0000950170-23-063354 | 10-Q | XBRL Viewer

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Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Total debt	$ 0	$ 16,765
Silicon Valley Bank Loan [Member]
Debt Instrument [Line Items]
Loan and Security Agreement	0	17,395
Unamortized discount on Term Loan Agreement	$ 0	$ (630)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Fair Value Measurements

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

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 September 30, 2023 and December 31, 2022 are as follows:


($ in thousands)			Fair Value Measurements at Reporting Date Using
Description	Balance as of September 30, 2023		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents	$	11,681	$	11,681	$	—	$	—


($ in thousands)			Fair Value Measurements at Reporting Date Using
Description	Balance as of December 31, 2022		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents	$	38,058	$	38,058	$	—	$	—

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 or nine months ended September 30, 2023. We had no financial assets or liabilities that were classified as Level 2 or Level 3 during the three or nine months ended September 30, 2023.

Fair Value of Non-Financial Instruments

The Company evaluates assets for impairment whenever events or changes in circumstances indicate that indicators of impairment exist. In those evaluations, the Company compares estimated future undiscounted cash flows generated by each asset (or asset group) to the carrying value of the asset (or asset group) to determine if an impairment charge is required. If the undiscounted cash flows test fails, the Company estimates the fair value of the asset (or asset group) to determine the impairment.

Following the Company’s announced strategic reprioritization on August 14, 2023, the Company determined that changes in the intended use of certain property and equipment represented an indicator of impairment, resulting in an impairment charge of $1.0 million, which was primarily related to lab equipment of $0.9 million and leasehold improvements of $0.1 million.

In addition, the Company determined certain prepaid expense balances to be impaired given the Company’s strategic reprioritization, and therefore, has recorded an impairment charge of $0.1 million related to prepaid expenses and other current assets, which is recorded in research and development expenses within the condensed statement of operations.

On November 9, 2023, the Company executed an agreement to sell laboratory equipment for gross proceeds of $1.5 million. As of September 30, 2023, the laboratory equipment had a carrying value of $1.5 million recorded within Property and Equipment, net in the condensed balance sheet.

Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2023	Nov. 09, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
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		240,627,055
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
Securities Act File Number	001-33038
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-1475642
Entity Address, Address Line One	8030 El Rio Street
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77054
City Area Code	346
Local Phone Number	355-4099

Restructuring - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Aug. 14, 2023
Restructuring and Related Activities [Abstract]
Intended percentage of reduction in workforce	60.00%	60.00%	80.00%
Termination benefits	$ 0.4	$ 0.4

Warrants - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands						3 Months Ended		9 Months Ended
	Dec. 28, 2021	Aug. 06, 2021	Oct. 22, 2019	Sep. 12, 2019	Nov. 11, 2018	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Fair Value Assumptions Expected volatility Rate Maximum							85.89%	95.63%	85.89%
Fair Value Assumptions Risk Free Interest Rate Maximum							3.62%	4.01%	3.62%
Fair Value Assumptions Expected Term1						6 years 3 months
Aggregate offering price								$ 92
Proceeds from private placement				$ 52,500
Expected volatility						90.65%
Risk-free interest rate						4.01%
Silicon Valley Bank Loan [Member]
Warrant exercise per share	$ 1.16	$ 2.22
Number of warrants issued		432,844
MD Anderson Warrant [Member]
Number of securities into which the class of warrant converted			3,333,333
Warrant exercise per share			$ 0.001
Fair value of warrants			$ 14,500
Warrant Expiry date			Dec. 31, 2026
SVB Warrants [Member]
Common stock		432,844
Exercise price		$2.22
Warrants fully vested upon issuance		10 years
Warrants exercised						0		0
Black-Scholes Model [Member] \| Silicon Valley Bank Loan [Member]
Exercise price	$1.16
Number of warrants issued	649,615
Black-Scholes Model [Member] \| SVB Warrants [Member]
Fair value of warrants		$ 800
Fair Value Assumptions Expected Term1		10 years
Expected volatility		79.00%
Risk-free interest rate		1.31%
Dividends		$ 0
Securities Purchase Agreement [Member]
Aggregate offering price					$ 47,100
Private Placement [Member]
Number of securities into which the class of warrant converted				17,803,031	18,939,394
Warrant exercise per share				$ 3.01	$ 3.01
Fair value of warrants					$ 18,400
Fair Value Assumptions Expected volatility Rate Maximum					71.00%
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
Dividends					$ 0
Private Placement [Member] \| New Warrants [Member]
Number of securities into which the class of warrant converted				17,803,031
Warrant exercise per share				$ 7
Non-cash inducement warrant expense				$ 60,800

Related Party Transactions

9 Months Ended

Sep. 30, 2023

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.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

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+ Details

Stock-Based Compensation

9 Months Ended

Sep. 30, 2023

Text Block [Abstract]

Stock-Based Compensation

10.

