Sensei Biotherapeutics (SNSE) 10-Q7 Nov 232023 Q3 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2023	Nov. 02, 2023
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Entity Registrant Name	Sensei Biotherapeutics, Inc.
Entity Central Index Key	0001829802
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		24,996,517
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity File Number	001-39980
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	83-1863385
Entity Address, Address Line One	1405 Research Blvd
Entity Address, Address Line Two	Suite 125
Entity Address, City or Town	Rockville
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20850
City Area Code	240
Local Phone Number	243-8000
Document Quarterly Report	true
Document Transition Report	false
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	SNSE
Security Exchange Name	NASDAQ
Series A Preferred Stock Purchase Rights
Document Information [Line Items]
Title of 12(b) Security	Series A Preferred Stock Purchase Rights
No Trading Symbol Flag	true
Security Exchange Name	NASDAQ

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 11,343	$ 17,795
Marketable securities	60,670	89,321
Prepaid expenses	1,505	1,129
Other current assets	318	344
Total current assets	73,836	108,589
Right of use assets - operating leases, net	4,700	5,355
Right of use assets - financing leases, net	1,737	2,319
Property and equipment, net	1,299	2,049
Other non-current assets	86	63
Total assets	81,658	118,375
Current liabilities:
Accounts payable and accrued liabilities	2,727	4,473
Compensation and employee benefits liabilities	1,093	2,462
Operating lease liabilities, current	1,532	1,251
Financing lease liabilities, current	874	880
Total current liabilities	6,226	9,066
Operating lease liabilities, non-current	3,403	4,323
Financing lease liabilities, non-current	962	1,579
Other non-current liabilities	67	0
Total liabilities	10,658	14,968
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, $0.0001 par value and 10,000,000 shares authorized as of September 30, 2023 and December 31, 2022; zero shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively
Common stock, $0.0001 par value and 250,000,000 shares authorized as of September 30, 2023 and December 31, 2022; 24,996,517 and 30,764,160 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively	2	3
Additional paid-in capital	295,881	302,202
Accumulated deficit	(224,481)	(197,794)
Accumulated other comprehensive loss	(402)	(1,004)
Total stockholders' equity	71,000	103,407
Total liabilities and stockholders' equity	$ 81,658	$ 118,375

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	24,996,517	30,764,160
Common stock, shares outstanding	24,996,517	30,764,160

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 3,818	$ 9,190	$ 13,806	$ 23,038
General and administrative	3,919	4,751	15,116	14,102
Total operating expenses	7,737	13,941	28,922	37,140
Loss from operations	(7,737)	(13,941)	(28,922)	(37,140)
Other income (expense):
Interest income	877	515	2,798	1,174
Interest expense	(33)	(10)	(113)	(425)
Loss on asset disposal	(6)		(302)
Other (expense) income, net	(225)	20	(148)	35
Net loss	$ (7,124)	$ (13,416)	$ (26,687)	$ (36,356)
Net loss per common share, basic	$ (0.28)	$ (0.44)	$ (0.92)	$ (1.18)
Net loss per common share, diluted	$ (0.28)	$ (0.44)	$ (0.92)	$ (1.18)
Weighted-average number of shares used in computing net loss per common share, basic	25,514,115	30,720,291	28,942,803	30,690,175
Weighted-average number of shares used in computing net loss per common share, diluted	25,514,115	30,720,291	28,942,803	30,690,175
Comprehensive loss:
Net loss	$ (7,124)	$ (13,416)	$ (26,687)	$ (36,356)
Other comprehensive items:
Unrealized gain (loss) on marketable securities	147	7	602	(872)
Total other comprehensive income (loss)	147	7	602	(872)
Total comprehensive loss	$ (6,977)	$ (13,409)	$ (26,085)	$ (37,228)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMMON STOCK AND STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2021	$ 146,513	$ 3	$ 296,049	$ (149,206)	$ (333)
Beginning balance, shares at Dec. 31, 2021		30,609,029
Stock-based compensation expense	1,515		1,515
Exercise of options into common stock	237		237
Exercise of options into common stock, shares		73,784
Employee stock purchase plan expense	14		14
Unrealized gain (loss) on marketable securities	(566)				(566)
Net loss	(12,405)			(12,405)
Ending balance at Mar. 31, 2022	135,308	$ 3	297,815	(161,611)	(899)
Ending balance, shares at Mar. 31, 2022		30,682,813
Beginning balance at Dec. 31, 2021	146,513	$ 3	296,049	(149,206)	(333)
Beginning balance, shares at Dec. 31, 2021		30,609,029
Unrealized gain (loss) on marketable securities	(872)
Net loss	(36,356)
Ending balance at Sep. 30, 2022	113,986	$ 3	300,750	(185,562)	(1,205)
Ending balance, shares at Sep. 30, 2022		30,720,291
Beginning balance at Mar. 31, 2022	135,308	$ 3	297,815	(161,611)	(899)
Beginning balance, shares at Mar. 31, 2022		30,682,813
Stock-based compensation expense	1,396		1,396
Employee stock purchase plan expense	60		60
Employee stock purchase plan expense, Shares		37,478
Unrealized gain (loss) on marketable securities	(313)				(313)
Net loss	(10,535)			(10,535)
Ending balance at Jun. 30, 2022	125,916	$ 3	299,271	(172,146)	(1,212)
Ending balance, shares at Jun. 30, 2022		30,720,291
Stock-based compensation expense	1,479		1,479
Unrealized gain (loss) on marketable securities	7				7
Net loss	(13,416)			(13,416)
Ending balance at Sep. 30, 2022	113,986	$ 3	300,750	(185,562)	(1,205)
Ending balance, shares at Sep. 30, 2022		30,720,291
Beginning balance at Dec. 31, 2022	103,407	$ 3	302,202	(197,794)	(1,004)
Beginning balance, shares at Dec. 31, 2022		30,764,160
Stock-based compensation expense	1,213		1,213
Issuance of equity in exchange for compensation	302		302
Issuance of equity in exchange for compensation, Shares		208,510
Surrender of shares for tax withholding	(76)		(76)
Surrender of shares for tax withholding, Shares		(50,343)
Vesting of restricted stock shares, shares		49,014
Unrealized gain (loss) on marketable securities	181				181
Net loss	(10,177)			(10,177)
Ending balance at Mar. 31, 2023	94,850	$ 3	303,641	(207,971)	(823)
Ending balance, shares at Mar. 31, 2023		30,971,341
Beginning balance at Dec. 31, 2022	103,407	$ 3	302,202	(197,794)	(1,004)
Beginning balance, shares at Dec. 31, 2022		30,764,160
Unrealized gain (loss) on marketable securities	602
Net loss	(26,687)
Ending balance at Sep. 30, 2023	71,000	$ 2	295,881	(224,481)	(402)
Ending balance, shares at Sep. 30, 2023		24,996,517
Beginning balance at Mar. 31, 2023	94,850	$ 3	303,641	(207,971)	(823)
Beginning balance, shares at Mar. 31, 2023		30,971,341
Stock-based compensation expense	1,095		1,095
Employee stock purchase plan expense	31		31
Employee stock purchase plan expense, Shares		25,964
Purchase agreement, net of issuance costs and excise tax	(7,663)		(7,663)
Purchase agreement, net of issuance costs and excise tax, Shares		(4,454,248)
Vesting of restricted stock shares, shares		40,762
Unrealized gain (loss) on marketable securities	274				274
Net loss	(9,386)			(9,386)
Ending balance at Jun. 30, 2023	79,201	$ 3	297,104	(217,357)	(549)
Ending balance, shares at Jun. 30, 2023		26,583,819
Stock-based compensation expense	1,048		1,048
Purchase agreement, net of issuance costs and excise tax	(2,272)	$ (1)	(2,271)
Purchase agreement, net of issuance costs and excise tax, Shares		(1,587,302)
Unrealized gain (loss) on marketable securities	147				147
Net loss	(7,124)			(7,124)
Ending balance at Sep. 30, 2023	$ 71,000	$ 2	$ 295,881	$ (224,481)	$ (402)
Ending balance, shares at Sep. 30, 2023		24,996,517

