Alaunos Therapeutics (TCRT) 10-Q15 May 242024 Q1 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	3 Months Ended
Cover Page - shares	Mar. 31, 2024	May 12, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Document Quarterly Report	true
Document Transition Report	false
Entity Registrant Name	Alaunos Therapeutics, Inc.
Entity Central Index Key	0001107421
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Trading Symbol	TCRT
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Common Stock, Shares Outstanding		16,012,522
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-33038
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-1475642
Entity Address, Address Line One	2617 Bissonnet Street
Entity Address, Address Line Two	Suite 225
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77005
City Area Code	346
Local Phone Number	355-4099

CONDENSED BALANCE SHEETS

CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 4,145	$ 6,062
Receivables	1	1
Prepaid expenses and other current assets	1,891	2,198
Total current assets	6,037	8,261
Property and equipment, net	0	2
Total assets	6,037	8,263
Current liabilities:
Accounts payable	597	616
Accrued expenses	643	1,340
Total current liabilities	1,240	1,956
Total liabilities	1,240	1,956
Commitments and contingencies (Note 8)
Stockholders' equity
Common stock $0.001 par value; 34,666,667 shares authorized, 16,012,522 shares issued and outstanding at March 31, 2024 and at December 31, 2023	16	16
Additional paid-in capital	922,230	922,058
Accumulated deficit	(917,449)	(915,767)
Total stockholders' equity	4,797	6,307
Total liabilities and stockholders' equity	$ 6,037	$ 8,263

CONDENSED BALANCE SHEETS (Paren

CONDENSED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	34,666,667	34,666,667
Common stock, shares issued	16,012,522	16,012,522
Common stock, shares outstanding	16,012,522	16,012,522

CONDENSED STATEMENTS OF OPERATI

CONDENSED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
CONDENSED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Collaboration revenue	$ 1	$ 0
Operating expenses:
Research and development	126	6,504
General and administrative	1,617	3,168
Total operating expenses	1,743	9,672
Loss from operations	(1,742)	(9,672)
Other income (expense):
Interest expense	0	(853)
Other income, net	60	477
Other income (expense), net	60	(376)
Net loss	$ (1,682)	$ (10,048)
Earnings per share, Basic	$ (0.11)	$ (0.63)
Earnings per share, Diluted	$ (0.11)	$ (0.63)
Weighted average common shares outstanding, basic	16,012,522	15,978,623
Weighted average common shares outstanding, diluted	16,012,522	15,978,623

CONDENSED STATEMENTS OF CHANGES

CONDENSED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid In Capital	Accumulated Deficit
Balance at Dec. 31, 2022	$ 38,555	$ 16	$ 919,166	$ (880,627)
Balance (in shares) at Dec. 31, 2022		16,027,384
Stock-based compensation	910		910
Issuance of common stock, net of expenses	92		92
Issuance of common stock, net of expenses, (in shares)		14,420
Net loss	(10,048)			(10,048)
Balance at Mar. 31, 2023	29,509	$ 16	920,168	(890,675)
Balance (in shares) at Mar. 31, 2023		16,041,804
Balance at Dec. 31, 2023	6,307	$ 16	922,058	(915,767)
Balance (in shares) at Dec. 31, 2023		16,012,522
Stock-based compensation	172		172
Net loss	(1,682)			(1,682)
Balance at Mar. 31, 2024	$ 4,797	$ 16	$ 922,230	$ (917,449)
Balance (in shares) at Mar. 31, 2024		16,012,522

CONDENSED STATEMENTS OF CASH FL

CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (1,682)	$ (10,048)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2	696
Amortization of financing costs	0	472
Stock-based compensation	172	910
Decrease in the carrying amount of right-of-use assets	0	113
(Increase) decrease in:
Receivables	0	4
Prepaid expenses and other current assets	307	49
Increase (decrease) in:
Accounts payable	(19)	(110)
Accrued expenses	(697)	(1,334)
Lease liabilities	0	(133)
Net cash used in operating activities	(1,917)	(9,381)
Cash flows from investing activities:
Purchases of property and equipment	0	(61)
Proceeds from the disposal of property and equipment	0	38
Net cash used in investing activities	0	(23)
Cash flows from financing activities:
Proceeds from the issuance of common stock	0	92
Repayment of long-term debt	0	(6,250)
Net cash used in financing activities	0	(6,158)
Net decrease in cash, cash equivalents and restricted cash	(1,917)	(15,562)
Cash, cash equivalents and restricted cash, beginning of period	6,062	52,996
Cash and cash equivalents, end of period	4,145	37,434
Supplementary disclosure of cash flow information:
Cash paid for interest	0	439
Amounts included in accrued expenses and accounts payable related to property and equipment	$ 0	$ 101

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (1,682)	$ (10,048)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Organization