Stock-Based Compensation

The Company recognized stock-based compensation expense on all employee and non-employee awards as follows:


	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
(in thousands)	2023		2022		2023		2022
Research and development		90		145		446		673
General and administrative		636		663		2,104		1,978
Stock-based compensation expense	$	726	$	808	$	2,550	$	2,651

The Company granted an aggregate of 10,000 stock options during the three months ended September 30, 2023, with a weighted-average grant date fair value of $0.39 per share, and granted an aggregate of 3,695,167 stock options during the nine months ended September 30, 2023, with a weighted-average grant date fair value of $0.39 per share. The Company granted an aggregate of 1,275,000 stock options during the three months ended September 30, 2022, with a weighted-average grant date fair value of $1.52 per share, and granted an aggregate of 7,150,438 stock options during the nine months ended September 30, 2022, with a weighted-average grant date fair value of $1.91 per share.

For the three and nine months ended September 30, 2023 and 2022, the fair value of stock options was estimated on the date of grant using a Black-Scholes option valuation model with the following assumptions:


	For the Three Months Ended September 30,		For the Nine Months Ended September 30,
	2023	2022	2023	2022
Risk-free interest rate	4.01%	2.94 – 3.62%	3.51 – 4.01%	1.63 – 3.62%
Expected life in years	6.25	6.23 – 6.25	5.06 – 6.25	5.27 – 6.25
Expected volatility	90.65%	82.43 – 85.89%	89.69 – 95.63%	74.49 – 85.89%
Expected dividend yield	—%	—%	—%	—%

Stock option activity under the Company’s stock option plans for the nine months ended September 30, 2023 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, 2022		10,408,622		$	1.84
Granted		3,695,167			0.51
Cancelled		(1,686,760	)		1.35
Outstanding, September 30, 2023		12,417,029		$	1.51		8.89	$	—
Options exercisable, September 30, 2023		6,126,738		$	2.02		5.56	$	—
Options exercisable, December 31, 2022		3,891,598		$	2.46		8.08	$	—
Options available for future grant, September 30, 2023		13,451,681

At September 30, 2023, total unrecognized compensation costs related to unvested stock options outstanding amounted to $4.2 million. The cost is expected to be recognized over a weighted-average period of 1.70 years.

A summary of the status of unvested restricted stock for the nine months ended September 30, 2023 was as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value
Unvested, December 31, 2022		939,062		$	1.40
Vested		(501,562	)		1.20
Unvested, September 30, 2023		437,500		$	1.64

At September 30, 2023, total unrecognized compensation costs related to unvested restricted stock outstanding amounted to $0.7 million. The cost is expected to be recognized over a weighted-average period of 1.48 years.

Debt

9 Months Ended

Sep. 30, 2023

Debt Disclosure [Abstract]

Debt

The carrying values of the Company's debt obligation were as follows:


	September 30,		December 31,
($ in thousands)	2023		2022
Loan and Security Agreement	$	—	$	17,395
Unamortized discount on Loan and Security Agreement		—		(630	)
Total debt	$	—	$	16,765

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 432,844 shares of the Company’s common stock, in the aggregate, and (ii) up to an additional 432,842 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 $2.22.

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 649,615 shares of the Company's common stock, in the aggregate, with an exercise price of $1.16 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 September 30, 2023 and was $1.9 million for the nine months ended September 30, 2023, compared to $0.8 million for the three months ended September 30, 2022 and $2.3 million for the nine months ended September 30, 2022.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2023

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 September 30, 2023 and December 31, 2022 are as follows:


($ in thousands)			Fair Value Measurements at Reporting Date Using
Description	Balance as of September 30, 2023		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents	$	11,681	$	11,681	$	—	$	—


($ in thousands)			Fair Value Measurements at Reporting Date Using
Description	Balance as of December 31, 2022		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents	$	38,058	$	38,058	$	—	$	—

Stock-Based Compensation - Stock Option Activity Under Stock Option Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Number of Shares
Beginning Balance			10,408,622
Granted	10,000	1,275,000	3,695,167	7,150,438
Cancelled			(1,686,760)
Ending Balance	12,417,029		12,417,029		10,408,622
Options exercisable, at end of period	6,126,738		6,126,738		3,891,598
Options available for future grant	13,451,681		13,451,681
Weighted Average Exercise Price
Beginning Balance			$ 1.84
Granted			0.51
Cancelled			1.35
Ending Balance	$ 1.51		1.51		$ 1.84
Options exercisable, at end of period	$ 2.02		$ 2.02		$ 2.46
Weighted Average Contractual Term (Years)
Outstanding, at end of period			8 years 10 months 20 days
Options exercisable, at end of period			5 years 6 months 21 days		8 years 29 days
Aggregate Intrinsic Value
Outstanding, at end of period	$ 0		$ 0
Options exercisable, at end of period	$ 0		$ 0		$ 0

