with Nature Technology Corporation (“NTC”) whereby the Company licenses certain rights to the technology of radiopharmaceutical products from NTC for commercialization. Under the terms of the License Agreement, NTC granted to the Company and its affiliates a non-exclusive, royalty-bearing, sublicensable license to research, have researched, develop, have developed, make, have made, use, have used, import, have imported, sell, offer to sell, and have sold or offered for sale any product in the defined license field. Unless terminated earlier, the NTC license agreement will continue until no valid claim of any licensed patent exists in any country. The Company can voluntarily terminate the license agreement with prior notice to NTC. The Company paid NTC an initial, upfront fee of $ 50 which was recorded as research and development expense upon entering into the License Agreement. Beginning on the first anniversary of the effective date of the License Agreement and on each subsequent anniversary, the Company is required to pay NTC a $ 50 annual maintenance fee. The Company is also required to make a payment to NTC of $ 50 upon assigning the License Agreement to a third party. The License Agreement provides for a one-time payment of $ 50 for the first dose of a milestone product, as defined in the License Agreement, in the first patient in a Phase I clinical trial or, if there is no Phase I clinical trial, in a Phase II clinical trial, as well as a one-time payment of $ 450 upon regulatory approval of a milestone product by the U.S. Food and Drug Administration. The first milestone related to the first dose of a milestone product, was achieved during the year ended October 31, 2021. The second milestone, regulatory approval of a milestone product, has not been achieved as of the year ended October 31, 2023. The Company is also required to pay NTC a royalty percentage in the low single digits of the aggregate net product sales in a calendar year by the Company, its affiliates or sublicensees on a product-by-product and country-by-country basis, as long as the composition or use of the applicable product is covered by a valid claim in the country where the net sales occurred. Royalty obligations under the license agreement will continue until the expiration of the last valid claim of a licensed patent covering such licensed product in such country. In the event that the Company or any of its affiliates or sublicensees manufactures any Good Manufacturing Practice (“GMP”) lot of a product, then the Company or any such affiliate or sublicensee will be obligated to pay NTC an amount per manufactured gram of GMP (or its equivalent) lot of product, which varies based on the volume manufactured. The payment will expire on a product-by-product basis upon receipt of regulatory approval to market a product in any country in the licensed territory. During each of the years ended October 31, 2023 and 2022, the Company incurred $ 50 of expenses related to the annual maintenance fee under the License Agreement which is recorded within research and development expenses.

Notes Payable

Notes Payable	12 Months Ended
Notes Payable	Oct. 31, 2023
Debt Disclosure [Abstract]
Notes Payable	8. Notes Payable 2021 Loan and Security Agreement On December 30, 2021, the Company entered into a Loan and Security Agreement with Hercules Capital, Inc. (“Hercules” or the “Lender”) for the issuance of a term loan facility of up to an aggregate principal amount of up to $ 20.0 million (the “Term Loans”). The Loan Agreement provides for (i) an initial term loan advance of $ 7.0 million, which closed on December 30, 2021, (ii) subject to the achievement of certain Clinical Milestones (“Clinical Milestone”), a right of the Company to request that the Lender make additional term loan advances to the Company in an aggregate principal amount of up to $ 4.0 million from the achievement of the Clinical Milestone through June 15, 2022, which was drawn in June 2022 , and (iii) subject to the achievement of certain financial milestones (“Financial Milestone”), a right of the Company to request that the Lender make additional term loan advances to the Company in an aggregate principal amount of up to $ 9.0 million from achievement of the Financial Milestone through December 15, 2022, which was not achieved. The Company is required to pay an end of term fee (“End of Term Charge”) equal to 6.35 % of the aggregate principal amount of the Term Loans advances upon repayment. The Term Loans mature on July 1, 2025 , with no option for extension (the “Maturity Date”). The Term Loan bears interest at an annual rate equal to the greater of (i) 8.25 % plus the prime rate of interest as reported in the Wall Street Journal minus 3.25 % and (ii) 8.25 % provided, that, from and after the date the Company achieves the financial milestone, as defined within the agreement, the reference to 8.25 % in clauses (i) and (ii) is reduced to 8.15 %. Borrowings under the Loan and Security Agreement are repayable in monthly interest-only payments through June 2023. After the interest-only payment period, borrowings under the Loan and Security Agreement are repayable in equal monthly payments of principal and accrued interest until the Maturity Date. At the Company’s option, the Company may elect to prepay all, but not less than all, of the outstanding term loan by paying the entire principal balance and all accrued and unpaid interest thereon plus a prepayment charge equal to the following percentage of the principal amount being prepaid: (i) 3.0 % of the principal amount outstanding if the prepayment occurs in any of the first twelve months following the closing date of the last draw down; (ii) 2.0 % of the principal amount outstanding if the prepayment occurs after the first twelve months following the closing date of the last draw down, but on or prior to twenty-four months following the closing date of the last draw down; and 1.0 % of the principal amount outstanding at any time thereafter but prior to the Maturity Date. In connection with the Loan Agreement, the Company granted Hercules a security interest senior to any current and future debts and to any security interest, in all of the Company’s right, title, and interest in, to and under all of Company’s property and other assets, and certain equity interests and accounts of enGene, subject to limited exceptions including the Company's intellectual property. The Loan Agreement also contains certain events of default, representations, warranties and non-financial covenants of the Company. The debt discount and issuance costs are being accreted to the principal amount of debt and being amortized from the date of issuance through the Maturity Date to interest expense using the effective-interest rate method. The effective interest rate of the outstanding debt under the Loan Agreement is approximately 18.3 % and 15.9 % as of October 31, 2023 and 2022, respectively. As of October 31, 2023 and 2022, the carrying value of the Term Loan consists of the following: October 31, 2023 October 31, 2022 Note payable, including End of Term Charge $ 10,144 $ 11,699 Debt discount, net of accretion ( 474 ) ( 891 ) Accrued interest 108 106 Note payable, net of discount $ 9,778 $ 10,914 As of October 31, 2023, the Company classified $ 0.6 million of the note payable as current, which represents the principal payments due and amortization of the debt discount between October 31, 2023 and the date the Term Loan was amended in December 2023, as the debt was refinanced on a long-term basis in the subsequent event period (see Note 18). As of October 31, 2022, the Company classified $ 1.3 million of the note payable as current which represents the principal payments due and amortization of the debt discount to be recorded within twelve months from the balance sheet date. During the years ended October 31, 2023 and 2022, the Company recognized $ 1.8 million and $ 1.0 million of interest expense related to the Loan Agreement, respectively, of which $ 0.4 million and $ 0.3 million was related to the amortization of the debt discount, respectively. Through October 31, 2023, the Company borrowed $ 11.0 million under the Loan Agreement and incurred $ 1.1 million of debt discount and issuance costs inclusive of facility fees, legal fees, End of Term Charge and initial fair value of the warrants. As of October 31, 2023, and prior to the amendment of the Term Loan (see Note 18), the e stimated future principal payments due under the Loan Agreement, including the contractual End of Term Charge, are as follows: Note Principal 2024 $ 5,106 2025 5,038 Total principal payments, including End of Term Charge 10,144 As of October 31, 2023, based on borrowing rates available to the Company for loans with similar terms and consideration of the Company’s credit risk, the carrying value of the Company’s variable interest rate debt, excluding unamortized debt issuance costs, approximates fair value. Hercules Warrants Under the Loan and Security Agreement, the Company agreed to issue to Hercules warrants (the “Hercules Warrants”) to purchase a number of shares of Old enGene’s redeemable convertible preferred shares at the exercise price equal to 2.5 % of the aggregate amount of the Term Loans that are funded, as such amounts are funded. On the Closing Date, the Company issued a warrant to purchase 84,714 Class C Preferred Shares which were determined to have a fair value of $ 34 upon issuance. On the second tranche closing, in June 2022, the Company issued an additional warrant to purchase 48,978 Class C Preferred Shares which were determined to have a fair value of $ 23 upon issuance. The initial Hercules Warrant values are recorded as a discount to the term loan and are being amortized to interest expense using the effective interest method over the life of the Term Loans. The Company remeasured the fair value of the warrants at each reporting date with changes being recorded as a change in the fair value of the warrant liabilities. The Hercules Warrants were initially exercisable for a period of ten years from the date of the issuance of each warrant at a per-share exercise price equal to $ 2.632 Canadian Dollars, subject to certain adjustments as specified in the warrants. In addition, the Company has granted to the holders of the Hercules Warrants certain registration rights on a pari passu basis with the holders of outstanding Preferred Shares and warrants to purchase Preferred Shares. Upon the close of the Reverse Recapitalization, the Preferred Share Warrants were surrendered for no consideration. The Company accounted for the warrants as a liability prior to the consummation of the Reverse Recapitalization since they were indexed to Old enGene’s redeemable convertible preferred shares that were classified as temporary equity. April 2023 Notes On April 4, 2023, the Company entered into a note purchase agreement (the “April 2023 Notes”) for a principal amount of $ 8.0 million with Merck Lumira Biosciences Fund, L.P., Merck Lumira Biosciences Fund (Quebec), L.P., Lumira Ventures III, L.P., Lumira Ventures III (International), L.P., Lumira Ventures IV, L.P., Lumira Ventures IV (International), L.P., Fond de solidarité des travailleurs du Québec (F.T.Q.), and Forbion Capital Fund III Cooperatief U.A. (collectively the “April 2023 Investors”). The April 2023 Notes had an interest free period of 45 days from the date of issuance, and commencing on the 46th day, is to accrue interest at a rate of 15% per annum. The April 2023 Notes are classified as current as they mature on the earlier of (i) July 31, 2023; or (ii) the date the Company completes a qualified financing, as defined within the April 2023 Notes as a financing pursuant to which the Company sells convertible promissory notes, warrants, preferred shares, common shares, or a combination thereof of the Company for an aggregate amount of at least $ 20.0 million. Upon the completion of the 2023 Financing in May 2023, the Company issued convertible debentures and warrants of the Company to the April 2023 Note investors, on the same terms and conditions of the convertible debentures and warrants that were issued to the investors of the 2023 Financing, as repayment of the April 2023 Notes. The Company elected the fair value option of accounting for the April 2023 Notes. The Company recorded the April 2023 Notes at fair value upon the date of issuance, which was determined to be $ 8.0 million. As part the 2023 Financing, the terms of the April 2023 Notes were modified, in which the repayment of the April 2023 Notes resulted in the Company issuing convertible debentures and warrants of the Company to the April 2023 Note investors, on the same terms and conditions of the convertible debentures and warrants that were issued to the investors of the 2023 Financing. Upon the completion of the 2023 Financing in May 2023, the Company issued $ 8.0 million in convertible notes and warrants in repayment for the April 2023 Notes. No change in fair value was recorded on the April 2023 Notes during the year ended October 31, 2023, and prior to the extinguishment of the April 2023 Notes in May 2023 given the short period of time that the April 2023 Notes were outstanding. No gain or loss was recorded as a result of the extinguishment of the April 2023 Notes as the fair value of the notes upon extinguishment was determined to be equal to the fair value of the repayment amount.

Convertible Debentures

Convertible Debentures	12 Months Ended
Convertible Debentures	Oct. 31, 2023
Debt Disclosure [Abstract]
Convertible Debentures	9. Convertible Debentures The Company has issued convertible debentures to various investors. The outstanding principal, accrued interest, and unamortized deferred financing costs of the convertible debentures recorded on the balance sheet as of each period end are as follows: October 31, October 31, 2023 2022 BDC Notes $ — $ 2,497 2022 Notes — 14,908 Total Convertible debentures $ — $ 17,405 BDC Notes In September 2020, the Company issued a convertible debenture to the Business Development Bank of Canada (“BDC”) in the amount of $ 2.2 million (the “BDC Notes”). The debt bears interest at rate of 8 % per annum and had an initial maturity date of September 28, 2023 . In December 2021 the Company amended the agreement which resulted in the maturity date extending to September 29, 2025 . The BDC Notes are convertible at the option of the Holder into the Company’s Class B redeemable convertible preferred shares at a price of 80 % of the price paid per share in qualified financing, as defined within the BDC convertible debenture agreement. The issuance of the Term Loan in 2021 met the definition of a qualified financing per the BDC convertible debenture agreement. As the conversion option was not exercised upon the issuance of the Term Loan, the conversion rights upon a qualified financing were waived. There are optional conversion options that still exist if the Company is in default, as defined under the terms of the BDC Notes, or in the event of certain liquidation events, as defined within the BDC Notes, which allow for conversion of the BDC Note into the most senior share outstanding at the time of the event. If a liquidation event, as defined within the BDC Note agreement, and which includes a SPAC transaction, is consummated after a qualified financing, and optional conversion is not elected, the Company is required to pay the investor in cash, the outstanding principal and the accrued but unpaid interest and in addition an amount equal to 20 % of the principal. Upon issuance of the BDC Notes, the Company identified embedded derivatives related to the equity conversion features and liquidity event repayment features which required bifurcation as a single compound derivative instrument. The Company estimated the fair value of the embedded derivative liabilities upon issuance at $ 0.2 million. The Company remeasured the fair value of the embedded derivatives in effect at each reporting period, with the subsequent changes in the fair value of the derivative being recognized in changes in fair value of derivatives within the Company’s consolidated statements of operations and comprehensive loss. During the year ended October 31, 2023, the Company recorded a change in fair value of the convertible debentures embedded derivative liability associated with the BDC Note of $ 0.3 million. Total interest expense, including the amortization of debt discounts, of $ 0.3 million was recorded for the year ended October 31, 2023. Upon the close of the Reverse Recapitalization the Company repaid the BDC Note, including the liquidity event repayment amount, resulting in full settlement of the note and extinguishment of the embedded derivative liability. The estimated fair value of the embedded derivative liabilities at October 31, 2022 was $ 0.3 million, resulting in $ 0.3 million of expense recorded as change in fair value of convertible debentures embedded derivative liabilities in the consolidated statement of operations and comprehensive loss for the year ended October 31, 2022. Total interest expense, including the amortization of debt discounts, was $ 0.4 million for the year ended October 31, 2022. As part of the issuance of the BDC Notes, the Company incurred an aggregate of $ 36 of debt issuance costs of which a portion were recorded as a reduction of the carrying value of the BDC Notes, and a portion was allocated to the embedded derivative liabilities which were expensed as incurred. On May 12, 2023, the Company consented to certain modifications of the BDC Notes pursuant to which the Company will be required on the Closing Date to repay in cash (i) the outstanding principal and the accrued but unpaid interest; and (ii) an amount equal to 20 % of the principal. Upon the close of the Reverse Recapitalization, the Company repaid the BDC Note in full, resulting in a loss on extinguishment of $ 9 thousand due to the difference between the repayment amount and the carrying amount of the debenture and fair value of the embedded derivative lability at the time of repayment. 2022 Notes During the year ended October 31, 2022, the Company issued convertible debentures for an aggregate amount of $ 18.4 million on October 20, 2022 (the “2022 Notes”). The 2022 Notes had an initial maturity that is the later of (i) three years from the date of issuance; or (ii) the maturity date of the Term Loan (see Note 9). The 2022 Notes bear interest at 10 % per annum commencing on the date of issuance. The 2022 Notes are automatically convertible into common shares or redeemable convertible preferred shares (“Capital Shares”) of the Company, whichever is issued by the Company in a qualified financing of Capital Shares that is not a listing event with an aggregate consideration of $ 50.0 million. The outstanding principal and accrued interest will convert at a price of 85 % of the price paid in such qualified financing. In the event of a non-qualified financing, the noteholder majority has the option to convert the debentures to Capital Shares issued in the non-qualified financing event, at a price equal to 85 % of the price paid per share in the non-qualified financing. Additionally, prior to the amendment of the 2022 Notes in May 2023 (as further described below), upon a listing event such as an initial public offering, the 2022 Notes would be automatically converted into the number of common shares equal to the quotient by dividing the outstanding principal and interest by the listing price, except if the listing event is a SPAC business combination, following which the 2022 Notes will be automatically converted into common shares based on the outstanding principal excluding interest. As part of amendment in May 2023, the conversion terms of the 2022 Notes associated with a listing event were amended to remove conversion upon an initial public offering and to fix the conversion price at $ 8.84 . Further, given that the Company entered into a SPAC transaction agreement, as defined in the Notes agreement, before July 31, 2023, in the event that the SPAC transaction agreement was to terminate in accordance with its terms, the Company could be required, at the election of the noteholder majority, to repay the principal amount and accrued and unpaid interest or to convert this amount into the number of the then most senior share class of the Company. In the event of default, the noteholder majority has the option to require payment of the principal and accrued interest amounts or to convert the outstanding principal and accrued interest into the number of the then most senior share class of the Company or common shares at the issue price of such shares at that date. Further, upon maturity of the 2022 Notes, at the option of a noteholder majority, the principal amount and accrued and unpaid interest shall be repaid in full or converted into the number of the then most senior share class of the Company or common shares at the issue price of such shares at that date. Upon the close of the Reverse Recapitalization, the 2022 Notes were converted into 2,081,359 common shares of the Company. Upon issuance of the 2022 Notes, the Company identified embedded derivatives related to the equity conversion features which required bifurcation as a single compound derivative instrument. The Company estimated the fair value of the embedded derivative liabilities upon issuance at $ 3.5 million. Given the close proximity between the issuance date of the notes and the Company’s year ended October 31, 2022, no change in fair value was recorded related to the embedded derivative liabilities identified as part of the issuance of the 2022 Notes. During the year ended October 31, 2023, the Company recorded a change in fair value associated with the 2022 Notes embedded derivative liability of $ 21.2 million in the consolidated statement of operations and comprehensive loss for the year ended October 31, 2023. As of October 31, 2023 no embedded derivative liability is recorded for the 2022 Notes as they converted to shares of the Company upon the consummation of the Reverse Recapitalization. Total interest expense, including the amortization of debt discounts, was $ 2.8 million for the year ended October 31, 2023, respectively. As part of the issuance of the 2022 Notes, the Company incurred an aggregate of $ 44 of debt issuance costs of which a portion were recorded as a reduction of the carrying value of the 2022 Notes, and a portion was allocated to the embedded derivative liabilities which were expensed as incurred. On May 16, 2023, the Company agreed to certain modifications of the 2022 Notes having an aggregate principal amount of $ 18.4 million (the “Amended 2022 Notes”), which included a change in the definition of the maturity date by allowing an extension of the maturity date upon election of a noteholder majority, increasing the percentage required for a noteholder majority, and modifying terms of certain conversion options. The amendments to the 2022 Notes did not result in the addition or termination of any substantive conversion terms, and t he amendment to the 2022 Notes was determined to be non-substantial and was accounted for as a modification. In addition, as part of the May 2023 Financing, the holders of the 2022 Notes which participated in the 2023 Financing received warrants to purchase common shares of the Company. The fair value of the warrants at the time of issuance to the holders of the 2022 Notes was determined to be $ 0.5 million and was recorded as reduction of the carrying value of the 2022 Notes as part of the modification, which is being amortized to interest expense through the maturity date of the 2022 Notes. On October 31, 2023 upon the close of the Reverse Recapitalization, the 2022 Notes were converted into 2,081,359 common shares of the Company. The Company accounted for the conversion as an extinguishment and recorded a loss on extinguishment of $ 3.1 million, relating to the difference between the fair value of the common shares issued and the carrying value of the 2022 Notes and fair value of the embedded derivative liability at the time of conversion. May 2023 Notes On May 16, 2023, concurrently with the execution and delivery of the Merger Agreement, the Company entered into agreements pursuant to which it issued new convertible notes and warrants (i) for cash in an aggregate principal amount of $ 30.0 million and (ii) in repayment of the April 2023 Notes in an aggregate amount of $ 8.0 million (collectively, the “May 2023 Notes” and, together with the warrants purchased concurrently, the “2023 Financing”; the 2023 Financing together with the Amended 2022 Financing, the “Convertible Bridge Financing”). The 2023 Financing occurred in two separate issuances with $ 28.0 million issued in May 2023 for $ 20.0 million in cash and $ 8.0 million in repayment of the April 2023 Notes, and an additional $ 10.0 million issued in June 2023 for $ 10.0 million in cash, of which Forbion Growth Sponsor FEAC I B.V. funded an aggregate amount of $ 20.0 million of the total $ 38.0 million. The May 2023 Notes issued as part of the 2023 Financing, if not converted, have an initial maturity date of three years from the issuance date and are to accrue interest at 10 % per annum, which is payable upon maturity. The May 2023 Notes have the same conversion terms as the Amended 2022 Notes (as described above). The warrants issued as part of the 2023 Financing were for the purchase of common shares of Old enGene. The number of 2023 Warrants issued to each participating investor in the 2023 Financing was equal to the number of warrants the investor would receive had they invested the same amount in the PIPE Financing, divided by the Company Exchange Ratio. The 2023 Warrants were only to become exercisable upon the completion of the merger. Upon the close of the Reverse Recapitalization, the 2023 Warrants were exchanged for 2,679,432 warrants of the Company and have the same terms as the public warrants issued upon the FEAC initial public offering, with an exercise price of $ 11.50 , and which will expire five years after the completion of the merger. The warrants issued as part of the 2023 Financing were concluded to be liability classified upon issuance, as they failed the fixed for fixed criteria that is required for a contract to be considered indexed to the Company’s own stock as prescribed by ASC 815. The terms of the warrants initially required the Company to issue a variable number of shares until the PIPE Financing was executed, at which time the number of warrants will become fixed. The 2023 Warrants were initially and subsequently measured at fair value with any changes in fair value recorded as a component of other income and expense within the change in fair value of warrant liabilities. Refer to Note 3. Upon the execution of the PIPE Financing and consummation of the Reverse Recapitalization, the warrants were reclassified to equity as the number of warrants became fixed and it was determined that the warrants met the fixed for fixed criteria that is required for a contract to be considered indexed to the Company’s own stock as prescribed by ASC 815. The Company elected the fair value option of accounting for the May 2023 Notes. The Company recorded May 2023 Notes at fair value upon the date of issuance. At inception the fair value of the May 2023 Notes was determined to be $ 37.0 million and the fair value of the related warrants was determined to be $ 1.4 million, of which $ 0.5 million related to the fair value of the warrants issued to the holders of the 2022 Notes, as described above. During the year ended October 31, 2023, the Company recorded a change in fair value of the May 2023 Notes of $ 56.2 million. The Company incurred $ 0.8 million of debt issuance costs associated with the May 2023 Notes which have been expensed and are included within general and administrative expenses. Refer to Note 3. On October 31, 2023 upon the close of the Reverse Recapitalization, the 2023 Notes were converted into 4,298,463 common shares of the Company. The Company accounted for the conversion as an extinguishment, with no gain or loss recorded on extinguishment as the fair value of the common shares issued was determined to equal the fair value of the 2023 Notes at the time of conversion.

