MiNK Therapeutics (INKT) 10-K 18 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Feb. 28, 2022	Oct. 15, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Registrant Name	MiNK Therapeutics, Inc.
Entity Central Index Key	0001840229
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 43.2
Entity Common Stock, Shares Outstanding		33,558,000
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Title of 12(b) Security	Common Stock, par value $0.00001 per share
Trading Symbol	INKT
Security Exchange Name	NASDAQ
Entity File Number	001-40908
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-2142067
Entity Address, Address Line One	149 Fifth Avenue
Entity Address, Address Line Two	Suite 500
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10010
City Area Code	212
Local Phone Number	994-8250
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Entity Ex Transition Period	false
Auditor Name	KPMG LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	185
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the Registrant’s Definitive Proxy Statement relating to the 2022 Annual Meeting of Stockholders, which the registrant intends to file with the Securities and Exchange Commission pursuant to Regulation 14A within 120 days after the end of the registrant’s fiscal year ended December 31, 2021, are incorporated by reference into Part III of this Report.

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($)	Dec. 31, 2021	Dec. 31, 2020
ASSETS
Cash	$ 38,888,828	$ 2,691,156
Prepaid expenses	1,761	492,060
Other current assets	744,321	913,578
Total current assets	39,634,910	4,096,794
Equipment, net of accumulated depreciation of $168,605 and $98,160 as of December 31, 2021 and 2020, respectively	606,595	458,384
Total assets	40,241,505	4,555,178
LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)
Accounts payable	2,995,645	3,141,844
Accrued liabilities	1,763,688	1,859,068
Other current liabilities	5,760,609	5,690,796
Due to related parties	5,945,094	3,530,589
Total current liabilities	16,465,036	14,222,297
Convertible affiliated note		43,824,000
Other long-term liabilities		383,058
Commitments and contingencies
Stockholders’ equity (deficit)
Common stock, par value $0.00001 per share, 150,000,000 and 35,000,000 shares authorized, 33,476,523 and 24,177,315 shares issued and outstanding as of December 31, 2021 and 2020, respectively	335	242
Additional paid-in capital	107,349,265	383,711
Accumulated other comprehensive loss	(625,269)	(1,523,038)
Accumulated deficit	(82,947,862)	(52,735,092)
Total stockholders’ equity (deficit)	23,776,469	(53,874,177)
Total liabilities and stockholders’ equity (deficit)	$ 40,241,505	$ 4,555,178

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Equipment, net of accumulated depreciation	$ 168,605	$ 98,160
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	150,000,000	35,000,000
Common stock, shares issued	33,476,523	24,177,315

Consolidated Statement of Opera

Consolidated Statement of Operations and Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 13,966,368	$ 9,509,055
General and administrative	4,639,928	1,287,656
Change in fair value of convertible affiliated note	9,752,295	3,840,475
Operating loss	(28,358,591)	(14,637,186)
Other expense, net:
Interest expense	(2,431,614)	(2,440,903)
Gain on extinguishment of debt	355,515
Other income, net	221,920	839,191
Net loss	$ (30,212,770)	$ (16,238,898)
Per common share data:
Basic and diluted net loss per common share	$ (1.16)	$ (0.67)
Weighted average number of common shares outstanding	26,025,489	24,108,316
Other comprehensive gain (loss)
Foreign currency translation gain (loss)	$ 897,769	$ (1,390,448)
Comprehensive loss	$ (29,315,001)	$ (17,629,346)

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity (Deficit) - USD ($)	Total	Common Stock	Additional Paid-In Capital	Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2019	$ (36,333,760)	$ 241	$ 294,783	$ (132,590)	$ (36,496,194)
Beginning Balance, Shares at Dec. 31, 2019		24,059,037
Net Loss	(16,238,898)				(16,238,898)
Other comprehensive (loss) gain	(1,390,448)			(1,390,448)
Option exercises	900	$ 1	899
Option exercises, shares		62,618
Issuance of restricted stock	200		200
Issuance of restricted stock, Shares		55,660
Grant and recognition of stock options	1,368		1,368
Recognition of parent stock options	86,461		86,461
Ending Balance at Dec. 31, 2020	(53,874,177)	$ 242	383,711	(1,523,038)	(52,735,092)
Ending Balance, Shares at Dec. 31, 2020		24,177,315
Net Loss	(30,212,770)				(30,212,770)
Other comprehensive (loss) gain	897,769			897,769
Initial public offering, net of offering costs of approximately $6.2 million	39,797,377	$ 38	39,797,339
Initial public offering, net of offering costs, shares		3,833,334
Conversion of convertible affiliated note	$ 65,423,496	$ 55	65,423,441
Conversion of convertible affiliated note, shares	5,451,958	5,451,958
Option exercises	$ 150		150
Option exercises, shares	41,746	41,746
Forfeiture of restricted stock	$ (100)		(100)
Forfeiture of restricted stock, shares		(27,830)
Grant and recognition of stock options	1,620,461		1,620,461
Recognition of parent stock options	124,263		124,263
Ending Balance at Dec. 31, 2021	$ 23,776,469	$ 335	$ 107,349,265	$ (625,269)	$ (82,947,862)
Ending Balance, Shares at Dec. 31, 2021		33,476,523

Consolidated Statement of Sto_2

Consolidated Statement of Stockholders' Equity (Deficit) (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)
Statement Of Stockholders Equity [Abstract]
Offering cost	$ 6.2