Organization	3 Months Ended
Organization	Mar. 31, 2024
Accounting Policies [Abstract]
Organization	1. Organization Overview Alaunos Therapeutics, Inc., which is referred to herein as “Alaunos,” or the “Company,” is a clinical-stage oncology-focused cell therapy company that was historically involved in the development of adoptive TCR therapies, designed to treat multiple solid tumor types in large cancer patient populations with unmet clinical needs. The Company is leveraging its proprietary, non-viral Sleeping Beauty gene transfer platform and its novel cancer mutation hotspot TCR library to design and manufacture personalized cell therapies that target neoantigens arising from common tumor-related mutations in key oncogenic genes, including KRAS, TP53 and EGFR. The Company’s operations to date have consisted primarily of conducting research and development and raising capital to fund those efforts. As of March 31, 2024, there were 16,012,522 shares of common stock outstanding and an additional 1,714,489 shares of common stock reserved for issuance pursuant to outstanding stock options and warrants. On August 14, 2023, the Company announced a strategic reprioritization of its business and wind down of its TCR-T Library Phase 1/2 Trial. In connection with the reprioritization, the Company has significantly reduced its workforce and continues working to reduce costs in order to extend its cash runway. The Company continues to explore strategic alternatives, including, but not limited to, an acquisition, merger, reverse merger, sale of assets, strategic partnerships, capital raises or other transactions. The Company has engaged Cantor Fitzgerald & Co., or Cantor , to act as strategic advisor for this process. Separately, the Company is evaluating several potential in-licensing opportunities in obesity, oncology and virology. The accompanying condensed financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities and commitments in the normal course of business. The Company follows the guidance of Accounting Standards Codification, or ASC, Topic 205-40, Presentation of Financial Statements - Going Concern, in order to determine whether there is substantial doubt about its ability to continue as a going concern for one year after the date its condensed financial statements are issued. This evaluation initially does not take into consideration the potential mitigating effect of management's plans that have not been fully implemented as of the date the condensed financial statements are issued. When substantial doubt exists, management evaluates whether the mitigating effect of its plans sufficiently alleviates the substantial doubt about the Company's ability to continue as a going concern. The mitigating effect of management's plans, however, is only considered if both (i) it is probable that the plans will be effectively implemented within one year after the date that the condensed financial statements are issued and (ii) it is probable that the plans, when implemented, will mitigate the relevant conditions or events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date that the condensed financial statements are issued. The Company has operated at a loss since its inception in 2003 and has no recurring revenue from operations. The Company anticipates that losses will continue for the foreseeable future. As of March 31, 2024, the Company had approximately $ 4.1 million of cash and cash equivalents. The Company’s accumulated deficit at March 31, 2024 was approximately $ 917.4 million. Given its current development plans and cash management efforts, the Company anticipates cash resources will be sufficient to fund operations into the third quarter of 2024. The Company’s ability to continue operations after its current cash resources are exhausted depends on future events outside of the Company's control, including its ability to obtain additional financing or to achieve profitable results, as to which no assurances can be given. If adequate additional funds are not available when required, or if the Company is unsuccessful in entering into partnership agreements for further development of its product candidates, management may need to curtail its development efforts and planned operations to conserve cash until sufficient additional capital is raised. There can be no assurances that such a plan would be successful. Based on the current cash forecast and the Company's dependence on its ability to obtain additional financing to fund its operations after the current resources are exhausted, about which there can be no certainty, management has determined that the Company's present capital resources will not be sufficient to fund its planned operations for at least one year from the issuance date of the condensed financial statements, and substantial doubt as to the Company's ability to continue as a going concern exists. This forecast of cash resources is forward-looking information that involves risks and uncertainties, and the actual amount of expenses could vary materially and adversely as a result of a number of factors. Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC. Certain information and note disclosures required by generally accepted accounting principles in the United States, or GAAP, have been condensed or omitted pursuant to such rules and regulations. It is management’s opinion that the accompanying unaudited interim condensed financial statements reflect all adjustments (which are normal and recurring) that are necessary for a fair presentation of the financial position of the Company and its results of operations and cash flows for the periods presented. The unaudited interim condensed financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2023, included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 filed with the SEC on April 1, 2024, or the Annual Report. The results disclosed in the statements of operations for the three months ended March 31, 2024 are not necessarily indicative of the results to be expected for the full fiscal year 2024. Use of Estimates The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of revenues and expenses during the reporting period. Although the Company regularly assesses these estimates, actual results could differ from those estimates. Changes in estimates are recorded in the period in which they become known. Reverse Stock Split On January 31, 2024, the Company filed a Second Amended and Restated Certificate of Incorporation (the “Charter Amendment”) with the Secretary of State of the State of Delaware in order to effect a reverse stock split of the Company’s common stock at a ratio of 1-for-15 (the “Reverse Split”). The Charter Amendment decreased the number of authorized shares of common stock from 520,000,000 to 34,666,667 . The Charter Amendment does not affect the par value of the Company’s common stock or change the number of authorized shares or par value of the Company’s preferred stock. The Charter Amendment became effective on January 31, 2024 at 5:00 p.m. Eastern Time, at which time every 15 shares of the Company’s issued and outstanding common stock automatically combined and converted into 1 share of common stock. No fractional shares were issued in connection with the Reverse Split. Stockholders of record who would otherwise have been entitled to receive fractional shares as a result of the Reverse Split received a cash payment in lieu thereof at a price equal to the fraction to which the stockholder would otherwise be entitled multiplied by the closing sales price per share of the common stock (as adjusted for the Reverse Split) on The Nasdaq Capital Market on January 31, 2024. All share and per share amounts of common stock, options, warrants, and restricted stock in the accompanying financial statements and notes thereto have been retroactively adjusted for all periods presented to reflect the Reverse Split as if it had occurred at the beginning of the earliest period presented.

Financings

Financings	3 Months Ended
Financings	Mar. 31, 2024
Text Block [Abstract]
Financings	2. Financings 2021 Loan and Security Agreement On August 6, 2021, the Company entered into a Loan and Security Agreement, or the Loan and Security Agreement, with Silicon Valley Bank and affiliates of Silicon Valley Bank, or collectively, SVB. The Loan and Security Agreement provided for an initial term loan of $ 25.0 million funded at the closing, or the Term A Tranche, with an additional tranche of $ 25.0 million available if certain funding and clinical milestones were met by August 31, 2022, or the Term B Tranche. Effective December 28, 2021, the Company, entered into an amendment to the Loan and Security Agreement, or the First Amendment. The First Amendment extended the interest-only period through August 31, 2022. The First Amendment also eliminated the Term B Tranche, which remained unfunded, leaving only the Term A Tranche, or the SVB Facility. Under the amended Loan and Security Agreement, the SVB Facility was to mature on August 1, 2023. On May 1, 2023, the Company repaid its outstanding debt obligations under the amended Loan and Security Agreement in their entirety. Refer to Note 4, Debt, for further discussion of the Loan and Security Agreement and the First Amendment. 2022 Equity Distribution Agreement On August 12, 2022, the Company entered into an Equity Distribution Agreement, or the Equity Distribution Agreement, with Piper Sandler & Co., or Piper Sandler, pursuant to which the Company can offer and sell, from time to time at its sole discretion, shares of its common stock having an aggregate offering price of up to $ 50.0 million through Piper Sandler as its sales agent in an "at the market offering." Piper Sandler will receive a commission of 3.0 % of the gross proceeds of any common stock sold under the Equity Distribution Agreement. During the three months ended March 31, 2024 and 2023, there have been no sales of the Company's common stock under the Equity Distribution Agreement. 2022 Public Offering On November 29, 2022, the Company entered into an underwriting agreement, or the Underwriting Agreement, with Cantor as the sole underwriter, relating to the issuance and sale in an underwritten offering, or the Offering, of 1,615,248 shares, or the Firm Shares, of the Company’s common stock to Cantor at a price of $ 9.2865 per share. The net proceeds to the Company from the Offering were $ 14.7 million (before accounting for the partial exercise of Cantor's option as described below) after deducting underwriting discounts and commissions and offering expenses payable by the Company. Under the terms of the Underwriting Agreement, the Company granted Cantor an option, exercisable for 30 days , to purchase up to an additional 242,287 shares of common stock, which we refer to, together with the Firm Shares, as the Shares, at the same price per share as the Firm Shares. On January 5, 2023, Cantor partially exercised its option to purchase an additional 14,420 shares of common stock.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies The Company’s significant accounting policies were identified in the Company’s Annual Report. There have been no material changes in those policies since the filing of its Annual Report.