Redeemable Convertible Preferre

Redeemable Convertible Preferred Shares	12 Months Ended
Redeemable Convertible Preferred Shares	Oct. 31, 2023
Equity [Abstract]
Redeemable Convertible Preferred Shares	10. Redeemable Convertible Preferred Shares As of October 31, 2022, Old enGene’s Articles of Amendment had an unlimited number of authorized shares of each class of redeemable convertible preferred shares. Class A Redeemable Convertible Preferred Shares On July 26, 2013, the Company entered into a subscription agreement (the “Class A Agreement”) with multiple investors, whereby the Company agreed to sell to the investors an initial aggregate amount of 610,333 Class A redeemable convertible preferred shares at a price of $ 1.5929 ($ 1.63845 CAD) per share for total aggregate proceeds of $ 1.0 million (the “Class A Initial Closing”). Included within the Class A Agreement were three additional future tranche obligations (the “Class A Second Tranche,” “Class A Third Tranche” and “Class A Fourth Tranche”) for the Company to issue and sell shares of Class A redeemable convertible preferred shares upon the achievement of certain milestone events. Only the Class A Second Tranche closed under the Class A Agreement. The Class A Second Tranche obligated the Company to sell and the Class A Investors to purchase 1,830,999 shares of Class A redeemable convertible preferred shares at a price of $ 1.56967 ($ 1.63845 CAD) per share for total proceeds of $ 2.9 million, upon the establishment of the Company’s headquarters in Montreal Quebec and completion of experiments required to bolster a patent application for dually-derivatized chitosan (the “Second Closing Milestone Event”), which occurred in 2013. Additionally, upon completing the Class A redeemable convertible preferred share financing, convertible notes of the Company held by multiple investors converted into Class A redeemable convertible preferred shares. Class B Redeemable Convertible Preferred Shares On January 6, 2015, the Company entered into a subscription agreement (the “Class B Agreement”) with multiple investors, where the Company agreed to sell to the investors an initial aggregate amount of 2,758,221 Class B redeemable convertible preferred shares at a price of $ 1.85032 ($ 2.17532 CAD) per share for total proceeds of $ 5.1 million (the “Class B Initial Closing”). Included within the Class B Agreement were two additional closings (the “Class B Second Tranche,” and the “Class B Third Tranche,” respectively) which obligated the Company to sell and Class B investors to purchase additional Class B redeemable convertible preferred shares upon certain events. The Class B Second Tranche obligated the Company to sell and the Class B Investors to purchase 1,838,815 Class B Shares at a price of $ 1.63419 ($ 2.17532 CAD) per share for total proceeds of $ 3.0 million and the Class B Third Tranche obligated the Company the sell and the Class B Investors to purchase 1,608,963 Class B Shares at a price of $ 1.63419 ($ 2.17532 CAD) per share for total proceeds of $ 2.6 million. The Class B Second Tranche and Class B Third Tranche closed on March 1, 2017. Class B-1 Redeemable Convertible Preferred Shares On September 10, 2015, the Company entered into a Subscription Agreement (the Class “B-1 Agreement”), in which the Company was to issue 1,523,809 Class B-1 redeemable convertible preferred shares for a purchase price of $ 1.64367 ($ 2.17532 CAD) per share, resulting in aggregate proceeds of $ 2.5 million. During the year ended October 31, 2020, the Class B-1 redeemable convertible preferred shares converted to common shares on a 1: 1 basis. Therefore, as of each of the years ended October 31, 2023, October 31, 2022, and October 31, 2021, no shares of the Class B-1 redeemable convertible preferred shares remained outstanding. The Company presented these shares within temporary equity, as they contained the same redemption features as the Class B redeemable convertible preferred shares (further described above). Upon conversion to common shares, the carrying value of the Class B-1 redeemable convertible preferred shares was reclassified to additional paid in capital within shareholders’ deficit. Class C Redeemable Convertible Preferred Shares The Class C redeemable convertible preferred shares are issuable in series, of which an unlimited number are designated as Series 1 Class C redeemable convertible preferred shares with an issue price per share of $ 1.5929 ($ 1.63845 CAD); an unlimited number are designated as Series 2 Class C redeemable convertible preferred shares with an issue price per share of $ 1.85032 ($ 2.175315 CAD); an unlimited number are designated as Series 3 Class C redeemable convertible preferred shares with an issue price per share of $ 2.12376 ($ 2.6320 CAD); and an unlimited number are designated as Series 4 Class C redeemable convertible preferred shares that is reserved for the potential conversion of the BDC Notes, and will each have an issue price per share of $ 1.69901 ($ 2.10559 CAD). On June 30, 2021, the Company entered into a subscription agreement (the “Class C Agreement”) with multiple investors, where the Company agreed to sell to the Investors an initial aggregate amount of 3,662,813 Series 3 Class C redeemable convertible preferred shares (the “Series 3 Class C Shares”) at a price of $ 2.12376 ($ 2.6320 CAD) per share for total proceeds of $ 7.8 million (the “Class C Initial Closing”). Included within the Class C Agreement was one additional closing (the “Class C Second Tranche”) which obligated the Company to sell and Class C investors to purchase additional Class C redeemable convertible preferred shares upon the achievement of certain milestone events. The Class C Second Tranche obligated the Company to sell and the Class C investors to purchase 3,662,810 Series 3 Class C Shares at a price of $ 2.13192 ($ 2.6320 CAD) per share for total proceeds of $ 7.8 million. The Class C Second Tranche closed on October 29, 2021. As part of each of the Class C Initial Closing and Class C Second Tranche, each Class C investor received 3,662,813 and 3,662,810 warrants, respectively, to purchase Class C redeemable convertible preferred shares (the “Class C Warrants”), resulting in an aggregate issued amount of 7,325,623 Class C Warrants. The Class C Warrants have an exercise price of $ 2.12376 ($ 2.6320 CAD) per share and a term of 10 years . The Class C Warrants were determined to be liabilities. The Company estimated the fair value of the warrant liabilities upon issuance and remeasured the fair value of the warrant liabilities at each reporting period, with the subsequent changes in the fair value of the warrant liabilities being recognized in changes in fair value of warrant liabilities within the Company’s consolidated statements of operations and comprehensive loss. Upon the completion of the merger with FEAC, all existing Class C Warrants of the Company will be extinguished. Under the terms of the Class C Agreement, certain convertible notes held by various Class C investors and other investors were exchanged for an aggregate amount of 16,464,646 Class B redeemable convertible preferred shares. Additionally, upon entering into the Class C Agreement, the Company also entered into a share exchange agreement (the “Share Exchange Agreement”) with the Class A investors and the Class B investors. As part of the Share Exchange Agreement, certain of the Class A redeemable convertible preferred shares issued to Class A investors were exchanged for Series 1 Class C redeemable convertible preferred shares and certain of the Class B redeemable convertible preferred shares issued to the Class B investors were exchanged for Series 2 Class C redeemable convertible preferred shares. This exchange resulted in the derecognition of Class A and B redeemable convertible preferred shares and the recognition of Class C redeemable convertible preferred shares at the fair value of the Class C redeemable convertible preferred shares. The difference between the carrying value of the Class A and Class B redeemable convertible preferred shares and the fair value of the Class C redeemable convertible preferred shares for which they converted into was recorded within additional paid in capital and no gain or loss on extinguishment was recorded within the consolidated statements of operations and comprehensive loss. Further, the February 2020 Warrants, June 2020 Warrants, and 2021 Warrants, which consisted of warrants to purchase the Company’s Class B redeemable convertible preferred shares and were issued as part of the convertible debentures were cancelled and replaced by the terms of the Class C Warrants. The aggregate amount of outstanding warrants of 10,242,130 from the February 2020 Warrants, the June 2020 Warrants, and the 2021 Warrants converted into 10,242,130 Class C Warrants, which have an exercise price of $ 2.12376 ($ 2.6320 CAD) per share and a term expiring on February 14, 2030 . Immediately prior to conversion, the warrants were marked to fair value, with the change in the fair value of the warrant liabilities being recognized in changes in fair value of warrant liabilities within the Company’s consolidated statements of operations and comprehensive loss. Upon issuance of each series of Class A, Class B, and Class C Preferred Shares, the Company assessed the embedded conversion and liquidation features of the shares and determined that such features did not require the Company to separately account for these features. Conversion of Redeemable Convertible Preferred Stock Pursuant to the terms of the Merger Agreement, upon the consummation of the Reverse Recapitalization, each share of Old enGene’s redeemable convertible preferred stock issued and outstanding immediately prior to the close was exchanged for common shares of the Company using the Company Exchange Ratio of approximately 0.18048 . A retrospective adjustment has been applied to all periods presented to reflect the Reverse Recapitalization. Refer to Note 3 for additional discussion. Undesignated Preferred Stock The Company’s Certificate of Incorporation, as amended and restated, authorizes the Company to issue an unlimited number of preferred shares with no par value. The shares of preferred stock are currently undesignated.