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (30,212,770)	$ (16,238,898)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	77,960	55,060
Share-based compensation	1,744,724	87,829
Interest accrued on convertible affiliated note	2,430,067	2,440,903
Change in fair value of convertible affiliated note	9,752,295	3,840,475
Gain on extinguishment of debt	(355,515)
Changes in operating assets and liabilities:
Prepaid expenses	488,752	(400,692)
Accounts payable	(152,042)	607,855
Deferred revenue		(194,371)
Accrued liabilities	(72,607)	(802,764)
Repayable advance received		1,801,793
Other operating assets and liabilities	3,472,019	465,040
Net cash used in operating activities	(12,827,117)	(8,337,770)
Cash flows from investing activities:
Purchases of equipment	(248,983)	(95,212)
Net cash used in investing activities	(248,983)	(95,212)
Cash flows from financing activities:
Proceeds from initial public offering, net of offering costs of approximately $6.2 million	39,797,377
Proceeds from issuance of convertible affiliated note	9,459,346	10,749,863
Proceeds from issuance of long-term debt		355,515
Proceeds from option exercises	150	900
Net cash provided by financing activities	49,256,873	11,106,278
Effect of exchange rate changes on cash	16,899	(281,176)
Net increase (decrease) in cash	36,197,672	2,392,120
Cash, beginning of period	2,691,156	299,036
Cash, end of period	38,888,828	$ 2,691,156
Supplemental disclosures - non-cash activities:
Conversion of convertible affiliated note to common stock, $0.00001 par value	65,423,496
Insurance financing agreement	$ 643,000

Consolidated Statement of Cas_2

Consolidated Statement of Cash Flows (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Statement Of Cash Flows [Abstract]
Offering cost	$ 6.2
Common stock, par value	$ 0.00001	$ 0.00001	$ 0.00001

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	(1) Description of Business MiNK Therapeutics, Inc. (“MiNK” or the “Company”) is a clinical stage biopharmaceutical company focused on developing allogeneic invariant natural killer T (“iNKT”) cell therapies to treat cancer and other life-threatening illnesses. The Company has incurred losses since inception and, as of December 31, 2021, had an accumulated deficit of $82.9 million. Since inception until the completion of the Company’s initial public offering (“IPO”), the Company financed its operations primarily through funding from Agenus Inc. (“Agenus”), its parent company. MiNK expects to continue incurring operating losses and negative cash flows for the foreseeable future. Based on the Company’s current plans and projections, MiNK believes its cash balance as of December 31, 2021 of $38.9 million will be sufficient to satisfy its liquidity requirements for more than one year from when these financial statements were issued. Management continually addresses the Company’s liquidity position and adjusts spending as needed in order to preserve liquidity. The Company’s future liquidity needs will be determined primarily by the success of its operations with respect to the progression of the Company’s product candidates and key development and regulatory events in the future. Potential sources of additional funding for the Company include: (1) pursuing collaboration, out-licensing and/or partnering opportunities for the Company’s portfolio programs and product candidates with one or more third parties, (2) securing additional debt financing and/or (3) selling equity securities. MiNK’s product candidates are in various stages of development and significant additional expenditures will be required if the Company starts new trials, encounters delays in its programs, applies for regulatory approvals, continues development of its technologies, expands its operations, and/or brings its product candidates to market. The eventual total cost of each clinical trial is dependent on a number of factors such as trial design, length of the trial, number of clinical sites, and number of patients. The process of obtaining and maintaining regulatory approvals for new therapeutic products is lengthy, expensive, and uncertain. Because all of the Company’s programs are at an early stage of clinical development, the Company is unable to reliably estimate the cost of completing its research and development programs or the timing for bringing such programs to various markets or substantial partnering or out-licensing arrangements, and, therefore, when, if ever, material cash inflows are likely to commence.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	( 2) Summary of Significant Accounting Policies (a) Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and include the accounts of MiNK and its subsidiaries. All significant intercompany transactions and accounts have been eliminated in consolidation. (b) Segment Information MiNK is managed and operated as one business segment. The entire business is managed by a single executive operating committee that reports to the chief executive officer. The Company does not operate separate lines of business with respect to any of its product candidates or geographic locations. Accordingly, the Company does not prepare discrete financial information with respect to separate product areas or by location and does not have separately reportable segments as defined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 280, Segment Reporting (c) Use of Estimates The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases those estimates on historical experience and on various assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates. (d) Equipment Equipment is carried at cost, $607,000 and $458,000 at December 31, 2021, and 2020, respectively. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, typically 4-10 years. Additions are capitalized, while repairs and maintenance are charged to expense as incurred. Depreciation expense was $ and $ , for the years ended December 31, 2021 and 2020 , respectively. (e) Fair Value Option Under the Fair Value Option subsection of ASC Subtopic 825-10, Financial Instruments – Overall, (f) Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash and the Note are carried at fair value (a Level 1 measurement and Level 2 measurement, respectively), determined according to the fair value hierarchy described above (see Note 12). The carrying values of the Company’s, accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities. (g) Foreign Currency Transactions Gains and losses from the Company’s foreign currency-based accounts and transactions, such as those resulting from the translation and settlement of receivables and payables denominated in foreign currencies, are included in the consolidated statements of operations within other income (expense). The Company does not currently use derivative financial instruments to manage the risks associated with foreign currency fluctuations. The Company recorded foreign currency losses of $407,000 for the year ended December 31, 2021 and foreign currency gains of $487,000 for the year ended December 31, 2020. (h) Research and Development Research and development expenses include the costs associated with the Company’s internal research and development activities, including salaries and benefits, share-based compensation, occupancy costs, clinical manufacturing costs, related administrative costs and research and development conducted for the Company by outside advisors. Research and development expenses also include the cost of clinical trial materials shipped to the Company’s research partners. Research and development costs are expensed as incurred. (i) Share-Based Compensation MiNK accounts for share-based compensation in accordance with the provisions of ASC 718, Compensation—Stock Compensation. (j) Income Taxes The Company’s operations were historically included in the consolidated U.S. Federal and state income tax returns of Agenus. The provision for income taxes has been determined based on the separate return method for the period presented. Income taxes are accounted for under the asset and liability method with deferred tax assets and liabilities recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and net operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which such items are expected to be reversed or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the consolidated statement of operations in the period that includes the enactment date. Deferred tax assets are recognized when they are more likely than not expected to be realized. (k) Net Loss Per Share Basic income and loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding. Diluted income per common share is calculated by dividing net income attributable to common stockholders by the weighted average number of common shares outstanding plus the dilutive effect of outstanding instruments such as stock options. Because the Company reported a net loss attributable to common stockholders for all periods presented, diluted loss per common share is the same as basic loss per common share, as the effect of utilizing the fully diluted share count would have reduced the net loss per common share. Therefore, the following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as of December 31, 2021 and 2020, as they would be anti-dilutive: 2021 2020 Stock options 4,871,822 2,713,418 Nonvested shares 695,750 — (l) Recent Accounting Pronouncements Recently Issued and Adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): simplifying the Accounting for Income Taxes. This ASU enhances and simplifies multiple aspects of the income tax accounting guidance in ASC 740. The Company adopted the standard on January 1, 2021. The adoption did not have a material impact on the Company’s consolidated financial statements. No other new accounting pronouncement issued or effective during the year ended December 31, 2021 had or is expected to have a material impact on the Company’s consolidated financial statements or disclosures.