Debt

Debt	3 Months Ended
Debt	Mar. 31, 2024
Debt Disclosure [Abstract]
Debt	4. Debt There were no debt obligations outstanding at March 31, 2024 and December 31, 2023. On August 6, 2021, the Company entered into the Loan and Security Agreement with SVB. The Loan and Security Agreement provided for the funding of the Term A Tranche at the closing, with the Term B Tranche available if certain funding and clinical milestones were met by August 31, 2022. The SVB Facility and related obligations under the Loan and Security Agreement were secured by substantially all of the Company's properties, rights and assets, except for its intellectual property (which was subject to a negative pledge under the Loan and Security Agreement). In addition, the Loan and Security Agreement contained customary representations, warranties, events of default and covenants. On December 28, 2021, the Company entered into the First Amendment to the Loan and Security Agreement. The First Amendment eliminated the unfunded Term B Tranche, among other things. The SVB Facility bore interest at a floating rate per annum on outstanding loans, payable monthly, at the greater of (a) 7.75 % and (b) the current published U.S. prime rate, plus a margin of 4.5 % . All outstanding obligations under the amended Loan and Security Agreement were due and payable on August 1, 2023 . In connection with the payment of all of the Company's outstanding obligations, the Company also owed SVB 5.75 % of the original principal amounts borrowed as a final payment, or the Final Payment. Effective March 30, 2023, the Company entered into a Third Amendment to the Loan and Security Agreement, or the Third Amendment. Under the terms of the Third Amendment, the Company was no longer required to maintain all of its operating accounts, depository accounts and excess cash with SVB or one of its affiliates, and was instead only required to maintain a single operating or depository account at Silicon Valley Bank. The Third Amendment also modified the cash collateralization requirement, such that the Company was required to cash collateralize the entire sum of the outstanding principal amount of the SVB Facility, plus an amount equal to the Final Payment, which amount was to be reduced commensurate with each regularly scheduled monthly payment of principal and interest on the SVB Facility. On May 1, 2023, the Company paid SVB an amount equal to the entire outstanding principal amount under the SVB Facility, all accrued and unpaid interest and the Final Payment. In accordance with the First Amendment, the payment was subject to a prepayment premium of 2.00 %. During the second quarter of 2023, the Company recorded the remaining amounts associated with the Final Payment of $ 0.5 million and the prepayment premium of $ 0.1 million as interest expense within the condensed statement of operations. In connection with its entry into the Loan and Security Agreement in August 2021, the Company issued to SVB warrants to purchase (i) up to 28,856 shares of the Company’s common stock, in the aggregate, and (ii) up to an additional 28,856 shares of common stock, in the aggregate, in the event the Company achieved certain clinical milestones, in each case at an exercise price per share of $ 33.30 . In connection with its entry into the First Amendment in December 2021, the Company amended and restated the warrants issued to SVB. As amended and restated, the warrants are for up to 43,308 shares of the Company's common stock, in the aggregate, with an exercise price of $ 17.40 per share, or the SVB Warrants. The SVB Warrants expire on August 6, 2031 . The issuance costs for the Loan and Security Agreement, including the First Amendment, were approximately $ 1.2 million and primarily related to the issuance of the SVB Warrants, which were amortized into interest expense over the term of the loan. Interest expense, including the amortization of issuance costs, was $ 0 for the three months ended March 31, 2024, compared to $0 .9 million for the three months ended March 31, 2023.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
Fair Value Measurements	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	5. Fair Value Measurements Fair Value of Financial Instruments The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements. • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Assets and liabilities measured at fair value on a recurring and nonrecurring basis as of March 31, 2024 and December 31, 2023 are as follows: ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Significant Cash equivalents $ 3,832 $ 3,832 $ — $ — ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Significant Cash equivalents $ 5,744 $ 5,744 $ — $ — The cash equivalents represent demand deposit accounts and deposits in a short-term United States treasury money market mutual fund quoted in an active market and classified as a Level 1 asset. There have been no changes to the valuation methods during the three months ended March 31, 2024. We had no financial assets or liabilities that were classified as Level 2 or Level 3 during the three months ended March 31, 2024.

Net Loss per Share

Net Loss per Share	3 Months Ended
Net Loss per Share	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Loss per Share	6. Net loss per share Basic net loss per share of common stock is computed by dividing net loss applicable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted net loss per share is computed using the weighted-average number of shares of common stock outstanding during the period, plus the dilutive effect of outstanding options and warrants, using the treasury stock method and the average market price of the Company's common stock during the applicable period, unless their effect on net loss per share is antidilutive. The effect of computing diluted net loss per common share was antidilutive for any potentially issuable shares of common stock from the conversion of stock options, unvested restricted stock and warrants and, as such, have been excluded from the calculation. Such potentially dilutive shares of common stock consisted of the following as of March 31, 2024 and 2023: March 31, 2024 2023 Common stock options 251,457 887,549 Unvested restricted stock - 59,875 Warrants 1,452,399 1,528,156 1,703,856 2,475,580