Common Shares

Common Shares	12 Months Ended
Common Shares	Oct. 31, 2023
Equity [Abstract]
Common Shares	11. Common Shares The Company has an unlimited number of authorized shares of common shares, with no par value. As of October 31, 2023 and 2022 there were 23,197,976 and 665,767 common shares outstanding, respectively, as adjusted to reflect the Reverse Recapitalization through the application of a retrospective adjustment. The holders of the common stock are entitled to one vote for each share of common stock held on all matters submitted to a vote of shareholders. Common shareholders are entitled to receive dividends, as may be declared by the board of directors, or the Board, if any, subject to the preferential dividend rights of preferred stock. Through October 31, 2023, no cash dividends had been declared or paid. Common share warrants As of October 31, 2023, the Company had 10,411,641 warrants to purchase common shares of the Company outstanding. As of October 31, 2022 the Company did no t have any warrants to purchase common shares outstanding. The warrants to purchase common shares as of October 31, 2023 have the same terms as the FEAC public warrants issued in connection with FEAC’s IPO, have an exercise price of $ 11.50 , are exercisable beginning 30 days after the completion of the Reverse Recapitalization and expire on October 31, 2028 , or five years after the completion of the Reverse Recapitalization. The common share warrants have been determined to be equity classified as they do not meet the definition of a liability under ASC 480 and are considered indexed to the Company’s own stock as prescribed by ASC 815. As of October 31, 2023, and 2022, the Company has reserved the following shares of common shares for the exercise of common share warrants, share options, and remaining shares reserved for future issuance under the Plan: October 31, October 31, 2023 2022 Preferred Stock, as converted — 5,983,339 Warrants to purchase redeemable convertible preferred shares — 3,194,756 Warrants to purchase common shares 10,411,641 — Options to purchase common shares* 2,706,941 1,575,785 Remaining shares reserved for future issuance under 2,607,943 170,158 Total 15,726,525 10,924,038 *As of October 31, 2023, amount includes the 1,046,764 shares with exercisability conditions of (i) the completion of the Reverse Recapitalization, and (ii) the filing an effective registration statement to register the shares underlying the option award, which is deemed probable as of October 31, 2023.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
Share-Based Compensation	Oct. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	12. Share-Based Compensation Pursuant to the terms of the Reverse Recapitalization, upon the Closing Date, each outstanding option to purchase Old enGene’s common stock issued under the Old Plan’s was exchanged for an option to purchase common shares of the Company, and the number of shares and exercise price of each granted option was adjusted using the exchange ratio of approximately 0.18048 . Further, the currency of all exercise prices of the options issued under the Old Plans were converted from CAD to USD using the exchange rate in effect on the day immediately prior to the Closing Date. A retrospective adjustment has been applied to the number of options and exercise price of stock options for all periods presented to reflect the Reverse Recapitalization as discussed further in Note 3. The Old Plans Old enGene had an employee share option plan (the “ESOP”) and an equity incentive plan (the “EIP”) (collectively, the “ Old Plans”) which was adopted by the Board of Directors, and approved by the shareholders, effective July 5, 2018. Under the Old Plans, options to purchase non-voting common shares of Old enGene’s shares may be granted to directors, officers, employees, consultants and members of the scientific advisory board. The Old Plans provide for the issuance of common stock options up to a maximum of 15 % of the aggregate issued and outstanding common shares and non-voting common shares of Old enGene calculated on an as converted and fully diluted basis. The Old Plans were administered by Old enGene’s Board of Directors. Old enGene’s Board of Directors determined the number of options to be granted, the vesting period and the exercise price of new options. It was Old enGene’s policy to establish the exercise price at an amount that approximates the fair value of the underlying shares on the date of grant as determined by Old enGene’s Board of Directors. The options vest in accordance with the vesting terms determined for each grant by Old enGene’s Board of Directors. The vesting terms of Old enGene’s granted stock options with service only conditions are typically 100 % vesting immediately upon grant date, or over a three - or four-year service period. Upon the consummation of the Reverse Recapitalization, the Company recognized share-based compensation expense of $ 0.4 million associated with the acceleration of the vesting for the outstanding awards with service only vesting conditions under the Old Plan. As of October 31, 2023, no unrecognized compensation cost remains for the outstanding awards granted under the Old Plan with service only vesting conditions. On July 7, 2023, the Board of Directors approved the reservation of an additional 1,046,764 non-voting common shares for issuance under the Company’s employee equity incentive plan, revising the number of shares reserved from 1,775,729 to 2,822,493 . Also on July 7, 2023, the Company granted 1,046,764 options to employees at an exercise price of $ 5.87 CAD ($ 4.24 USD). These options are not exercisable unless and until the completion of the Reverse Recapitalization and there is an effective registration statement for the shares underlying such granted options and will terminate automatically in the event of the termination of the Merger Agreement. The Company has valued these awards at the grant date using Black-Scholes pricing model in which the fair value of the stock on the grant date was equal to the exercise price of the award. The expected term has been determined using management’s best estimate considering the characteristics of the award, contractual life, the timing of the expected achievement of the performance conditions, the remaining time-based vesting period, if any, and comparison to expected terms used by peers. Upon the grant date, 794,643 of the issued options were fully vested, and the remaining 252,121 options will vest over varying terms up to four years on a pro rata basis. The Company recognizes compensation expense when achievement of the performance condition is deemed probable using an accelerated attribution method, as if each vesting tranche was treated as an individual award. During the year ended October 31, 2023, $ 2.6 million of stock based compensation expense was recorded associated with the 1,046,764 stock options granted in July 2023 because the Reverse Recapitalization was completed and the Company determined that the filing of the registration statement was probable to occur. As of October 31, 2023, there was $ 0.6 million of unrecognized compensation expense related to outstanding stock options associated with the 1,046,764 stock options granted in July 2023, which is expected to be recognized over a weighted-average period of 3.68 years. Upon the consummation of the Reverse Recapitalization on October 31, 2023, all options outstanding under the Old Plans were exchanged for 2,706,941 shares options to purchase common shares of the Company based on the Exchange Ratio determined in accordance with the terms of the Merger Agreement. Further, all exercise prices were adjusted by the Exchange Ratio and the currency of the exercise prices was changed from CAD to USD based on the exchange rate in effect on October 30, 2023, the day immediately before the consummation of the Reverse Recapitalization. No incremental compensation cost was recorded as a result of the change in underlying common shares from Old enGene to the Company, or as a result of the change of the exercise prices to reflect the adjustment for the Exchange Ratio and the change in currency from CAD to USD, as it was concluded that the fair value of the awards immediately before and immediately after the modifications did not change. No options remain available for grant under the Old Plans as of October 31, 2023. The 2023 Plan On October 31, 2023, upon the completion of the Reverse Recapitalization, the shareholders approved and the Company adopted the 2023 Plan, which superseded the Old Plans. The 2023 Plan authorizes the award of incentive stock options, or ISOs, non-qualified stock options, or NQSOs, Stock Units, Stock Appreciation Rights, or SARs, and other share-based awards including performance awards and stock bonus awards. The number of shares initially reserved for issuance under the 2023 Plan is 2,607,943 shares of common stock, plus 2,706,941 shares of common stock subject to the outstanding grants under the Old Plans, and shall automatically increase on January 1 of each calendar year beginning in 2024 by a number of shares equal to the lesser of 1,946,226 million common shares and such lesser number as may be determined by the Board. The 2023 Plan is administered by the Board or, at the discretion of the Board, by a committee of the Board. The exercise prices, vesting and other restrictions are determined at the discretion of the Board, or its committee if so delegated, except that the exercise price per share of stock options may not be less than 100 % of the fair market value of the share of common stock on the date of grant and the term of stock option may not be greater than ten years . Shares that are expired terminated, surrendered or cancelled under the 2023 Plan without having been fully exercised will be available for future awards. Stock Options The assumptions that the Company used to determine the grant-date fair value of stock options, were as follows: Year ended October 31, 2023 2022 Expected term (in years) 5.2 – 6.08 6.08 Expected volatility 79.92 – 81.48 % 75.3 % Risk-free interest rate 3.56 – 4.35 % 2.16 % Expected dividend yield — — Fair value of common shares and exercise $ 2.11 – 12.36 $ 1.22 Fair value of common shares and exercise $ 1.52 – 8.93 $ 0.88 The following table summarizes the Company’s stock option activity: Number of Weighted- Weighted- Aggregate Outstanding as of October 31, 2022 1,575,785 $ 0.88 7.7 $ 1,026 Granted 1,308,081 4.05 Exercised ( 84,072 ) 0.88 Forfeited or expired ( 92,853 ) 0.88 Outstanding as of October 31, 2023 2,706,941 $ 2.40 8.1 $ 52,192 Options vested and exercisable as of October 31, 2023 1,660,177 $ 1.26 7.1 $ 33,921 Options vested and not exercisable as of October 31, 2023 807,025 $ 4.24 9.7 $ 14,087 Options unvested as of October 31, 2023 239,739 $ 4.24 9.7 $ 4,185 * - All options outstanding at October 31, 2022 were issued in Canadian dollars with an exercise price of $ 1.22 . All options granted during the year ended October 31, 2023 were issued in Canadian dollars at exercise prices of $ 2.11 , $ 5.87 , and $ 12.36 . Upon the close of the Reverse Recapitalization, all exercise prices were converted to United States dollars at the exchange rate in effect on the day immediately before the close of the Reverse Recapitalization. The Weighted Average Exercise Price above was adjusted to reflect such change. ** - Retrospectively restated to reflect exchange of shares upon the close of Reverse Recapitalization. See Notes 1 and 3. During the year ended October 31, 2023, included within the stock options exercised are 15,494 shares of common shares issued upon cashless exercise of the stock options. The aggregate intrinsic value of share options is calculated as the difference between the exercise price of the share options and the fair value of the Company’s common share as of October 31, 2023, and 2022, respectively. The weighted-average grant-date fair value per share of share options granted during the year ended October 31, 2023 and 2022 was $ 3.90 CAD and $ 0.82 CAD, respectively. Share-based Compensation Expense Share-based compensation expense included in the Company’s consolidated statements of operations and comprehensive loss was as follows: Year Ended October 31, 2023 2022 Research and development $ 780 $ 31 General and administrative 2,670 85 Total share-based compensation expense $ 3,450 $ 116 As of October 31, 2023, there was $ 0.6 million of unrecognized compensation, which is expected to be recognized over a weighted-average period of 3.68 years.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
Net Loss Per Share	Oct. 31, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	13. Net Loss Per Share The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented, retrospectively restated to reflect the exchange of shares upon the close of the Reverse Recapitalization: Year Ended October 31, 2023 2022 Numerator: Net loss $ 99,917 $ 24,462 Deemed dividend attributable to redeemable convertible 4,822 4,562 Net loss attributable to common shareholders, basic and $ 104,739 $ 29,024 Denominator: Weighted-average number of common shares used in net 692,609 655,153 Net loss per common share, basic and diluted $ 151.22 $ 44.30 The Company excluded the following shares from the computation of diluted net loss per share attributable to common shareholders during the year ended October 31, 2023, and 2022 because including them would have had an anti-dilutive effect: Year Ended October 31, 2023 2022 Redeemable convertible preferred shares — 5,983,339 Warrants to purchase redeemable convertible preferred shares — 3,194,756 Warrants to purchase common shares 10,411,641 — Options to purchase common shares 2,706,941 1,575,785 Total 13,118,582 10,753,880

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Oct. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes Loss before provision for income taxes consisted of the following: Year ended October 31, 2023 2022 Domestic (Canada) $ ( 99,157 ) $ ( 23,965 ) Foreign (US) ( 743 ) ( 475 ) Loss before provision for income taxes $ ( 99,900 ) $ ( 24,440 ) The components of the provision for income taxes is as follows: Year ended October 31, 2023 2022 Current expense (benefit): Domestic (Canada) $ — $ — Foreign (US) 17 22 Total current expense (benefit) 17 22 Deferred expense (benefit) Domestic (Canada) — — Foreign (US) — — Total deferred tax expense (benefit) — — Total income tax expense (benefit) $ 17 $ 22 A reconciliation of the Company's statutory income tax rate to the Company's effective income tax rate is as follows: Year ended October 31, 2023 2022 Income at Canada statutory rate 26.50 % 26.50 % Conversion of debentures ( 21.90 )% — State taxes, net of federal benefit 0.05 % 0.12 % Permanent differences 1.68 % ( 3.90 )% Tax credits 0.19 % 0.29 % Foreign rate differential ( 0.04 )% ( 0.11 )% Valuation allowance ( 6.52 )% ( 22.86 )% Other 0.03 % ( 0.14 )% ( 0.01 )% ( 0.09 )% The net deferred income tax balances related to the following: October 31, 2023 2022 Deferred tax assets: R&D expenditures 7,012 6,441 Net operating loss (NOL) carryforwards 18,918 13,862 ITC credits 1,210 963 Property and equipment 791 742 Convertible debenture embedded derivative liabilities — 13 Financing costs 2,440 — Accruals 149 101 Section 174 capitalized R&D costs 393 — Other 172 — Total deferred tax assets 31,085 22,122 Valuation allowance ( 31,085 ) ( 22,048 ) Net deferred tax assets (liability) - 74 Deferred tax liabilities: Convertible debentures — ( 9 ) Other — ( 65 ) Total deferred tax liabilities — ( 74 ) Net deferred tax assets (liability) — — The calculation of the Company’s tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations for both federal taxes and the provinces and states in which the Company operates or does business in. ASC 740 states that a tax benefit from an uncertain tax position may be recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, on the basis of the technical merits. The Company records uncertain tax positions as liabilities in accordance with ASC 740 and adjusts these liabilities when the Company’s judgment changes as a result of the evaluation of new information not previously available. Because of the complexity of some of these uncertainties, the ultimate resolution may result in a payment that is materially different from the current estimate of the unrecognized tax benefit liabilities. These differences will be reflected as increases or decreases to income tax expense in the period in which new information is available. As of October 31, 2023 and 2022, no uncertain tax positions have been recorded in the consolidated financial statements. The Company recognizes interest and penalties related to unrecognized tax benefits on the income tax expense line in the accompanying consolidated statement of operations and comprehensive loss. As of October 31, 2023 and 2022, no accrued interest or penalties are included on the related tax liability line in the consolidated balance sheet. As of October 31, 2023, the Company has Canadian Federal NOL carryforwards of $ 71.9 million, that expire between 2028 and 2043 and Canadian provincial NOL carryforwards of $ 68.5 million, that expire between 2031 and 2043 . As of October 31, 2023, the Company has a U.S. Federal NOL carryforward of $ 0.9 million, that may be carried forward indefinitely, and a U.S. state NOL carryforward of $ 0.5 million, that begin to expire in 2039 . As of October 31, 2023, the Company also has Canadian investment tax credits of $ 1.8 million that expire between 2028 and 2043 .

Leases

Leases	12 Months Ended
Leases	Oct. 31, 2023
Leases [Abstract]
Leases	15. Leases The Company’s leases are comprised of all operating leases for office and lab space. In April 2019, the Company entered into an office space lease approximating 12,271 rentable square feet or a portion of an office building located at 201 Jones Road, Waltham, Massachusetts. The lease commenced in April 2019 and the lease term is to expire on March 30, 2022 , with no options to renew. The lease expired on March 30, 2022 . In November 2021, the Company entered into an office and lab space lease approximating 9,360 of rentable square feet for designated office and lab spaces located at 7171 Frederick-Banting, City of Montreal, judicial district of Montreal, Province of Quebec. The lease commenced in November 2021 and had an initial term of 12 months that would have expired on October 31, 2022 , and includes options to renew for consecutive twelve-month periods upon landlord consent at new lease rates. As the Company has elected to not recognize leases with a lease term of 12 months or less on the balance sheet, this was considered short-term leases, and no operating lease right of use assets and liabilities were recognized. In October 2022, the Company entered into a lease amendment to extend the lease for an additional term of six months through April 2023 , with an option to extend the lease through September 2023 . In April 2023, the Company extended the lease through September 2023 . The lease was further extended through November 5, 2023. The amendment resulted in $ 0.2 million of additional lease commitments to be paid during the extended term, inclusive of the extension through November 5, 2023. On December 29, 2022, the Company signed a new lease for approximately 10,620 square feet of new laboratory and office space at 4868 Rue Levy, Montreal, QC. The term of the lease is for 10 years, beginning on the commencement date, and requires an annual initial base rent of $ 36.50 CAD per square foot, which is subject to annual increases of 2 %. The lease did not commence as of October 31, 2023 as the Company did not have access to the space as of that date. The lease commenced in November 2023 . During the year ended October 31, 2023, and 2022, the components of operating lease cost were as follows, and are reflected in general and administrative expenses and research and development expenses, as determined by the underlying activities: Year Ended October 31, 2023 2022 Lease Cost: Operating lease cost — 62 Variable operating lease cost 62 53 Short-term operating lease cost 411 355 Total operating lease cost 473 470 The following table summarizes the cash paid for amounts included in the measurement of the Company’s operating lease liabilities for the year ended October 31, 2023, and 2022: Year Ended October 31, 2023 2022 Cash paid for amounts included in the measurement $ — $ 62 As of October 31, 2023, the Company does no t have any operating lease liabilities recorded on the balance sheet.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Oct. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	16. Commitments and Contingencies Legal Proceedings From time to time, in the ordinary course of business, the Company is subject to litigation and regulatory examinations as well as information gathering requests, inquiries and investigations. As of October 31, 2023 and 2022, there were no matters which would have a material impact on the Company’s financial results. Purchase and Other Obligations The Company enters into contracts in the normal course of business with CROs, CDMOs and other third-party vendors for nonclinical research studies and testing, clinical trials and testing and manufacturing services. Most contracts do not contain minimum purchase commitments and are cancellable by us upon written notice. Payments due upon cancellation consist of payments for services provided or expenses incurred, including those incurred by subcontractors of our suppliers.

Related Party Transactions

Related Party Transactions	12 Months Ended
Related Party Transactions	Oct. 31, 2023
Related Party Transactions [Abstract]
Related Party Transactions	17. Related Party Transactions During the year ended October 31, 2023, the Company had the following transactions with shareholders that hold more than 10 % of the total outstanding shares of the Company: On April 4, 2023, the Company entered into the April 2023 Notes for a principal amount of $ 8.0 million with the April 2023 investors, as described in Note 8. The April 2023 Notes had an interest free period of 45 days from the date of issuance, and commencing on the 46th day, is to accrue interest at a rate of 15 % per annum. The April 2023 Notes had a maturity date which was the earlier of (i) July 31, 2023 ; or (ii) the date the Company completes a qualified financing, as defined within the April 2023 Notes as a financing pursuant to which the Company sells convertible promissory notes, warrants, preferred shares, common shares, or a combination thereof of the Company for an aggregate amount of at least $ 20.0 million. Upon the completion of the 2023 Financing, which met the definition of a qualified financing as defined within the April 2023 Notes, the Company issued and aggregate amount of $ 8.0 million of convertible debentures and warrants of the Company to the April 2023 Note investors, on the same terms and conditions of the convertible debentures and warrants that were issued to the investors of the 2023 Financing, for the extinguishment and settlement of the April 2023 Notes. On May 16, 2023, concurrently with the execution and delivery of the Merger Agreement, the Company entered into agreements pursuant to which it issued new convertible indebtedness and warrants (i) for cash in an aggregate principal amount of $ 30.0 million and (ii) in settlement and extinguishment of the April 2023 Notes for an aggregate amount of $ 8.0 million, as described in Note 9. The 2023 Financing occurred in two separate issuances with $ 28.0 million issued in May 2023 for $ 20.0 million in cash and $ 8.0 million in repayment of the April 2023 Notes, and an additional $ 10.0 million issued in June 2023 for $ 10.0 million in cash. The 2023 Notes issued as part of the 2023 Financing have an initial maturity date of three years from the closing date and are to accrue interest at 10 % per annum, which is payable upon maturity. The 2023 Notes have the same conversion terms as the 2022 Notes (as described in Note 9). Of the $ 38.0 million of convertible debentures and warrants issued, $ 8.0 million was issued to existing shareholders of the Company, $ 20.0 million was issued to Forbion Growth Sponsor FEAC I B.V., and $ 10 million which was issued to Investissement Québec. On October 31, 2023, upon the consummation of the Reverse Recapitalization, all of the Old enGene’s redeemable convertible preferred shares outstanding immediately prior to the close were exchanged for shares of the Company’s common shares, with no dividends or distributions being declared or paid on Old enGene’s redeemable convertible preferred shares. Further, certain of Old enGene’s existing convertible notes were converted into common shares of Old enGene at the conversion ratio in place at the time of conversion, and all of Old enGene’s common shares were exchanged for common shares of Company at the Exchange Ratio of approximately 0.18048 . A total of 13,091,608 common shares of the Company were issued to the Old enGene’s equity and convertible note holders upon the close of the Reverse Recapitalization, of which 2,262,351 were issued to Forbion Growth Sponsor FEAC I B.V, as a result of its’ participation in the 2023 Financing. Each of Old enGene’s outstanding warrants to purchase common shares were exchanged for 2,679,432 common share warrants upon the close of the Reverse Recapitalization of which 950,153 were issued to Forbion Growth Sponsor FEAC I B.V, as a result of its’ participation in the 2023 Financing. All of Old enGene’s existing outstanding Class C Warrants outstanding at the time of the Reverse Recapitalization were terminated. Additionally, there were 3,670,927 common shares of the Company issued to FEAC and its shareholders, as part of the Reverse Recapitalization, along with 5,029,444 warrants to purchase common shares. During the years ended October 31, 2022, the Company had the following transactions with shareholders that hold more than 10 % of the total outstanding shares of the Company: On October 20, 2022, the Company issued an aggregate amount of $ 18.4 million of convertible debentures to existing shareholders including Forbion Capital Fund III Cooperatief U.A. (“Forbion Capital Fund III”), Fonds de Solidarité des Travailleurs du Québec (F.T.Q.) (“FSTQ”), Lumira Ventures III, L.P. (“Lumira III”), Lumira Ventures III (International), L.P. (“Lumira International III”), Merck Lumira Biosciences Fund, L.P. (“Merck”), Merck Lumira Biosciences Fund (Québec), L.P. Refer to Note 9.