Other Current Assets

Other Current Assets	12 Months Ended
	Dec. 31, 2021
Other Assets [Abstract]
Other Current Assets	( 3) Other Current Assets Other current assets consist of the following as of December 31, 2021 and 2020 (in thousands): December 31, 2021 2020 VAT receivable $ 23 $ 20 Insurance recovery — 234 Deferred offering costs — 539 Other 721 121 Total $ 744 $ 914

Equipment

Equipment	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Equipment	( 4) Equipment Equipment, net, consist of the following as of December 31, 2021 and 2020 (in thousands): December 31, 2021 2020 Equipment $ 776 $ 556 Less accumulated depreciation (169 ) (98 ) Equipment, net $ 607 $ 458

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	( 5) Income Taxes The Company is subject to taxation in the United States and in various state, local and foreign jurisdictions. The Company remains subject to examination by U.S. Federal, state, local and foreign tax authorities for tax years 2018 through 2021. With few exceptions, the Company is no longer subject to U.S. Federal state, and foreign examinations by tax authorities for the tax year 2017. However, net operating losses from the tax year 2017 would be subject to examination if and when used in a future tax return to offset taxable income. The Company’s policy is to recognize income tax related penalties and interest, if any, in its provision for income taxes and, to the extent applicable, in the corresponding income tax assets and liabilities, including any amounts for uncertain tax positions. As of December 31, 2021, the Company had available net operating loss carryforwards of $45.1 million for Federal and state income tax purposes, which are available to offset future Federal and state taxable income, if any. $44.9 million of these Federal net operating loss carryforwards do not expire, while the remaining net operating loss carryforwards expire in 2037. The Company’s ability to use these net operating losses is limited by change of control provisions under Internal Revenue Code Section 382 and may expire unused. The Company also has foreign net operating loss carryforwards, which do not expire, available to offset future foreign taxable income of $11.2 million generated in the United Kingdom and $11.8 million in Belgium. The potential impacts of such provisions are among the items considered and reflected in the Company’s assessment of its valuation allowance requirements. The tax effect of temporary differences and net operating loss carryforwards that give rise to significant portions of the deferred tax assets and deferred tax liabilities as of December 31, 2021 and 2020 are presented below (in thousands). December 31, 2021 2020 Deferred tax assets: U.S. Federal and state net operating loss carryforwards $ 12,356 $ 6,923 Foreign net operating loss carryforwards 5,641 4,349 Share-based compensation 472 52 Other 162 32 Total deferred tax assets 18,631 11,356 Less: valuation allowance (18,631 ) (11,356 ) Net deferred tax assets $ — $ — In assessing the realizability of deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which the net operating loss and tax credit carryforwards can be utilized or the temporary differences become deductible. The Company considers projected future taxable income and tax planning strategies in making this assessment. To fully realize the deferred tax asset, the Company will need to generate future taxable income sufficient to utilize net operating losses prior to their expiration. Based upon the Company’s history of not generating taxable income, the Company believes that it is more likely than not that deferred tax assets will not be realized through future earnings. Accordingly, a valuation allowance has been established for the full value of the deferred tax assets. The valuation allowance on the deferred tax assets increased by $7.3 million and $2.8 million during the years ended December 31, 2021 and 2020, respectively. Income tax benefit was nil for the years ended December 31, 2021 and 2020. Income taxes recorded differed from the amounts computed by applying the U.S. Federal income tax rate of 21% in 2021 and 2020 to loss before income taxes as a result of the following (in thousands). December 31, 2021 2020 Computed “expected” Federal tax benefit $ (6,344 ) $ (3,410 ) (Increase) reduction in income taxes benefit resulting from: Change in valuation allowance 6,404 2,836 Uncertain tax positions 68 (77 ) State and local income benefit, net of Federal income tax benefit (1,395 ) (557 ) Change in fair value of convertible affiliated note 677 806 Foreign rate differential 88 (113 ) Permanent differences 511 513 Other, net (9 ) 2 Income tax benefit $ — $ —

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2021
Accrued Liabilities Current [Abstract]
Accrued Liabilities	(6) Accrued Liabilities Accrued liabilities consist of the following as of December 31, 2021 and 2020 (in thousands): December 31, 2021 2020 Payroll $ 575 $ 240 Professional fees 531 1,186 Research services 656 66 VAT — 324 Other 2 43 Total $ 1,764 $ 1,859

Equity

Equity	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Equity	( 7) Equity In September 2021, the Company effected a 2.783-for-one split of the Company’s common stock. All common share, per share and related information included in the accompanying financial statements have been adjusted retroactively, where applicable, to reflect the split. In September 2021, the Company’s stockholders approved an amendment to the Company’s Amended and Restated Certificate of Incorporation, to increase the number of authorized shares of common stock to 35,000,000, with a par value $0.00001 per share. In connection with the Company’s IPO, the Company’s authorized capital stock increased to 155,000,000 shares, all with a par value of $0.00001 per share, of which: • 150,000,000 • 5,000,000 In October 2021, the Company completed an IPO of 3,333,334 shares of its common stock, at a public offering price of $12.00 per share. The gross proceeds from the offering, before deducting underwriting discounts, commissions and other offering expenses, were approximately $46.0 million, which includes the exercise of the underwriters option to acquire an additional 500,000 shares at the public offering price, which shares were delivered in November 2021. Underwriting discounts, commissions and other offering expenses, were approximately $6.2 million, resulting in net proceeds of approximately $39.8 million. Subsequent to the completed offering, the Company continues to be majority owned by Agenus. In October 2021, in connection with the Company’s IPO, the Note was automatically converted into 5,451,958 shares of the Company’s common stock. Refer to Note 10 for additional detail.