Related Party Transactions

Related Party Transactions	3 Months Ended
Related Party Transactions	Mar. 31, 2024
Related Party Transactions [Abstract]
Related Party Transactions	7. Related Party Transactions Joint Venture with TriArm Therapeutics/Eden BioCell On December 18, 2018, the Company and TriArm Therapeutics, Ltd., or TriArm, launched Eden BioCell, Ltd., or Eden BioCell, as a joint venture to lead commercialization of the Company’s Sleeping Beauty -generated CAR-T therapies in the People’s Republic of China (including Macau and Hong Kong), Taiwan and Korea. The Company licensed to Eden BioCell the rights in Greater China for its third-generation Sleeping Beauty -generated CAR-T therapies targeting the CD19 antigen. Eden BioCell is owned equally by the Company and TriArm and the parties share decision-making authority. TriArm contributed $ 10.0 million to Eden BioCell and has committed up to an additional $ 25.0 million to this joint venture. TriArm also managed all clinical development in the territory pursuant to a master services agreement between TriArm and Eden BioCell. James Huang was the founder and serves as managing partner of Panacea Venture, which is an investor in TriArm. Mr. Huang was the Chair of the Company's board of directors until September 22, 2023 and had been a director since July 2020. He also serves as a member of Eden BioCell’s board of directors. In September 2021, TriArm and Alaunos mutually agreed to dissolve the Eden BioCell joint venture. The joint venture agreement has been terminated and the Eden BioCell entity has been dissolved as of July 2023. Refer to Note 13, Joint Venture , for further details. Collaboration with Dune Lake Capital In January 2023, the Company entered into a consulting agreement with Dune Lake Capital, LLC, or Dune Lake Capital, which was founded by Dale Curtis Hogue, Jr., the Company's interim Chief Executive Officer. During the three months ended March 31, 2024 and 2023, the Company recorded expenses of approximately $ 0 and $ 7 thousand, respectively, for consulting services performed by Dune Lake Capital.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies License Agreements Exclusive License Agreement with Precigen On October 5, 2018, the Company entered into an exclusive license agreement, or License Agreement, with PGEN Therapeutics, or PGEN, a wholly owned subsidiary of Precigen Inc., or Precigen, which was formerly known as Intrexon Corporation. Except where the context otherwise requires, the Company refers to PGEN and Precigen together as Precigen. Pursuant to the terms of the License Agreement, the Company had exclusive, worldwide rights to research, develop and commercialize (i) TCR products designed for neoantigens for the treatment of cancer, (ii) products utilizing Precigen’s RheoSwitch® gene switch, or RTS, for the treatment of cancer, referred to as IL-12 Products and (iii) CAR products directed to (A) CD19 for the treatment of cancer, referred to as CD19 Products, and (B) BCMA for the treatment of cancer, subject to certain obligations to pursue such target under the License and Collaboration Agreement effective March 27, 2015 between the Company, Precigen and ARES TRADING S.A., a subsidiary of Merck KGaA, as assigned by Precigen to PGEN. Under the License Agreement, the Company also had exclusive, worldwide rights for certain patents relating to the Sleeping Beauty technology to research, develop and commercialize TCR products for both neoantigens and shared antigens for the treatment of cancer, referred to as TCR Products. The Company was responsible for all aspects of the research, development and commercialization and was required to use commercially reasonable efforts to develop certain products. In consideration of the licenses and other rights granted by Precigen, the Company was required to pay Precigen an annual license fee of $ 0.1 million, reimburse Precigen for certain historical costs, pay Precigen milestones up to an additional $ 52.5 million for each exclusively licensed program upon the achievement of certain milestones, and pay Precigen tiered royalties up to a maximum royalty amount of $ 100.0 million in the aggregate. The Company was also obligated to pay Precigen 20 % of any sublicensing income received by us relating to the licensed products. The Company was responsible for all development costs associated with each of the licensed products. Precigen was obligated to pay the Company royalties up to a maximum royalty amount of $ 100.0 million. No royalty amounts were incurred during the three months ended March 31, 2023. On April 3, 2023, the Company entered into the Amended and Restated Exclusive License Agreement with Precigen, or the A&R License Agreement, which restated and amended the License Agreement in full. Under the A&R License Agreement, the Company still has exclusive, worldwide rights to research, develop and commercialize TCR products designed for neoantigens or driver mutations for the treatment of cancer and non-exclusive rights to use non-driver mutation TCRs. The Company further maintains its exclusive, worldwide rights for certain patents relating to the Sleeping Beauty technology to research, develop and commercialize TCR products for both neoantigens and shared antigens for the treatment of cancer, referred to as TCR Products. The Company remains solely responsible for all aspects of the research, development and commercialization of the exclusively licensed products for the treatment of cancer. The (i) products utilizing Precigen’s RheoSwitch® gene switch, or RTS, for the treatment of cancer, referred to as IL-12 Products and (ii) CAR products directed to (A) CD19 for the treatment of cancer, referred to as CD19 Products, and (B) BCMA for the treatment of cancer, subject to certain obligations to pursue such target under the License and Collaboration Agreement effective March 27, 2015 between the Company, Precigen and ARES TRADING S.A., a subsidiary of Merck KGaA, as assigned by Precigen to PGEN are no longer exclusively licensed to the Company. The Company is no longer obligated to use commercially reasonable efforts for the exclusively licensed products. The A&R License Agreement further eliminates any royalty or milestone obligations to Precigen, with an annual license fee of $ 75 thousand due on the anniversary of the A&R License Agreement effective date. Precigen is no longer obligated to pay the Company royalties on the net sales derived from the sale of Precigen's CAR products. License Agreement and 2015 Research and Development Agreement —The University of Texas MD Anderson Cancer Center On January 13, 2015 , the Company, together with Precigen, entered into a license agreement, or the MD Anderson License with MD Anderson (which Precigen subsequently assigned to PGEN). Pursuant to the MD Anderson License, the Company, together with Precigen, holds an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel CAR T-cell therapies, non-viral gene transfer systems, genetic modification and/or propagation of immune cells and other cellular therapy approaches, Natural Killer, or NK Cells, and TCRs. On August 17, 2015, the Company, Precigen and MD Anderson entered into the 2015 R&D Agreement to formalize the scope and process for the transfer by MD Anderson, pursuant to the terms of the MD Anderson License, of certain existing research programs and related technology rights, as well as the terms and conditions for future collaborative research and development of new and ongoing research programs. The rights and obligations of Precigen under the 2015 R&D Agreement were assigned to the Company pursuant to the Fourth Amendment to 2015 R&D Agreement which was entered into on September 19, 2019 (the “Fourth Amendment”) with an effective date of October 5, 2018. The activities under the 2015 R&D Agreement are directed by a joint steering committee comprised of two members from the Company and one member from MD Anderson. As provided under the MD Anderson License, the Company provided funding for research and development activities in support of the research programs under the 2015 R&D Agreement for a period of three years and in an amount of no less than $ 15.0 million and no greater than $ 20.0 million per year. On November 14, 2017, the Company entered into an amendment to the 2015 R&D Agreement, extending its term until April 15, 2021. In connection with the execution of the 2019 R&D Agreement described below, on October 22, 2019, the Company amended the 2015 R&D Agreement to extend the term of the 2015 R&D Agreement until December 31, 2026 and to allow cash resources on hand at MD Anderson under the 2015 R&D Agreement to be used for development costs under the 2019 Research and Development Agreement, or the 2019 R&D Agreement, which the Company entered into on October 22, 2019, with MD Anderson, pursuant to which the Company agreed to collaborate with respect to the TCR program. The Company did no t incur clinical costs from MD Anderson related to the 2015 R&D Agreement for the three months ended March 31, 2024 and 2023. The term of the MD Anderson License expires on the last to occur of (a) the expiration of all patents licensed thereunder, or (b) the twentieth anniversary of the date of the MD Anderson License; provided, however, that following the expiration of the term of the MD Anderson License, the Company, together with Precigen, shall then have a fully-paid up, royalty free, perpetual, irrevocable and sublicensable license to use the licensed intellectual property thereunder. After ten years from the date of the MD Anderson License and subject to a 90-day cure period, MD Anderson will have the right to convert the MD Anderson License into a non-exclusive license if the Company and Precigen are not using commercially reasonable efforts to commercialize the licensed intellectual property on a case-by-case basis. After five years from the date of the MD Anderson License and subject to a 180-day cure period, MD Anderson will have the right to terminate the MD Anderson License with respect to specific technology(ies) funded by the government or subject to a third-party contract if the Company and Precigen are not meeting the diligence requirements in such funding agreement or contract, as applicable. MD Anderson may also terminate the agreement with written notice upon material breach by the Company and Precigen, if such breach has not been cured within 60 days of receiving such notice. In addition, the MD Anderson License will terminate upon the occurrence of certain insolvency events for both the Company and Precigen and may be terminated by the mutual written agreement of the Company, Precigen, and MD Anderson. 