Subsequent Events

Subsequent Events	12 Months Ended
Subsequent Events	Oct. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	18. Subsequent Events The Company has evaluated subsequent events through the date these financial statements were issued. Except as noted below, the Company concluded that no additional subsequent events have occurred that require disclosure. On November 30, 2023, the Company granted 385,000 options to purchase common shares in connection with the hiring of the Company's Chief Financial Officer and Chief Medical Officer, which vest over a four-year period, and 203,000 options to purchase common shares other various employees, which vest over three - and four-year periods, under the 2023 Plan. All the options granted have an exercise price of $ 7.66 per share, which is equal to the closing price of the Company’s common stock on the date of the grant. On December 22, 2023, the Company entered into an Amended and Restated Loan and Security Agreement (the "Amended Loan Agreement”), with Hercules, as agent and lender, and the several banks and other financial institutions or entities from time to time parties thereto (with Hercules, the "Lenders”). The Amended Loan Agreement amends and restates in its entirety that certain Loan and Security Agreement with Hercules dated December 30, 2021 (the "Prior Loan Agreement”). See Note 8. The Amended Loan Agreement provides for a term loan facility of up to $ 50 million available in multiple tranches (the "Amended Term Loan”), as follows: (i) an initial term loan advance (the "Tranche 1 Advance”) that was made on the Amended Term Loan closing date of $ 22.5 million, approximately $ 8.6 million of which was applied to refinance in full the term loans outstanding under the Prior Loan Agreement, (ii) subject to the achievement of the specified Interim Milestone (the "Interim Milestone”) and satisfaction of certain other conditions precedent, a right of the Company to request that the Lenders make additional term loan advances to the Company in an aggregate principal amount of up to $ 7.5 million from the achievement of the Interim Milestone through the earlier of (x) 60 days following the Interim Milestone and (y) March 31, 2025 , and (iii) an uncommitted tranche subject to the Lenders’ investment committee approval and satisfaction of certain other conditions precedent (including payment of a 0.75 % facility charge on the amount borrowed), pursuant to which the Company may request from time to time up to and including the Amortization Date (defined below) that the Lenders make additional term loan advances to the Company in an aggregate principal amount of up to $ 20.0 million. The Company is are required to pay upon the earlier of January 1, 2028 ( the “Amended Term Loan Maturity Date”) or payment in full of the Amended Term Loans, an end of term fee equal to 5.50 % of the aggregate principal amount of the Amended Term Loans. The Company is also required to pay on July 1, 2025 or, if earlier, the date the Company prepays the Amended Term Loans, $ 0.7 million representing the end of term charge under the Prior Loan Agreement. The Amended Term Loans mature on January 1, 2028 , with no option for extension. The Amended Term Loan bears cash interest payable monthly at an annual rate equal to the greater of (a) the prime rate of interest as reported in the Wall Street Journal plus 0.75 % (capped at 9.75 %) and (b) 9.25 %. The Amended Term Loan also bears additional payment-in-kind interest at an annual rate of 1.15 %, which is added to the outstanding principal balance of the Amended Term Loan on each monthly interest payment date. Borrowings under the Amended Loan Agreement are repayable in monthly interest-only payments through the "Amortization Date”, which is either: (x) July 1, 2025 or (y) if the Interim Milestone is achieved and there has been no default, January 1, 2026 , or (z) if the Interim Milestone and certain clinical milestones are achieved and there has been no default, July 1, 2026 . After the Amortization Date, the outstanding Amended Term Loans and interest shall be repayable in equal monthly payments of principal and accrued interest until the Amended Term Loan Maturity Date. At the Company's option, the Company may elect to prepay all, but not less than all, of the outstanding Amended Term Loan by paying the entire principal balance and all accrued and unpaid interest thereon plus a prepayment charge of 1.0 % to 3.0 % of the principal amount being repaid, the rate depending upon the date of repayment. In connection with the Amended Loan Agreement, the Company granted Hercules a security interest senior to any current and future debts and to any security interest in all of the Company's right, title, and interest in, to and under all of the Company's property and other assets, subject to limited exceptions including the Company's intellectual property. The Amended Loan Agreement contains negative covenants that, among other things and subject to certain exceptions, could restrict the Company's ability to incur additional liens, incur additional indebtedness, make investments, including acquisitions, engage in fundamental changes, sell or dispose of assets that constitute collateral, including certain intellectual property, pay dividends or make any distribution or payment on or redeem, retire or purchase any equity interests, amend, modify or waive certain material agreements or organizational documents and make payments of certain subordinated indebtedness. The Amended Loan Agreement also contains certain events of default and representations, warranties and non-financial covenants of the Company. Beginning from an initial test date of October 1, 2024 (which date can be extended based on certain milestones), the Amended Loan Agreement contains a minimum liquidity covenant requiring the Company to maintain at least 35 % of the aggregate outstanding principal as unrestricted cash. This percentage can be lowered based on certain milestones and other events. In connection with the Amended Loan Agreement, the Company also agreed to issue to the Lenders in connection with each advance of Term Loans warrants ("Lender Warrants”) to purchase that number of the Company’s common shares as shall equal to 2 % of the aggregate principal amount of such Term Loan advance divided by the Warrant per share exercise price of $ 7.21 (which exercise price equals the ten-day volume weighted average price for the ten (10) trading days preceding the Closing Date and is subject to customary adjustments under the terms of the Warrants). Warrants are exercisable for a period of seven years from issuance. On the Amended Term Loan Closing Date, the Company issued to the Lenders 62,413 Warrants in connection with the Tranche 1 Advance of the Term Loans. Under the terms of the Amended Loan Agreement, the maximum number of Warrants and resultant underlying common shares of the Company that could be issued is 138,696 . On January 1, 2024, the Company entered into a lease agreement, in which the Company is sub-leasing approximately 6,450 square feet of office space located at 200 Fifth Avenue, Waltham, MA. The Company will make an aggregate amount of base rental payments of $ 0.5 million, under the initial term of the lease, which is set to expire on December 30, 2026 and does not have an option to renew .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Oct. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates (“ASU’s”) of the Financial Accounting Standards Board (“FASB”). The consolidated financial statements are expressed in US dollars. The consolidated financial statements have been prepared on a historical cost basis, except for items that are required to be accounted for at fair value. As the merger with FEAC has been accounted for as a reverse recapitalization, the historical operations of the Company represent that of Old enGene which is the accounting predecessor. The number of common shares, net loss per common share, the number of warrants to purchase common shares, and the number of stock options and the related exercise prices of the stock options issued and outstanding prior to the Reverse Recapitalization have been retrospectively restated to reflect the Exchange Ratio of approximately 0.18048 established in the Merger Agreement. For additional information on the Reverse Recapitalization, please refer to Note 3.
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include but are not limited to the accrual of research and development expenses, the recoverability of investment tax credits receivable and the valuations of common shares, redeemable convertible preferred shares, warrants to purchase redeemable convertible preferred shares, convertible debentures, embedded derivatives on convertible debt and share-based compensation. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. Actual results could differ from those estimates and such differences may be material to the consolidated financial statements.
Segment Information	Segment Information Operating segments are defined as components of an entity about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company operates as a single business segment focused on research, discovery, and clinical development of human gene therapy products. The majority of the Company’s tangible assets are held in Canada.
Functional Currency Change	Functional Currency Change Prior to November 1, 2022, Old enGene’s functional currency was the Canadian dollar (“CAD”), and its reporting currency was the U.S. dollar (“USD”). During the period, Old enGene reassessed its functional currency and determined that its functional currency changed from the Canadian dollar to the USD based on management’s analysis as a result of evaluating criteria within ASC 830 . The change in functional currency is accounted for prospectively from November 1, 2022, and prior year financial statements have not been restated for the change in functional currency. All assets and liabilities were reported using the same USD values as previously reported under the USD reporting currency described above. As a result, the cumulative translation adjustment balance as of October 31, 2022, is carried forward and will remain unchanged. The Company reported net realized and unrealized foreign currency transaction losses of $ 0.1 million and $ 0.7 million for the years ended October 31, 2023 and 2022, respectively. These gains and losses are reflected within other expense (income), net in the Company’s consolidated statements of operations and comprehensive loss.
Risk of Concentrations of Credit and Off-Balance Sheet Risk	Risk of Concentrations of Credit and Off-Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash. The Company regularly maintains deposits in accredited financial institutions in excess of federally insured limits. As of October 31, 2023, the Company held cash deposits at Silicon Valley Bank, or SVB, in excess of Federal Deposit Insurance Corporation (FDIC) insured limits. On March 10, 2023, SVB was closed by the California Department of Financial Protection and Innovation, and the FDIC, was appointed as receiver. No losses were incurred by the Company on deposits that were held at SVB. Management believes that the Company is not currently exposed to significant credit risk as the Company’s deposits were held in custody at third-party financial institutions. The Company is dependent on third-party Contract Development and Manufacturing Organization (“CDMOs”) and Contract Research Organization (“CRO”) with whom it does business. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements of active pharmaceutical ingredients and formulated drugs in order to perform research and development activities in its programs. The Company also relies on a limited number of third-party CROs to perform research and development activities on its behalf. These programs could be adversely affected by significant interruption from these providers.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all short-term, highly liquid investments purchased with an original maturity of three months or less at the date of purchase to be cash equivalents. The Company’s cash and cash equivalents include bank balances, demand deposits and other short-term, highly liquid investments. Cash and cash equivalents have been measured at amortized cost. The Company had no cash equivalents as of the years ended October 31, 2023 and 2022.
Restricted Investments	Restricted Investments Restricted investments consist of temporary holdings of highly liquid Canadian guaranteed investment certificates held with a bank and is used as a guarantee of the Company’s short term borrowings and security deposits for it's lease agreements. As of October 31, 2023, the Company classified $ 70 thousand of restricted investments within other assets on the Consolidated Balance Sheet associated with its lease agreement that has a term longer than twelve months.
Property and Equipment	Property and Equipment Property and equipment are comprised mainly of research and development equipment, computer hardware and software, office furniture and equipment, and leasehold improvements. Property and equipment are stated at cost less accumulated depreciation and accumulated impairment losses, if applicable. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset, as follows: Estimated Useful Life Lab equipment 5 years Computer equipment 3 years Computer software 5 years Office furniture 5 years Leasehold improvements Shorter of remaining lease term or useful life Estimated useful lives are periodically assessed to determine if changes are appropriate. Maintenance and repairs are charged to expense as incurred. When assets are retired or otherwise disposed of, the cost of these assets and related accumulated depreciation or amortization are eliminated from the consolidated balance sheet and any resulting gains or losses are included in the consolidated statements of operations and comprehensive loss in the period of disposal. The Company reviews long-lived assets, such as property and equipment, for impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. If indicators of impairment are present, the assets are tested for recoverability by comparing the carrying amount of the assets to the related estimated future undiscounted cash flows that the assets are expected to generate. If the expected undiscounted cash flows are less than the carrying value of the assets, then the assets are considered to be impaired and its carrying value is written down to fair value, based on the related estimated discounted future cash flows. To date, no such impairment losses have been recorded.
Leases	Leases The Company adopted FASB ASC 842 with an effective date of November 1, 2019, using the modified retrospective transition approach which uses the effective date as the date of initial application. In accordance with ASC 842, the Company determines whether an arrangement is or contains a lease at inception. A contract is or contains a lease if the contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. The Company classifies leases at the lease commencement date, when control of the underlying asset is transferred from the lessor to the lessee, as operating or finance leases and records a right-of-use (“ROU”) asset and a lease liability on the consolidated balance sheet for all leases with an initial lease term of greater than 12 months. The Company has elected to not recognize leases with a lease term of 12 months or less on the balance sheet. The Company enters into contracts that contain both lease and non-lease components. Non-lease components may include maintenance, utilities, and other operating costs. For leases of real estate, the Company combines the lease and associated non-lease components in its lease arrangements as a single lease component. Variable costs, such as utilities or maintenance costs, are not included in the measurement of right-of-use assets and lease liabilities, but rather are expensed when the event determining the amount of variable consideration to be paid occurs. Lease assets and liabilities are recognized at the lease commencement date based on the present value of the lease payments over the lease term using the discount rate implicit in the lease if readily determinable. If the rate implicit is not readily determinable, the Company utilizes an estimate of its incremental borrowing rate based upon the available information at the lease commencement date. ROU assets are further adjusted for initial direct costs, prepaid rent, or incentives received. Operating lease payments are expensed using the straight-line method as an operating expense over the lease term. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option.
Fair Value Measurements of Financial Instruments	Fair Value Measurements of Financial Instruments Certain assets and liabilities of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: o Level 1—Quoted prices in active markets for identical assets or liabilities. o Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. o Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s convertible debentures embedded derivative, certain of its convertible debentures and warrant liabilities were carried at fair value, and were determined according to Level 3 inputs in the fair value hierarchy described above.
Fair Value Option	Fair Value Option The Company elected the fair value option of accounting of ASC 825 for all convertible debentures issued in fiscal 2023 from their issuance date in order to not have to bifurcate any embedded derivatives in accordance with ASC 815. The notes for which the fair value option of accounting is elected are recorded at fair value upon the date of issuance and subsequently remeasured to fair value at each reporting period. Changes in the fair value of the notes accounted for at fair value, which include accrued interest, if any, are recorded as a component of other expense (income), net in the consolidated statement of operations and comprehensive loss. The Company has not elected to present interest expense separately from changes in fair value and therefore will not present interest expense associated with the notes. Any changes in fair value caused by instrument-specific credit risk are presented separately in other comprehensive income. During the year ended October 31, 2023, the Company did not record any changes in fair value related to instrument-specific credit risk. All costs associated with the issuance of the convertible debentures accounted for using the fair value option were expensed upon issuance.
Debt Issuance Costs	Debt Issuance Costs The Company capitalizes certain legal, accounting, and other third-party fees that are directly associated with the issuance of debt not accounted for using the fair value option as debt issuance costs. Debt issuance costs are recorded as a direct reduction of the carrying amount of the associated debt on the Company’s consolidated balance sheets and amortized as interest expense on the Company’s consolidated statements of operations and comprehensive loss using the effective interest method.
Convertible Debenture Embedded Derivative Liabilities	Convertible Debenture Embedded Derivative Liabilities The Company’s convertible debentures contained certain features that meet the definition of embedded derivatives requiring b ifurcation from the convertible debenture instrument, for which the fair value option was not elected, as a separate compound derivative. The convertible debenture embedded derivative liabilities are initially measured at fair value on issuance and is subject to remeasurement at each reporting period with changes in fair value recognized in the change in fair value of derivative liabilities, net in the consolidated statements of operations and comprehensive loss.
Common Share and Preferred Share Warrants	Common Share and Preferred Share Warrants The Company accounts for its common share warrants and redeemable convertible preferred shares warrants issued in connection with its various financing transactions based upon the characteristics and provisions of the instrument. Warrants that have been determined to be classified as liabilities are recorded on the consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value at each reporting period, with the changes in fair value recognized in the change in fair value of warrant liabilities, net in the consolidated statements of operations and comprehensive loss. The Company adjusted the liability for changes in the fair value of these warrants until the earlier of the exercise of the warrants, the expiration of the warrants, or until such time as the warrants were no longer considered liability.
Convertible Debentures	Convertible Debentures The Company’s 2022 Notes (as defined in Note 9) are convertible debentures that consist of a debt instrument, a minimum interest obligation, and a share conversion feature. Certain of the convertible debentures issued by the Company also included warrants to purchase redeemable convertible preferred shares, which were classified as liabilities. The Company identified embedded derivatives related to certain share conversion and repayment features within the convertible notes that required bifurcation as a single compound derivative instrument. At inception, the Company utilized the residual method to determine the value of the debt instrument based on the difference between gross proceeds and the estimated fair value of the embedded derivative and any warrants that were issued. The debt instrument is accounted for using the amortized cost method. The discounts on debt resulting from any issuance costs, embedded derivatives and warrants are amortized over the life of the debt using the effective interest method. The issuance costs allocated to the embedded derivatives and warrants are expensed at inception.
Research and Development Expenses	Research and Development Expenses Research and development expenses are comprised primarily of costs incurred for our drug discovery efforts and development of our product candidates. These expenses include salaries, employee benefits, and share-based compensation expense for our research and development personnel, materials, supplies, depreciation on and maintenance of research equipment, the cost of services provided by outside CROs and consultants to conduct research and development activities including costs of clinical trials and manufacturing, and the allocable portions of facility costs, such as rent, utilities, and general support services. All costs associated with research and development are expensed as incurred. Management estimates the Company’s accrued research and development expenses as of each balance sheet date in the Company’s financial statements based on facts and circumstances known to the Company at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Nonrefundable advance payments for goods and services are deferred and recognized as expense in the period that the related goods are consumed or services are performed.
Patent Costs	Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications such as direct application fees, and legal and consulting expenses are expensed as incurred due to the uncertainty about the recovery of the expenditure. Patent-related costs are classified as general and administrative expenses within the Company’s consolidated statements of operations.
Share-Based Compensation	Share-Based Compensation The Company has an incentive equity plan (the “2023 Incentive Equity Plan” or the “2023 Plan”), whereby employees render services as consideration for equity instruments. The Plan was adopted on October 31, 2023 upon the completion of the Reverse Recapitalization and superseded Old enGene’s employee stock option plan (the “ESOP”) and equity incentive plan (the “EIP”) (collectively, the “Old Plans”). The Company measures all share-based awards granted to employees, officers, directors and non-employees based on their fair value on the date of the grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award. The Company accounts for forfeitures of its share-based awards as they occur. The Company issues share-based awards with service-based vesting conditions and awards with both performance and service-based vesting conditions. For share-based awards with service-based vesting conditions, the Company records the expense using the straight-line method including when such awards have graded vesting. For share-based awards with both performance and service-based vesting conditions, the Company records the expense using an accelerated attribution method, once the performance conditions are considered probable of being achieved, using management’s best estimate. The fair value of each stock option is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the fair value of the Company’s common shares, expected share price volatility, the expected term of the award, the risk-free interest rate for a period that approximates the expected term of the option, and the Company’s expected dividend yield. The Company determines the volatility for awards granted based on an analysis of reported data for a group of guideline companies that have issued options with substantially similar terms. The expected volatility has been determined using a weighted average of the historical volatility measures of this group of guideline companies. The expected option term was calculated based on the simplified method for awards with only service based vesting conditions, which uses the midpoint between the vesting date and the contractual term, as the Company does not have sufficient historical data to develop an estimate based on participant behavior. For awards with both performance and service based vesting conditions, the expected term has been determined using management’s best estimate considering the characteristics of the award, contractual life, the timing of the expected achievement of the performance conditions, the remaining time-based vesting period, if any, and comparison to expected terms used by peers. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company has not paid, and does not anticipate paying, cash dividends on its common shares; therefore, the expected dividend yield is assumed to be zero. Prior to the consummation of the Reverse Recapitalization, because there was no public market for the Company’s common shares, the Board of Directors has determined the fair value of the Company’s common stock based on third-party valuations of the Company’s common shares. Initially, the estimated enterprise equity value of the Company was determined using a market approach and/or cost approach by considering the weighting of scenarios estimated using a back-solve method based on recent financing transactions of the Company. This value was then allocated towards the Company’s various securities of its capital structure using an option pricing method, or OPM, and a waterfall approach based on the order of the superiority of the rights and preferences of the various securities relative to one another. Significant assumptions used in the OPM to determine the fair value of common shares include volatility, discount for lack of marketability, and the expected timing of a future liquidity event such as an initial public offering (“IPO”), or sale of the Company in light of prevailing market conditions. This valuation process creates a range of equity values both between and within scenarios. In addition, the Company’s Board of Directors considered various objective and subjective factors to determine the fair value of the Company’s common shares as of each grant date, including the prices at which Old enGene sold shares of redeemable convertible preferred shares and the superior rights and preferences of the redeemable convertible preferred shares relative to its common shares at the time of each grant, external market conditions, the progress of the Company’s research and development programs, the Company’s financial position, including cash on hand, and its historical and forecasted performance and operating results, and the lack of an active public market for the Company’s common shares and redeemable convertible preferred shares, among other factors. The assumptions underlying these valuations represented management’s best estimate, which involved inherent uncertainties and the application of management’s judgment and these valuations are sensitive to changes in the unobservable inputs. As a result, if the Company had used different assumptions or estimates or if there are changes to the unobservable inputs, the fair value of its common shares and share-based compensation expense could have been materially different. Subsequent to becoming a publicly traded Company upon the consummation of the Reverse Recapitalization, the fair value of common stock underlying equity awards is based on the market price of the Company’s common stock at the date of the grant. The Company’s share-based compensation expense is recorded in general and administrative and research and development expenses in the Company’s consolidated statements of operations and comprehensive loss.
Income Taxes	Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the Company’s consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on differences between the consolidated financial statement carrying amounts and the tax basis of the assets and liabilities using the enacted tax rates in effect in the years in which the differences are expected to reverse. A valuation allowance against deferred tax assets is recorded if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of benefit that may be recognized is the largest amount that has a greater than 50 % likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss as well as other changes in shareholders’ deficit that result from transactions and economic events other than those with shareholders. The Company’s comprehensive loss includes foreign currency translation.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common shares. Net loss per share attributable to common shareholders is calculated using the two-class method, which is an earnings allocation formula that determines net loss per share for the holders of the Company’s common shares and participating securities. Net loss attributable to common shareholders is allocated first based on dividend rights and then to common and preferred shareholders based on ownership interests on an as-converted basis as if all the earnings for the period had been distributed. When considering the impact of the convertible equity instruments, diluted net loss per share is computed using the more dilutive of (a) the two-class method or (b) the if-converted method. The Company allocates earnings first to preferred shareholders and warrant holders based on dividend rights and then to common and preferred shareholders and warrant holders based on ownership interests. The weighted-average number of common shares included in the computation of diluted net loss gives effect to all potentially dilutive common equivalent shares, including outstanding stock options, warrants, and the potential issuance of common shares upon the conversion of the convertible notes. Common stock equivalent shares are excluded from the computation of diluted net loss per share if their effect is antidilutive. In periods in which the Company reports a net loss attributable to common shareholders, diluted net loss per share attributable to common shareholders is generally the same as basic net loss per share attributable to common shareholders because dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. See Note 13, Net Loss per Share, for further detail.
Deferred Transaction Costs	Deferred Transaction Costs The Company capitalized certain legal, professional accounting and other third-party fees that were directly associated with the Reverse Recapitalization and PIPE Financing as deferred transaction costs until such transaction was consummated. After the consummation of such transaction, these costs were recorded within equity as a reduction of the common share and warrants value within additional paid in capital, for both instruments issued and assumed to shareholders of FEAC and to PIPE financing investors, were allocated to each on a relative fair value basis. The Company incurred a total of $ 11.3 million of transaction costs as part of the Reverse Recapitalization and PIPE Financing. The Company did no t have any deferred transaction costs recorded on the balance sheet as of October 31, 2023 and 2022. In addition, transaction costs of $ 0.8 million related to the issuance of the April 2023 Notes and the May 2023 Notes for which the fair value option of accounting was elected and those allocated to the liability classified warrants issued as part of the 2023 Financing are not deferred and are included in general and administrative expenses in the Company’s consolidated statements of operations and comprehensive loss.
Government Assistance Programs for Research and Development Expenditures	Government Assistance Programs for Research and Development Expenditures The Company was eligible to claim Canadian federal and provincial tax credits as a Canadian controlled private corporation (“CCPC”) on eligible research and development expenditures through September 2023, at which time the Company lost its status as a CCPC. In addition, effective for fiscal 2023, the Company’s maximum refundable tax credits were reduced due to the Company’s taxable capital, as defined by the tax authorities, which reduction in credits has been recorded in the fourth quarter. The Canadian federal government offers a tax incentive to companies performing research and development activities in Canada and this tax incentive can be refunded or used to reduce federal income taxes in Canada otherwise payable. Such credits, if not refunded or used in the year earned, can be carried forward for a period of twenty years. The Quebec provincial government offers a similar refundable incentive. The investment tax credits recorded are based on management’s estimates of amounts expected to be recovered and are subject to audit by the taxation authorities, the resulting adjustments of which could be significant. Following the loss of CCPC status, the Company’s eligible research and development expenditures tax credits will be earned at a lower rate and some will no longer be refundable. Amounts received or receivable resulting from government assistance programs, including investment tax credits for research and development, are recognized when there is reasonable assurance that the amount will be received, and all attached conditions will be complied with. Reimbursements of eligible research and development expenditures pursuant to government assistance programs are received in cash. The amounts receivable are recorded as reductions of research and development costs when the related costs have been incurred and there is reasonable assurance regarding collection of the claim. During the years ended October 31, 2023 and 2022, the Company recorded $ 1.1 million and $ 1.4 million, respectively, as a reduction of research and development expense associated with research and development investment tax credits.
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements - Not Yet Adopted	Recently Adopted Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, or ASU-2019-12, Simplifying the Accounting for Income Tax, which contains several provisions that reduce financial statement complexity including removing the exception to the incremental approach for intra-period tax expense allocation when a company has a loss from continuing operations and income from other items not included in continuing operations. The Company adopted this accounting standard as of November 1, 2021 with no material impact on its consolidated financial statements and related disclosures. In August 2020, the FASB issued ASU 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity ("ASU 2020-06”), which simplifies and clarifies certain calculation and presentation matters related to convertible and equity and debt instruments. Specifically, ASU2020-06 removes requirements to separately account for conversion features as a derivative under ASC Topic 815 and removing the requirement to account for beneficial conversion features on such instruments. ASU 2020-06 also provides clearer guidance surrounding disclosure of such instruments and provides specific guidance for how such instruments are to be incorporated in the calculation of Diluted EPS. The Company adopted this standard on November 1, 2020 and the adoption did no t have a material impact on the consolidated financial statements and related disclosures. In November 2021, the FASB issued ASU 2021-10, Government Assistance (Topic 832): Disclosure by Business Entities about Government Assistance (“ASU 2021-10”), which improves the transparency of government assistance received by most business entities by requiring the disclosure of: (1) the types of government assistance received; (2) the accounting for such assistance; and (3) the effect of the assistance on a business entity’s financial statements. This guidance is effective for financial statements issued for annual periods beginning after December 15, 2021. The Company adopted ASU 2021-10 effective November 1, 2021 and included incremental financial statement disclosures, and the adoption did no t have a material impact on its consolidated financial statements. Recently Issued Accounting Pronouncements – Not Yet Adopted In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326)—Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). This new standard changes the impairment model for most financial assets and certain other instruments. Entities will be required to use a model that will result in the earlier recognition of allowances for losses for trade and other receivables, held-to-maturity debt securities, loans, and other instruments. For available-for-sale debt securities with unrealized losses, the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. In November 2019, the FASB issued ASU 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) (“ASC 2019-10”), which defers the effective date of ASU 2016-13 to fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, for entities meeting the definition of a smaller reporting company. The Company will adopt ASU 2016-13 effective November 1, 2023. The Company does not expect the adoption of ASU 2016-13 will have a material impact on the consolidated financial statements. In June 2022, the FASB issued ASU No. 2022-03, Fair Value Measurement (Topic 820) – Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions, which amends guidance in ASC 820 to clarify that a contractual sales restriction is not considered in measuring an equity security at fair value and introduces new disclosure requirements for equity securities subject to contractual sale restrictions that are measured at fair value. This ASU is effective for public entities for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years. The Company does not expect that the adoption of this standard will have a material impact on its financial statements and related disclosures. In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280) – Improvements to Reportable Segment Disclosures, which requires incremental disclosure of segment information on an interim and annual basis. This ASU is effective for public entities for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Retrospective application to all prior periods presented in the financial statements is required for public entities. The Company is currently evaluating the impact of the guidance on the financial statements disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Oct. 31, 2023
Accounting Policies [Abstract]
Summary of Estimated Useful Life of Each Asset	Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset, as follows: Estimated Useful Life Lab equipment 5 years Computer equipment 3 years Computer software 5 years Office furniture 5 years Leasehold improvements Shorter of remaining lease term or useful life