CONDENSED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid In Capital	Accumulated Deficit
Balance at Dec. 31, 2021	$ 58,057	$ 216	$ 900,693	$ (842,852)
Balance (in shares) at Dec. 31, 2021		216,127,443
Stock-based compensation	2,651		2,651
Restricted stock awards (in shares)		280,000
Cancelled restricted common stock (in shares)		(232,901)
Exercise of employee stock options	21		21
Exercise of employee stock options (in shares)		26,250
Repurchase of common stock	(45)			(45)
Repurchase of common stock (in Shares)		(18,750)
Net loss	(28,571)			(28,571)
Balance at Sep. 30, 2022	32,113	$ 216	903,365	(871,468)
Balance (in shares) at Sep. 30, 2022		216,182,042
Balance at Jun. 30, 2022	40,180	$ 216	902,536	(862,572)
Balance (in shares) at Jun. 30, 2022		216,174,542
Stock-based compensation	808		808
Exercise of employee stock options	21		21
Exercise of employee stock options (in shares)		26,250
Repurchase of common stock	(45)			(45)
Repurchase of common stock (in Shares)		(18,750)
Net loss	(8,851)			(8,851)
Balance at Sep. 30, 2022	32,113	$ 216	903,365	(871,468)
Balance (in shares) at Sep. 30, 2022		216,182,042
Balance at Dec. 31, 2022	38,555	$ 240	918,942	(880,627)
Balance (in shares) at Dec. 31, 2022		240,410,761
Stock-based compensation	2,550		2,550
Issuance of common stock, net of expenses (in shares)		216,294
Issuance of common stock, net of expenses	92	$ 1	91
Net loss	(27,297)			(27,297)
Balance at Sep. 30, 2023	13,900	$ 241	921,583	(907,924)
Balance (in shares) at Sep. 30, 2023		240,627,055
Balance at Jun. 30, 2023	21,650	$ 241	920,857	(899,448)
Balance (in shares) at Jun. 30, 2023		240,627,055
Stock-based compensation	726		726
Net loss	(8,476)			(8,476)
Balance at Sep. 30, 2023	$ 13,900	$ 241	$ 921,583	$ (907,924)
Balance (in shares) at Sep. 30, 2023		240,627,055

Net Loss Per Share - Potentially Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	35,776,871	34,485,557
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	22,922,342	22,922,342
Common stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	12,417,029	10,623,215
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	437,500	940,000

Stock-Based Compensation - Summary of Non-Vested Restricted Stock (Details) - Non Vested Restricted Stock [Member]	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Number of Shares
Beginning Balance \| shares	939,062
Vested \| shares	(501,562)
Ending Balance \| shares	437,500
Weighted Average Grant Date Fair Value
Beginning Balance \| $ / shares	$ 1.4
Vested \| $ / shares	1.2
Ending Balance \| $ / shares	$ 1.64

Financings

9 Months Ended

Sep. 30, 2023

Text Block [Abstract]

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 and nine months ended September 30, 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 24,228,719 shares, or the Firm Shares, of the Company’s common stock to Cantor at a price of $0.6191 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 3,634,307 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 216,294 shares of common stock.

Restructuring	9 Months Ended
Restructuring	Sep. 30, 2023
Restructuring and Related Activities [Abstract]
Restructuring	12. Restructuring 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 reduced its workforce by approximately 60% during the third quarter of 2023. Concurrently, the Company began considering certain strategic alternatives, including, but not limited to, an acquisition, merger, reverse merger, sale of assets, strategic partnerships, capital raises or other transactions. During the three and nine months ended September 30, 2023, the Company recorded termination benefits of $0.4 million, recorded in restructuring costs within the condensed statement of operations. The termination benefits were fully paid as of September 30, 2023.

CONDENSED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
CONDENSED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Collaboration revenue	$ 0	$ 2,911	$ 4	$ 2,911
Operating expenses:
Research and development	3,656	7,893	15,346	19,411
General and administrative	3,578	3,282	9,791	10,217
Gain on lease modification	0	0	(245)	(133)
Restructuring costs	419	0	419	0
Property and equipment and right-of-use assets impairment	1,011	0	1,011	0
Total operating expenses	8,664	11,175	26,322	29,495
Loss from operations	(8,664)	(8,264)	(26,318)	(26,584)
Other income (expense):
Interest Expense	0	(841)	(1,921)	(2,266)
Other income, net	188	254	942	279
Other income (expense), net	188	(587)	(979)	(1,987)
Net loss	$ (8,476)	$ (8,851)	$ (27,297)	$ (28,571)
Earnings per share, Basic	$ (0.04)	$ (0.04)	$ (0.11)	$ (0.13)
Earnings per share, Diluted	$ (0.04)	$ (0.04)	$ (0.11)	$ (0.13)
Weighted Average Number Of Shares Outstanding Basic	240,046,026	215,098,995	239,842,327	215,015,377
Weighted Average Number Of Diluted Shares Outstanding	240,046,026	215,098,995	239,842,327	215,015,377

Leases - Additional Information (Details) $ in Thousands			3 Months Ended		9 Months Ended
Leases - Additional Information (Details) $ in Thousands	Nov. 15, 2023 USD ($)	Apr. 19, 2023	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Nov. 01, 2023 ft²	Aug. 31, 2023 USD ($) ft²	Dec. 31, 2022 USD ($)	Apr. 30, 2022 USD ($) ft²
Lease termination date					Apr. 19, 2023
Sublease term amendment		Jul. 31, 2026
Termination costs					$ 200
Gain on lease termination					245	$ 133
Operating Lease Area \| ft²							14,037
Right of use assets					$ 1,039				$ 2,136
Gain (Loss) On Modification Of Lease				$ 100
Lease term, description		a term expiring on June 30, 2025 with an option to extend through July 31, 2026
Final payment	$ 100
Boston, MA
Gain on lease termination			$ 200
Houston, TX
Operating Lease Area \| ft²								3,228		3,228
Right of use assets								$ 19		$ 400
Houston, TX \| Previously Reported
Operating Lease Area \| ft²										18,111

Leases

9 Months Ended

Sep. 30, 2023

Leases, Operating [Abstract]

Leases

In April 2022, the Company modified its real estate lease agreement executed on December 15, 2020 with MD Anderson for office space in Houston, Texas, which reduced the Company's leased space from 18,111 square feet to 3,228 square feet. As a result, the associated lease liability and right-of-use asset were remeasured to $0.4 million based on revised lease payments. A gain of $0.1 million was recorded on the lease modification during the second quarter of 2022.