2019 Research and Development Agreement—The University of Texas MD Anderson Cancer Center Under the 2019 R&D Agreement, the Company and MD Anderson will, among other things, collaborate on programs to expand the Company's TCR library and conduct clinical trials. The activities under the 2019 R&D Agreement are directed by a joint steering committee comprised of two members from the Company and one member from MD Anderson. The Company will own all inventions and intellectual property developed under the 2019 R&D Agreement and the Company will retain all rights to all intellectual property, patentable or not, for oncology products manufactured using non-viral gene transfer technologies under the 2019 R&D Agreement, including the Company's Sleeping Beauty technology. The Company has granted MD Anderson an exclusive license for such intellectual property to develop and commercialize autologous TCR products manufactured using viral gene transfer technologies and any products outside the field of oncology and a non-exclusive license for allogenic TCR products manufactured using viral-based technologies. Under the 2019 R&D Agreement, the Company agreed, beginning on January 1, 2021, to reimburse MD Anderson up to a total of $ 20.0 million for development costs under the 2019 R&D Agreement, after the funds from the 2015 R&D Agreement are exhausted. In addition, the Company will pay MD Anderson royalties on net sales of its TCR products. The Company is required to make performance-based payments upon the successful completion of clinical and regulatory benchmarks relating to its TCR products. The aggregate potential benchmark payments are $ 36.5 million, of which only $ 3.0 million will be due prior to the first marketing approval of the Company's TCR products. The royalty rates and benchmark payments owed to MD Anderson may be reduced upon the occurrence of certain events. The Company also agreed to sell its TCR products to MD Anderson at preferential prices and will sell the Company's TCR products in Texas exclusively to MD Anderson for a limited period of time following the first commercial sale of the Company's TCR products. For the three months ended March 31, 2024 the Company did no t incur clinical expenses from MD Anderson related to the 2019 R&D Agreement, compared to $ 0.2 million for the three months ended March 31, 2023. The 2019 R&D Agreement will terminate on December 31, 2026 and either party may terminate the 2019 R&D Agreement following written notice of a material breach. The 2019 R&D Agreement also contains customary provisions related to indemnification obligations, confidentiality and other matters. In connection with the execution of the 2019 R&D Agreement, on October 22, 2019, the Company issued MD Anderson a warrant to purchase 222,222 shares of the Company's common stock, which is referred to as the MD Anderson Warrant. The MD Anderson Warrant has an initial exercise price of $ 0.015 per share, expires on December 31, 2026 , and vests upon the occurrence of certain clinical milestones. As of March 31, 2024, the milestones have not been met. License Agreement with the NCI On May 28, 2019, the Company entered into a patent license agreement, or the Patent License, with the NCI. Pursuant to the Patent License, the Company held an exclusive, worldwide license to certain intellectual property to develop and commercialize patient-derived (autologous), peripheral blood T-cell therapy products engineered by transposon-mediated gene transfer to express TCRs reactive to mutated KRAS, TP53 and EGFR neoantigens. In addition, pursuant to the Patent License, the Company held an exclusive, worldwide license to certain intellectual property for manufacturing technologies to develop and commercialize autologous, peripheral blood T-cell therapy products engineered by non-viral gene transfer to express TCRs, as well as a non-exclusive, worldwide license to certain additional manufacturing technologies. On May 29, 2019, January 8, 2020, September 28, 2020, April 16, 2021, May 4, 2021 and August 13, 2021 the Company amended the Patent License to expand its TCR library to include additional TCRs reactive to mutated KRAS and TP53 neoantigens licensed from the NCI. On October 27, 2023, the Company provided the NCI the requisite notice of its intent to terminate the Patent License, effective December 26, 2023. The Company discovered multiple proprietary TCRs targeting driver mutations through its hunTR TCR discovery platform, including many of the same KRAS and TP53 mutations licensed from the NCI. For the three months ended March 31, 2024, the Company did no t incur expenses to the NCI under this agreement, compared to $ 0.3 million for the three months ended March 31, 2023. Cooperative Research and Development Agreement (CRADA) with the NCI On January 9, 2017, the Company entered into a Cooperative Research and Development Agreement, or the CRADA, with the NCI. The purpose of this collaboration was to advance a personalized TCR-T approach for the treatment of solid tumors. Using the Company's Sleeping Beauty technology, the NCI would analyze a patient’s own cancer cells, identify their unique neoantigens and TCRs reactive against those neoantigens and then use the Company's Sleeping Beauty technology to transpose one or more TCRs into T cells for re-infusion. Research conducted under the CRADA was under the direction of Steven A. Rosenberg, M.D., Ph.D., Chief of the Surgery Branch at the NCI, in collaboration with the Company's researchers. On August 14, 2023, the Company announced that it had provided the requisite notice to terminate the CRADA, pursuant to its terms, effective October 13, 2023 , in light of the Company’s exploration of strategic alternatives. The Company did no t record expenses under the CRADA for the three months ended March 31, 2024, compared to $ 0.3 million for the three months ended March 31, 2023. Patent and Technology License Agreement—The University of Texas MD Anderson Cancer Center and the Texas A&M University System On August 24, 2004, the Company entered into a patent and technology license agreement with MD Anderson and the Texas A&M University System, which the Company refers to, collectively, as the Licensors. Under this agreement, the Company was granted an exclusive, worldwide license to rights (including rights to U.S. and foreign patent and patent applications and related improvements and know-how) for the manufacture and commercialization of two classes of organic arsenicals (water- and lipid-based) for human and animal use. The class of water-based organic arsenicals includes darinaparsin. Under the terms of the agreement, the Company may be required to make additional payments to the Licensors upon achievement of certain milestones in varying amounts which, on a cumulative basis could total up to an additional $ 4.5 million. In addition, the Licensors are entitled to receive royalty payments on sales from a licensed product and will also be entitled to receive a portion of any fees that the Company may receive from a possible sublicense under certain circumstances. During the three months ended March 31, 2024 and 2023, the Company did no t incur any milestone expenses or royalty expenses on sales under this agreement. Collaboration Agreement with Solasia Pharma K.K. On March 7, 2011, the Company entered into a License and Collaboration Agreement with Solasia Pharma K. K., or Solasia, which was amended on July 31, 2014 to include an exclusive worldwide license and amended on October 14, 2021 to revise certain payment schedule details, or, as so amended, the Solasia License and Collaboration Agreement. Pursuant to the Solasia License and Collaboration Agreement, the Company granted Solasia an exclusive license to develop and commercialize darinaparsin in both intravenous and oral forms and related organic arsenic molecules, in all indications for human use. As consideration for the license, the Company is eligible to receive from Solasia development- and sales-based milestones, a royalty on net sales of darinaparsin, once commercialized, and a percentage of any sublicense revenue generated by Solasia. Solasia will be responsible for all costs related to the development, manufacturing and commercialization of darinaparsin. The Company’s licensors, as defined in the Solasia License and Collaboration Agreement, will receive a portion of all milestone and royalty payments made by Solasia to the Company in accordance with the terms of the Solasia License and Collaboration Agreement with the licensors, as described above. In June 2022, Solasia announced that darinaparsin had been approved from relapsed or refractory Peripheral T-Cell Lymphoma by the Minis try of Health, Labor and Welfare in Japan. During the three months ended March 31, 2024 and 2023, the Company did no t earn collaboration revenue and earned royalty revenues of $ 1 thousand and $ 0 , respectively, of royalty revenues on net sales under the Solasia License and Collaboration Agreement. KBI Biopharma Litigation On March 17, 2023, KBI Biopharma , Inc., or KBI, filed a complaint against the Company in the District Court of Harris County, Texas, 165th Judicial District, asserting breach of an Amended and Restated Master Services Agreement between the Company and KBI relating to the development of an autologous gene modified T-cell therapy product, or the KBI Agreement. KBI was primarily seeking unspecified monetary damages in excess of $ 3.2 million. On May 1, 2023, the Company filed an answer generally denying all of KBI’s allegations and asserting affirmative and other defenses as well as counterclaims for breach of the KBI Agreement and conversion. On October 20, 2023, the Company entered into an agreement with KBI to settle all claims asserted by KBI against the Company and the Company's counterclaims against KBI at issue in the litigation for $ 1.0 million.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
Stock-Based Compensation	Mar. 31, 2024
Text Block [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation The Company recognized stock-based compensation expense on all employee and non-employee awards as follows: Three Months Ended March 31, (in thousands) 2024 2023 Research and development $ 11 $ 175 General and administrative 161 735 Stock-based compensation expense $ 172 $ 910 The Company granted an aggregate of 40,000 stock options during the three months ended March 31, 2024, with a weighted-average grant date fair value of $ 1.50 per share, and granted an aggregate of 204,344 stock options during the three months ended March 31, 2023, with a weighted-average grant date fair value of $ 5.85 per share. For the three months ended March 31, 2024 and 2023, the fair value of stock options was estimated on the date of grant using a Black-Scholes option valuation model with the following assumptions: Three Months Ended March 31, 2024 2023 Risk-free interest rate 4.09 % 3.58 – 3.87 % Expected life in years 5.27 5.06 – 6.25 Expected volatility 114.65 % 89.69 – 95.63 % Expected dividend yield — % — % 2. Stock option activity under the Company’s stock option plans for the three months ended March 31, 2024 was as follows: (in thousands, except share and per share data) Number of Shares Weighted- Average Exercise Price Weighted- Average Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2023 465,898 $ 26.85 Granted 40,000 1.80 Exercised - - Cancelled ( 254,441 ) 19.61 Outstanding, March 31, 2024 251,457 $ 21.15 6.92 $ — Options exercisable, March 31, 2024 161,844 $ 28.28 5.53 $ — Options available for future grant, March 31, 2024 1,514,087 At March 31, 2024, total unrecognized compensation costs related to unvested stock options outstanding amounted to $ 0.1 million. The cost is expected to be recognized over a weighted-average period of 1.28 years.