Share-based Compensation Plans

Share-based Compensation Plans	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-based Compensation Plans	(8) Share-based Compensation Plans The Company’s 2018 Equity Incentive Plan (the “2018 Plan”) provided for the grant of incentive stock options intended to qualify under Section 422 of the Internal Revenue Code, nonstatutory stock options, restricted stock, unrestricted stock and other equity-based awards, such as stock appreciation rights, and stock units including restricted stock units for up to approximately 13.9 million shares of the Company’s common stock (subject to adjustment in the event of stock splits and other similar events). As of December 31, 2021, no shares remain available for issuance under the 2018 Plan. In connection with the Company’s IPO, MiNK’s board of directors adopted the MiNK Therapeutics, Inc. 2021 Equity Incentive Plan (the “2021 Plan”). The 2021 Plan provides for the grant of incentive stock options intended to qualify under Section 422 of the Code, nonstatutory stock options, restricted stock, unrestricted stock and other equity-based awards, for an initial share pool of approximately 6.1 million shares of the Company’s common stock (subject to adjustment in the event of stock splits and other similar events). The initial share pool will automatically increase on January 1st of each year from 2022 to 2031 by the lesser of (i) four percent of the number of shares of the Company’s common stock outstanding as of the close of business on the immediately preceding December 31st and (ii) the number of shares determined by the Company’s board of directors on or prior to such date for such year. In connection with the Company’s IPO, MiNK’s board of directors adopted the MiNK Therapeutics, Inc. 2021 Employee Stock Purchase Plan (the “ESPP”). The ESPP provides eligible employees the opportunity to acquire the Company’s common stock in a program designed to comply with Section 423 of the Code. There are 375,000 shares reserved for issuance under the ESPP, plus an automatic annual increase, as of January 1st of each year beginning in 2022 and continuing through and including 2031, equal to the lesser of (i) one percent of the number of shares of the Company’s common stock outstanding as of the close of business on the immediately preceding December 31st and (ii) the number of shares determined by the Company’s board of directors on or prior to such date for such year, up to a maximum of approximately 3.5 million shares in the aggregate. The Company primarily uses the Black-Scholes option pricing model to value options granted to employees and non-employees, as well as options granted to members of the Company’s Board of Directors. All stock option grants have 10-year terms and generally vest ratably over a 3 or 4-year period. The fair value of each option granted during the period was estimated on the date of grant using the following weighted average assumptions: 2021 2020 Expected volatility 67 % 65 % Expected term in years 6 7 Risk-free interest rate 0.6 % 1.8 % Dividend yield 0 % 0 % The expected term of stock options granted is based on historical data and other factors and represents the period of time that stock options are expected to be outstanding prior to exercise. The risk-free interest rate is based on U.S. Treasury strips with maturities that match the expected term on the date of grant. A summary of option activity for 2021 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at December 31, 2020 2,713,418 $ 0.01 Granted 2,239,576 3.03 Exercised (41,746 ) 0.01 Forfeited (39,426 ) 1.39 Outstanding at December 31, 2021 4,871,822 1.38 8.41 $ 14,982,873 Vested or expected to vest at December 31, 2021 4,871,822 1.38 8.41 $ 14,982,873 Exercisable at December 31, 2021 1,696,250 $ 0.08 7.84 $ 7,428,962 The weighted average grant-date fair values of options granted during the years ended December 31, 2021 and 2020, was $1.76 and $0.01, respectively. During both 2021 and 2020, all options were granted with exercise prices equal to the market value of the underlying shares of common stock on the grant date. As of December 31, 2021, there was $2.6 million of unrecognized share-based compensation expense related to stock options granted to employees, consultants and directors which, if all milestones are achieved, will be recognized over a weighted average period of 2.2 years. A summary of non-vested stock activity for 2021 is presented below: Nonvested Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2020 55,660 $ 0.01 Granted 695,750 $ 3.03 Forfeited (27,830 ) $ 0.01 Outstanding at December 31, 2021 723,580 $ 2.91 As of December 31, 2021, there was $1.8 million of unrecognized share-based compensation expense related to these non-vested shares which will be recognized over a weighted average period of 1.7 years. Stock based compensation expense also includes expense related to awards granted to employees of the Company from the Agenus 2019 Equity Incentive Plan. The impact on the Company’s results of operations from share-based compensation for the year ended December 31, 2021 and 2020, was as follows (in thousands): 2021 2020 Research and development $ 200 $ 56 General and administrative 1,545 32 Total share-based compensation expense $ 1,745 $ 88