On April 19, 2023, the Company terminated its office lease in Boston, Massachusetts, which was set to expire on August 31, 2026. In connection with the termination, the Company also assigned to the landlord its sub-sublease of the Boston office space, which had a term expiring on June 30, 2025 with an option to extend through July 31, 2026. Termination costs for the Boston office lease were $0.2 million. A gain of $0.2 million was recorded on the lease termination during the second quarter of 2023.

In August 2023, in accordance with the lease agreement executed on December 15, 2020, the Company notified MD Anderson, as landlord, of its intention to terminate office space of 3,228 square feet in Houston, Texas. As a result, the associated lease liability and right-of-use asset were remeasured to $19 thousand, reflecting the revised lease payments and term end date of November 2023.

On November 1, 2023, the Company and MD Anderson, as landlord, agreed to mutually terminate the leases dated October 15, 2019 and April 7, 2020, which represent office space totaling 14,037 square feet. The termination will be effective November 15, 2023 and the Company has agreed to make a final payment of $0.1 million to the landlord.

Warrants

9 Months Ended

Sep. 30, 2023

Warrants Disclosure [Abstract]

Warrants

11.

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 18,939,394 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 $3.01 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 17,803,031 shares of common stock, at an exercise price of $3.01 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 17,803,031 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 $7.00. 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 3,333,333 shares of common stock. The MD

Anderson Warrant has an initial exercise price of $0.001 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 and nine months ended September 30, 2023 and 2022, 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 432,844 shares of common stock with an exercise price of $2.22 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 649,615 shares of common stock, in the aggregate, with an exercise price of $1.16 per share. The SVB Warrants expire on August 6, 2031 and were fully vested upon issuance. As of September 30, 2023, none of the SVB Warrants have been exercised.

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 11,681	$ 38,058
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	$ 11,681	$ 38,058

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

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:


	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
(in thousands)	2023		2022		2023		2022
Research and development		90		145		446		673
General and administrative		636		663		2,104		1,978
Stock-based compensation expense	$	726	$	808	$	2,550	$	2,651

Fair Value of Stock Options Assumptions Using Black-Scholes Option Valuation Model


	For the Three Months Ended September 30,		For the Nine Months Ended September 30,
	2023	2022	2023	2022
Risk-free interest rate	4.01%	2.94 – 3.62%	3.51 – 4.01%	1.63 – 3.62%
Expected life in years	6.25	6.23 – 6.25	5.06 – 6.25	5.27 – 6.25
Expected volatility	90.65%	82.43 – 85.89%	89.69 – 95.63%	74.49 – 85.89%
Expected dividend yield	—%	—%	—%	—%

Stock Option Activity under Stock Option Plan

Stock option activity under the Company’s stock option plans for the nine months ended September 30, 2023 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, 2022		10,408,622		$	1.84
Granted		3,695,167			0.51
Cancelled		(1,686,760	)		1.35
Outstanding, September 30, 2023		12,417,029		$	1.51		8.89	$	—
Options exercisable, September 30, 2023		6,126,738		$	2.02		5.56	$	—
Options exercisable, December 31, 2022		3,891,598		$	2.46		8.08	$	—
Options available for future grant, September 30, 2023		13,451,681

Summary of Unvested Restricted Stock

A summary of the status of unvested restricted stock for the nine months ended September 30, 2023 was as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value
Unvested, December 31, 2022		939,062		$	1.40
Vested		(501,562	)		1.20
Unvested, September 30, 2023		437,500		$	1.64

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	50.00%

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, granted	10,000	1,275,000	3,695,167	7,150,438
Weighted-average grant date fair value	$ 0.39	$ 1.52	$ 0.39	$ 1.91
Unvested Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to unvested restricted stock outstanding	$ 4.2		$ 4.2
Expected recognition period			1 year 8 months 12 days
Unvested Restricted Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to unvested restricted stock outstanding	$ 0.7		$ 0.7
Expected recognition period			1 year 5 months 23 days

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-1D

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
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+ Details

Organization - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
	Aug. 14, 2023	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Intended percentage of reduction in workforce	80.00%	60.00%	60.00%
Cash, cash equivalents and restricted cash		$ 11,944	$ 11,944	$ 52,996	$ 51,745	$ 76,054
Accumulated deficit		$ 907,924	$ 907,924	$ 880,627
Common stock, shares authorized		520,000,000	520,000,000	420,000,000
Common stock, shares outstanding		240,627,055	240,627,055	240,410,761
Strategic advisor name	Cantor
Research and Development [Member]
Reversal of accrued expenses		$ 300	$ 1,000
Common Stock [Member]
Common stock, shares outstanding		240,627,055	240,627,055
Common stock reserved for future issuance		35,339,371	35,339,371