Warrants

Warrants	3 Months Ended
Warrants	Mar. 31, 2024
Warrants Disclosure [Abstract]
Warrants	10. Warrants In connection with the Company’s November 2018 private placement that provided net proceeds of approximately $ 47.1 million, the Company issued warrants to purchase an aggregate of 1,262,626 shares of common stock, which became exercisable six months after the closing of the private placement, or the November 2018 Warrants. The November 2018 Warrants had an exercise price of $ 45.15 per share and have a five-year term. The fair value of the November 2018 Warrants was estimated at $ 18.4 million using a Black-Scholes model with the following assumptions: expected volatility of 71 %, risk free interest rate of 2.99 %, expected life of five years and no dividends. On July 26, 2019 and September 12, 2019, the Company entered into agreements with existing investors whereby the investors exercised the November 2018 Warrants for an aggregate of 1,186,869 shares of common stock, at an exercise price of $ 45.15 per share. Proceeds from the warrant exercise after deducting placement agent fees and other related expenses of $ 1.1 million were approximately $ 52.5 million. The Company issued participating investors new warrants to purchase up to 1,186,869 additional shares of common stock (the "2019 Warrants") as consideration for the warrant holders to exercise their November 2018 Warrants. The 2019 Warrants will expire on the fifth anniversary of the initial exercise date and have an exercise price of $ 105.00 . The 2019 Warrants were valued using a Black-Scholes valuation model and resulted in a $ 60.8 million non-cash charge in the Company’s statement of operations in 2019. On October 22, 2019, the Company entered into the 2019 R&D Agreement with MD Anderson. In connection with the execution of the 2019 R&D Agreement, the Company issued the MD Anderson Warrant to purchase 222,222 shares of common stock. The MD Anderson Warrant has an initial exercise price of $ 0.015 per share and grant date fair value of $ 14.5 million. The MD Anderson Warrant expires on December 31, 2026 and vests upon the occurrence of certain clinical milestones. The Company will recognize expense on the MD Anderson Warrant in the same manner as if the Company paid cash for services to be rendered. For the three months ended March 31, 2024 and 2023, the Company did not recognize any expense related to the MD Anderson Warrant as the clinical milestones had not been achieved. On August 6, 2021, the Company entered into the Loan and Security Agreement with SVB. Refer to Note 4, Debt . In connection with the Loan and Security Agreement, the Company issued SVB warrants to purchase 28,856 shares of common stock with an exercise price of $ 33.30 per share. The warrants have a ten-year life and were fully vested upon issuance. The fair value of the warrants was estimated at $ 0.8 million using a Black-Scholes model with the following assumptions: expected volatility of 79 %, risk free interest rate of 1.31 %, expected life of ten years and no dividends. On December 28, 2021, the Company entered into the First Amendment, as described in Note 4, Debt, in connection with which, the original warrants issued to SVB were amended and restated. As amended and restated, the SVB Warrants are for up to 43,308 shares of common stock, in the aggregate, with an exercise price of $17.40 per share. The SVB Warrants expire on August 6, 2031 and were fully vested upon issuance. As of March 31, 2024, none of the SVB Warrants have been exercised.

Joint Venture

Joint Venture	3 Months Ended
Joint Venture	Mar. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
Joint Venture	11. Joint Venture On December 18, 2018, the Company entered into a Framework Agreement with TriArm whereby the parties agreed to launch Eden BioCell, to lead clinical development and commercialization of certain Sleeping Beauty -generated CAR-T therapies as set forth in a separate license agreement. On January 3, 2019, Eden BioCell was incorporated in Hong Kong as a private company. Eden BioCell, the Company and TriArm entered into a Share Subscription Agreement on January 23, 2019, where the Company and TriArm agreed to contribute certain intellectual property, services and cash (only with respect to TriArm) to Eden BioCell to subscribe for a certain number of newly issued ordinary shares in the share capital of Eden BioCell. The closing of the transaction occurred on July 5, 2019. The Framework Agreement and Share Subscription Agreements were each respectively amended to be effective as of this date. Upon consummation of the joint venture, Eden BioCell and the Company also entered into a license agreement, pursuant to which the Company licensed the rights to Eden BioCell for third generation Sleeping Beauty -generated CAR-T therapies targeting the CD19 antigen for the territory of China (including Macau and Hong Kong), Taiwan and Korea. TriArm and the Company each received a 50 % equity interest in the joint venture in exchange for their contributions to Eden BioCell. The Company determined that Eden BioCell was considered a variable interest entity, or VIE, and concluded that it was not the primary beneficiary of the VIE as it did not have the power to direct the activities of the VIE. As a result, the Company accounted for the equity interest in Eden BioCell under the equity method of accounting as it had the ability to exercise significant influence. In September 2021, TriArm and the Company mutually agreed to dissolve the joint venture, which has now been terminated. The Eden BioCell entity has been dissolved as of July 2023.

Subsequent Events

Subsequent Events	3 Months Ended
Subsequent Events	Mar. 31, 2024
Subsequent Events [Abstract]
Subsequent Events	12. Subsequent Events The Company has evaluated subsequent events from the balance sheet date through the date on which these condensed financial statements were issued. Other than as described in the notes above, the Company did not have any material subsequent events that impacted its condensed financial statements or disclosures.

Organization (Policies)

Organization (Policies)	3 Months Ended
Organization (Policies)	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC. Certain information and note disclosures required by generally accepted accounting principles in the United States, or GAAP, have been condensed or omitted pursuant to such rules and regulations. It is management’s opinion that the accompanying unaudited interim condensed financial statements reflect all adjustments (which are normal and recurring) that are necessary for a fair presentation of the financial position of the Company and its results of operations and cash flows for the periods presented. The unaudited interim condensed financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2023, included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 filed with the SEC on April 1, 2024, or the Annual Report. The results disclosed in the statements of operations for the three months ended March 31, 2024 are not necessarily indicative of the results to be expected for the full fiscal year 2024.
Use of Estimates	Use of Estimates The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of revenues and expenses during the reporting period. Although the Company regularly assesses these estimates, actual results could differ from those estimates. Changes in estimates are recorded in the period in which they become known.
Reverse Stock Split	Reverse Stock Split On January 31, 2024, the Company filed a Second Amended and Restated Certificate of Incorporation (the “Charter Amendment”) with the Secretary of State of the State of Delaware in order to effect a reverse stock split of the Company’s common stock at a ratio of 1-for-15 (the “Reverse Split”). The Charter Amendment decreased the number of authorized shares of common stock from 520,000,000 to 34,666,667 . The Charter Amendment does not affect the par value of the Company’s common stock or change the number of authorized shares or par value of the Company’s preferred stock. The Charter Amendment became effective on January 31, 2024 at 5:00 p.m. Eastern Time, at which time every 15 shares of the Company’s issued and outstanding common stock automatically combined and converted into 1 share of common stock. No fractional shares were issued in connection with the Reverse Split. Stockholders of record who would otherwise have been entitled to receive fractional shares as a result of the Reverse Split received a cash payment in lieu thereof at a price equal to the fraction to which the stockholder would otherwise be entitled multiplied by the closing sales price per share of the common stock (as adjusted for the Reverse Split) on The Nasdaq Capital Market on January 31, 2024. All share and per share amounts of common stock, options, warrants, and restricted stock in the accompanying financial statements and notes thereto have been retroactively adjusted for all periods presented to reflect the Reverse Split as if it had occurred at the beginning of the earliest period presented.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
Fair Value Measurements (Tables)	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring and nonrecurring basis as of March 31, 2024 and December 31, 2023 are as follows: ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Significant Cash equivalents $ 3,832 $ 3,832 $ — $ — ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Significant Cash equivalents $ 5,744 $ 5,744 $ — $ —