Research and Development Agreem

Research and Development Agreement	12 Months Ended
	Dec. 31, 2021
Research And Development [Abstract]
Research and Development Agreement	(9) Research and Development Agreement In December 2018, the Company entered into an agreement with the Belgium Walloon Region Government in which the Walloon Region agreed to provide a grant of €1.3 million and a repayable advance of €8.3 million for the development of one of the Company’s research programs. As of December 31, 2019, the Company received $881,000 of the grant portion and $3.4 million of the repayable advance. During the year ended December 31, 2019 the Company recognized grant revenue of $690,000 in accordance with ASC 958-605 and included in its consolidated balance sheet at December 31, 2019 deferred revenue of $191,000 related to the grant funds received and a long-term liability of $3.4 million related to the repayable advance received. During 2020, the Company discontinued research efforts related to this program and is evaluating its options in accordance with the terms of the agreement. Accordingly, in the year ended December 31, 2020, the Company recorded the balance of the deferred revenue as other income in its consolidated statement of operations. In addition, due to the uncertainty of the terms of the termination of the agreement, the Company has included the refundable advance balance of $5.3 million in other current liabilities in its consolidated balance sheet at December 31, 2021.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	(10) Related Party Transactions Until the completion of its IPO, the Company relied on Agenus for all of its working capital requirements. For the periods presented, certain of the Company’s operations were fully integrated with Agenus, including, but not limited to, corporate functions such as finance, human resources, information technology and legal functions. The Company’s consolidated financial statements reflect all costs of doing business related to these operations. In September 2021, the Company entered into a new Intellectual Property Assignment and License Agreement with Agenus (the “New Assignment and License Agreement”), upon which the prior intercompany agreement between Agenus and MiNK was terminated. Pursuant to the New Assignment and License Agreement, Agenus assigned to the Company certain patent rights and know-how related to its iNKT product candidates and other patents and know-how related to its business. In addition to the patent rights assigned to the Company by Agenus, the Company also received an exclusive, royalty-free, sublicensable license to research, develop, manufacture and commercialize certain licensed technology in the field. The New Assignment and License Agreement further provides for the Company to grant Agenus a field-limited, non-exclusive, royalty-free license under the assigned patent rights, subject to MiNK’s discretion and provided such access would not reasonably result in a disruption of planned MiNK activities. Agenus has also agreed to provide the Company with Agenus’ biological material upon written request in order for the Company to use such material in its development activities of a combination therapy. Agenus may withhold the transfer of biological material, including, but not limited to, checkpoint modulating antibodies, for various reasons, including if such transfer would reasonably result in a disruption of planned Agenus activities. For any materials Agenus does share with the Company, the parties have agreed to enter into a separate agreement governing the transfer and providing for joint ownership of the data. Agenus has agreed that during the full term of the New Assignment and License Agreement, and for three years thereafter, it will not develop, manufacture or commercialize an iNKT cell therapy, directly or indirectly by transferring such technology. The Company has the sole responsibility to develop, manufacture and commercialize products under this New Assignment and License Agreement. The Company may terminate the New Assignment and License Agreement without cause upon 90 days ’ prior written notice to Agenus. Either party may terminate if they believe there has been a material breach which has not been cured within 90 days (or 45 days for breach of payment obligations) of receiving such notice . In September 2021, the Company entered into a new Intercompany General & Administrative Services Agreement with Agenus (the “New Intercompany Services Agreement”). Pursuant to the New Intercompany Services Agreement, Agenus provides MiNK with administrative support, including, without limitation, financial, legal, information technology and human resources administrative support and non-administrative services as may be agreed to between the parties from time to time. Agenus provides the services under the New Intercompany Services Agreement on a cost-plus basis and the Company is required to pay 105% of Agenus’ costs. Under the New Intercompany Services Agreement, the Company is also entitled to use Agenus’ business offices and laboratory space and equipment in exchange for the Company contributing a proportionate payment for the use of such facilities and equipment. Either party may terminate the New Intercompany Services Agreement upon 30 days’ prior written notice Allocated Agenus services primarily include payroll related expenses, facility costs and stock-based compensation and are included in the accompanying financial statements based on certain estimates and allocations. The allocation methods primarily include time devoted to activities and headcount-based allocations. Agenus business services and occupancy costs are allocated to the Company based on the Company’s headcount as a percentage of Agenus’. Under the prior intercompany services agreement between Agenus and MiNK, research services were charged between the entities based on hours spent on specific projects applied to hourly wage rates. As such, these allocations may not be indicative of the actual amounts that would have been recorded had the Company operated as an independent, publicly traded company for the periods presented. Allocation of Agenus Services, net, of $2.4 and $1.3 million for the periods ended December 31, 2021 and 2020, respectively, is included in Operating expenses in the Company’s statement of operations and comprehensive loss and Due to related parties in the Company’s consolidated balance sheet. In February 2021, the Company entered into the Note with Agenus with terms identical to the convertible promissory note, as amended, issued to Agenus on April 1, 2019, increasing the amount of borrowing capacity to up to $50.0 million and extending the maturity to July 1, 2022. In September 2021, the Company entered into an amendment to the Note with Agenus to provide, among other things, that the Note would automatically convert into the Company’s common stock upon the completion of the Company’s IPO. In accordance with the terms of the Note, interest was computed on the basis of a 360-day year at 8% and accrued but was not payable until converted or paid. The Note was automatically converted, at a rate equal to the quotient obtained by dividing (i) the amount due on the date of conversion by (ii) 80% of the per share price of the Company’s common stock sold in the Company’s IPO, into 5,451,958 shares of the Company’s common stock upon completion of the IPO in October 2021, and was not outstanding at December 31, 2021. The Note had a principal balance of $36.1 million at December 31, 2020.

Other Long-term Liabilities

Other Long-term Liabilities	12 Months Ended
	Dec. 31, 2021
Other Longterm Debt Current And Noncurrent [Abstract]
Other Long-Term Liabilities	(11) Other Long-Term Liabilities