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities
Net loss	$ (26,687)	$ (36,356)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	3,356	4,413
Depreciation and amortization	436	452
(Accretion) amortization on marketable securities	(910)	285
Non-cash lease expense	987	887
Amortization of financing lease right-of-use assets	586	544
Realized gain on marketable securities		(15)
Loss (gain) on fixed asset disposition	302	(15)
Changes in operating assets and liabilities:
Prepaid expenses	(436)	(1,040)
Other assets	29	31
Accounts payable and accrued liabilities	(1,550)	2,201
Compensation and employee benefits	(1,067)	9
Operating lease liabilities	(971)	(833)
Other liabilities	65	(15)
Net cash used in operating activities	(25,860)	(29,452)
Investing activities
Purchases of property and equipment	(180)	(321)
Purchases of short-term investments	(18,536)	(65,017)
Sales of short-term investments		7,864
Maturities of short-term investments	48,700	91,365
Proceeds from sale of property and equipment	166	15
Net cash provided by investing activities	30,150	33,906
Financing activities
Principal payments for financing leases	(565)	(452)
Proceeds from the exercise of common stock options		238
Payment of employee restricted stock tax withholdings	(76)
Employee stock purchase plan proceeds	31	51
Payments for repurchase of common stock	(10,132)
Net cash used in financing activities	(10,742)	(163)
Net (decrease) increase in cash and cash equivalents	(6,452)	4,291
Cash and cash equivalents at beginning of period	17,795	7,159
Cash and cash equivalents at end of period	11,343	11,450
Supplemental disclosure of noncash financing information:
Share repurchase issuance costs	(337)
Issuance of equity in exchange for compensation included in compensation and employee benefits	302
Property and equipment disposals included in other assets	25
Initial measurement of operating lease right-of-use assets	331	6,549
Initial measurement of operating lease liabilities	$ 331	5,574
Initial measurement of finance lease right-of-use assets		$ 600

Organization and Operations

Organization and Operations	9 Months Ended
Organization and Operations	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND OPERATIONS	1. ORGANIZATION AND OPERATIONS Business Sensei Biotherapeutics, Inc. (the “Company” or “Sensei”) is an immuno-oncology company that was incorporated in 1999 as a Maryland corporation until incorporated in Delaware on December 1, 2017. The Company is focused on the discovery and development of next-generation therapeutics for cancer patients. Liquidity and capital resources Since its inception, the Company has devoted substantially all of its resources to advancing development of its portfolio of programs, establishing and protecting its intellectual property, conducting research and development activities, organizing and staffing the Company, business planning, raising capital and providing general and administrative support for these operations. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, technical risks associated with the successful research, development and manufacturing of product candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Current and future programs will require significant research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure. Even if the Company’s drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. Since its inception, the Company has incurred substantial losses and had a net loss of $ 26.7 million for the nine months ended September 30, 2023. As of September 30, 2023, the Company had an accumulated deficit of $ 224.5 million . The Company expects to generate operating losses and negative operating cash flows for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities as of September 30, 2023 of $ 72.0 million will be sufficient to fund its operations for at least the next twelve months from the date of issuance of these financial statements. The Company will need additional financing to support its continuing operations and pursue its growth strategy. Until such time as the Company can generate significant revenue from product sales, if ever, it expects to finance its operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. The Company may be unable to raise additional funds or enter into such other agreements when needed on favorable terms or at all. The inability to raise capital as and when needed would have a negative impact on the Company’s financial condition and its ability to pursue its business strategy. The Company will need to generate significant revenue to achieve profitability, and it may never do so.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2023
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Principles of Consolidation The Company has prepared the accompanying condensed consolidated financial statements in conformity with generally accepted accounting principles in the United States (“US GAAP”). The condensed consolidated financial statements include those accounts of the Company and its subsidiaries after elimination of all intercompany accounts and transactions. Unaudited interim financial information The condensed consolidated financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and note disclosures normally included in financial statements prepared in accordance with US GAAP have been condensed or omitted from these condensed consolidated financial statements, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K. The results for any interim period are not necessarily indicative of results for any future period. Use of Estimates The preparation of condensed consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of expenses during the reporting periods presented. Estimates are used for, but are not limited to, depreciation of equipment, the Company’s enterprise value, fair value of financial instruments, the Company’s ability to continue as a going concern and contingencies. Actual results may differ from those estimates. Cash and cash equivalents Cash equivalents are highly liquid investments with an original maturity of 90 days or less at the date of purchase and consist of time deposits and investments in money market funds with commercial banks and financial institutions. At September 30, 2023 , cash and cash equivalents included cash on deposit at commercial banks and a money market fund that invests in U.S. Government securities. Marketable securities Investments consist of marketable securities with original maturities greater than 90 days. The Company has classified its investments with maturities beyond one year as short-term, based on their highly liquid nature and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of marketable securities to be available-for-sale. Accordingly, these investments are recorded at fair value (Level 2). Unrealized gains and losses are reported as the accumulated other comprehensive items in stockholders’ equity. Amortization and accretion of premiums and discounts are recorded in other income (expense). Realized gains or losses on debt securities are included in interest income or interest expense, respectively. If any adjustment to fair value reflects a decline in value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is other than temporary and, if so, marks the investment to market on the Company’s statement of operations and comprehensive loss. Property and Equipment Property and equipment are recorded at cost and depreciated or amortized over the estimated useful lives of the assets. Repairs or maintenance costs are expensed as incurred. Depreciation is computed using the straight-line method over the following estimated useful lives: Office equipment and furniture 3 — 7 years Research equipment 1 — 7 years Leases Effective January 1, 2022 , the Company adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update No. 2016-02, Leases (Topic 842) (“ASC 842”) using the modified retrospective method. At lease inception, the Company determines if an arrangement is or contains a lease, and if so, assesses the lease for classification as either an operating or finance lease. A lease is classified as a finance lease if any one of the following criteria are met: (i) the lease transfers ownership of the asset by the end of the lease term, (ii) the lease contains an option to purchase the asset that is reasonably certain to be exercised, (iii) the lease term is for a major part of the remaining useful life of the asset, (iv) the present value of the lease payments equals or exceeds substantially all of the fair value of the asset, or (v) the leased asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease. A lease is classified as an operating lease if it does not meet any of these criteria. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and current and non-current lease liabilities, as applicable. The Company elected not to separate lease and non-lease components for all underlying assets. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The incremental borrowing rate is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment. Lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise the options. For leases that existed prior to the adoption of ASC 842, the Company used the remaining lease term to determine the appropriate incremental borrowing rate. Share Purchase Agreement On July 31, 2023, the Company entered into a Purchase Agreement (the “Cambrian Purchase Agreement”) with Cambrian BioPharma, Inc. and its associates and controlled affiliates (“Cambrian”), pursuant to which the Company agreed to repurchase 1,587,302 shares of its common stock from Cambrian at a price of $ 1.26 per share and for an aggregate purchase price of approximately $ 2 million. The transaction closed on August 15, 2023 and the 1,587,302 repurchased shares have been retired and cancelled. The Cambrian Purchase Agreement is a liability in accordance with ASC 480, Distinguishing Liabilities from Equity resulting in unconditional forward purchase contracts that requires physical settlement by repurchase of a fixed number of the Company’s shares for cash and recorded as a treasury stock transaction that used borrowed funds. At inception of the Cambrian Purchase Agreement a liability of $ 2.3 million, net of issuance costs, was recorded at the contractual value because the fair value exceeded the contractual value of the shares on July 31, 2023. Recently Issued Accounting Standards Updates 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 provides guidance for estimating credit losses on certain types of financial instruments, including trade receivables, by introducing an approach based on expected losses. ASU 2016-13 also amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. The guidance requires a modified retrospective transition method and early adoption is permitted. In November 2019, FASB issued ASU No. 2019-10, Financial Instruments – Credit Losses, Derivatives and Hedging, and Leases (“ASU 2019-10”), which defers the adoption of ASU 2016-13 for smaller reporting companies until periods beginning after December 15, 2022. The Company has adopted the new guidance as of January 1, 2023 , and it did not have a material impact on its financial statements and related disclosures.

Marketable Securities

Marketable Securities	9 Months Ended
Marketable Securities	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
MARKETABLE SECURITIES	3. MARKETABLE SECURITIES Marketable securities consist of the following as of September 30, 2023 (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value Commercial paper $ 13,247 $ — $ ( 36 ) $ 13,211 Corporate bonds 39,224 — ( 100 ) 39,124 U.S. Government agencies 8,601 — ( 266 ) 8,335 Total $ 61,072 — $ ( 402 ) $ 60,670 As of September 30, 2023 , all marketable securities held by the Company had remaining contractual maturities of one year or less. As of September 30, 2023, $ 0.4 million of unrealized losses were associated with marketable securities with contractual maturities of one year or less. There were no impairments of the Company’s assets measured and carried at fair value during the nine months ended September 30, 2023 .