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
Net Loss per Share (Tables)	Mar. 31, 2024
Earnings Per Share [Abstract]
Potentially Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share	Such potentially dilutive shares of common stock consisted of the following as of March 31, 2024 and 2023: March 31, 2024 2023 Common stock options 251,457 887,549 Unvested restricted stock - 59,875 Warrants 1,452,399 1,528,156 1,703,856 2,475,580

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
Stock-Based Compensation (Tables)	Mar. 31, 2024
Text Block [Abstract]
Stock-Based Compensation Expense on All Employee and Non-Employee Awards	The Company recognized stock-based compensation expense on all employee and non-employee awards as follows: Three Months Ended March 31, (in thousands) 2024 2023 Research and development $ 11 $ 175 General and administrative 161 735 Stock-based compensation expense $ 172 $ 910
Fair Value of Stock Options Assumptions Using Black-Scholes Option Valuation Model	For the three months ended March 31, 2024 and 2023, the fair value of stock options was estimated on the date of grant using a Black-Scholes option valuation model with the following assumptions: Three Months Ended March 31, 2024 2023 Risk-free interest rate 4.09 % 3.58 – 3.87 % Expected life in years 5.27 5.06 – 6.25 Expected volatility 114.65 % 89.69 – 95.63 % Expected dividend yield — % — %
Stock Option Activity under Stock Option Plan	Stock option activity under the Company’s stock option plans for the three months ended March 31, 2024 was as follows: (in thousands, except share and per share data) Number of Shares Weighted- Average Exercise Price Weighted- Average Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2023 465,898 $ 26.85 Granted 40,000 1.80 Exercised - - Cancelled ( 254,441 ) 19.61 Outstanding, March 31, 2024 251,457 $ 21.15 6.92 $ — Options exercisable, March 31, 2024 161,844 $ 28.28 5.53 $ — Options available for future grant, March 31, 2024 1,514,087

Organization - Additional Infor

Organization - Additional Information (Details) - USD ($) $ in Thousands	Jan. 31, 2024	Aug. 14, 2023	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash, cash equivalents and restricted cash			$ 4,145	$ 6,062	$ 37,434	$ 52,996
Accumulated deficit			$ 917,449	$ 915,767
Common stock, shares authorized			34,666,667	34,666,667
Common stock, shares outstanding			16,012,522	16,012,522
Strategic advisor name		Cantor
Pre Stock Split Shares Authorized	520,000,000
Post Stock Split Shares Authorized	34,666,667
Stockholders' Equity, Reverse Stock Split	The Charter Amendment became effective on January 31, 2024 at 5:00 p.m. Eastern Time, at which time every 15 shares of the Company’s issued and outstanding common stock automatically combined and converted into 1 share of common stock.
Common Stock [Member]
Common stock, shares outstanding			16,012,522
Common stock reserved for future issuance			1,714,489

Financings - Additional Informa

Financings - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended
	Jan. 05, 2023	Nov. 29, 2022	Aug. 12, 2022	Mar. 31, 2024	Mar. 31, 2023	Aug. 06, 2021
Debt Instrument [Line Items]
Aggregate offering price					$ 92
At The Market Offering [Member]
Debt Instrument [Line Items]
Number of additional option available to the underwriter to purchase		242,287
Term A Tranche [Member] \| Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Loan and Security Agreement						$ 25,000
Term B Tranche [Member] \| Silicon Valley Bank [Member]
Debt Instrument [Line Items]
Additonal tranche facility						$ 25,000
Equity Distribution Agreement [Member]
Debt Instrument [Line Items]
Stock issued during period				0	0
Aggregate offering price			$ 50,000
Percentage Of Commission On Gross Proceeds From Sale Of Common Stock			3%
Cantor [Member]
Debt Instrument [Line Items]
Common stock issuance		1,615,248
Underwriter par or stated value per share		$ 9.2865
Threshold period for exercise or conversion of stock		30 days
Cantor [Member] \| Stock Option [Member]
Debt Instrument [Line Items]
Stock issued during period	14,420
Sale of stock consideration received on transaction		$ 14,700

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)			3 Months Ended
Debt - Additional Information (Details) - USD ($)	Dec. 28, 2021	Aug. 06, 2021	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Debt Instrument [Line Items]
Debt obligations			$ 0		$ 0
Line of credit facility, interest rate		4.50%
Interest expense			$ 0	$ 900,000
Term Loan [Member]
Debt Instrument [Line Items]
Percentage of original principal due as a final payment		5.75%
Line of credit facility, interest rate		7.75%
Silicon Valley Bank Loan [Member]
Debt Instrument [Line Items]
Warrants issued	43,308
Warrants expiration date	Aug. 06, 2031
Description of payment terms		the Company also owed SVB 5.75% of the original principal amounts borrowed as a final payment, or the Final Payment. Effective March 30, 2023, the Company entered into a Third Amendment to the Loan and Security Agreement, or the Third Amendment. Under the terms of the Third Amendment, the Company was no longer required to maintain all of its operating accounts, depository accounts and excess cash with SVB or one of its affiliates, and was instead only required to maintain a single operating or depository account at Silicon Valley Bank. The Third Amendment also modified the cash collateralization requirement, such that the Company was required to cash collateralize the entire sum of the outstanding principal amount of the SVB Facility, plus an amount equal to the Final Payment, which amount was to be reduced commensurate with each regularly scheduled monthly payment of principal and interest on the SVB Facility.
Debt instrument description of variable rate basis			The SVB Facility bore interest at a floating rate per annum on outstanding loans, payable monthly, at the greater of (a) 7.75% and (b) the current published U.S. prime rate, plus a margin of 4.5%
Extinguishment of debt, amount			$ 500,000
Amount of prepayments premium			$ 100,000
Number of warrants issued		28,856
Warrant exercise per share	$ 17.4	$ 33.3
Additional number warrants issued		28,856
Debt instrument, initial maturity date			Aug. 01, 2023
Silicon Valley Bank Loan [Member] \| Debt Instrument Redemption Period One
Debt Instrument [Line Items]
Percentage of prepayments premium			2%
Silicon Valley Bank Loan [Member] \| Warrants [Member]
Debt Instrument [Line Items]
Issuance costs	$ 1,200,000

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 3,832	$ 5,744
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 3,832	$ 5,744

Fair Value Measurements (Detail

Fair Value Measurements (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Fair Value, Inputs, Level 2, and Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets (liabilities)	$ 0

Net Loss Per Share - Potentiall

Net Loss Per Share - Potentially Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	1,703,856	2,475,580
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	1,452,399	1,528,156
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	251,457	887,549
Unvested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	59,875