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurement	(12) Fair Value Measurement The Company measured the Note at fair value. In connection with the Company’s IPO, the Note was automatically converted into 5,451,958 shares of the Company’s common stock and was not outstanding as of December 31, 2021. The fair value of the Note at December 31, 2020 was $43.8 million, based on the Level 2 valuation hierarchy of the fair value measurements standard using a scenario based present value methodology that was derived by evaluating the nature and terms of each note and considering the prevailing economic and market conditions at the balance sheet date. The principal amount of the Note at December 31, 2020 was $36.1 million.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2021
Loss Contingency [Abstract]
Contingencies	(13) Contingencies The Company may currently be, or may become, a party to legal proceedings. While the Company currently believes that the ultimate outcome of any of these proceedings will not have a material adverse effect on its financial position, results of operations, or liquidity, litigation is subject to inherent uncertainty. Furthermore, litigation consumes both cash and management attention.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2021
Compensation And Retirement Disclosure [Abstract]
Benefit Plans	(14) Benefit Plans The Company’s employees are eligible to participate in the Agenus Inc. 401(k) Savings Plan in the United States and a defined contribution Group Personal Pension Plan in the United Kingdom (the “Plans”) for all eligible employees, as defined in the Plans. Participants may contribute a portion of their compensation, subject to a maximum annual amount, as established by the applicable taxing authority. Each participant is fully vested in his or her contributions and related earnings and losses. For the years ended December 31, 2021 and 2020, the Company expensed $86,000 and $84,000, respectively, related to the discretionary contribution to the Plans.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	(a) Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and include the accounts of MiNK and its subsidiaries. All significant intercompany transactions and accounts have been eliminated in consolidation.
Segment Information	(b) Segment Information MiNK is managed and operated as one business segment. The entire business is managed by a single executive operating committee that reports to the chief executive officer. The Company does not operate separate lines of business with respect to any of its product candidates or geographic locations. Accordingly, the Company does not prepare discrete financial information with respect to separate product areas or by location and does not have separately reportable segments as defined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 280, Segment Reporting
Use of Estimates	(c) Use of Estimates The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The Company bases those estimates on historical experience and on various assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates.
Equipment	(d) Equipment Equipment is carried at cost, $607,000 and $458,000 at December 31, 2021, and 2020, respectively. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, typically 4-10 years. Additions are capitalized, while repairs and maintenance are charged to expense as incurred. Depreciation expense was $ and $ , for the years ended December 31, 2021 and 2020 , respectively.
Fair Value Option	(e) Fair Value Option Under the Fair Value Option subsection of ASC Subtopic 825-10, Financial Instruments – Overall,
Fair Value Measurements	(f) Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash and the Note are carried at fair value (a Level 1 measurement and Level 2 measurement, respectively), determined according to the fair value hierarchy described above (see Note 12). The carrying values of the Company’s, accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities.
Foreign Currency Transactions	(g) Foreign Currency Transactions Gains and losses from the Company’s foreign currency-based accounts and transactions, such as those resulting from the translation and settlement of receivables and payables denominated in foreign currencies, are included in the consolidated statements of operations within other income (expense). The Company does not currently use derivative financial instruments to manage the risks associated with foreign currency fluctuations. The Company recorded foreign currency losses of $407,000 for the year ended December 31, 2021 and foreign currency gains of $487,000 for the year ended December 31, 2020.
Research and Development	(h) Research and Development Research and development expenses include the costs associated with the Company’s internal research and development activities, including salaries and benefits, share-based compensation, occupancy costs, clinical manufacturing costs, related administrative costs and research and development conducted for the Company by outside advisors. Research and development expenses also include the cost of clinical trial materials shipped to the Company’s research partners. Research and development costs are expensed as incurred.
Share-Based Compensation	(i) Share-Based Compensation MiNK accounts for share-based compensation in accordance with the provisions of ASC 718, Compensation—Stock Compensation.
Income Taxes	(j) Income Taxes The Company’s operations were historically included in the consolidated U.S. Federal and state income tax returns of Agenus. The provision for income taxes has been determined based on the separate return method for the period presented. Income taxes are accounted for under the asset and liability method with deferred tax assets and liabilities recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and net operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which such items are expected to be reversed or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the consolidated statement of operations in the period that includes the enactment date. Deferred tax assets are recognized when they are more likely than not expected to be realized.
Net Loss Per Share	(k) Net Loss Per Share Basic income and loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding. Diluted income per common share is calculated by dividing net income attributable to common stockholders by the weighted average number of common shares outstanding plus the dilutive effect of outstanding instruments such as stock options. Because the Company reported a net loss attributable to common stockholders for all periods presented, diluted loss per common share is the same as basic loss per common share, as the effect of utilizing the fully diluted share count would have reduced the net loss per common share. Therefore, the following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as of December 31, 2021 and 2020, as they would be anti-dilutive: 2021 2020 Stock options 4,871,822 2,713,418 Nonvested shares 695,750 —
Recent Accounting Pronouncements	(l) Recent Accounting Pronouncements Recently Issued and Adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): simplifying the Accounting for Income Taxes. This ASU enhances and simplifies multiple aspects of the income tax accounting guidance in ASC 740. The Company adopted the standard on January 1, 2021. The adoption did not have a material impact on the Company’s consolidated financial statements. No other new accounting pronouncement issued or effective during the year ended December 31, 2021 had or is expected to have a material impact on the Company’s consolidated financial statements or disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedule of Anti-dilutive Securities	Therefore, the following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding as of December 31, 2021 and 2020, as they would be anti-dilutive: 2021 2020 Stock options 4,871,822 2,713,418 Nonvested shares 695,750 —

Other Current Assets (Tables)

Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2021
Other Assets [Abstract]
Schedule of Other Current Assets	Other current assets consist of the following as of December 31, 2021 and 2020 (in thousands): December 31, 2021 2020 VAT receivable $ 23 $ 20 Insurance recovery — 234 Deferred offering costs — 539 Other 721 121 Total $ 744 $ 914

Equipment (Tables)

Equipment (Tables)	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Summary of Equipment, Net	Equipment, net, consist of the following as of December 31, 2021 and 2020 (in thousands): December 31, 2021 2020 Equipment $ 776 $ 556 Less accumulated depreciation (169 ) (98 ) Equipment, net $ 607 $ 458

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Components of Deferred Tax Assets and Liabilities	The tax effect of temporary differences and net operating loss carryforwards that give rise to significant portions of the deferred tax assets and deferred tax liabilities as of December 31, 2021 and 2020 are presented below (in thousands). December 31, 2021 2020 Deferred tax assets: U.S. Federal and state net operating loss carryforwards $ 12,356 $ 6,923 Foreign net operating loss carryforwards 5,641 4,349 Share-based compensation 472 52 Other 162 32 Total deferred tax assets 18,631 11,356 Less: valuation allowance (18,631 ) (11,356 ) Net deferred tax assets $ — $ —
Income Taxes Recorded Differed from Amounts Computed	Income taxes recorded differed from the amounts computed by applying the U.S. Federal income tax rate of 21% in 2021 and 2020 to loss before income taxes as a result of the following (in thousands). December 31, 2021 2020 Computed “expected” Federal tax benefit $ (6,344 ) $ (3,410 ) (Increase) reduction in income taxes benefit resulting from: Change in valuation allowance 6,404 2,836 Uncertain tax positions 68 (77 ) State and local income benefit, net of Federal income tax benefit (1,395 ) (557 ) Change in fair value of convertible affiliated note 677 806 Foreign rate differential 88 (113 ) Permanent differences 511 513 Other, net (9 ) 2 Income tax benefit $ — $ —