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
Property and Equipment, Net	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	4. PROPERTY AND EQUIPMENT, NET Property and equipment, net consist of the following (in thousands): September 30, December 31, Research equipment $ 2,107 $ 2,707 Office equipment and furniture 532 532 Leasehold improvement 253 253 Total property and equipment 2,892 3,492 Less accumulated depreciation and amortization ( 1,593 ) ( 1,442 ) Property and equipment, net $ 1,299 $ 2,049 Depreciation and amortization expense for the three months ended September 30, 2023 and 2022 was $ 137 thousand and $ 151 thousand , respectively, and for the nine months ended September 30, 2023 and 2022 was $ 436 thousand and $ 452 thousand , respectively. Effective January 1, 2022, the Company adopted ASC 842 and reclassed capital leases that were previously classified as property and equipment, net were presented separately under right of use assets - financing leases, net on the Company's condensed consolidated balance sheet. $ 2.2 million related to items previously classified under research equipment and $ 70 thousand related to items previously classified under office equipment and furniture on the table above. These leases are further described in Note 6.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2023
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	5. FAIR VALUE MEASUREMENTS The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values (in thousands): Fair value measurements at September 30, 2023 Level 1 Level 2 Level 3 Total Assets: Cash equivalents Money market funds $ 10,565 $ — $ — $ 10,565 Investments: Commercial paper — 13,211 — 13,211 Corporate bonds — 39,124 — 39,124 U.S. Government agencies — 8,335 — 8,335 Total $ 10,565 $ 60,670 $ — $ 71,235 When developing fair value estimates, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs. When available, the Company uses quoted market prices to measure fair value. The valuation technique used to measure fair value for the Company's Level 1 and Level 2 assets is a market approach, using prices and other relevant information generated by market transactions involving identical or comparable assets. If market prices are no t available, the fair value measurement is based on models that use primarily market-based parameters including yield curves, volatilities, credit ratings and currency rates. In certain cases where market rate assumptions are no t available, the Company is required to make judgments about assumptions market participants would use to estimate the fair value of a financial instrument. There were no transfers among Level 1, Level 2 or Level 3 categories in the nine months ended September 30, 2023 and 2022 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	6. COMMITMENTS AND CONTINGENCIES Operating Leases As of September 30, 2023 , the Company leases office and laboratory facilities under operating leases, which expire at various dates through 2027 . The Company has $ 678 thousand in letters of credit outstanding as security on certain of these leases. As part of its adoption of ASC 842, the Company recorded operating right-of-use assets and operating lease liabilities for these leases as of January 1, 2022. The Company entered into an operating sublease agreement on January 18, 2023 (the "Sublease") with respect to part of its existing Boston office and laboratory facilities (the "Head Lease"). The Company accounted for the Head Lease and the Sublease as separate contracts and there was no effect on the right-of-use asset or lease liability associated with the Head Lease. The Sublease has an effective end date of June 30, 2024. The Head Lease rent expense is presented separately from income related to the Sublease and both are reported as components of operating expenses on the condensed consolidated statements of operations and comprehensive loss. The Company recorded $ 239 thousand of income related to the Sublease for the nine months ended September 30, 2023. Finance Leases The Company leases research equipment and furniture under finance leases. The following table contains a summary of the lease costs recognized under ASC 842 pertaining to the Company’s finance and operating leases for the nine months ended September 30, 2023 (in thousands): Nine Months Ended September 30, 2023 Lease Cost: Amortization of finance right-of-use assets $ 586 Interest on finance lease liabilities 113 Operating lease cost 1,336 Variable lease cost 515 Total lease costs 2,550 Operating Sublease income ( 239 ) Total lease costs, net $ 2,311 The following table contains a summary of other information pertaining to the Company’s finance and operating leases for the nine months ended September 30, 2023 (in thousands, except lease term and discount rate): Nine Months Ended September 30, 2023 Other Operating Lease Information: Operating cash flows for operating leases $ 1,320 Operating cash flows for operating subleases $ ( 250 ) Operating cash flows for finance leases $ 112 Financing cash flows from finance leases $ 565 Weighted average remaining lease term Operating leases 3.0 years Financing leases 2.3 years Weighted average discount rate Operating leases 7.8 % Financing leases 8.3 % The following table presents supplemental balance sheet information related to operating and financing leases as of September 30, 2023 (in thousands): September 30, Operating leases Right-of-use assets, net $ 4,700 Right-of-use lease liabilities, current $ 1,532 Right-of-use lease liabilities, noncurrent 3,403 Total operating lease liabilities $ 4,935 Financing leases Right-of-use assets, net $ 1,737 Right-of-use lease liabilities, current $ 874 Right-of-use lease liabilities, noncurrent 962 Total financing lease liabilities $ 1,836 The following table presents the maturity of the Company’s operating and finance lease liabilities as of September 30, 2023 (in thousands): Operating Financing 2023 $ 457 $ 227 2024 1,853 900 2025 1,734 757 2026 1,413 107 2027 59 — Total future minimum lease payments $ 5,516 $ 1,991 Less amount representing interest 581 155 Total lease liabilities $ 4,935 $ 1,836 License Agreements In the normal course of business, the Company enters into licensing agreements with various parties to obtain the right to make, use, and sell licensed products currently in development. Litigation The Company records estimated losses from loss contingencies, such as a loss arising from a litigation, when it determines that it is probable a liability has been incurred and the amount of loss can be reasonably estimated. Litigation is subject to many factors that are difficult to predict so that there can be no assurance, in the event of a material unfavorable result in one or more claims, the Company will not incur material costs. During 2017, the Company became actively involved in a matter pending in the Ontario (Canada) Superior Court of Justice which names, among multiple other defendants, the Company and two former officers of the Company. The claims pending in this matter allege breach of contract by the Company and seek declaratory and other relief, including monetary damages from the Company, and the individual defendants, including the Company’s former officers. The claims by such plaintiffs were originally made in a lawsuit filed in Ontario during October 2011, but was not pursued by such plaintiffs in any material manner until 2017. The Company believes that there is no merit to the claims alleged against the Company and its former officers, including no alleged breach of contract by the Company, and intends to vigorously defend against the claims pertaining to the Company and its former officers. At the present stage of the suit, management believes the outcome in this matter is not likely to have any material impact on the Company’s results, cash flows, or financial position.