Reverse Recapitalization (Table

Reverse Recapitalization (Tables)	12 Months Ended
Reverse Recapitalization (Tables)	Oct. 31, 2023
Stockholders' Equity Note [Abstract]
Summary of Net Proceeds from Reverse Recapitalization and PIPE Financing	The following table summarizes the elements of the net proceeds from the Reverse Recapitalization and PIPE Financing transaction as of October 31, 2023: Recapitalization Cash – FEAC’s Trust Account and Cash (net of redemptions $ 7,363 Cash – PIPE Financing 56,892 Less transaction costs withheld from cash proceeds on Closing ( 6,024 ) Cash proceeds received from the Reverse Recapitalization and $ 58,231 Less transaction costs previously deferred and netted against ( 5,086 ) Net cash proceeds from the Reverse Recapitalization and PIPE 53,145
Summary of Number of Shares of Common Stock Outstanding	The following table summarizes the number of shares of common stock outstanding immediately following the consummation of the Reverse Recapitalization and PIPE Financing transaction: Number of Shares Old enGene Shareholders (Excluding Convertible Notes) 6,711,786 FEAC Shareholders, including sponsor's and shareholder with 3,670,927 Convertible Notes - Common Shares Issued 6,379,822 Common shares issued to PIPE Investors 6,435,441 Total common shares outstanding immediately after the 23,197,976

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Oct. 31, 2023
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Schedule of Fair Value Hierarchy for Financial Liabilities Measured at Fair Value	The following table presents the Company's fair value hierarchy for financial liabilities measured at fair value as of October 31, 2022: October 31, 2022 Description Total Quoted Prices in Significant Other Significant Other Liabilities Convertible debenture embedded derivative liabilities $ 3,791 $ — $ — $ 3,791 Warrant liabilities 11,456 — — 11,456 Total financial liabilities $ 15,247 $ — $ — $ 15,247
Convertible Debentures Embedded Derivative Liabilities
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Assumptions Used to Determine Fair Value of Liabilities	The assumptions ranges that the Company used to determine the fair value of the convertible debentures embedded derivative liabilities for the 2022 Notes and BDC Notes that were outstanding as of each respective period (refer to Note 9 for description of notes) were as follows: Immediately prior to settlement on October 31, As of October 31, 2022 Probability of qualified financing* 100 % 60 % Volatility n/a 85 % Class C Preferred Share price (CAD) n/a $ 2.20 Liquidity price at conversion of listing event* $ 8.84 n/a Fair value of common share at conversion of listing $ 21.70 $ n/a Discount rate** 18.4 % 10.4 - 18.4 % Expected time to respective scenarios 0.0 years 0.4 years
Summary of Change in Estimated Fair Value of Liabilities	The following table provides a summary of the change in the estimated fair value of the Company’s convertible debentures embedded derivative liabilities for the year ended October 31, 2023, and 2022. Total Balance as of October 31, 2021 $ 602 Fair value of convertible debenture embedded derivative 3,500 Change in fair value of convertible debenture embedded ( 269 ) Foreign exchange rate translation adjustment ( 42 ) Balance as of October 31, 2022 3,791 Change in fair value of convertible debenture embedded 21,421 Foreign exchange rate translation adjustment 5 Settlement of derivative liability in accordance with ( 25,217 ) Balance as of October 31, 2023 $ —
May 2023 Notes
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Assumptions Used to Determine Fair Value of Liabilities	The assumptions that the Company used to determine the fair value of the May 2023 Notes as of the issuance date are as follows: As of Issuance Date Probability of qualified financing* 60 % Volatility 85 % Class C Preferred Share Price (CAD) $ 2.074 Liquidity price at conversion of listing event $ 8.42 Fair value of common share at conversion of listing event $ 10.25 Discount rate*** 40.8 % Expected time to respective scenarios 0.3 years
Summary of Change in Estimated Fair Value of Liabilities	he following table provides a summary of the change in the estimated fair value of the Company’s 2023 Notes for the year ended October 31, 2023. Upon the close of the Reverse Recapitalization the 2023 Notes were exchanged for common shares of the Company, resulting in an extinguishment of the 2023 Notes. Refer to Note 3 and Note 9. Total Balance as of October 31, 2022 $ — Issuance of May 2023 Notes 37,043 Change in fair value of May 2023 Notes 56,212 Settlement of 2023 Notes upon the consummation of the Reverse ( 93,255 ) Balance as of October 31, 2023 $ —
Preferred Share Warrant Liabilities
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Assumptions Used to Determine Fair Value of Liabilities	The assumptions that the Company used to determine the fair value of the Preferred Share Warrant liabilities as of October 31, 2022 were as follows: As of October 31, 2022 Weighted average expected life (in years) 3.0 Expected volatility 78.0 % Risk-free interest rate 3.92 % Expected dividend yield — Preferred share price – Class C (CAD) $ 2.20 Exercise price – Class C (CAD) $ 2.632
Summary of Change in Estimated Fair Value of Liabilities	The following table provides a summary of the change in the estimated fair value of the Company’s warrant liabilities for the year ended October 31, 2023: Total Balance as of October 31, 2021 $ 9,088 Warrant liabilities recognized upon issuance of term loan 90 Change in fair value of warrant liabilities 3,326 Foreign exchange rate translation adjustment ( 1,048 ) Balance as of October 31, 2022 11,456 Warrant liability recognized upon issuance of May 2023 Notes 1,420 Change in fair value of warrant liabilities ( 10,849 ) Foreign exchange rate translation adjustment ( 44 ) Reclassification of 2023 Warrants to equity upon consummation ( 1,983 ) Balance as of October 31, 2023 $ —

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
Property and Equipment, Net (Tables)	Oct. 31, 2023
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	As of October 31, 2023, and 2022, property and equipment, consisted of the following: October 31, October 31, 2023 2022 Lab equipment $ 1,779 $ 1,472 Computer equipment 269 221 Computer software 70 70 Office furniture 69 55 Leasehold improvements 129 122 Property and equipment 2,316 1,940 Less: Accumulated depreciation and amortization 1,727 1,553 Property and equipment, net $ 589 $ 387

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Oct. 31, 2023
Payables and Accruals [Abstract]
Summary of Accrued Expenses and Other Current Liabilities	As of October 31, 2023 and 2022, accrued expenses and other current liabilities consisted of the following: October 31, October 31, 2023 2022 Accrued research and development expenses $ 759 $ 1,845 Professional fees 1,708 573 Employee compensation and related benefits 814 676 Accrued income tax payable 39 22 Other 219 — Total accrued expenses and other current liabilities $ 3,539 $ 3,116

Notes Payable (Tables)

Notes Payable (Tables)	12 Months Ended
Notes Payable (Tables)	Oct. 31, 2023
Debt Disclosure [Abstract]
Schedule of Carrying Value of Term Loan	As of October 31, 2023 and 2022, the carrying value of the Term Loan consists of the following: October 31, 2023 October 31, 2022 Note payable, including End of Term Charge $ 10,144 $ 11,699 Debt discount, net of accretion ( 474 ) ( 891 ) Accrued interest 108 106 Note payable, net of discount $ 9,778 $ 10,914
Schedule of Estimated Future Principal Payments Due Under the Loan Agreement	stimated future principal payments due under the Loan Agreement, including the contractual End of Term Charge, are as follows: Note Principal 2024 $ 5,106 2025 5,038 Total principal payments, including End of Term Charge 10,144

Convertible Debentures (Tables)

Convertible Debentures (Tables)	12 Months Ended
Convertible Debentures (Tables)	Oct. 31, 2023
Debt Disclosure [Abstract]
Summary of Outstanding Principal, Accrued Interest and Unamortized Deferred Financing Costs of Convertible Debentures Recorded on Balance Sheet	The Company has issued convertible debentures to various investors. The outstanding principal, accrued interest, and unamortized deferred financing costs of the convertible debentures recorded on the balance sheet as of each period end are as follows: October 31, October 31, 2023 2022 BDC Notes $ — $ 2,497 2022 Notes — 14,908 Total Convertible debentures $ — $ 17,405

Common Shares (Tables)