Debt - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended			9 Months Ended
	Dec. 28, 2021	Aug. 06, 2021	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Line of credit facility, interest rate		4.50%
Interest expense			$ 0.0		$ 0.8	$ 1.9	$ 2.3
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	649,615
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.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%.
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				$ 0.5
Amount of prepayments premium				$ 0.1
Number of warrants issued		432,844
Warrant exercise per share	$ 1.16	$ 2.22
Additional number warrants issued		432,842
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						2.00%
Silicon Valley Bank Loan [Member] \| Warrants [Member]
Debt Instrument [Line Items]
Issuance costs	$ 1.2

Related Party Transactions - Additional Information (Details) - Eden Biocell [Member] $ in Millions	Dec. 18, 2018 USD ($)
Related Party Transaction [Line Items]
Payments to Fund Long-term Loans to Related Parties	$ 10.0
Additional Loans Committed	$ 25.0

Financings - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended	9 Months Ended
	Jan. 05, 2023	Nov. 29, 2022	Aug. 12, 2022	Sep. 30, 2023	Sep. 30, 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		3,634,307
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			3.00%
Cantor [Member]
Debt Instrument [Line Items]
Common stock issuance		24,228,719
Underwriter par or stated value per share		$ 0.6191
Threshold period for exercise or conversion of stock		30 days
Cantor [Member] \| Stock Option [Member]
Debt Instrument [Line Items]
Stock issued during period	216,294
Sale of stock consideration received on transaction		$ 14,700

Debt (Tables)

9 Months Ended

Sep. 30, 2023

Debt Disclosure [Abstract]

Schedule of Debt

The carrying values of the Company's debt obligation were as follows:


	September 30,		December 31,
($ in thousands)	2023		2022
Loan and Security Agreement	$	—	$	17,395
Unamortized discount on Loan and Security Agreement		—		(630	)
Total debt	$	—	$	16,765

Net Loss per Share (Tables)

9 Months Ended

Sep. 30, 2023

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 September 30, 2023 and 2022:


	September 30,
	2023		2022
Common stock options		12,417,029		10,623,215
Unvested restricted stock		437,500		940,000
Warrants		22,922,342		22,922,342
		35,776,871		34,485,557

CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (27,297)	$ (28,571)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2,074	2,065
Property and equipment right-of-use asset impairment	1,011	0
Amortization of financing costs	1,339	634
Stock-based compensation	2,550	2,651
Decrease in the carrying amount of right-of-use assets	1,332	2,306
Gain on lease modification	(245)	(133)
Loss on disposal of equipment	12	0
(Increase) decrease in:
Receivables	4	(1,800)
Prepaid expenses and other current assets	(126)	817
Deposits	42	0
Other non-current assets	500	131
Increase (decrease) in:
Accounts payable	(92)	616
Accrued expenses	(2,258)	1,525
Lease liabilities	(1,575)	(2,371)
Other non-current liabilities	(28)	28
Net cash used in operating activities	(22,757)	(22,102)
Cash flows from investing activities:
Purchases of property and equipment	(197)	(100)
Proceeds from the disposal of property and equipment	40	0
Net cash used in investing activities	(157)	(100)
Cash flows from financing activities:
Proceeds from the issuance of common stock	92	0
Proceeds from the exercise of stock options	0	21
Repurchase of common stock	0	(45)
Repayment of long-term debt	(18,105)	(2,083)
Debt extinguishment costs	(125)	0
Net cash used in financing activities	(18,138)	(2,107)
Net decrease in cash, cash equivalents and restricted cash	(41,052)	(24,309)
Cash, cash equivalents and restricted cash, beginning of period	52,996	76,054
Cash and cash equivalents, end of period	11,944	51,745
Supplementary disclosure of cash flow information:
Cash paid for interest	2,063	1,603
Amounts included in accounts payable and accrued expenses related to property and equipment	$ 1	$ 348

CONDENSED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	520,000,000	420,000,000
Common stock, shares issued	240,627,055	240,410,761
Common stock, shares outstanding	240,627,055	240,410,761

Joint Venture

9 Months Ended

Sep. 30, 2023

Equity Method Investments and Joint Ventures [Abstract]

Joint Venture

13.

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.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

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 or nine months ended September 30, 2023 and 2022.

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 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 September 30, 2023 the Company incurred clinical expenses of $0.2 million from MD Anderson related to the 2019 R&D Agreement, compared to $0.3 million for the three months ended September 30, 2022. For the nine months ended September 30, 2023, the Company incurred clinical expenses of $0.7 million from MD Anderson related to the 2019 R&D Agreement compared to $0.7 million for the nine months ended September 30, 2022.

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 3,333,333 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 $0.001 per share, expires on December 31, 2026, and vests upon the occurrence of certain clinical milestones. As of September 30, 2023, 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 National Cancer Institute, or the NCI. Pursuant to the Patent License, the Company holds 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 holds 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. Prior to January 1, 2023, the Company had entered into several amendments to the Patent License in order to expand its TCR library to include additional TCRs reactive to mutated KRAS and TP53 neoantigens licensed from the NCI.