Equity

Equity	9 Months Ended
Equity	Sep. 30, 2023
Equity [Abstract]
EQUITY	7. Equity Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are not entitled to receive dividends, unless declared by the board of directors. Common Stock Warrants The following is a summary of the common stock warrant activity for the nine months ended September 30, 2023 related to common stock warrants issued in conjunction with equity and debt fundraising events: Number Weighted- Weighted- Aggregate Outstanding at December 31, 2022 412,262 $ 9.81 4.71 $ — Granted — — — — Exercised — — — — Expired — — — — Outstanding at September 30, 2023 412,262 $ 9.81 3.96 $ — Share Purchase Agreement On July 31, 2023, the Company entered into the Cambrian Purchase Agreement, pursuant to which the Company agreed to repurchase 1,587,302 shares of its common stock from Cambrian at a price of $ 1.26 per share and for an aggregate purchase price of approximately $2 million. The transaction closed on August 15, 2023 and the 1,587,302 repurchased shares were retired and cancelled on or about the date of the closing. On August 16, 2022, the Inflation Reduction Act of 2022 (“IRA”) was signed into law, which contains certain revisions to the Internal Revenue Code, including a 1 % excise tax on the value of net corporate stock repurchases that is effective beginning on January 1, 2023. The excise tax is recorded as an incremental cost in equity on the Company's condensed consolidated balance sheets and was not significant as of September 30, 2023.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
Stock-Based Compensation	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	8. STOCK-BASED COMPENSATION 2018 Equity Incentive Plan The Company’s 2018 Stock Incentive Plan (the “2018 Plan”) provided for the Company to grant qualified incentive options, nonqualified options, stock grants and other stock-based awards to employees and non-employees to purchase the Company’s common stock. Upon the effectiveness of the 2021 Plan (as defined below), the Company ceased issuing new awards under the 2018 Plan. 2021 Equity Incentive Plan The Company’s 2021 Equity Incentive Plan (the “2021 Plan”) was approved by the board of directors on January 27, 2021 and the Company’s stockholders on January 28, 2021, and became effective on the execution of the underwriting agreement related to the Company's initial public offering. The 2021 Plan provides for the grant of incentive stock options to employees, including employees of any parent or subsidiary corporations, and for the grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards and other forms of stock awards to employees, directors, and consultants, including employees and consultants of the Company’s affiliates. The number of shares initially reserved for issuance under the 2021 Plan was 5,000,000 , which began automatically increasing on January 1 of each calendar year, starting on January 1, 2022 through January 1, 2031, in an amount equal to 4.0 % of the total number of shares of the Company’s capital stock outstanding on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the board of directors. In December 2022, the Company's board of directors determined that the automatic increase of available shares for calendar year 2023 would be reduced from 4.0 % to 1.0 % of the Company's capital stock. As a result, on January 1, 2023 the number of shares available for issuance pursuant to the 2021 Plan increased to 2,900,096 shares. As of September 30, 2023, 2,537,629 shares remained available for issuance pursuant to the 2021 Plan. 2021 Employee Stock Purchase Plan The 2021 Employee Stock Purchase Plan (the “2021 ESPP”) was approved by the Company’s board of directors on January 27, 2021 and became effective on the execution of the underwriting agreement related to the initial public offering. A total of 333,333 shares of common stock were initially reserved for issuance under the 2021 ESPP, which will automatically increase on January 1 of each calendar year, beginning on January 1, 2022 through January 1, 2031, by an amount equal to 1.0 % of the total shares of common stock outstanding on December 31st of the preceding calendar year. The purchase price of the shares under the 2021 ESPP are at 85 % of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the purchase date. As of September 30, 2023, the Company had issued 119,011 shares under the 2021 ESPP. As of September 30, 2023, 828,053 shares were available to be issued under the 2021 ESPP. During the nine months ended September 30, 2023 , the Company issued 25,964 shares of common stock related to the ESPP offering that ended on May 15, 2023. The Company recognized $ 6 thousand of share-based compensation expense related to the ESPP for the nine months ended September 30, 2023. Stock Options During 2023, the Company has granted options to purchase shares of common stock to employees and non-employee directors pursuant to the 2021 Plan at a weighted average fair value of $ 1.05 per share. The Company uses the Black-Scholes option-pricing model to estimate the fair value of the stock options on the applicable grant dates. The following is a summary of the stock option award activity during the nine months ended September 30, 2023: Number Weighted- Weighted- Aggregate Outstanding at December 31, 2022 3,333,434 $ 8.80 8.09 $ 1 Granted 658,371 $ 1.36 Forfeited ( 397,289 ) $ 5.61 Expired ( 213,755 ) $ 8.73 Outstanding at September 30, 2023 3,380,761 $ 7.73 7.44 0 Options expected to vest as of September 30, 2023 1,305,528 $ 3.48 8.58 0 Exercisable at September 30, 2023 2,075,233 $ 10.40 6.72 0 The aggregate intrinsic value of the outstanding stock option awards is calculated as the difference between the exercise price and the market price of the Company’s common stock at September 30, 2023. There were no stock options exercised in the nine months ended September 30, 2023. The grant date fair value of options vested during the nine months ended September 30, 2023 and 2022 was $ 3.5 million and $ 6.9 million, respectively. At September 30, 2023, there was $ 5.1 million of unrecognized stock-based compensation expense associated with the stock options, which is expected to be recognized over a weighted-average period of 1.63 years. Restricted Stock Units The Company has granted restricted stock units with service-based vesting conditions. The following is a summary of the restricted stock unit activity during the nine months ended September 30, 2023: Restricted Stock Units Weighted- Unvested at December 31, 2022 215,854 $ 3.69 Granted 361,097 $ 1.45 Vested ( 298,286 ) $ 2.00 Forfeited ( 45,957 ) $ 2.92 Unvested at September 30, 2023 232,708 $ 3.17 Pursuant to the 2021 Plan, the Company granted restricted stock units which vest annually over a period of one , two , three or four years . At September 30, 2023, there was approximately $ 0.5 million of unrecognized stock-based compensation expense associated with the restricted stock units which is expected to be recognized over a weighted-average period of 2.46 years. Common Stock Warrants The following is a summary of the employee-issued common stock warrant activity during the nine months ended September 30, 2023: Number Weighted- Weighted- Aggregate Outstanding and exercisable at December 31, 2022 57,004 $ 6.94 1.91 $ — Expired ( 312 ) 144 — — Outstanding and exercisable at September 30, 2023 56,692 $ 6.19 1.41 $ — As of September 30, 2023 there was no unrecognized stock-based compensation expense associated with the common stock warrants. For the nine months ended September 30, 2023 , the Company utilized the Black-Scholes option-pricing model for estimating the fair value of the stock options granted. The following table presents the assumptions and the Company’s methodology for developing each of the assumptions used: Nine Months Ended September 30, 2023 2022 Volatility 93 %- 97 % 94 %- 97 % Expected term (years) 5.5 - 7.0 5.5 - 7.0 Risk-free interest rate 3.6 %– 4.6 % 1.7 %- 4.0 % Dividend rate —% —% • Volatility—The Company estimates the expected volatility of its common stock at the date of grant based on the historical volatility of comparable public companies over the expected term. • Expected life—The expected life is estimated as the contractual term. • Risk-free interest rate—The risk-free rate for periods within the estimated life of the stock award is based on the U.S. Treasury yield curve in effect at the time of grant. • Dividend rate—The assumed dividend yield is based upon the Company’s expectation of not paying dividends in the foreseeable future. Stock-based compensation expense was recorded in the following line items in the condensed consolidated statements of operations for the three and nine months ended September 30, 2023 and 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 234 $ 505 $ 786 $ 1,540 General and administrative 814 974 2,570 2,850 Total stock-based compensation expense $ 1,048 $ 1,479 $ 3,356 $ 4,390

Employee Retirement Plan

Employee Retirement Plan	9 Months Ended
Employee Retirement Plan	Sep. 30, 2023
Retirement Benefits [Abstract]
EMPLOYEE RETIREMENT PLAN	9. EMPLOYEE RETIREMENT PLAN The Company maintains a defined contribution 401(k) profit-sharing plan (the “Plan”) for all employees. Under the Plan, participants may make voluntary contributions up to the maximum amount allowable by law. The Plan is based on employees’ salary deferral, and the Company matches employees’ contributions up to 4 % of the employees’ base salary. Employees are 100 % vested in the Company’s match contributions. During the three months ended September 30, 2023 and 2022 , the Company’s matching contributions were $ 43 thousand and $ 85 thousand, respectively. During the nine months ended September 30, 2023 and 2022 , the Company’s matching contributions were $ 190 thousand and $ 268 thousand, respectively.