Common Shares (Tables)	12 Months Ended
Common Shares (Tables)	Oct. 31, 2023
Equity [Abstract]
Schedule of Shares Reserved for Future Issuance Under the Plan	As of October 31, 2023, and 2022, the Company has reserved the following shares of common shares for the exercise of common share warrants, share options, and remaining shares reserved for future issuance under the Plan: October 31, October 31, 2023 2022 Preferred Stock, as converted — 5,983,339 Warrants to purchase redeemable convertible preferred shares — 3,194,756 Warrants to purchase common shares 10,411,641 — Options to purchase common shares* 2,706,941 1,575,785 Remaining shares reserved for future issuance under 2,607,943 170,158 Total 15,726,525 10,924,038 *As of October 31, 2023, amount includes the 1,046,764 shares with exercisability conditions of (i) the completion of the Reverse Recapitalization, and (ii) the filing an effective registration statement to register the shares underlying the option award, which is deemed probable as of October 31, 2023.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
Share-Based Compensation (Tables)	Oct. 31, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Assumptions Used to Determine Grant-Date Fair Value of Stock Options	The assumptions that the Company used to determine the grant-date fair value of stock options, were as follows: Year ended October 31, 2023 2022 Expected term (in years) 5.2 – 6.08 6.08 Expected volatility 79.92 – 81.48 % 75.3 % Risk-free interest rate 3.56 – 4.35 % 2.16 % Expected dividend yield — — Fair value of common shares and exercise $ 2.11 – 12.36 $ 1.22 Fair value of common shares and exercise $ 1.52 – 8.93 $ 0.88
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity: Number of Weighted- Weighted- Aggregate Outstanding as of October 31, 2022 1,575,785 $ 0.88 7.7 $ 1,026 Granted 1,308,081 4.05 Exercised ( 84,072 ) 0.88 Forfeited or expired ( 92,853 ) 0.88 Outstanding as of October 31, 2023 2,706,941 $ 2.40 8.1 $ 52,192 Options vested and exercisable as of October 31, 2023 1,660,177 $ 1.26 7.1 $ 33,921 Options vested and not exercisable as of October 31, 2023 807,025 $ 4.24 9.7 $ 14,087 Options unvested as of October 31, 2023 239,739 $ 4.24 9.7 $ 4,185 * - All options outstanding at October 31, 2022 were issued in Canadian dollars with an exercise price of $ 1.22 . All options granted during the year ended October 31, 2023 were issued in Canadian dollars at exercise prices of $ 2.11 , $ 5.87 , and $ 12.36 . Upon the close of the Reverse Recapitalization, all exercise prices were converted to United States dollars at the exchange rate in effect on the day immediately before the close of the Reverse Recapitalization. The Weighted Average Exercise Price above was adjusted to reflect such change. ** - Retrospectively restated to reflect exchange of shares upon the close of Reverse Recapitalization. See Notes 1 and 3.
Summary of Share-based Compensation Expense	Share-based compensation expense included in the Company’s consolidated statements of operations and comprehensive loss was as follows: Year Ended October 31, 2023 2022 Research and development $ 780 $ 31 General and administrative 2,670 85 Total share-based compensation expense $ 3,450 $ 116

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
Net Loss Per Share (Tables)	Oct. 31, 2023
Earnings Per Share [Abstract]
Summary of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented, retrospectively restated to reflect the exchange of shares upon the close of the Reverse Recapitalization: Year Ended October 31, 2023 2022 Numerator: Net loss $ 99,917 $ 24,462 Deemed dividend attributable to redeemable convertible 4,822 4,562 Net loss attributable to common shareholders, basic and $ 104,739 $ 29,024 Denominator: Weighted-average number of common shares used in net 692,609 655,153 Net loss per common share, basic and diluted $ 151.22 $ 44.30
Summary of Shares Excluded from Computation of Diluted Net Loss Per Share	The Company excluded the following shares from the computation of diluted net loss per share attributable to common shareholders during the year ended October 31, 2023, and 2022 because including them would have had an anti-dilutive effect: Year Ended October 31, 2023 2022 Redeemable convertible preferred shares — 5,983,339 Warrants to purchase redeemable convertible preferred shares — 3,194,756 Warrants to purchase common shares 10,411,641 — Options to purchase common shares 2,706,941 1,575,785 Total 13,118,582 10,753,880

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Oct. 31, 2023
Income Tax Disclosure [Abstract]
Summary of Loss Before Provision for Income Taxes	Loss before provision for income taxes consisted of the following: Year ended October 31, 2023 2022 Domestic (Canada) $ ( 99,157 ) $ ( 23,965 ) Foreign (US) ( 743 ) ( 475 ) Loss before provision for income taxes $ ( 99,900 ) $ ( 24,440 )
Summary Of Components Of The Provision For Income Taxes	The components of the provision for income taxes is as follows: Year ended October 31, 2023 2022 Current expense (benefit): Domestic (Canada) $ — $ — Foreign (US) 17 22 Total current expense (benefit) 17 22 Deferred expense (benefit) Domestic (Canada) — — Foreign (US) — — Total deferred tax expense (benefit) — — Total income tax expense (benefit) $ 17 $ 22
Summary Of Reconciliation Of Company's Statutory Income Tax Rate	A reconciliation of the Company's statutory income tax rate to the Company's effective income tax rate is as follows: Year ended October 31, 2023 2022 Income at Canada statutory rate 26.50 % 26.50 % Conversion of debentures ( 21.90 )% — State taxes, net of federal benefit 0.05 % 0.12 % Permanent differences 1.68 % ( 3.90 )% Tax credits 0.19 % 0.29 % Foreign rate differential ( 0.04 )% ( 0.11 )% Valuation allowance ( 6.52 )% ( 22.86 )% Other 0.03 % ( 0.14 )% ( 0.01 )% ( 0.09 )%
Summary Of Net Deferred Income Tax	The net deferred income tax balances related to the following: October 31, 2023 2022 Deferred tax assets: R&D expenditures 7,012 6,441 Net operating loss (NOL) carryforwards 18,918 13,862 ITC credits 1,210 963 Property and equipment 791 742 Convertible debenture embedded derivative liabilities — 13 Financing costs 2,440 — Accruals 149 101 Section 174 capitalized R&D costs 393 — Other 172 — Total deferred tax assets 31,085 22,122 Valuation allowance ( 31,085 ) ( 22,048 ) Net deferred tax assets (liability) - 74 Deferred tax liabilities: Convertible debentures — ( 9 ) Other — ( 65 ) Total deferred tax liabilities — ( 74 ) Net deferred tax assets (liability) — —

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Oct. 31, 2023
Lessee Disclosure [Abstract]
Schedule of Components of Operating Lease Cost	During the year ended October 31, 2023, and 2022, the components of operating lease cost were as follows, and are reflected in general and administrative expenses and research and development expenses, as determined by the underlying activities: Year Ended October 31, 2023 2022 Lease Cost: Operating lease cost — 62 Variable operating lease cost 62 53 Short-term operating lease cost 411 355 Total operating lease cost 473 470
Summary of Cash Paid for Amounts Included in the Measurement of the Operating Lease Liabilities	The following table summarizes the cash paid for amounts included in the measurement of the Company’s operating lease liabilities for the year ended October 31, 2023, and 2022: Year Ended October 31, 2023 2022 Cash paid for amounts included in the measurement $ — $ 62

Description of Business - Addit

Description of Business - Additional Information (Details)			12 Months Ended
Description of Business - Additional Information (Details)	Oct. 31, 2023 USD ($) shares	May 16, 2023 USD ($) $ / shares shares	Oct. 31, 2023 USD ($) shares	Oct. 31, 2022 USD ($) shares	May 16, 2023 $ / shares	Jun. 30, 2021 shares
Description of Business [Line Items]
Date of incorporation			Aug. 09, 2021
Exchange ratio			0.18048%
Proceeds from trust account \| $			$ 7,363,000
Common stock shares issued	23,197,976		23,197,976	665,767
Proceeds from convertible debt \| $			$ 38,000,000	$ 18,400,000
Warrants outstanding	10,411,641		10,411,641	0		10,242,130
Net loss \| $			$ (99,917,000)	$ (24,462,000)
Cash flows from operating activities \| $			24,743,000	17,592,000
Accumulated deficit \| $	$ 199,588,000		$ 199,588,000	$ 99,671,000
Old enGenes Share Option
Description of Business [Line Items]
Common stock shares issued	2,706,941		2,706,941
FEAC [Member]
Description of Business [Line Items]
Goodwill \| $		$ 0
Intangible assets \| $		$ 0
Exchange ratio		0.18048%	0.18048%
Warrants, exercise price per share \| $ / shares		$ 11.5
Class of warrants or rights number of shares covered by each warrant or right		1
Shares converted		3,670,927
Number of securities into which the class of warrant or right may be converted		5,029,444
Business combination event shares issued on exchange of common share warrants	2,679,432
Business combination event shares issued to holders of equity and convertible note holders	13,091,608
Proceeds from trust account \| $	$ 7,400,000
FEAC [Member] \| Class B common shares
Description of Business [Line Items]
Temporary equity stock issued during the period shares		10
Temporary equity redemption price per share \| $ / shares					$ 1
PIPE Financing
Description of Business [Line Items]
Number of securities into which the class of warrant or right may be converted	2,702,791		2,702,791
Business combination aggregate commitment amount \| $	$ 56,900,000
Number of new stock issued during the period	6,435,441
Value of stock and warrant issued during the period \| $	$ 56,900,000
PIPE Financing \| FEAC [Member] \| Private Placement Warrants [Member]
Description of Business [Line Items]
Number of new stock issued during the period	5,463,381
PIPE Financing \| FEAC [Member] \| Class B common shares
Description of Business [Line Items]
Number of new stock issued during the period	1,789,004
Amended 2022 Financing [Member]
Description of Business [Line Items]
Modification of existing debt \| $		$ 18,400,000
Convertible Bridge Financing [Member]
Description of Business [Line Items]
Shares converted		35,349,238
Business combination event shares issued on exchange of common share warrants	2,679,432
Number of new stock issued during the period	23,197,976
Repayment of other long term debt \| $		$ 8,000,000
Reverse recapitalization shares converted on exchange of common share		6,379,822
Warrants outstanding	10,411,641		10,411,641
Convertible Bridge Financing [Member] \| New Convertible Debt [Member]
Description of Business [Line Items]
Proceeds from convertible debt \| $		$ 30,000,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Summary of Significant Accounting Policies [Line Items]
Exchange ratio	0.18048%
Realized foreign currency transaction losses	$ 100,000	$ 700,000
Unrealized foreign currency transaction losses	100,000	700,000
Cash equivalents	0	0
Restricted investments	$ 76,000	74,000
Percentage of tax benefit to be realized for recognition in the income statement	50%
Transaction costs as part of reverse recapitalization and pipe financing	$ 11,300,000
Transaction costs related to issuance of notes	800,000
Deferred transaction costs	0	0
Research and development investment tax credits	1,100,000	$ 1,400,000
Other Assets [Member]
Summary of Significant Accounting Policies [Line Items]
Restricted investments	$ 70,000
ASU-2019-12
Summary of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Nov. 01, 2021
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect	true
ASU 2020-06
Summary of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Nov. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect	true
ASU 2021-10
Summary of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Nov. 01, 2021
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect	true

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Estimated Useful Life of Each Asset (Details)	12 Months Ended
	Oct. 31, 2023
Lab equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Computer Equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Computer Software
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Office Furniture
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Estimated Useful Life	Shorter of remaining lease term or useful life

Reverse Recapitalization -Addit

Reverse Recapitalization -Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 31, 2023	Oct. 31, 2023	Oct. 31, 2022	Jun. 30, 2021
Equity, Class of Treasury Stock [Line Items]
Common stock shares outstanding	23,197,976	23,197,976	665,767
Warrants outstanding	10,411,641	10,411,641	0	10,242,130
Common stock shares issued	23,197,976	23,197,976	665,767
Proceeds from trust account		$ 7,363
Proceeds from PIPE financing		56,892
Transactions costs deferred and netted against proceeds		$ (5,086)
FEAC
Equity, Class of Treasury Stock [Line Items]
Common stock shares outstanding	3,670,927	3,670,927
Warrants outstanding	5,029,444	5,029,444
Proceeds from trust account		$ 7,400
Merger Agreement [Member]
Equity, Class of Treasury Stock [Line Items]
Business combination reverse recapitalization description		On October 31, 2023 (the "Closing Date”), FEAC, Old enGene, and the Company consummated the merger pursuant to the Merger Agreement, dated as of May 16, 2023. As a result of the Reverse Recapitalization, the Company became a publicly traded company, with old enGene, a subsidiary of the Company, continuing the existing business operations.
Merger agreement date	May 16, 2023
PIPE Financing
Equity, Class of Treasury Stock [Line Items]
Common stock shares outstanding	23,197,976	23,197,976
Warrants outstanding	10,411,641	10,411,641
Value of stock and warrant issued during the period		$ 56,900
Transaction costs	$ 11,100	11,100
Transactions costs deferred and netted against proceeds		5,100
PIPE Financing \| FEAC
Equity, Class of Treasury Stock [Line Items]
Value of stock and warrant issued during the period		$ 56,900
Number of new stock issued during the period		6,435,441
Number of new warrant issued during the period		2,702,791
Common stock, value issued		$ 56,100
Warrants issued during period, value		800
Proceeds from PIPE financing		56,900
Transaction costs withheld from proceeds received		$ 6,000
Old enGenes Equity and Convertible Note
Equity, Class of Treasury Stock [Line Items]
Common stock shares issued	13,091,608	13,091,608
Old enGenes Warrant
Equity, Class of Treasury Stock [Line Items]
Share warrants issued	2,679,432	2,679,432
Old enGenes Share Option
Equity, Class of Treasury Stock [Line Items]
Common stock shares issued	2,706,941	2,706,941
Common share options issued	2,706,941	2,706,941

Reverse Recapitalization - Summ

Reverse Recapitalization - Summary of Net Proceeds from Reverse Recapitalization and PIPE Financing (Details) $ in Thousands	12 Months Ended
	Oct. 31, 2023 USD ($)
Stockholders' Equity Note [Abstract]
Cash - FEAC's Trust Account and Cash (net of redemptions and cash paid for FEAC expenses prior to close)	$ 7,363
Cash - PIPE Financing	56,892
Less transaction costs withheld from cash proceeds on Closing Date	(6,024)
Cash proceeds received from the Reverse Recapitalization and PIPE Financing on Closing Date	58,231
Less transaction costs previously deferred and netted against proceeds	(5,086)
Net cash proceeds from the Reverse Recapitalization and PIPE Financing	$ 53,145

Reverse Recapitalization - Su_2

Reverse Recapitalization - Summary of Number of Shares of Common Stock Outstanding (Details) - shares	Oct. 31, 2023	Oct. 31, 2022
Reverse Recapitalization [Line Items]
Total common shares outstanding immediately after the Reverse Recapitalization and PIPE Financing	23,197,976	665,767
Old enGene Shareholders (Excluding Convertible Notes)
Reverse Recapitalization [Line Items]
Total common shares outstanding immediately after the Reverse Recapitalization and PIPE Financing	6,711,786
FEAC Shareholders, including sponsor's and shareholder with non-redemption agreement
Reverse Recapitalization [Line Items]
Total common shares outstanding immediately after the Reverse Recapitalization and PIPE Financing	3,670,927
Convertible Notes - Common Shares Issued
Reverse Recapitalization [Line Items]
Total common shares outstanding immediately after the Reverse Recapitalization and PIPE Financing	6,379,822
Common Shares Issued to Pipe Investors
Reverse Recapitalization [Line Items]
Total common shares outstanding immediately after the Reverse Recapitalization and PIPE Financing	6,435,441

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)			2 Months Ended	12 Months Ended
Fair Value Measurements - Additional Information (Details)	Oct. 31, 2023 USD ($) shares	May 15, 2023 $ / shares	May 31, 2023 $ / shares	Oct. 31, 2023 USD ($)	Oct. 31, 2022 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers or reclassifications into level 3				$ 0	$ 0
Transfers or reclassifications out of level 3				0	0
Proceeds from convertible debt				$ 38,000,000	$ 18,400,000
Quoted market price of public warrants \| $ / shares		$ 0.74	$ 0.53
Preferred Share Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants, contractual term	10 years			10 years
May 2023 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debt instrument	$ 93,300,000			$ 93,300,000
May 2023 Notes \| Common Shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Shares issued in exchange of debt instrument \| shares	4,298,463
2022 Notes and BDC Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reverse recapitalization embedded derivative fair value of embedded derivative	$ 24,800,000			24,800,000
Embedded Derivative, Fair Value of Embedded Derivative Liability	$ 400,000			400,000
April 2023 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proceeds from convertible debt				8,000,000
Repayments of convertible notes and warrants				$ 8,000,000
Measurement Input, Expected Term \| 2022 Notes and BDC Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded derivative liability measurement term	0 years			0 years	4 months 24 days
Fair Value of Common Share \| May 2023 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value debt inputs measurement input	0.217			0.217
Fair Value Measurement Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	$ 0			$ 0	$ 0
Financial liabilities, fair value	$ 0			$ 0	$ 15,247,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value Hierarchy for Financial Liabilities Measured at Fair Value (Details) - Fair Value Measurement Recurring - USD ($)	Oct. 31, 2023	Oct. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	$ 0	$ 15,247,000
Warrant Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities		11,456,000
Convertible Debentures Embedded Derivative Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities		3,791,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities		15,247,000
Level 3 \| Warrant Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities		11,456,000
Level 3 \| Convertible Debentures Embedded Derivative Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities		$ 3,791,000

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Convertible Debentures Embedded Derivative Liabilities (Details)	Oct. 31, 2023 USD ($)	May 16, 2023 USD ($) CAD ($)	Oct. 31, 2022 CAD ($)
Probability of Qualified Financing \| 2022 Notes and BDC Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement input	1		0.60
Probability of Qualified Financing \| May 2023 Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value debt inputs measurement input		0.60
Volatility \| 2022 Notes and BDC Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement input			0.85
Volatility \| May 2023 Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value debt inputs measurement input		0.85
Class C Preferred Share price (CAD) \| 2022 Notes and BDC Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement input			2.2
Class C Preferred Share price (CAD) \| May 2023 Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value debt inputs measurement input		2.074
Liquidity Price at Conversion of Listing Event \| 2022 Notes and BDC Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement input	8,840
Liquidity Price at Conversion of Listing Event \| May 2023 Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value debt inputs measurement input		8,420
Fair Value of Common Share at Conversion of Listing Event \| 2022 Notes and BDC Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement input	21,700
Fair Value of Common Share at Conversion of Listing Event \| May 2023 Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value debt inputs measurement input		10,250
Discount Rate \| 2022 Notes and BDC Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement input	0.184
Discount Rate \| 2022 Notes and BDC Notes \| Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement input			0.104
Discount Rate \| 2022 Notes and BDC Notes \| Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement input			0.184
Discount Rate \| May 2023 Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value debt inputs measurement input		0.408
Expected Time to Respective Scenarios \| 2022 Notes and BDC Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability measurement term	0 years		4 months 24 days
Expected Time to Respective Scenarios \| May 2023 Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value debt inputs, term		3 months 18 days

Fair Value Measurements - Summa

Fair Value Measurements - Summary Of Change In Estimated Fair Value Of Convertible Debentures Embedded Derivative Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Change In Fair Value Of Convertible Debentures Embedded Derivative Liabilities	Change In Fair Value Of Convertible Debentures Embedded Derivative Liabilities
2022 Notes and BDC Notes
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 3,791	$ 602
Fair value of convertible debenture embedded derivative liabilities recognized upon issuance		3,500
Change in fair value of convertible debenture embedded derivative liabilities	21,421	(269)
Foreign exchange rate translation adjustment	5	(42)
Settlement of derivative liability in accordance with repayment and conversion of convertible debentures upon the consummation of the Reverse Recapitalization	$ (25,217)
Balance		$ 3,791