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2021
Accrued Liabilities Current [Abstract]
Summary of Accrued liabilities	Accrued liabilities consist of the following as of December 31, 2021 and 2020 (in thousands): December 31, 2021 2020 Payroll $ 575 $ 240 Professional fees 531 1,186 Research services 656 66 VAT — 324 Other 2 43 Total $ 1,764 $ 1,859

Share-based Compensation Plans

Share-based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Fair value of Options Granted Under Weighted Average Assumptions	The fair value of each option granted during the period was estimated on the date of grant using the following weighted average assumptions: 2021 2020 Expected volatility 67 % 65 % Expected term in years 6 7 Risk-free interest rate 0.6 % 1.8 % Dividend yield 0 % 0 %
Summary of Option Activity	A summary of option activity for 2021 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at December 31, 2020 2,713,418 $ 0.01 Granted 2,239,576 3.03 Exercised (41,746 ) 0.01 Forfeited (39,426 ) 1.39 Outstanding at December 31, 2021 4,871,822 1.38 8.41 $ 14,982,873 Vested or expected to vest at December 31, 2021 4,871,822 1.38 8.41 $ 14,982,873 Exercisable at December 31, 2021 1,696,250 $ 0.08 7.84 $ 7,428,962
Summary of Non-vested Stock Activity	A summary of non-vested stock activity for 2021 is presented below: Nonvested Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2020 55,660 $ 0.01 Granted 695,750 $ 3.03 Forfeited (27,830 ) $ 0.01 Outstanding at December 31, 2021 723,580 $ 2.91
Summary of Share-based Compensation Expense	The impact on the Company’s results of operations from share-based compensation for the year ended December 31, 2021 and 2020, was as follows (in thousands): 2021 2020 Research and development $ 200 $ 56 General and administrative 1,545 32 Total share-based compensation expense $ 1,745 $ 88

Description of Business - Addit

Description of Business - Additional Information (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ 82,947,862	$ 52,735,092
Cash	$ 38,888,828	$ 2,691,156

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021USD ($)Segmentshares	Dec. 31, 2020USD ($)
Accounting Policies [Line Items]
Number of business segment | Segment	1
Equipment	$ 606,595	$ 458,384
Depreciation expense	$ 77,960	55,060
Conversion of convertible affiliated note, shares | shares	5,451,958
Foreign currency gains	$ (407,000)	487,000
Agenus
Accounting Policies [Line Items]
Outstanding principal amount of notes		36,100,000
Equipment
Accounting Policies [Line Items]
Depreciation expense	$ 78,000	$ 55,000
Equipment | Minimum
Accounting Policies [Line Items]
Estimated useful lives of assets	4 years
Equipment | Maximum
Accounting Policies [Line Items]
Estimated useful lives of assets	10 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Anti-dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total anti-dilutive securities	4,871,822	2,713,418
Non-Vested Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total anti-dilutive securities	695,750

Other Current Assets - Schedule

Other Current Assets - Schedule of Other Current Assets (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Other Assets [Abstract]
VAT receivable	$ 23,000	$ 20,000
Insurance recovery		234,000
Deferred offering costs		539,000
Other	721,000	121,000
Total	$ 744,321	$ 913,578

Equipment - Summary of Equipmen

Equipment - Summary of Equipment, Net (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Equipment	$ 776,000	$ 556,000
Less accumulated depreciation	(168,605)	(98,160)
Equipment, net	$ 606,595	$ 458,384

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax [Line Items]
Tax years open for examination	2018 2019 2020 2021
Net operating loss carryforwards	$ 44.9
Net operating loss carryforwards, Expiration date	Dec. 31, 2037
Valuation allowance, Deferred tax asset, increase (decrease)	$ 7.3	$ 2.8
Federal income tax rate	21.00%	21.00%
Federal
Income Tax [Line Items]
Net operating loss carryforwards	$ 45.1
State
Income Tax [Line Items]
Net operating loss carryforwards	45.1
Foreign | United Kingdom
Income Tax [Line Items]
Net operating loss carryforwards	11.2
Foreign | Belgium
Income Tax [Line Items]
Net operating loss carryforwards	$ 11.8

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
U.S. Federal and state net operating loss carryforwards	$ 12,356	$ 6,923
Foreign net operating loss carryforwards	5,641	4,349
Share-based compensation	472	52
Other	162	32
Total deferred tax assets	18,631	11,356
Less: valuation allowance	$ (18,631)	$ (11,356)

Income Taxes - Income Taxes Rec

Income Taxes - Income Taxes Recorded Differed from Amounts Computed (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Computed “expected” Federal tax benefit	$ (6,344)	$ (3,410)
(Increase) reduction in income taxes benefit resulting from:
Change in valuation allowance	6,404	2,836
Uncertain tax positions	68	(77)
State and local income benefit, net of Federal income tax benefit	(1,395)	(557)
Change in fair value of convertible affiliated note	677	806
Foreign rate differential	88	(113)
Permanent differences	511	513
Other, net	$ (9)	$ 2

Accrued Liabilities - Summary o

Accrued Liabilities - Summary of Accrued liabilities (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Accrued Liabilities Current [Abstract]
Payroll	$ 575,000	$ 240,000
Professional fees	531,000	1,186,000
Research services	656,000	66,000
VAT		324,000
Other	2,000	43,000
Total	$ 1,763,688	$ 1,859,068

Equity - Additional Information

Equity - Additional Information (Details) $ / shares in Units, $ in Millions	1 Months Ended
	Nov. 30, 2021shares	Oct. 31, 2021USD ($)$ / sharesshares	Sep. 30, 2021$ / sharesshares	Dec. 31, 2021$ / sharesshares	Dec. 31, 2020$ / sharesshares
Class Of Stock [Line Items]
Stock split ratio			2.783
Stock split ratio, description			In September 2021, the Company effected a 2.783-for-one split of the Company’s common stock.
Common stock, shares authorized			35,000,000	150,000,000	35,000,000
Common stock, par value | $ / shares			$ 0.00001	$ 0.00001	$ 0.00001
Note converted into common stock		5,451,958
IPO
Class Of Stock [Line Items]
Common stock, shares authorized			150,000,000
Common stock, par value | $ / shares			$ 0.00001
Authorized capital stock increased			155,000,000
Preferred stock, shares authorized			5,000,000
Initial public offering, net of offering costs, shares	500,000	3,333,334
Shares issued, price per share | $ / shares		$ 12
Proceeds from issuance of common stock | $		$ 46
Underwriting discounts, commissions and other offering expenses | $		6.2
Net proceeds from issuance of common stock | $		$ 39.8