Related-Party Transactions

Related-Party Transactions	9 Months Ended
Related-Party Transactions	Sep. 30, 2023
Related Party Transactions [Abstract]
RELATED-PARTY TRANSACTIONS	10. RELATED-PARTY TRANSACTIONS Service Agreement - Hope Farms During 2020, the Company entered into a service agreement with Hope Farms at Disco Bay LLC (“Hope Farms”) to provide animal vaccination testing and provide samples to the Company (the “Hope Farms Service Agreement”). The Company’s Chief Research and Development Officer is a co-founder and partial owner of Hope Farms. Further, the CEO of Hope Farms is the spouse of the Company’s Chief Research and Development Officer. In October 2022, the Company and Hope Farms agreed to terminate the Hope Farms Services Agreement, effective as of September 30, 2022. The Company recognized no expense and $ 104 thousand for the nine months ended September 30, 2023 and 2022, respectively, relating to the Hope Farms Service Agreement. Service Agreement - Binney Street Partners During 2022, the Company entered into a service agreement with Binney Street Partners LLC (“Binney Street Partners”) to provide business development services (the “BSP Service Agreement”). The Company subsequently hired a managing partner of Binney Street Partners to serve as the Company's Chief Business Officer, effective June 1, 2022. In September 2022, the Company and Binney Street Partners agreed to terminate the BSP Service Agreement, effective as of August 11, 2022. The Company recognized no expense and $ 221 thousand for the nine months ended September 30, 2023 and 2022, respectively, relating to the BSP Service Agreement. Purchase Agreement - Apeiron Investment Group On May 23, 2023, the Company entered into a purchase agreement (the “Apeiron Purchase Agreement”) with Apeiron Investment Group Ltd., Presight Sensei Co-Invest Fund, L.P., Presight Sensei Co-Invest Management, L.L.C., Christian Angermayer, Apeiron SICAV Ltd. - Presight Capital Fund ONE, and Altarius Asset Management Ltd. (collectively, the “Apeiron Parties”), pursuant to which the Company agreed to purchase 4,454,248 shares of the Company ’ s common stock from certain of the Apeiron Parties for a purchase price of $ 1.58 per share. The closing of the purchase transaction was completed on June 1, 2023, pursuant to which t he Company paid approximately $ 7.8 million in the aggregate to the Aperion Parties, including $ 0.75 million for costs related to the negotiation and execution of the Purchase Agreement. Prior to the closing, certain of the Apeiron Parties beneficially owned more than 5 % of the Company's outstanding shares of common stock. Following the closing, the Apeiron Parties owned no outstanding shares of the Company’s common stock. The price per share and the transaction were unanimously approved by the independent directors of our board of directors. Under the terms of the Apeiron Purchase Agreement, the Apeiron Parties agreed to withdraw their notice of intent to nominate director candidates for election to our board of directors at the 2023 annual meeting of stockholders. The Apeiron Parties additionally agreed to customary standstill restrictions, including an agreement to not acquire any additional shares of the Company’s voting securities or any of the Company’s indebtedness until the date that is the earlier of (i) four years from the date of the Apeiron Purchase Agreement and (ii) 30 days prior to the nomination deadline for the nomination of director candidates for election to our board of directors at the Company’s 2027 annual meeting of stockholders. Purchase Agreement - Cambrian BioPharma, Inc. On July 31, 2023, the Company entered into the Cambrian Purchase Agreement, pursuant to which the Company agreed to repurchase 1,587,302 shares of its common stock from Cambrian, a beneficial owner of more than 5% of the Company’s outstanding shares of common stock, at a purchase price of $ 1.26 per share and for an aggregate purchase price of approximately $ 2 million. The transaction closed on August 15, 2023 and the 1,587,302 repurchased shares were retired and cancelled on or about the date of the closing. James Peyer, a director of the Company, is the CEO of Cambrian. The price per share and the transaction were unanimously approved by the independent directors of our board of directors. Under the terms of the Cambrian Purchase Agreement, Cambrian agreed to vote, until thirty days prior to the deadline for delivery of notice for the nomination of director candidates for election to our board of directors at the Company’s 2025 annual meeting of stockholders (the “Effective Period”), all of Cambrian’s shares of the Company’s common stock at all meetings of stockholders, as well as in any consent solicitations of the Company’s stockholders, in accordance with the board’s recommendations. In the event that Institutional Shareholder Services, Inc. and Glass Lewis & Co., LLC recommend otherwise with respect to any Company proposals (other than the election or removal of directors), Cambrian will be permitted to vote in accordance with such recommendations. Under the terms of the Cambrian Purchase Agreement, Cambrian has also agreed to certain standstill restrictions during the Effective Period including, among other things, with respect to nominating persons for election to the board of directors, submitting any stockholder proposal for consideration at any stockholder meeting, soliciting any proxies, and conducting any “withhold” or similar campaign.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2023
Income Tax Disclosure [Abstract]
INCOME TAXES	11. INCOME TAXES The Company recorded no provision for income taxes for the nine months ended September 30, 2023 and 2022. Deferred tax assets and deferred tax liabilities are recognized based on temporary differences between the financial reporting and tax bases of assets and liabilities using statutory rates. Management of the Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets, which are comprised principally of net operating loss carryforwards, equity-based compensation, research and development tax credit carryforwards, and capitalized research and development expenditures. Under the applicable accounting standards, management has considered the Company’s history of losses and concluded that it is more likely than not that the Company will not recognize the benefits of federal and state deferred tax assets. Accordingly, a full valuation allowance has been established against the Company’s otherwise recognizable net deferred tax assets. On August 16, 2022, the IRA was signed into law, which contains certain revisions to the Internal Revenue Code, including a 1% excise tax on the value of net corporate stock repurchases that is effective beginning on January 1, 2023. The excise tax is recorded as an incremental cost in equity on the Company's condensed consolidated balance sheets and was not significant as of September 30, 2023.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
Net Loss Per Share	Sep. 30, 2023
Earnings Per Share [Abstract]
NET LOSS PER SHARE	12. NET LOSS PER SHARE Basic and diluted net loss per share attributable to common stockholders is calculated as follows (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Net loss $ ( 7,124 ) $ ( 13,416 ) $ ( 26,687 ) $ ( 36,356 ) Net loss per share—basic and diluted $ ( 0.28 ) $ ( 0.44 ) $ ( 0.92 ) $ ( 1.18 ) Weighted-average number of shares used in computing net loss per share—basic and diluted 25,514,115 30,720,291 28,942,803 30,690,175 The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share, as their effect is anti-dilutive: For the Nine Months Ended September 30, 2023 2022 Stock options to purchase common stock 3,380,761 3,523,211 Unvested restricted stock units 232,708 225,200 Warrants issued to employees and contractor to purchase common stock 56,692 57,004 Warrants issued related to convertible notes and other equity agreements 412,262 412,262

Restructuring and Related Charg

Restructuring and Related Charges	9 Months Ended
Restructuring and Related Charges	Sep. 30, 2023
Restructuring and Related Activities [Abstract]
RESTRUCTURING AND RELATED CHARGES	13. RESTRUCTURING AND RELATED CHARGES In December 2022 , the Company began implementing a restructuring plan to reduce operating costs primarily associated with a reduction in the Company's workforce (the “Restructuring”). In connection with the Restructuring, the Company incurred expenses within research and development and general and administrative expenses of $ 0.2 million during the nine months ended September 30, 2023 . These costs primarily related to one-time termination benefits and ongoing benefit arrangements, both of which included severance payments and extended benefits coverage support and were contingent upon the impacted employees’ execution and non-revocation of separation agreements. Aggregate costs in connection with the Restructuring also included certain contract termination costs. The following table summarizes the accrued liabilities activity recorded in connection with the Restructuring, including the reduction in workforce in December 2022 and related activities as of September 30, 2023 (in thousands): Personnel Other Total Balance at January 1, 2022 $ — $ — $ — Restructuring and other costs, net 973 95 1,068 Cash payments ( 103 ) — ( 103 ) Balance at December 31, 2022 870 95 965 Restructuring and other costs, net 202 2 204 Cash payments ( 1,054 ) ( 71 ) ( 1,125 ) Balance at March 31, 2023 18 26 44 Restructuring and other costs, net 12 ( 20 ) ( 8 ) Cash payments ( 30 ) ( 6 ) ( 36 ) Balance at June 30, 2023 — — — Balance at September 30, 2023 $ — $ — $ —

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The Company has prepared the accompanying condensed consolidated financial statements in conformity with generally accepted accounting principles in the United States (“US GAAP”). The condensed consolidated financial statements include those accounts of the Company and its subsidiaries after elimination of all intercompany accounts and transactions.
Unaudited interim financial information	Unaudited interim financial information The condensed consolidated financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and note disclosures normally included in financial statements prepared in accordance with US GAAP have been condensed or omitted from these condensed consolidated financial statements, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K. The results for any interim period are not necessarily indicative of results for any future period.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of expenses during the reporting periods presented. Estimates are used for, but are not limited to, depreciation of equipment, the Company’s enterprise value, fair value of financial instruments, the Company’s ability to continue as a going concern and contingencies. Actual results may differ from those estimates.
Cash and Cash Equivalents	Cash and cash equivalents Cash equivalents are highly liquid investments with an original maturity of 90 days or less at the date of purchase and consist of time deposits and investments in money market funds with commercial banks and financial institutions. At September 30, 2023 , cash and cash equivalents included cash on deposit at commercial banks and a money market fund that invests in U.S. Government securities.
Marketable Securities	Marketable securities Investments consist of marketable securities with original maturities greater than 90 days. The Company has classified its investments with maturities beyond one year as short-term, based on their highly liquid nature and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of marketable securities to be available-for-sale. Accordingly, these investments are recorded at fair value (Level 2). Unrealized gains and losses are reported as the accumulated other comprehensive items in stockholders’ equity. Amortization and accretion of premiums and discounts are recorded in other income (expense). Realized gains or losses on debt securities are included in interest income or interest expense, respectively. If any adjustment to fair value reflects a decline in value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is other than temporary and, if so, marks the investment to market on the Company’s statement of operations and comprehensive loss.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and depreciated or amortized over the estimated useful lives of the assets. Repairs or maintenance costs are expensed as incurred. Depreciation is computed using the straight-line method over the following estimated useful lives: Office equipment and furniture 3 — 7 years Research equipment 1 — 7 years
Leases	Leases Effective January 1, 2022 , the Company adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update No. 2016-02, Leases (Topic 842) (“ASC 842”) using the modified retrospective method. At lease inception, the Company determines if an arrangement is or contains a lease, and if so, assesses the lease for classification as either an operating or finance lease. A lease is classified as a finance lease if any one of the following criteria are met: (i) the lease transfers ownership of the asset by the end of the lease term, (ii) the lease contains an option to purchase the asset that is reasonably certain to be exercised, (iii) the lease term is for a major part of the remaining useful life of the asset, (iv) the present value of the lease payments equals or exceeds substantially all of the fair value of the asset, or (v) the leased asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease. A lease is classified as an operating lease if it does not meet any of these criteria. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and current and non-current lease liabilities, as applicable. The Company elected not to separate lease and non-lease components for all underlying assets. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The incremental borrowing rate is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment. Lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise the options. For leases that existed prior to the adoption of ASC 842, the Company used the remaining lease term to determine the appropriate incremental borrowing rate.
Share Purchase Agreement	Share Purchase Agreement On July 31, 2023, the Company entered into a Purchase Agreement (the “Cambrian Purchase Agreement”) with Cambrian BioPharma, Inc. and its associates and controlled affiliates (“Cambrian”), pursuant to which the Company agreed to repurchase 1,587,302 shares of its common stock from Cambrian at a price of $ 1.26 per share and for an aggregate purchase price of approximately $ 2 million. The transaction closed on August 15, 2023 and the 1,587,302 repurchased shares have been retired and cancelled. The Cambrian Purchase Agreement is a liability in accordance with ASC 480, Distinguishing Liabilities from Equity resulting in unconditional forward purchase contracts that requires physical settlement by repurchase of a fixed number of the Company’s shares for cash and recorded as a treasury stock transaction that used borrowed funds. At inception of the Cambrian Purchase Agreement a liability of $ 2.3 million, net of issuance costs, was recorded at the contractual value because the fair value exceeded the contractual value of the shares on July 31, 2023.
Recently Issued Accounting Standards Updates	Recently Issued Accounting Standards Updates 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 provides guidance for estimating credit losses on certain types of financial instruments, including trade receivables, by introducing an approach based on expected losses. ASU 2016-13 also amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. The guidance requires a modified retrospective transition method and early adoption is permitted. In November 2019, FASB issued ASU No. 2019-10, Financial Instruments – Credit Losses, Derivatives and Hedging, and Leases (“ASU 2019-10”), which defers the adoption of ASU 2016-13 for smaller reporting companies until periods beginning after December 15, 2022. The Company has adopted the new guidance as of January 1, 2023 , and it did not have a material impact on its financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
Summary of Significant Accounting Policies (Tables)	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Summary of Estimated Useful Lives of Property and Equipment	Depreciation is computed using the straight-line method over the following estimated useful lives: Office equipment and furniture 3 — 7 years Research equipment 1 — 7 years