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Change in Estimated Fair Value of Debt Instrument (Details) - May 2023 Notes $ in Thousands	12 Months Ended
	Oct. 31, 2023 USD ($)
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Issuance	$ 37,043
Change in fair value	56,212
Settlement upon the consummation of the Reverse Recapitalization	$ (93,255)

Fair Value Measurements - Assum

Fair Value Measurements - Assumptions Used to Determine Fair Value of Preferred Share Warrant Liabilities (Details) - Preferred Share Warrant Liabilities	Oct. 31, 2022
Measurement Input, Expected Term
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Weighted average expected life (in years)	3 years
Measurement Input, Expected Volatility
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Warrants outstanding, measurement input	0.78
Measurement Input, Risk-free Interest Rate
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Warrants outstanding, measurement input	0.0392
Measurement Input, Preferred Share Price - Class C (CAD)
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Warrants outstanding, measurement input	2.2
Measurement Input, Exercise Price - Class C (CAD)
Fair Value, off-Balance-Sheet Risks, Disclosure Information [Line Items]
Warrants outstanding, measurement input	2.632

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Change in Estimated Fair Value of Warrant Liabilities (Details) - USD ($)	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 11,456	$ 9,088
Change in fair value of warrant liabilities	(10,849)	3,326
Foreign exchange rate translation adjustment	(44)	(1,048)
Ending Balance		11,456
2023 Warrants
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Reclassification of Warrants to equity upon consummation of the Reverse Recapitalization	(1,983)
Term Loan
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Warrant liabilities recognized upon issuance		$ 90
May 2023 Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Warrant liabilities recognized upon issuance	$ 1,420

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Oct. 31, 2023	Oct. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment	$ 2,316	$ 1,940
Less: Accumulated depreciation and amortization	1,727	1,553
Property and equipment, net	589	387
Lab Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	1,779	1,472
Computer Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	269	221
Computer Software
Property, Plant and Equipment [Line Items]
Property and equipment	70	70
Office Furniture
Property, Plant and Equipment [Line Items]
Property and equipment	69	55
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment	$ 129	$ 122

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 0.2	$ 0.2

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Oct. 31, 2023	Oct. 31, 2022
Payables and Accruals [Abstract]
Accrued research and development expenses	$ 759	$ 1,845
Professional fees	1,708	573
Employee compensation and related benefits	814	676
Accrued income tax payable	39	22
Other	219	0
Total accrued expenses and other current liabilities	$ 3,539	$ 3,116

License Agreement and Clinica_2

License Agreement and Clinical Research Organization - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
	Apr. 10, 2020	Oct. 31, 2023	Oct. 31, 2022
License Agreement and Clinical Research Organization [Line Items]
Annual maintenance fee	$ 50
Payment to NTC upon assigning the License Agreement	50
Phase I Clinical Trial [Member]
License Agreement and Clinical Research Organization [Line Items]
One-time payment for milestone product	50
Phase II Clinical Trial [Member]
License Agreement and Clinical Research Organization [Line Items]
One-time payment for milestone product	450
Research and Development
License Agreement and Clinical Research Organization [Line Items]
Upfront fee	$ 50
Expenses related to the annual maintenance fee		$ 50	$ 50

Notes Payable - Additional Info

Notes Payable - Additional Information (Details)				12 Months Ended
Notes Payable - Additional Information (Details)	Apr. 04, 2023 USD ($)	Jun. 15, 2022 USD ($)	Dec. 30, 2021 USD ($)	Oct. 31, 2023 USD ($) shares	Oct. 31, 2022 USD ($)	Oct. 31, 2023 $ / shares	Dec. 15, 2022 USD ($)	Jun. 30, 2022 USD ($) shares
Debt Instrument [Line Items]
Note payable current				$ 562,000	$ 1,265,000
Hercules Warrants
Debt Instrument [Line Items]
Warrants exercisable period				10 years
Warrants, exercise price per share \| $ / shares						$ 2.632
Loan and Security Agreement \| Hercules Warrants
Debt Instrument [Line Items]
Exercise price equal to percentage of aggregate amount of term loans				2.50%
Loan and Security Agreement \| Hercules Warrants \| Class C Preferred Shares
Debt Instrument [Line Items]
Warrant issued to purchase preferred shares \| shares				84,714				48,978
Preferred share warrants fair value				$ 34				$ 23
2021 Loan and Security Agreement \| Hercules Capital
Debt Instrument [Line Items]
Term loan facility aggregate principal amount			$ 20,000,000
Percentage of aggregate principle amount of term loan advances amount fee			6.35%
Term loan maturity date			Jul. 01, 2025
Term loan annual interest rate			8.25%
Term loan reduced annual interest rate			8.15%
Percentage of prepayment premium of principal amount outstanding of the closing date			3%
Percentage of prepayment premium of principal amount outstanding prior to twenty-four months			2%
Percentage of prepayment premium of principal amount outstanding prior to maturity date			1%
Effective interest rate of outstanding debt				18.30%	15.90%
Note payable current				$ 600,000	$ 1,300,000
Interest expense				1,800,000	1,000,000
Amortization of debt discount				400,000	$ 300,000
Borrowed amount				11,000,000
Debt discount and issuance costs				$ 1,100,000
2021 Loan and Security Agreement \| Hercules Capital \| Prime Rate
Debt Instrument [Line Items]
Term loan annual interest rate			3.25%
2021 Loan and Security Agreement \| Tranche One \| Hercules Capital
Debt Instrument [Line Items]
Term loan facility aggregate principal amount			$ 7,000,000
2021 Loan and Security Agreement \| Tranche Two \| Hercules Capital
Debt Instrument [Line Items]
Term loan facility aggregate principal amount		$ 4,000,000
Term loan facility, drawn term		2022-06
2021 Loan and Security Agreement \| Tranche Three \| Hercules Capital
Debt Instrument [Line Items]
Term loan facility aggregate principal amount							$ 9,000,000
April 2023 Notes
Debt Instrument [Line Items]
Term loan maturity date	Jul. 31, 2023
Borrowed amount	$ 8,000,000
Interest free period	45 days
Fair value of debt instrument	$ 8,000,000
Convertible notes and warrants issued	8,000,000
April 2023 Notes \| Minimum
Debt Instrument [Line Items]
Aggregate sale of convertible promissory notes, warrants, preferred shares, common shares, or combined thereof	$ 20,000,000

Notes Payable - Schedule of Car

Notes Payable - Schedule of Carrying Value of Term Loan (Details) - Term Loan - USD ($) $ in Thousands	Oct. 31, 2023	Oct. 31, 2022
Debt Instrument [Line Items]
Note payable, including End of Term Charge	$ 10,144	$ 11,699
Debt discount, net of accretion	(474)	(891)
Accrued interest	108	106
Note payable, net of discount	$ 9,778	$ 10,914

Notes Payable - Schedule of Est

Notes Payable - Schedule of Estimated Future Principal Payments Due Under the Loan Agreement (Details) - 2021 Loan and Security Agreement $ in Thousands	Oct. 31, 2023 USD ($)
Debt Instrument [Line Items]
2024	$ 5,106
2025	5,038
Note payable, net of discount	$ 10,144

Convertible Debentures - Summar

Convertible Debentures - Summary of Outstanding Principal, Accrued Interest and Unamortized Deferred Financing Costs of Convertible Debentures Recorded on the Balance Sheet (Details) - USD ($)	Oct. 31, 2023	Oct. 31, 2022	Sep. 30, 2020
Short-Term Debt [Line Items]
Total Convertible debentures	$ 0	$ 17,405,000
BDC Notes
Short-Term Debt [Line Items]
Total Convertible debentures	0	2,497,000	$ 2,200,000
2022 Notes
Short-Term Debt [Line Items]
Total Convertible debentures	$ 0	$ 14,908,000

Convertible Debentures - Additi

Convertible Debentures - Additional Information (Details) - USD ($)			1 Months Ended				12 Months Ended
	May 16, 2023	May 12, 2023	Oct. 31, 2023	Jun. 30, 2023	May 31, 2023	Sep. 30, 2020	Oct. 31, 2023	Oct. 31, 2022
Short-Term Debt [Line Items]
Convertible debt			$ 0				$ 0	$ 17,405,000
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]							Change In Fair Value Of Convertible Debentures Embedded Derivative Liabilities	Change In Fair Value Of Convertible Debentures Embedded Derivative Liabilities
Loss on extinguishment of convertible debentures							$ (3,091,000)
Proceeds from Convertible Debt							38,000,000	$ 18,400,000
Repayment of aggregate amount							$ 3,176,000
Initial maturity period	3 years
Accrued interest percentage	10%
Warrants to purchase shares of common stock			2,679,432				2,679,432
Forbion Growth Sponsor FEAC I B.V
Short-Term Debt [Line Items]
Notes purchase principal amount				$ 20,000,000
BDC Notes
Short-Term Debt [Line Items]
Convertible debt			$ 0			$ 2,200,000	$ 0	2,497,000
Interest rate						8%
Initial maturity date						Sep. 28, 2023
Maturity date						Sep. 29, 2025
Percentage of price per share						80%
Percentage of principal						20%
Embedded derivative liability measured at fair value						$ 200,000		300,000
Change in fair value of convertible debenture embedded derivative liabilities							300,000
Interest expense, including the amortization of debt discounts							300,000	400,000
Debt issuance costs						$ 36,000
Percentage of repay on closing date amount equal to principal		20%
Loss on extinguishment							9,000
2022 Notes
Short-Term Debt [Line Items]
Convertible debt			0				0	14,908,000
Convertible notes net								$ 18,400,000
Interest rate								10%
Initial maturity term								3 years
Aggregate consideration								$ 50,000,000
Embedded derivative liability measured at fair value								3,500,000
Change in fair value of convertible debenture embedded derivative liabilities							21,200,000
Interest expense, including the amortization of debt discounts							2,800,000
Debt issuance costs								$ 44,000
Loss on extinguishment of convertible debentures							$ 3,100,000
Percentage of price paid in qualified financing								85%
Percentage of price paid per share in non qualified financing								85%
Conversion price					$ 8.84
Conversion and exchange of redeemable convertible preferred stock into common shares in connection with the Reverse Recapitalization (in shares)							2,081,359
Modification of existing debt	$ 18,400,000
Fair value of warrants	500,000							$ 500,000
May 2023 Notes
Short-Term Debt [Line Items]
Debt issuance costs			800,000				$ 800,000
Fair value of warrants	1,400,000
Proceeds from Convertible Debt	30,000,000
Initial maturity period					3 years
Accrued interest percentage					10%
Fair value of debt instrument	$ 37,000,000		$ 56,200,000				$ 56,200,000
Shares converted			4,298,463
2023 Financing
Short-Term Debt [Line Items]
Borrowed amount				10,000,000	$ 28,000,000
Cash				10,000,000	20,000,000
Warrants to purchase shares of common stock	2,679,432
Warrants, exercise price per share	$ 11.5
2023 Financing \| Forbion Growth Sponsor FEAC I B.V
Short-Term Debt [Line Items]
Borrowed amount				$ 38,000,000
April 2023 Notes
Short-Term Debt [Line Items]
Repayment of aggregate amount	$ 8,000,000
Repayment					$ 8,000,000

Redeemable Convertible Prefer_2

Redeemable Convertible Preferred Shares - Additional Information (Details) $ / shares in Units, $ in Millions	Jun. 30, 2021 USD ($) $ / shares shares	Sep. 10, 2015 USD ($) $ / shares shares	Jan. 06, 2015 USD ($) $ / shares shares	Jul. 26, 2013 USD ($) $ / shares shares	Oct. 31, 2023 $ / shares shares	Oct. 31, 2023 $ / shares shares	Oct. 31, 2022 shares	Jun. 30, 2021 $ / shares shares	Sep. 10, 2015 $ / shares	Jan. 06, 2015 $ / shares	Jul. 26, 2013 $ / shares
Class of Stock [Line Items]
Warrants outstanding	10,242,130				10,411,641	10,411,641	0	10,242,130
Share exchange ratio	0.18048
Class C Second Tranche
Class of Stock [Line Items]
Initial aggregate amount that company agreed to sell	3,662,810
Redeemable convertible preferred shares at a price per share \| (per share)	$ 2.13192							$ 2.632
Total aggregate proceeds \| $	$ 7.8
Share warrants issued	3,662,810							3,662,810
Class A Redeemable Convertible Preferred Shares \| Class A Initial Closing
Class of Stock [Line Items]
Initial aggregate amount that company agreed to sell				610,333
Redeemable convertible preferred shares at a price per share \| (per share)				$ 1.5929							$ 1.63845
Total aggregate proceeds \| $				$ 1
Class A Redeemable Convertible Preferred Shares \| Class A Second Tranche
Class of Stock [Line Items]
Initial aggregate amount that company agreed to sell				1,830,999
Redeemable convertible preferred shares at a price per share \| (per share)				$ 1.56967							$ 1.63845
Total aggregate proceeds \| $				$ 2.9
Class B Redeemable Convertible Preferred Shares \| Class B Intial Closing
Class of Stock [Line Items]
Initial aggregate amount that company agreed to sell			2,758,221
Redeemable convertible preferred shares at a price per share \| (per share)			$ 1.85032							$ 2.17532
Total aggregate proceeds \| $			$ 5.1
Class B Redeemable Convertible Preferred Shares \| Class B Second Tranche
Class of Stock [Line Items]
Initial aggregate amount that company agreed to sell			1,838,815
Redeemable convertible preferred shares at a price per share \| (per share)			$ 1.63419							2.17532
Total aggregate proceeds \| $			$ 3
Class B Redeemable Convertible Preferred Shares \| Class B Third Tranche
Class of Stock [Line Items]
Initial aggregate amount that company agreed to sell			1,608,963
Redeemable convertible preferred shares at a price per share \| (per share)			$ 1.63419							$ 2.17532
Total aggregate proceeds \| $			$ 2.6
Class B-1 Redeemable Convertible Preferred Shares
Class of Stock [Line Items]
Initial aggregate amount that company agreed to sell		1,523,809
Redeemable convertible preferred shares at a price per share \| (per share)		$ 1.64367							$ 2.17532
Total aggregate proceeds \| $		$ 2.5
Conversion ratio		1							1
Series 1 Class C Redeemable Convertible Preferred
Class of Stock [Line Items]
Shares issued, price per share \| (per share)					$ 1.5929	$ 1.63845
Series 2 Class C Redeemable Convertible Preferred
Class of Stock [Line Items]
Shares issued, price per share \| (per share)					1.85032	2.175315
Series 3 Class C Redeemable Convertible Preferred
Class of Stock [Line Items]
Shares issued, price per share \| (per share)					2.12376	2.632
Share warrants issued	3,662,813							3,662,813
Series 3 Class C Redeemable Convertible Preferred \| Class C Inital Closing
Class of Stock [Line Items]
Initial aggregate amount that company agreed to sell	3,662,813
Redeemable convertible preferred shares at a price per share \| (per share)	$ 2.12376							$ 2.632
Total aggregate proceeds \| $	$ 7.8
Series 4 Class C Redeemable Convertible Preferred
Class of Stock [Line Items]
Shares issued, price per share \| (per share)					$ 1.69901	$ 2.10559
Class C Warrants
Class of Stock [Line Items]
Share warrants issued	7,325,623							7,325,623
Warrants, exercise price per share \| (per share)	$ 2.12376							$ 2.632
Warrants outstanding	10,242,130							10,242,130
Warrant term	10 years
Expiring term of warrants	Feb. 14, 2030
Aggregate amount of shares exchanged	16,464,646							16,464,646

Common Shares - Additional Info

Common Shares - Additional Information (Details) - $ / shares	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022	Jun. 30, 2021
Class of Stock [Line Items]
Common stock shares authorized unlimited	Unlimited	Unlimited
Common stock no par value
Common stock shares outstanding	23,197,976	665,767
Common stock voting rights	common stock are entitled to one vote
Cash dividends declared	$ 0
Cash dividend paid	$ 0
Warrants outstanding	10,411,641	0	10,242,130
Warrants exercisable period	30 days
Warrants, maturity date	Oct. 31, 2028
Warrants, maturity period	5 years
FEAC [Member]
Class of Stock [Line Items]
Common stock shares outstanding	3,670,927
Warrants outstanding	5,029,444
Warrants, exercise price per share	$ 11.5

Common Shares - Schedule of Sha

Common Shares - Schedule of Shares Reserved For Future Issuance Under The Plan (Details) - shares	Oct. 31, 2023	Oct. 31, 2022
Class of Stock [Line Items]
Common stock shares reserved for future issuance	15,726,525	10,924,038
Remaining shares reserved for future issuance under the equity plans
Class of Stock [Line Items]
Common stock shares reserved for future issuance	2,607,943	170,158
Options to purchase common shares
Class of Stock [Line Items]
Common stock shares reserved for future issuance	2,706,941	1,575,785
Preferred Stock, as converted
Class of Stock [Line Items]
Common stock shares reserved for future issuance		5,983,339
Warrants to purchase common shares
Class of Stock [Line Items]
Common stock shares reserved for future issuance	10,411,641
Warrants to purchase redeemable convertible preferred shares
Class of Stock [Line Items]
Common stock shares reserved for future issuance		3,194,756

Common Shares - Schedule of S_2

Common Shares - Schedule of Shares Reserved For Future Issuance Under The Plan (Parenthetical) (Details) - shares	Oct. 31, 2023	Jul. 07, 2023
Equity [Abstract]
Shares Vesting	1,046,764	252,121