The terms of the Patent License require the Company to pay the NCI minimum annual royalties in the amount of $0.3 million, which will be reduced to $0.1 million once the aggregate minimum annual royalties paid by the Company equals $1.5 million.

The Company is also required to make performance-based payments upon successful completion of clinical and regulatory benchmarks relating to the licensed products. Of such payments, the aggregate potential benchmark payments are $4.3 million, of which aggregate payments of $3.0 million are due only after marketing approval in the United States or in Europe, Japan, Australia, China or India. The first benchmark payment of $0.1 million was paid during the year ended December 31, 2022 upon the initiation of the Company's TCR-T Library Phase 1/2 Trial, which was a qualifying Phase 1 clinical trial under the terms of the Patent License.

In addition, the Company is required to pay the NCI one-time benchmark payments following aggregate net sales of licensed products at certain aggregate net sales ranging from $250.0 million to $1.0 billion. The aggregate potential amount of these benchmark payments is $12.0 million. The Company must also pay the NCI royalties on net sales of products covered by the Patent License at rates in the low to mid-single digits depending upon the technology included in a licensed product. To the extent the Company enters into a sublicensing agreement relating to a licensed product, the Company is required to pay the NCI a percentage of all consideration received from a sublicensee, which percentage will decrease based on the stage of development of the licensed product at the time of the sublicense.

The Patent License will expire upon expiration of the last patent contained in the licensed patent rights, unless terminated earlier. The NCI may terminate or modify the Patent License in the event of a material breach, including if the Company does not meet certain milestones by certain dates, or upon certain insolvency events that remain uncured following the date that is 90 days following written notice of such breach or insolvency event. The Company may terminate the Patent License, or any portion thereof, in the Company's sole discretion at any time upon 60 days’ written notice to the NCI. In addition, the NCI has the right to: (i) require the Company to sublicense the rights to the product candidates covered by the Patent License upon certain conditions, including if the Company is not reasonably satisfying required health and safety needs and (ii) terminate or modify the Patent License, including if the Company is not satisfying requirements for public use as specified by federal regulations. On October 27, 2023, the Company provided the NCI the requisite notice of its intent to terminate the Patent License, effective 60 days from such notice. The Company has 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 September 30, 2023, the Company recognized $0.1 million in license expenses to the NCI under this agreement, compared to $0.1 million for the three months ended September 30, 2022. For the nine months ended September 30, 2023, the Company recognized $0.5 million in license expenses to the NCI under this agreement, compared to $0.5 million for the nine months ended September 30, 2022.

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.

The Company was responsible for providing the NCI with the test materials necessary for them to conduct their studies, and eventually, clinical trials pursuant to the CRADA. Inventions, data and materials discovered or produced in connection with performance of the research plan under the CRADA would have remained the sole property of the party who produced the discovery. The parties would have jointly owned all inventions jointly discovered under the research plan. The owner of any invention under the CRADA would have made the decision to file a patent covering the invention, or in the case of a jointly owned invention, the Company would have the first opportunity to file a patent covering the invention. If the Company failed to provide timely notice of its decision to the NCI or decided not to file a patent covering the joint invention, the NCI had the right to make the filing. For any invention solely owned by the NCI or jointly made by the NCI and the Company for which a patent application was filed, the U.S. Public Health service granted the Company an exclusive option to elect an exclusive or non-exclusive commercialization license. For inventions owned solely by the NCI or jointly owned by the NCI and the Company, which were licensed according to the terms described above, the Company agreed to grant to the U.S. government a non-exclusive, non-transferable, irrevocable and paid up license to practice the invention or have the invention practiced on its behalf throughout the world. The Company was also required to grant the U.S. government a non-exclusive, non-transferable, irrevocable and paid up license to practice the invention or have the invention practiced on its behalf throughout the world for any of the Company's solely owned inventions. The agreement could be terminated by any of the parties upon 60 days' prior written consent.

The NCI has a cleared Investigational New Drug Application, or IND, that would permit them to begin this trial. To the Company's knowledge, the trial had not yet begun enrollment. The progress and timeline for this trial, including the timeline for dosing patients, are under control of the NCI.

In February 2019, the Company extended the CRADA with the NCI until January 9, 2022, committing an additional $5.0 million to this program; however, for the third and fourth quarters of 2021, the Company was not required to make payments toward the program as agreed with the NCI. In March 2022, the Company entered into an amendment to the CRADA that is retroactive, effective January 9, 2022 to extend the term of the CRADA until January 9, 2023. In June 2022, the Company entered into the Fourth Amendment to the CRADA, or the CRADA Fourth Amendment, which, among other things, extended the term of the CRADA until January 9, 2025. In connection with the CRADA Fourth Amendment, the Company agreed to contribute $1.0 million per year, payable on a quarterly basis, beginning in the first quarter of 2023. The Company did not record expenses under the CRADA for the three months ended September 30, 2023 and recorded expenses of $0.5 million for the nine months ended September 30, 2023, compared to $0 for the three and nine months ended September 30, 2022.

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.