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
Marketable Securities (Tables)	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable Securities	Marketable securities consist of the following as of September 30, 2023 (in thousands): Amortized Cost Unrealized Gains Unrealized Losses Fair Value Commercial paper $ 13,247 $ — $ ( 36 ) $ 13,211 Corporate bonds 39,224 — ( 100 ) 39,124 U.S. Government agencies 8,601 — ( 266 ) 8,335 Total $ 61,072 — $ ( 402 ) $ 60,670

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
Property and Equipment, Net (Tables)	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment, Net	Property and equipment, net consist of the following (in thousands): September 30, December 31, Research equipment $ 2,107 $ 2,707 Office equipment and furniture 532 532 Leasehold improvement 253 253 Total property and equipment 2,892 3,492 Less accumulated depreciation and amortization ( 1,593 ) ( 1,442 ) Property and equipment, net $ 1,299 $ 2,049

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Financial Assets And Liabilities Measured at Fair Value on Recurring Basis	The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values (in thousands): Fair value measurements at September 30, 2023 Level 1 Level 2 Level 3 Total Assets: Cash equivalents Money market funds $ 10,565 $ — $ — $ 10,565 Investments: Commercial paper — 13,211 — 13,211 Corporate bonds — 39,124 — 39,124 U.S. Government agencies — 8,335 — 8,335 Total $ 10,565 $ 60,670 $ — $ 71,235

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
Commitments and Contingencies (Tables)	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Summary of Lease Costs Recognized under ASC 842 Pertaining to Finance and Operating Leases	The following table contains a summary of the lease costs recognized under ASC 842 pertaining to the Company’s finance and operating leases for the nine months ended September 30, 2023 (in thousands): Nine Months Ended September 30, 2023 Lease Cost: Amortization of finance right-of-use assets $ 586 Interest on finance lease liabilities 113 Operating lease cost 1,336 Variable lease cost 515 Total lease costs 2,550 Operating Sublease income ( 239 ) Total lease costs, net $ 2,311
Summary of Other Information Pertaining to Finance and Operating Leases	The following table contains a summary of other information pertaining to the Company’s finance and operating leases for the nine months ended September 30, 2023 (in thousands, except lease term and discount rate): Nine Months Ended September 30, 2023 Other Operating Lease Information: Operating cash flows for operating leases $ 1,320 Operating cash flows for operating subleases $ ( 250 ) Operating cash flows for finance leases $ 112 Financing cash flows from finance leases $ 565 Weighted average remaining lease term Operating leases 3.0 years Financing leases 2.3 years Weighted average discount rate Operating leases 7.8 % Financing leases 8.3 %
Supplemental Balance Sheet Information Related to Operating and Financing Leases	The following table presents supplemental balance sheet information related to operating and financing leases as of September 30, 2023 (in thousands): September 30, Operating leases Right-of-use assets, net $ 4,700 Right-of-use lease liabilities, current $ 1,532 Right-of-use lease liabilities, noncurrent 3,403 Total operating lease liabilities $ 4,935 Financing leases Right-of-use assets, net $ 1,737 Right-of-use lease liabilities, current $ 874 Right-of-use lease liabilities, noncurrent 962 Total financing lease liabilities $ 1,836
Summary of Maturity of Operating and Finance Lease Liabilities	The following table presents the maturity of the Company’s operating and finance lease liabilities as of September 30, 2023 (in thousands): Operating Financing 2023 $ 457 $ 227 2024 1,853 900 2025 1,734 757 2026 1,413 107 2027 59 — Total future minimum lease payments $ 5,516 $ 1,991 Less amount representing interest 581 155 Total lease liabilities $ 4,935 $ 1,836

Equity (Tables)

Equity (Tables)	9 Months Ended
Equity (Tables)	Sep. 30, 2023
Summary of Common Stock Warrant Activity	The following is a summary of the employee-issued common stock warrant activity during the nine months ended September 30, 2023: Number Weighted- Weighted- Aggregate Outstanding and exercisable at December 31, 2022 57,004 $ 6.94 1.91 $ — Expired ( 312 ) 144 — — Outstanding and exercisable at September 30, 2023 56,692 $ 6.19 1.41 $ —
Warrant \| Equity and Debt Fundraising Events
Summary of Common Stock Warrant Activity	The following is a summary of the common stock warrant activity for the nine months ended September 30, 2023 related to common stock warrants issued in conjunction with equity and debt fundraising events: Number Weighted- Weighted- Aggregate Outstanding at December 31, 2022 412,262 $ 9.81 4.71 $ — Granted — — — — Exercised — — — — Expired — — — — Outstanding at September 30, 2023 412,262 $ 9.81 3.96 $ —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
Stock-Based Compensation (Tables)	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Award Activity	The following is a summary of the stock option award activity during the nine months ended September 30, 2023: Number Weighted- Weighted- Aggregate Outstanding at December 31, 2022 3,333,434 $ 8.80 8.09 $ 1 Granted 658,371 $ 1.36 Forfeited ( 397,289 ) $ 5.61 Expired ( 213,755 ) $ 8.73 Outstanding at September 30, 2023 3,380,761 $ 7.73 7.44 0 Options expected to vest as of September 30, 2023 1,305,528 $ 3.48 8.58 0 Exercisable at September 30, 2023 2,075,233 $ 10.40 6.72 0
Summary of Restricted Stock Unit Activity	The following is a summary of the restricted stock unit activity during the nine months ended September 30, 2023: Restricted Stock Units Weighted- Unvested at December 31, 2022 215,854 $ 3.69 Granted 361,097 $ 1.45 Vested ( 298,286 ) $ 2.00 Forfeited ( 45,957 ) $ 2.92 Unvested at September 30, 2023 232,708 $ 3.17
Summary of Common Stock Warrant Activity	The following is a summary of the employee-issued common stock warrant activity during the nine months ended September 30, 2023: Number Weighted- Weighted- Aggregate Outstanding and exercisable at December 31, 2022 57,004 $ 6.94 1.91 $ — Expired ( 312 ) 144 — — Outstanding and exercisable at September 30, 2023 56,692 $ 6.19 1.41 $ —
Summary of Fair Value Assumptions and Methodology	The following table presents the assumptions and the Company’s methodology for developing each of the assumptions used: Nine Months Ended September 30, 2023 2022 Volatility 93 %- 97 % 94 %- 97 % Expected term (years) 5.5 - 7.0 5.5 - 7.0 Risk-free interest rate 3.6 %– 4.6 % 1.7 %- 4.0 % Dividend rate —% —%
Summary of Stock-Based Compensation Expense	Stock-based compensation expense was recorded in the following line items in the condensed consolidated statements of operations for the three and nine months ended September 30, 2023 and 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development $ 234 $ 505 $ 786 $ 1,540 General and administrative 814 974 2,570 2,850 Total stock-based compensation expense $ 1,048 $ 1,479 $ 3,356 $ 4,390

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
Net Loss Per Share (Tables)	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	Basic and diluted net loss per share attributable to common stockholders is calculated as follows (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Net loss $ ( 7,124 ) $ ( 13,416 ) $ ( 26,687 ) $ ( 36,356 ) Net loss per share—basic and diluted $ ( 0.28 ) $ ( 0.44 ) $ ( 0.92 ) $ ( 1.18 ) Weighted-average number of shares used in computing net loss per share—basic and diluted 25,514,115 30,720,291 28,942,803 30,690,175
Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share, as their effect is anti-dilutive: For the Nine Months Ended September 30, 2023 2022 Stock options to purchase common stock 3,380,761 3,523,211 Unvested restricted stock units 232,708 225,200 Warrants issued to employees and contractor to purchase common stock 56,692 57,004 Warrants issued related to convertible notes and other equity agreements 412,262 412,262