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details)			12 Months Ended
Share-Based Compensation - Additional Information (Details)	Jul. 07, 2023 $ / shares shares	Jul. 05, 2018	Oct. 31, 2023 USD ($) $ / shares shares	Oct. 31, 2023 USD ($) $ / shares $ / shares shares	Oct. 31, 2022 USD ($) $ / shares shares	Oct. 31, 2022 $ / shares $ / shares shares	Jul. 07, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exchange ratio			0.18048%
Stock-based compensation expense \| $			$ 3,450,000		$ 116,000
Unrecognized compensation expense \| $			$ 600,000	$ 600,000
Common stock shares reserved for future issuance			15,726,525	15,726,525	10,924,038	10,924,038
Shares Granted			1,308,081
Exercise price \| $ / shares			$ 2.4	$ 2.4	$ 0.88	$ 0.88
Issued options fully vested	794,643
Remaining options vesting	252,121		1,046,764	1,046,764			252,121
Award vesting period	4 years
Unrecognized compensation expense weighted-average period of recognition			3 years 8 months 4 days
Stock options exercised			84,072
weighted-average grant-date fair value per share of share options granted \| $ / shares				$ 3.9		$ 0.82
Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense \| $			$ 2,600,000
Unrecognized compensation expense \| $			$ 600,000	$ 600,000
Common stock shares reserved for future issuance			2,706,941	2,706,941	1,575,785	1,575,785
Shares Granted	1,046,764
Exercise price \| (per share)	$ 5.87						$ 4.24
Unrecognized compensation expense weighted-average period of recognition			3 years 8 months 4 days
Stock options exercised			15,494
The Old Plans
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense \| $			$ 400,000
Unrecognized compensation expense \| $			$ 0	$ 0
Common stock shares reserved for future issuance			2,706,941	2,706,941
Options to purchase common shares			2,706,941	2,706,941
Incremental compensation cost \| $			$ 0
Number of options remain available for grant			0	0
The Old Plans \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of issuance of common stock options		15%
The Old Plans \| Maximum \| Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock options vesting service period		4 years
The Old Plans \| Minimum \| Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock options vesting service period		3 years
2023 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock shares reserved for future issuance			2,607,943	2,607,943
Increase in number of share reserved for future issuance in the beginning of the year			1,946,226,000,000
2023 Plan \| Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of common stock value on date of grant			100%
2023 Plan \| Maximum \| Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock option term			10 years
Non-Voting Common Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Additional awards approved for issuance	1,046,764						1,046,764
Common stock shares reserved for future issuance	2,822,493				1,775,729	1,775,729	2,822,493
Vesting Immediately Upon Grant Date \| The Old Plans \| Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of vesting rights		100%

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of Assumptions Used to Determine Grant-Date Fair Value of Stock Options (Details) - Stock Options	12 Months Ended
	Oct. 31, 2023 $ / shares	Oct. 31, 2023 $ / shares	Oct. 31, 2022 $ / shares	Oct. 31, 2022 $ / shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)			6 years 29 days	6 years 29 days
Expected volatility, Minimum	79.92%	79.92%
Expected volatility, Maximum	81.48%	81.48%
Expected volatility			75.30%	75.30%
Risk-free interest rate, Minimum	3.56%	3.56%
Risk-free interest rate, Maximum	4.35%	4.35%
Risk-free interest rate			2.16%	2.16%
Fair value of common shares and exercise price of options, Minimum \| (per share)	$ 2.11	$ 1.52
Fair value of common shares and exercise price of options, Maximum \| (per share)	$ 12.36	$ 8.93
Fair value of common shares and exercise price of options \| (per share)			$ 1.22	$ 0.88
Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	5 years 2 months 12 days	5 years 2 months 12 days
Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	6 years 29 days	6 years 29 days

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Oct. 31, 2023 USD ($) $ / shares shares	Oct. 31, 2022 USD ($) $ / shares shares	Oct. 31, 2022 USD ($) $ / shares shares
Share-Based Payment Arrangement [Abstract]
Number of shares outstanding, Beginning balance	1,575,785
Granted	1,308,081
Exercised	(84,072)
Forfeited or expired	(92,853)
Number of shares outstanding, Ending balance	2,706,941	1,575,785	1,575,785
Options vested and exercisable	1,660,177
Options vested and not exercisable	807,025
Options unvested	239,739
Weighted-Average Exercise Price Outstanding, Beginning balance \| $ / shares	$ 0.88
Weighted-Average Exercise Price, Granted \| (per share)	4.05	$ 1.22
Weighted-Average Exercise Price, Exercised \| $ / shares	0.88
Weighted-Average Exercise Price, Forfeited or expired \| $ / shares	0.88
Weighted-Average Exercise Price Outstanding, Ending balance \| $ / shares	2.4		$ 0.88
Weighted-Average Exercise Price, Options vested and exercisable \| $ / shares	1.26
Weighted-Average Exercise Price, Options vested and not exercisable \| $ / shares	4.24
Weighted-Average Exercise Price, Options unvested \| $ / shares	$ 4.24
Weighted- Average Remaining Contractual Term (in years), Outstanding	8 years 1 month 6 days	7 years 8 months 12 days	7 years 8 months 12 days
Weighted- Average Remaining Contractual Term (in years), Options vested and exercisable	7 years 1 month 6 days
Weighted- Average Remaining Contractual Term (in years), Options vested and not exercisable	9 years 8 months 12 days
Weighted- Average Remaining Contractual Term (in years), Options unvested	9 years 8 months 12 days
Aggregate Intrinsic Value, Outstanding \| $	$ 52,192	$ 1,026	$ 1,026
Aggregate Intrinsic Value, Options vested and exercisable \| $	33,921
Aggregate Intrinsic Value, Options vested and not exercisable \| $	14,087
Aggregate Intrinsic Value, Options unvested \| $	$ 4,185

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Stock Option Activity (Parenthetical) (Details)	12 Months Ended
	Oct. 31, 2023 $ / shares	Oct. 31, 2023 $ / shares	Oct. 31, 2022 $ / shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price of options granted \| (per share)	$ 4.05		$ 1.22
Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price of options granted		$ 2.11
Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price of options granted		5.87
Tranche Three
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price of options granted		$ 12.36

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total share-based compensation expense	$ 3,450	$ 116
Research and Development
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total share-based compensation expense	780	31
General and Administrative
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total share-based compensation expense	$ 2,670	$ 85

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Numerator:
Net loss	$ 99,917	$ 24,462
Deemed dividend attributable to redeemable convertible preferred shareholders	4,822	4,562
Net loss attributable to common shareholders, basic	104,739	29,024
Net loss attributable to common shareholders, diluted	$ 104,739	$ 29,024
Denominator:
Weighted-average number of common shares used in net loss per share, basic	692,609	655,153
Weighted-average number of common shares used in net loss per share, diluted	692,609	655,153
Net loss per share of common shares, basic	$ 151.22	$ 44.30
Net loss per share of common shares, diluted	$ 151.22	$ 44.30

Net Loss Per Share - Summary _2

Net Loss Per Share - Summary of Diluted Net Loss Per Share Attributable To Common Shareholders (Details) - shares	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of diluted net loss per share	13,118,582	10,753,880
Redeemable convertible preferred shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of diluted net loss per share		5,983,339
Warrants to purchase redeemable convertible preferred shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of diluted net loss per share		3,194,756
Warrants to purchase common shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of diluted net loss per share	10,411,641
Options to purchase common shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of diluted net loss per share	2,706,941	1,575,785

Income Taxes - Summary of Loss

Income Taxes - Summary of Loss Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Income Tax Disclosure [Abstract]
Domestic (Canada)	$ (99,157)	$ (23,965)
Foreign (US)	(743)	(475)
Net loss before provision for income taxes	$ (99,900)	$ (24,440)

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of the Provision For Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Current expense (benefit):
Foreign (US)	$ 17	$ 22
Total current expense (benefit)	17	22
Deferred expense (benefit)
Total income tax expense (benefit)	$ 17	$ 22

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Company's Statutory Income Tax Rate (Details)	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Income Tax Disclosure [Abstract]
Income at Canada statutory rate	26.50%	26.50%
Conversion of debentures	(21.90%)	0%
State taxes, net of federal benefit	0.05%	0.12%
Permanent differences	1.68%	(3.90%)
Tax credits	0.19%	0.29%
Foreign rate differential	(0.04%)	(0.11%)
Valuation allowance	(6.52%)	(22.86%)
Other	0.03%	(0.14%)
Effective income tax rate	(0.01%)	(0.09%)

Income Taxes - Summary of Net D

Income Taxes - Summary of Net Deferred Income Tax (Details) - USD ($) $ in Thousands	Oct. 31, 2023	Oct. 31, 2022
Deferred tax assets:
R&D expenditures	$ 7,012	$ 6,441
Net operating loss (NOL) carryforwards	18,918	13,862
ITC credits	1,210	963
Property and equipment	791	742
Convertible debenture embedded derivative liabilities		13
Financing costs	2,440
Accruals	149	101
Section 174 capitalized R&D costs	393
Other	172
Total deferred tax assets	31,085	22,122
Valuation allowance	$ (31,085)	(22,048)
Net deferred tax assets (liability)		74
Deferred tax liabilities:
Convertible debentures		(9)
Other		(65)
Total deferred tax liabilities		$ (74)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
Income Taxes - Additional Information (Details) - USD ($)	Oct. 31, 2023	Oct. 31, 2022
Income Tax Contingency [Line Items]
No uncertain tax positions	$ 0	$ 0
Accrued interest related to unrecognized tax benefits	0	0
Accrued penalties related to unrecognized tax benefits	0	$ 0
Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards	900,000
U.S
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 500,000
U.S \| Earliest Tax Year
Income Tax Contingency [Line Items]
Investment tax credits expiration year	2039
Canadian
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 68,500,000
Investment tax credits	$ 1,800,000
Canadian \| Earliest Tax Year
Income Tax Contingency [Line Items]
Net operating loss carryforwards expiration year	2031
Investment tax credits expiration year	2028
Canadian \| Latest Tax Year
Income Tax Contingency [Line Items]
Net operating loss carryforwards expiration year	2043
Investment tax credits expiration year	2043
Canadian \| Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 71,900,000
Canadian \| Federal \| Earliest Tax Year
Income Tax Contingency [Line Items]
Net operating loss carryforwards expiration year	2028
Canadian \| Federal \| Latest Tax Year
Income Tax Contingency [Line Items]
Net operating loss carryforwards expiration year	2043

Leases - Additional Information

Leases - Additional Information (Details)		1 Months Ended				12 Months Ended
Leases - Additional Information (Details)	Dec. 29, 2022 ft² $ / ft²	Apr. 30, 2023	Oct. 31, 2022 USD ($)	Nov. 30, 2021 USD ($) ft²	Apr. 30, 2019 ft²	Oct. 31, 2023 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease liabilities						$ 0
Office Space
Lessee, Lease, Description [Line Items]
Rentable square feet \| ft²					12,271
Operating lease commencement period					2019-04
Lease expiration date					Mar. 30, 2022
Operating lease, option to extend					false
Office and Lab Space
Lessee, Lease, Description [Line Items]
Rentable square feet \| ft²				9,360
Operating lease commencement period				2021-11
Lease expiration date				Oct. 31, 2022
Operating lease initial term				12 months
Operating lease renewal term			6 months	12 months
Operating lease right of use assets				$ 0
Operating lease liabilities				$ 0
Lease expiration month and year		2023-09	2023-04
Operating lease, option to extend			true			true
Operating lease extended term			2023-09
Additional lease commitments to be paid			$ 200,000
New Laboratory and Office Space
Lessee, Lease, Description [Line Items]
Rentable square feet \| ft²	10,620
Operating lease commencement period	2023-11
Operating lease initial term	10 years
Initial annual base rent \| $ / ft²	36.50
Percentage of increase in annual base rent	2%

Leases - Schedule of Components

Leases - Schedule of Components of Operating Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Lease Cost:
Operating lease cost	$ 0	$ 62
Variable operating lease cost	62	53
Short-term operating lease cost	411	355
Total operating lease cost	$ 473	$ 470

Leases - Summary of Cash Paid f

Leases - Summary of Cash Paid for Amounts Included in the Measurement of the Operating Lease Liabilities (Details) $ in Thousands	12 Months Ended
	Oct. 31, 2022 USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 62

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)			12 Months Ended
	May 16, 2023	Apr. 04, 2023	Oct. 31, 2023	Oct. 31, 2022	Oct. 20, 2022
Related Party Transaction [Line Items]
Amount of convertible debentures and warrants	$ 38,000,000
Initial maturity period	3 years
Accrued interest percentage	10%
Dividends or distributions declared or paid			$ 0
Exchange ratio			0.18048%
Common stock shares issued			23,197,976	665,767
Warrants to purchase shares of common stock			2,679,432
Convertible debt			$ 0	$ 17,405,000
Debenture
Related Party Transaction [Line Items]
Convertible debt					$ 18,400,000
Company Shareholders
Related Party Transaction [Line Items]
Amount of convertible debentures and warrants	$ 8,000,000
Forbion Growth Sponsor FEAC I B.V
Related Party Transaction [Line Items]
Amount of convertible debentures and warrants	20,000,000
Common stock shares issued			2,262,351
Number of securities into which the class of warrant or right may be converted			950,153
Investissement Quebec
Related Party Transaction [Line Items]
Amount of convertible debentures and warrants	10,000,000
FEAC
Related Party Transaction [Line Items]
Common stock shares issued			3,670,927
Number of securities into which the class of warrant or right may be converted			5,029,444
Old enGene's Equity and Convertible Note Holders
Related Party Transaction [Line Items]
Common stock shares issued			13,091,608
April 2023 Notes
Related Party Transaction [Line Items]
Principal amount		$ 8,000,000
Interest rate		15%
Amount of convertible debentures and warrants		$ 8,000,000
Maturity date		Jul. 31, 2023
Settlement and extinguishment		$ 8,000,000
Repayment	8,000,000
May 2023 Notes
Related Party Transaction [Line Items]
Amount of convertible debentures and warrants	30,000,000
May 2023 Financing
Related Party Transaction [Line Items]
Amount of convertible debentures and warrants	28,000,000
Cash	20,000,000
June 2023 Financing
Related Party Transaction [Line Items]
Principal amount	10,000,000
Cash	$ 10,000,000
2022 Notes
Related Party Transaction [Line Items]
Convertible debt			$ 0	$ 14,908,000
Minimum
Related Party Transaction [Line Items]
Percentage of shares owned by shareholders			10%	10%
Minimum \| April 2023 Notes
Related Party Transaction [Line Items]
Aggregate sale of convertible promissory notes, warrants, preferred shares, common shares, or combined thereof		$ 20,000,000

Subsequent Events - Additional

Subsequent Events - Additional Information (Details)					12 Months Ended
Subsequent Events - Additional Information (Details)	Jan. 01, 2024 USD ($) ft²	Dec. 22, 2023 USD ($) $ / shares shares	Nov. 30, 2023 $ / shares shares	Jul. 07, 2023	Oct. 31, 2023 $ / shares shares	Oct. 31, 2022 $ / shares
Subsequent Event [Line Items]
Number of share options granted during the period \| shares					1,308,081
Options vesting period				4 years
Exercise price of options granted \| (per share)					$ 4.05	$ 1.22
Subsequent Event
Subsequent Event [Line Items]
Options exercise price \| $ / shares			$ 7.66
Aggregate amount of base rental payments	$ 500,000
Area of office space \| ft²	6,450
Lease expiration date	Dec. 30, 2026
Operating sublease, option to extend	false
Subsequent Event \| Chief Financial Officer and Chief Medical Officer
Subsequent Event [Line Items]
Number of share options granted during the period \| shares			385,000
Options vesting period			4 years
Subsequent Event \| Other Various Employees
Subsequent Event [Line Items]
Number of share options granted during the period \| shares			203,000
Subsequent Event \| Other Various Employees \| Minimum
Subsequent Event [Line Items]
Options vesting period			3 years
Subsequent Event \| Other Various Employees \| Maximum
Subsequent Event [Line Items]
Options vesting period			4 years
Subsequent Event \| Amended Loan Agreement
Subsequent Event [Line Items]
Percentage of aggregate principal amount of term loan advance to purchase number of common shares		2%
Warrants exercisable period		7 years
Warrants, exercise price per share \| $ / shares		$ 7.21
Minimum liquidity covenant percentage of aggregate outstanding principal		35%
Share warrants issued \| shares		138,696
Subsequent Event \| Amended Loan Agreement \| Minimum
Subsequent Event [Line Items]
Percentage of prepayment charge on principal amount		1%
Subsequent Event \| Amended Loan Agreement \| Maximum
Subsequent Event [Line Items]
Percentage of prepayment charge on principal amount		3%
Subsequent Event \| Term Loan \| Amended Loan Agreement
Subsequent Event [Line Items]
Line of credit, maturity date		Jan. 01, 2028
End of term fee percentage		5.50%
End of term charge		$ 700,000
Debt instrument, interest rate		9.25%
Payment-in-kind interest rate		1.15%
Loan amortization date		Jul. 01, 2025
Subsequent Event \| Term Loan \| Amended Loan Agreement \| Wall Street Journal
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate		0.75%
Subsequent Event \| Term Loan \| Amended Loan Agreement \| Wall Street Journal \| Maximum
Subsequent Event [Line Items]
Debt instrument, interest rate		9.75%
Subsequent Event \| Term Loan \| Tranche 1 Advance \| Amended Loan Agreement
Subsequent Event [Line Items]
Line of credit, maximum amount available		$ 50,000,000
Proceeds from line of credit		$ 22,500,000
Share warrants issued \| shares		62,413
Subsequent Event \| Term Loan \| Applied to Refinance of Amount Outstanding \| Prior Loan Agreement
Subsequent Event [Line Items]
Proceeds from line of credit		$ 8,600,000
Subsequent Event \| Term Loan \| Tranche 2 Advance Subject to Achievement of Specified Interim Milestone \| Amended Loan Agreement
Subsequent Event [Line Items]
Line of credit, maximum amount available		$ 7,500,000
Period within loan disbursements to be made		60 days
Line of credit, maturity date		Mar. 31, 2025
Subsequent Event \| Term Loan \| Tranche 3 Advance \| Amended Loan Agreement
Subsequent Event [Line Items]
Line of credit, maximum amount available		$ 20,000,000
Percentage of facility charge on amount borrowed		0.75%
Subsequent Event \| Term Loan \| If Interim Milestone Achieved and No Default \| Amended Loan Agreement
Subsequent Event [Line Items]
Loan amortization date		Jan. 01, 2026
Subsequent Event \| Term Loan \| If Interim Milestone and Certain Clinical Milestones Achieved and No Default \| Amended Loan Agreement
Subsequent Event [Line Items]
Loan amortization date		Jul. 01, 2026