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 and nine months ended September 30, 2023 and 2022, the Company did not 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 Ministry of Health, Labor and Welfare in Japan. During the three months ended September 30, 2023, the Company did not earn collaboration revenue and did not earn royalty revenues on net sales under the Solasia License and Collaboration Agreement, and for the nine months ended September 30, 2023, the Company earned $4 thousand in collaboration revenue and did not earn royalty revenues on net sales under the Solasia License and Collaboration Agreement. During the three and nine months ended September 30, 2022, the Company earned $2.9 million in collaboration revenue and did not earn 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. As a result, the Company has accrued $1.0 million as of September 30, 2023 for the settlement.

CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 11,944	$ 39,058
Restricted cash	0	13,938
Receivables	0	4
Prepaid expenses and other current assets	925	799
Total current assets	12,869	53,799
Property and equipment, net	5,532	8,460
Right of use assets	1,039	2,136
Deposits	0	42
Other non-current assets	0	500
Total assets	19,440	64,937
Current liabilities:
Accounts payable	1,298	1,389
Current portion of long-term debt	0	16,765
Accrued expenses	3,071	5,454
Lease liabilities, current	307	558
Total current liabilities	4,676	24,166
Lease liabilities, non-current	864	2,188
Other non-current liabilities	0	28
Total liabilities	5,540	26,382
Commitments and contingencies (Note 9)
Stockholders' equity
Common stock $0.001 par value; 520,000,000 shares authorized, 240,627,055 shares issued and outstanding at September 30, 2023 and 420,000,000 shares authorized, 240,410,761 shares issued and outstanding at December 31, 2022	241	240
Additional paid-in capital	921,583	918,942
Accumulated deficit	(907,924)	(880,627)
Total stockholders' equity	13,900	38,555
Total liabilities and stockholders' equity	$ 19,440	$ 64,937

Net Loss per Share

9 Months Ended

Sep. 30, 2023

Earnings Per Share [Abstract]

Net Loss per Share

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 September 30, 2023 and 2022:


	September 30,
	2023		2022
Common stock options		12,417,029		10,623,215
Unvested restricted stock		437,500		940,000
Warrants		22,922,342		22,922,342
		35,776,871		34,485,557

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

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.

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2023
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, 2022, included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 filed with the SEC on March 7, 2023, or the Annual Report. The results disclosed in the statements of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results to be expected for the full fiscal year 2023.
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. Our accrued expenses represent estimates of activity and costs incurred with vendors and counterparties. During the three and nine months ended September 30, 2023, the Company revised estimated accrued expenses related to de-prioritized clinical programs based on new information received from vendors. As a result, a $0.3 million credit has been recorded in research and development expense within the condensed statement of operations for the three months ended September 30, 2023, and a $1.0 million credit has been recorded for the nine months ended September 30, 2023.

Subsequent Events - Additional Information (Details)	Aug. 14, 2023	Sep. 30, 2023
Subsequent Event [Line Items]
Intended percentage of reduction in workforce	80.00%	60.00%
Strategic advisor name	Cantor
CRADA Agreement [Member]
Subsequent Event [Line Items]
Agreement Termination Date	Oct. 13, 2023

Organization

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

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. On January 25, 2022, the Company changed its corporate name from ZIOPHARM Oncology, Inc. to Alaunos Therapeutics, Inc. 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.

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 reduced its workforce by approximately 80% to date 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.

As of September 30, 2023, there were 240,627,055 shares of common stock outstanding and an additional 35,339,371 shares of common stock reserved for issuance pursuant to outstanding stock options and warrants.

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 September 30, 2023, the Company had approximately $11.9 million of cash and cash equivalents. The Company’s accumulated deficit at September 30, 2023 was approximately $907.9 million. Given its current development plans and cash management efforts, the Company anticipates cash resources will be sufficient to fund operations into the second 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, 2022, included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 filed with the SEC on March 7, 2023, or the Annual Report.

The results disclosed in the statements of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results to be expected for the full fiscal year 2023.

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.

Our accrued expenses represent estimates of activity and costs incurred with vendors and counterparties. During the three and nine months ended September 30, 2023, the Company revised estimated accrued expenses related to de-prioritized clinical programs based on new information received from vendors. As a result, a $0.3 million credit has been recorded in research and development expense within the condensed statement of operations for the three months ended September 30, 2023, and a $1.0 million credit has been recorded for the nine months ended September 30, 2023.

Fair Value Measurements (Details) - USD ($) $ in Thousands			9 Months Ended
Fair Value Measurements (Details) - USD ($) $ in Thousands	Nov. 09, 2023	Aug. 14, 2023	Sep. 30, 2023	Sep. 30, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges			$ 1,011	$ 0
Fixed asset impairment charges		$ 1,000
Laboratory equipment, gross proceeds			40	$ 0
Prepaid Expenses and Other Current Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges		100
Laboratory equipment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges		900
Laboratory equipment, gross proceeds	$ 1,500
Laboratory equipment carrying value			1,500
Leasehold Improvements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges		$ 100
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

Subsequent Events

9 Months Ended

Sep. 30, 2023

Subsequent Events [Abstract]

Subsequent Events

14.

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.