Restructuring and Related Cha_2

Restructuring and Related Charges (Tables)	9 Months Ended
Restructuring and Related Charges (Tables)	Sep. 30, 2023
Restructuring and Related Activities [Abstract]
Schedule of Accrued Liabilities Activity Related to Restructuring Activities	The following table summarizes the accrued liabilities activity recorded in connection with the Restructuring, including the reduction in workforce in December 2022 and related activities as of September 30, 2023 (in thousands): Personnel Other Total Balance at January 1, 2022 $ — $ — $ — Restructuring and other costs, net 973 95 1,068 Cash payments ( 103 ) — ( 103 ) Balance at December 31, 2022 870 95 965 Restructuring and other costs, net 202 2 204 Cash payments ( 1,054 ) ( 71 ) ( 1,125 ) Balance at March 31, 2023 18 26 44 Restructuring and other costs, net 12 ( 20 ) ( 8 ) Cash payments ( 30 ) ( 6 ) ( 36 ) Balance at June 30, 2023 — — — Balance at September 30, 2023 $ — $ — $ —

Organization and Operations - A

Organization and Operations - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ (7,124)	$ (9,386)	$ (10,177)	$ (13,416)	$ (10,535)	$ (12,405)	$ (26,687)	$ (36,356)
Accumulated deficit	(224,481)						(224,481)		$ (197,794)
Cash, cash equivalents and marketable securities	$ 72,000						$ 72,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Summary of Estimated Useful Lives of Property and Equipment (Details)	Sep. 30, 2023
Office Equipment and Furniture \| Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)	3 years
Office Equipment and Furniture \| Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)	7 years
Research Equipment \| Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)	1 year
Research Equipment \| Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)	7 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Aug. 15, 2023	Jul. 31, 2023	Sep. 30, 2023
Cambrian Purchase Agreement
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Shares repurchased and retired	1,587,302
Purchase price per share		$ 1.26
Share repurchase, agreed to purchase, shares		1,587,302
Aggregate purchase price		$ 2
Share repurchase liability, net of issuance cost, recorded at contractual value		$ 2.3
ASU 2016-02
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Change in accounting principle, accounting standards update, adopted			true
Change in accounting principle, accounting standards update, adoption date			Jan. 01, 2022
ASU 2016-13
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Change in accounting principle, accounting standards update, adopted			true
Change in accounting principle, accounting standards update, adoption date			Jan. 01, 2023
Change in accounting principle, accounting standards update, immaterial effect			true

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Fair Value	$ 60,670	$ 89,321
Marketable Securities
Marketable Securities [Line Items]
Amortized Cost	61,072
Unrealized Losses	(402)
Fair Value	60,670
Marketable Securities \| Commercial Paper
Marketable Securities [Line Items]
Amortized Cost	13,247
Unrealized Losses	(36)
Fair Value	13,211
Marketable Securities \| Corporate Bonds
Marketable Securities [Line Items]
Amortized Cost	39,224
Unrealized Losses	(100)
Fair Value	39,124
Marketable Securities \| U.S. Government Agencies
Marketable Securities [Line Items]
Amortized Cost	8,601
Unrealized Losses	(266)
Fair Value	$ 8,335

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Marketable securities, fair value	$ 60,670	$ 89,321
Marketable securities, unrealized loss position, fair value	400
Impairment of investments	$ 0
Maximum
Marketable Securities [Line Items]
Marketable securities remaining maturity term	1 year
Marketable securities unrealized loss position, maturity term	1 year

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Total property and equipment	$ 2,892	$ 3,492
Less accumulated depreciation and amortization	(1,593)	(1,442)
Property and equipment, net	1,299	2,049
Research Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	2,107	2,707
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Total property and equipment	532	532
Leasehold Improvement
Property Plant And Equipment [Line Items]
Total property and equipment	$ 253	$ 253

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Jan. 01, 2022
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 137	$ 151	$ 436	$ 452
Right of use assets - financing leases, net	$ 1,737		$ 1,737		$ 2,319
Research Equipment
Property, Plant and Equipment [Line Items]
Right of use assets - financing leases, net						$ 2,200
Office Equipment and Furniture
Property, Plant and Equipment [Line Items]
Right of use assets - financing leases, net						$ 70

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets And Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value Measurements Recurring Basis $ in Thousands	Sep. 30, 2023 USD ($)
Assets:
Total	$ 71,235
Level 1
Assets:
Total	10,565
Level 2
Assets:
Total	60,670
Money Market Funds
Assets:
Cash equivalents fair value disclosure	10,565
Money Market Funds \| Level 1
Assets:
Cash equivalents fair value disclosure	10,565
Commercial Paper
Assets:
Investments fair value disclosure	13,211
Commercial Paper \| Level 2
Assets:
Investments fair value disclosure	13,211
Corporate Bonds
Assets:
Investments fair value disclosure	39,124
Corporate Bonds \| Level 2
Assets:
Investments fair value disclosure	39,124
U.S. Government Agencies
Assets:
Investments fair value disclosure	8,335
U.S. Government Agencies \| Level 2
Assets:
Investments fair value disclosure	$ 8,335

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value, transfer of liabilities, from level 1 to level 2	$ 0	$ 0
Fair value, transfer of liabilities from level 2 to level 1	0	0
Fair value, transfer of assets into level 3	0	0
Fair value, transfer of assets out of level 3	0	0
Fair value, transfer of liabilities into level 3	0	0
Fair value, transfer of liabilities out of level 3	$ 0	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($)	Dec. 31, 2017 USD ($) Officer
Sale Leaseback Transaction [Line Items]
Lease expiration year	2027
Sublease income	$ 239,000
Letters of credit outstanding amount	$ 678,000
Number of former officers \| Officer		2
Loss contingency allegations claims		$ 0
Loss contingency, allegations	The Company believes that there is no merit to the claims alleged against the Company and its former officers, including no alleged breach of contract by the Company, and intends to vigorously defend against the claims pertaining to the Company and its former officers.
Office Space
Sale Leaseback Transaction [Line Items]
Sublease income	$ 239,000

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Lease Costs Recognized under ASC 842 Pertaining to Finance and Operating Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Lease Cost:
Amortization of finance right-of-use assets	$ 586	$ 544
Interest on finance lease liabilities	113
Operating lease cost	1,336
Variable lease cost	515
Total lease costs	2,550
Operating Sublease income	(239)
Total lease costs, net	$ 2,311

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Other Information Pertaining to Finance and Operating Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Other Operating Lease Information:
Operating cash flows for operating leases	$ 1,320
Operating cash flows for operating subleases	(250)
Operating cash flows for finance leases	112
Financing cash flows from finance leases	$ 565	$ 452
Weighted average remaining lease term
Operating leases	3 years
Financing leases	2 years 3 months 18 days
Weighted average discount rate
Operating leases	7.80%
Financing leases	8.30%

Commitments and Contingencies_4

Commitments and Contingencies - Supplemental Balance Sheet Information Related to Operating and Financing Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Operating leases
Right-of-use assets, net	$ 4,700	$ 5,355
Right-of-use lease liabilities, current	1,532	1,251
Right-of-use lease liabilities, noncurrent	3,403	4,323
Total operating lease liabilities	4,935
Financing leases
Right-of-use assets, net	1,737	2,319
Right-of-use lease liabilities, current	874	880
Right-of-use lease liabilities, noncurrent	962	$ 1,579
Total financing lease liabilities	$ 1,836

Commitments and Contingencies_5

Commitments and Contingencies - Summary of Maturity of Operating and Finance Lease Liabilities (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Operating
Remainder of 2023	$ 457
2024	1,853
2025	1,734
2026	1,413
2027	59
Total future minimum lease payments	5,516
Less amount representing interest	581
Total lease liabilities	4,935
Financing
Remainder of 2023	227
2024	900
2025	757
2026	107
Total future minimum lease payments	1,991
Less amount representing interest	155
Total lease liabilities	$ 1,836

Equity - Summary of Common Stoc

Equity - Summary of Common Stock Warrant activity (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Number of Common Stock Warrants Outstanding, Beginning Balance	57,004
Number of Common Stock Warrants, Expired	(312)
Number of Common Stock Warrants Outstanding, Ending Balance		57,004
Weighted-Average Exercise Price Outstanding, Beginning Balance	$ 6.94
Weighted Average Exercise Price, Expired	$ 144
Weighted-Average Exercise Price Outstanding, Ending Balance		$ 6.94
Weighted-Average Remaining Contractual Term, Outstanding	1 year 4 months 28 days
Warrant \| Equity and Debt Fundraising Events
Class Of Stock [Line Items]
Number of Common Stock Warrants Outstanding, Beginning Balance	412,262
Number of Common Stock Warrants Outstanding, Ending Balance	412,262	412,262
Weighted-Average Exercise Price Outstanding, Beginning Balance	$ 9.81
Weighted-Average Exercise Price Outstanding, Ending Balance	$ 9.81	$ 9.81
Weighted-Average Remaining Contractual Term, Outstanding	3 years 11 months 15 days	4 years 8 months 15 days