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended
	Dec. 18, 2018	Mar. 31, 2024	Mar. 31, 2023
Eden Biocell [Member]
Related Party Transaction [Line Items]
Payments to Fund Long-term Loans to Related Parties	$ 10,000
Additional Loans Committed	$ 25,000
Dune Lake Capital [Member]
Related Party Transaction [Line Items]
Consulting service amount		$ 0	$ 7

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)						3 Months Ended
	Oct. 20, 2023	Aug. 14, 2023	Mar. 17, 2023	Aug. 17, 2015	Jan. 13, 2015	Mar. 31, 2024	Mar. 31, 2023	Apr. 03, 2023	Oct. 22, 2019	Oct. 05, 2018	Aug. 24, 2004
Accrued Payments
Research and development expense						$ 126,000	$ 6,504,000
Royalty amount							0
Maximum royalty amount										$ 100,000,000
Collaboration revenue						1,000	0
Unspecified monetary damages			$ 3,200,000
Loss contingency, name of plaintiff			KBI Biopharma
Litigation expense	$ 1,000,000
MD Anderson Warrant [Member]
Accrued Payments
Number of warrants									222,222
Warrant exercise per share									$ 0.015
Warrant expiry date									Dec. 31, 2026
MD Anderson Agreement and Worldwide License [Member]
Accrued Payments
License agreement commencing date					Jan. 13, 2015
MD Anderson License and the Research and Development Agreement [Member]
Accrued Payments
Reimbursement of historical costs									$ 20,000,000
Quarterly expense incurred						0	200,000
Aggregate potential benchmark payments									36,500,000
Payments due prior to the first marketing approval									$ 3,000,000
CRADA Agreement [Member]
Accrued Payments
Agreement termination date		Oct. 13, 2023
Annual expense incurred						0	300,000
The University of Texas MD Anderson Cancer Center and The Texas A & M University System [Member]
Accrued Payments
Milestone maximum payment											$ 4,500,000
The University of Texas MD Anderson Cancer Center and The Texas A & M University System [Member] \| Royalty [Member]
Accrued Payments
Payment under license agreement						0	0
License Agreement with the National Cancer Institute [Member]
Accrued Payments
License expense						0	300,000
Collaboration Agreement with Solasia Pharma KK [Member]
Accrued Payments
Collaboration revenue						0	0
Collaboration Agreement with Solasia Pharma KK [Member] \| Royalty [Member]
Accrued Payments
Collaboration revenue						1,000	0
M D Anderson License and the Two Thousand Fifteen Research and Development Agreement [Member]
Accrued Payments
Clinical expenses						$ 0	$ 0
Intrexon Corporation [Member]
Accrued Payments
Annual license fee								$ 75,000		100,000
Expected additional milestones payable										52,500,000
Intrexon Corporation [Member] \| T-cell receptor [Member]
Accrued Payments
Maximum royalty amount										$ 100,000,000
Portion of income payable to related party										20%
Minimum [Member] \| MD Anderson License and the Research and Development Agreement [Member]
Accrued Payments
Research and development expense				$ 15,000,000
Maximum [Member] \| MD Anderson License and the Research and Development Agreement [Member]
Accrued Payments
Research and development expense				$ 20,000,000

Stock-Based Compensation Expens

Stock-Based Compensation Expense Included in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 172	$ 910
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	11	175
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 161	$ 735

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, granted	40,000	204,344
Weighted-average grant date fair value	$ 1.5	$ 5.85
Unvested Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to unvested restricted stock outstanding	$ 0.1
Expected recognition period	1 year 3 months 10 days

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Value of Stock Options Assumptions Using Black-Scholes Option Valuation Model (Details)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Risk-free interest rate	4.09%
Risk-free interest rate, Minimum		3.58%
Risk-free interest rate, Maximum		3.87%
Expected life in years	5 years 3 months 7 days
Expected volatility	114.65%
Expected volatility, Minimum		89.69%
Expected volatility, Maximum		95.63%
Expected dividend yield	0%	0%
Maximum [Member]
Expected life in years		6 years 3 months
Minimum [Member]
Expected life in years		5 years 21 days

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity Under Stock Option Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Number of Shares
Beginning Balance	465,898
Granted	40,000	204,344
Cancelled	(254,441)
Ending Balance	251,457
Options exercisable, at end of period	161,844
Options available for future grant	1,514,087
Weighted Average Exercise Price
Beginning Balance	$ 26.85
Granted	1.8
Cancelled	19.61
Ending Balance	21.15
Options exercisable, at end of period	$ 28.28
Weighted Average Contractual Term (Years)
Outstanding, at end of period	6 years 11 months 1 day
Options exercisable, at end of period	5 years 6 months 10 days
Aggregate Intrinsic Value
Outstanding, at end of period	$ 0
Options exercisable, at end of period	$ 0

Warrants - Additional Informati

Warrants - Additional Information (Details) - USD ($)						3 Months Ended
Warrants - Additional Information (Details) - USD ($)	Dec. 28, 2021	Aug. 06, 2021	Oct. 22, 2019	Sep. 12, 2019	Nov. 11, 2018	Mar. 31, 2024	Mar. 31, 2023
Fair Value Assumptions Expected volatility Rate Maximum							95.63%
Fair Value Assumptions Risk Free Interest Rate Maximum							3.87%
Fair Value Assumptions Expected Term1						5 years 3 months 7 days
Aggregate offering price							$ 92,000
Proceeds from private placement				$ 52,500,000
Expected volatility						114.65%
Risk-free interest rate						4.09%
Silicon Valley Bank Loan [Member]
Warrant exercise per share	$ 17.4	$ 33.3
Number of warrants issued		28,856
MD Anderson Warrant [Member]
Number of securities into which the class of warrant converted			222,222
Warrant exercise per share			$ 0.015
Fair value of warrants			$ 14,500,000
Warrant expiry date			Dec. 31, 2026
SVB Warrants [Member]
Common stock		28,856
Exercise price		33.30
Warrants fully vested upon issuance		10 years
Warrants exercised						0
Black-Scholes Model [Member] \| Silicon Valley Bank Loan [Member]
Exercise price	$17.40
Number of warrants issued	43,308
Black-Scholes Model [Member] \| SVB Warrants [Member]
Fair value of warrants		$ 800,000
Fair Value Assumptions Expected Term1		10 years
Expected volatility		79%
Risk-free interest rate		1.31%
Dividends		$ 0
Securities Purchase Agreement [Member]
Aggregate offering price					$ 47,100,000
Private Placement [Member]
Number of securities into which the class of warrant converted				1,186,869	1,262,626
Warrant exercise per share				$ 45.15	$ 45.15
Fair value of warrants					$ 18,400,000
Fair Value Assumptions Expected volatility Rate Maximum					71%
Fair Value Assumptions Risk Free Interest Rate Maximum					2.99%
Fair Value Assumptions Expected Term1					5 years
Placement agent fees and other expenses				$ 1,100,000
Dividends					$ 0
Private Placement [Member] \| New Warrants [Member]
Number of securities into which the class of warrant converted				1,186,869
Warrant exercise per share				$ 105
Non-cash inducement warrant expense				$ 60,800,000

Joint Venture - Additional Info

Joint Venture - Additional Information (Details)	Jul. 05, 2019
Ziopharm [Member] \| Eden Bio Cell [Member]
Subsidiary or Equity Method Investee [Line Items]
Equity interest in affilated entity	50%