Stock-Based Compensation - Fair Value of Stock Options Assumptions Using Black-Scholes Option Valuation Model (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Risk-free interest rate	4.01%
Risk-free interest rate, Minimum		2.94%	3.51%	1.63%
Risk-free interest rate, Maximum		3.62%	4.01%	3.62%
Expected life in years	6 years 3 months
Expected volatility	90.65%
Expected volatility, Minimum		82.43%	89.69%	74.49%
Expected volatility, Maximum		85.89%	95.63%	85.89%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Maximum [Member]
Expected life in years		6 years 3 months	6 years 3 months	6 years 3 months
Minimum [Member]
Expected life in years		6 years 2 months 23 days	5 years 21 days	5 years 3 months 7 days

Stock-Based Compensation Expense Included in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 726	$ 808	$ 2,550	$ 2,651
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	90	145	446	673
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 636	$ 663	$ 2,104	$ 1,978

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Commitments and Contingencies - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands								3 Months Ended		9 Months Ended
	Oct. 27, 2023	Oct. 20, 2023	Aug. 14, 2023	Mar. 17, 2023	May 28, 2019	Aug. 17, 2015	Jan. 13, 2015	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Apr. 03, 2023	Oct. 22, 2019	Feb. 19, 2019	Oct. 05, 2018	Aug. 24, 2004
Accrued Payments
Research and development expense								$ 3,656	$ 7,893	$ 15,346	$ 19,411
Royalty amount								0	0	0	0
Maximum Royalty Amount															$ 100,000
Collaboration revenue								0	2,911	4	2,911
Unspecified monetary damages				$ 3,200
Loss Contingency, Name of Plaintiff				KBI Biopharma
Accrued litigation liability								1,000		1,000
Subsequent Event [Member]
Accrued Payments
Litigation expense		$ 1,000
MD Anderson Warrant [Member]
Accrued Payments
Number of Warrants													3,333,333
Warrant exercise per share													$ 0.001
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
Quarterly expense incurred								200	300	700	700
Aggregate potential benchmark payments													36,500
Payments due prior to the first marketing approval													$ 3,000
CRADA Agreement [Member]
Accrued Payments
Quarterly expense incurred								0	0	500	0
Agreement termination date			Oct. 13, 2023
Contribution payable on per annum basis										1,000
Obligations due under contract														$ 5,000
The University of Texas MD Anderson Cancer Center and The Texas A & M University System
Accrued Payments
Milestone maximum payment																$ 4,500
The University of Texas MD Anderson Cancer Center and The Texas A & M University System \| Royalty [Member]
Accrued Payments
Payment under license agreement								0	0	0	0
License Agreement with the National Cancer Institute [Member]
Accrued Payments
License Expense								100	100	500	500
License Agreement with the National Cancer Institute [Member] \| One Time Benchmark Payments [Member]
Accrued Payments
First benchmark payment					$ 100
Ziop License Agreement With The National Cancer Institute [Member]
Accrued Payments
Minimum royalties amount payable					300
Royalties amount payable thereafter					100
Aggregate minimum annual royalties paid					$ 1,500
Description Of First Benchmark Payable					The first benchmark payment of $0.1 million was paid during the year ended December 31, 2022 upon the initiation of the Company's TCR-T Library Phase 1/2 Trial, which was a qualifying Phase 1 clinical trial under the terms of the Patent License.
Description Of option To terminate Agreement					The NCI may terminate or modify the Patent License in the event of a material breach, including if the Company does not meet certain milestones by certain dates, or upon certain insolvency events that remain uncured following the date that is 90 days following written notice of such breach or insolvency event.
Agreement termination, notice period					60 days
Ziop License Agreement With The National Cancer Institute [Member] \| Subsequent Event [Member]
Accrued Payments
Agreement termination, notice period	60 days
Ziop License Agreement With The National Cancer Institute [Member] \| Performance Based Payments Member [Member]
Accrued Payments
Aggregate Benchmark Payments Payable					$ 4,300
Ziop License Agreement With The National Cancer Institute [Member] \| One Time Benchmark Payments [Member]
Accrued Payments
Potential Benchmark Payments Payable					12,000
Ziop License Agreement With The National Cancer Institute [Member] \| Post Marketing Approval [Member] \| Performance Based Payments Member [Member]
Accrued Payments
Aggregate Benchmark Payments Payable					3,000
Ziop License Agreement With The National Cancer Institute [Member] \| licensed products [Member] \| One Time Benchmark Payments [Member]
Accrued Payments
Maximum Sales Revenue On Which Benchmark Payments Payable					1,000,000
Minimum sales revenue on which benchmark payments payable					$ 250,000
Collaboration Agreement With Solasia Pharma KK [Member]
Accrued Payments
Collaboration revenue								0	2,900	4	2,900
Collaboration Agreement With Solasia Pharma KK [Member] \| Royalty [Member]
Accrued Payments
Collaboration revenue								$ 0	$ 0	$ 0	$ 0
Intrexon Corporation
Accrued Payments
Annual License Fees												$ 75			100
Expected additional milestones payable															52,500
Intrexon Corporation \| T-cell receptor
Accrued Payments
Maximum royalty amount															$ 100,000
Portion of income payable to related party															20.00%
Minimum \| MD Anderson License and the Research and Development Agreement [Member]
Accrued Payments
Research and development expense						$ 15,000
Maximum \| MD Anderson License and the Research and Development Agreement [Member]
Accrued Payments
Research and development expense						$ 20,000