Equity - Additional Information

Equity - Additional Information (Details) - $ / shares	Aug. 15, 2023	Jul. 31, 2023	Jan. 01, 2023
Class of Stock [Line Items]
Excise tax on repurchases			1%
Cambrian Purchase Agreement [Member]
Class of Stock [Line Items]
Shares repurchased and retired	1,587,302
Purchase price per share		$ 1.26
Share repurchase, agreed to purchase, shares		1,587,302

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended
	May 15, 2023	Dec. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jan. 01, 2023	Jan. 01, 2022	Jan. 27, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Recognized share-based compensation expense			$ 1,048,000	$ 1,479,000	$ 3,356,000	$ 4,390,000
Weighted average fair value per share of options granted					$ 1.05
Grant date fair value of options vested					$ 3,500,000	$ 6,900,000
Unrecognized stock-based compensation expense			5,100,000		$ 5,100,000
Weighted-average period					1 year 7 months 17 days
Common Stock Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense			0		$ 0
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period					2 years 5 months 15 days
Unrecognized stock-based compensation expense			$ 500,000		$ 500,000
2021 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance			2,537,629		2,537,629		2,900,096	5,000,000
Number of capital stock outstanding percentage					4%
2021 Equity Incentive Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of increase of available shares		4%
2021 Equity Incentive Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of increase of available shares		1%
2021 Equity Incentive Plan \| Restricted Stock Units \| Vesting Period One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period					1 year
2021 Equity Incentive Plan \| Restricted Stock Units \| Vesting Period Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period					2 years
2021 Equity Incentive Plan \| Restricted Stock Units \| Vesting Period Three
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period					3 years
2021 Equity Incentive Plan \| Restricted Stock Units \| Vesting Period Four
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period					4 years
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance			828,053		828,053				333,333
Percentage of number of shares of capital stock outstanding on last day of preceding year					1%
Recognized share-based compensation expense					$ 6,000
Purchase price of fair value common stock, percent					85%
Stock issued under plan	25,964				119,011

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Award Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Number of Stock Options, Outstanding balance	3,333,434
Number of Stock Options, Granted	658,371
Number of Stock Options, Forfeited	(397,289)
Number of Stock Options, Expired	(213,755)
Number of Stock Options, Outstanding balance	3,380,761	3,333,434
Number of Stock Options, Options expected to vest	1,305,528
Number of Stock Options, Exercisable	2,075,233
Weighted-Average Exercise Price, Outstanding balance	$ 8.80
Weighted-Average Exercise Price, Granted	1.36
Weighted-Average Exercise Price, Forfeited	5.61
Weighted-Average Exercise Price, Expired	8.73
Weighted-Average Exercise Price,Outstanding balance	7.73	$ 8.80
Weighted-Average Exercise Price, Options expected to vest	3.48
Weighted-Average Exercise Price, Exercisable	$ 10.40
Weighted-Average Remaining Contractual Term, Outstanding balance	7 years 5 months 8 days	8 years 1 month 2 days
Weighted-Average Remaining Contractual Term, Options expected to vest	8 years 6 months 29 days
Weighted-Average Remaining Contractual Term, Exercisable	6 years 8 months 19 days
Aggregate Intrinsic Value, Outstanding	$ 0	$ 1
Aggregate Intrinsic Value, Options expected to vest	0
Aggregate Intrinsic Value, Exercisable	$ 0

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Restricted Stock Units, Unvested balance \| shares	215,854
Restricted Stock Units, Granted \| shares	361,097
Restricted Stock Units, Vested \| shares	(298,286)
Restricted Stock Units, Forfeited \| shares	(45,957)
Restricted Stock Units, Unvested balance \| shares	232,708
Weighted-Average Grant Date Fair Value, Unvested balance \| $ / shares	$ 3.69
Weighted-Average Grant Date Fair Value, Granted \| $ / shares	1.45
Weighted-Average Grant Date Fair Value, Vested \| $ / shares	2
Weighted-Average Grant Date Fair Value, Forfeited \| $ / shares	2.92
Weighted-Average Grant Date Fair Value, Unvested balance \| $ / shares	$ 3.17

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Employee-issued Common Stock Warrant Activity (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Number of Common Stock Warrants Outstanding, Beginning Balance	57,004
Number of Common Stock Warrants, Expired	(312)
Number of Common Stock Warrants Outstanding and Exercisable, Ending Balance	56,692
Weighted-Average Exercise Price Outstanding, Beginning Balance	$ 6.94
Weighted Average Exercise Price, Expired	144
Weighted-Average Exercise Price Outstanding and Exercisable, Ending Balance	$ 6.19
Weighted-Average Remaining Contractual Term Outstanding	1 year 4 months 28 days
Weighted-Average Remaining Contractual Term Outstanding and Exercisable		1 year 10 months 28 days

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Fair Value Assumptions and Methodology (Details)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility, Minimum	93%	94%
Volatility, Maximum	97%	97%
Risk-free interest rate, Minimum	3.60%	1.70%
Risk-free interest rate, Maximum	4.60%	4%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 6 months	5 years 6 months
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	7 years	7 years

Stock-Based Compensation - Su_5

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,048	$ 1,479	$ 3,356	$ 4,390
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	234	505	786	1,540
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 814	$ 974	$ 2,570	$ 2,850

Employee Retirement Plan - Addi

Employee Retirement Plan - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Company's matching contributions vesting percentage			100%
Accrued expense	$ 43	$ 85	$ 190	$ 268
Maximum
Defined Benefit Plan Disclosure [Line Items]
Percentage of company matching contributions of employee's base salary			4%

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				9 Months Ended
	Aug. 15, 2023	Jul. 31, 2023	Jun. 01, 2023	Sep. 30, 2023	Sep. 30, 2022	May 31, 2023
Related Party Transaction [Line Items]
Purchase transaction cost				$ 10,132
Service Agreement \| Hope Farms
Related Party Transaction [Line Items]
Expenses recognized with related party transactions				0	$ 104
Service Agreement \| Binney Street Partners LLC
Related Party Transaction [Line Items]
Expenses recognized with related party transactions				$ 0	$ 221
Purchase Agreement \| Apeiron Parties
Related Party Transaction [Line Items]
Shares repurchased and retired			4,454,248
Purchase price per share			$ 1.58
Company 's outstanding shares of common stock						5%
Purchase transaction cost			$ 7,800
Negotiation of purchase agreement cost			$ 750
Cambrian Purchase Agreement
Related Party Transaction [Line Items]
Share repurchase, agreed to purchase, shares		1,587,302
Shares repurchased and retired	1,587,302
Aggregate purchase price		$ 2,000
Purchase price per share		$ 1.26

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	9 Months Ended
Income Taxes - Additional Information (Details) - USD ($)	Sep. 30, 2023	Sep. 30, 2022	Jan. 01, 2023
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 0	$ 0
Excise tax on repurchases			1%

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net loss	$ (7,124)	$ (9,386)	$ (10,177)	$ (13,416)	$ (10,535)	$ (12,405)	$ (26,687)	$ (36,356)
Net loss per share-basic	$ (0.28)			$ (0.44)			$ (0.92)	$ (1.18)
Net loss per share-diluted	$ (0.28)			$ (0.44)			$ (0.92)	$ (1.18)
Weighted-average number of shares used in computing net loss per common share, basic	25,514,115			30,720,291			28,942,803	30,690,175
Weighted-average number of shares used in computing net loss per common share, diluted	25,514,115			30,720,291			28,942,803	30,690,175

Net Loss Per Share - Potentiall

Net Loss Per Share - Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	3,380,761	3,523,211
Unvested Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	232,708	225,200
Warrants Issued to Employees and Contractor to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	56,692	57,004
Warrants Issued Related to Convertible Notes and Other Equity Agreements
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	412,262	412,262

Restructuring and Related Cha_3

Restructuring and Related Charges - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, Description	In December 2022, the Company began implementing a restructuring plan to reduce operating costs primarily associated with a reduction in the Company's workforce (the “Restructuring”).
Implementing restructuring plan	Dec. 30, 2022
Research and Development and General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 0.2

Restructuring and Related Cha_4

Restructuring and Related Charges - Schedule of Accrued Liabilities Activity Related to Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs, net	$ (8)	$ 204	$ 1,068
Cash payments	(36)	(1,125)	(103)
Ending balance		44	965
Personnel
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs, net	12	202	973
Cash payments	(30)	(1,054)	(103)
Ending balance		18	870
Other
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs, net	(20)	2	95
Cash payments	$ (6)	(71)
Ending balance		$ 26	$ 95