Share-based Compensation Plan_2

Share-based Compensation Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant-date fair values of options granted	$ 1.76	$ 0.01
Unrecognized share-based compensation expense related to stock options	$ 2.6
Weighted average period of unrecognized share-based compensation expense	1 year 8 months 12 days
Unrecognized share-based compensation expense related to non-vested shares	$ 1.8
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option grants, term	10-year
Weighted average period of unrecognized share-based compensation expense	2 years 2 months 12 days
Maximum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option, vesting period	4 years
Minimum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option, vesting period	3 years
2018 EIP | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant	0
2018 EIP | Maximum | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant	13,900,000
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares grated as a result of equity incentive plan	6,100,000
Percentage of shares of company's common stock outstanding	4.00%
Shares reserved for issuance under ESPP	375,000
2021 Employee Stock Purchase Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance under ESPP	3,500,000
Ratio of annual increase shares reserved for issuance under ESPP to number of shares of common stock outstanding	1.00%

Share-based Compensation Plan_3

Share-based Compensation Plans - Summary of Fair value of Options Granted Under Weighted Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected volatility	67.00%	65.00%
Expected term in years	6 years	7 years
Risk-free interest rate	0.60%	1.80%
Dividend yield	0.00%	0.00%

Share-based Compensation Plan_4

Share-based Compensation Plans - Summary of Option Activity (Details)	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options, Outstanding at Beginning Balance | shares	2,713,418
Options, Granted | shares	2,239,576
Options, Exercised | shares	(41,746)
Options, Forfeited | shares	(39,426)
Options, Outstanding at Ending Balance | shares	4,871,822
Options, Vested or expected to vest at December 31, 2021 | shares	4,871,822
Options, Exercisable at December 31, 2021 | shares	1,696,250
Outstanding at Beginning Balance, Weighted Average Exercise Price | $ / shares	$ 0.01
Granted, Weighted Average Exercise Price | $ / shares	3.03
Exercised, Weighted Average Exercise Price | $ / shares	0.01
Forfeited, Weighted Average Exercise Price | $ / shares	1.39
Outstanding at Ending Balance, Weighted Average Exercise Price | $ / shares	1.38
Vested or expected to vest at December 31, 2021, Weighted Average Exercise Price | $ / shares	1.38
Exercisable at December 31, 2021, Weighted Average Exercise Price | $ / shares	$ 0.08
Outstanding at December 31, 2021, Weighted Average Remaining Contractual Term	8 years 4 months 28 days
Vested or expected to vest at December 31, 2021, Weighted Average Remaining Contractual Term	8 years 4 months 28 days
Exercisable at December 31, 2021, Weighted Average Remaining Contractual Term	7 years 10 months 2 days
Outstanding at December 31, 2021, Aggregate Intrinsic Value | $	$ 14,982,873
Vested or expected to vest at December 31, 2021, Aggregate Intrinsic Value | $	14,982,873
Exercisable at December 31, 2021, Aggregate Intrinsic Value | $	$ 7,428,962

Share-based Compensation Plan_5

Share-based Compensation Plans - Summary of Non-vested Stock Activity (Details)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Nonvested Shares, Outstanding at Beginning Balance | shares	55,660
Nonvested Shares, Granted | shares	695,750
Nonvested Shares, Forfeited | shares	(27,830)
Nonvested Shares, Outstanding at Ending Balance | shares	723,580
Outstanding at Beginning Balance, Weighted Average Grant Date Fair Value | $ / shares	$ 0.01
Granted, Weighted Average Grant Date Fair Value | $ / shares	3.03
Forfeited, Weighted Average Grant Date Fair Value | $ / shares	0.01
Outstanding at Ending Balance, Weighted Average Grant Date Fair Value | $ / shares	$ 2.91

Share-based Compensation Plan_6

Share-based Compensation Plans - Summary of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 1,745	$ 88
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	200	56
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 1,545	$ 32

Research and Development Agre_2

Research and Development Agreement - Additional Information (Details) € in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2018EUR (€)	Dec. 31, 2019USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Other current liabilities			$ 5,760,609	$ 5,690,796
Research and Development Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development agreement amount granted	€ 1.3	$ 881,000
Repayable advance of development	€ 8.3	3,400,000
Revenue recognized		690,000
Deferred revenue, revenue recognized		191,000
Repayable advance received noncurrent		$ 3,400,000
Other current liabilities			$ 5,300,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Feb. 28, 2021
Related Party Transaction [Line Items]
Promissory note principal balance			$ 36.1
Agenus
Related Party Transaction [Line Items]
Period of license agreement	3 years
Terminate license agreement period	90 days
Period for breach of payment obligations	45 days
Related party transaction, description		The Company has the sole responsibility to develop, manufacture and commercialize products under this New Assignment and License Agreement. The Company may terminate the New Assignment and License Agreement without cause upon 90 days’ prior written notice to Agenus. Either party may terminate if they believe there has been a material breach which has not been cured within 90 days (or 45 days for breach of payment obligations) of receiving such notice.
Promissory note principal balance			36.1
Initial public offering, net of offering costs, shares		5,451,958
Percentage value of common stock sold in initial public offering		80.00%
Percentage of computation of interest		8.00%
Agenus | Maximum
Related Party Transaction [Line Items]
Increasing amount of borrowing capacity				$ 50
Agenus | Operating Expenses
Related Party Transaction [Line Items]
Expenses from transactions with related party		$ 2.4	$ 1.3
Agenus | New Intercompany Service Agreement
Related Party Transaction [Line Items]
Percentage of service cost	105.00%
Service agreement notice period	30 days

Other Long-term Liabilities - A

Other Long-term Liabilities - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2020	Dec. 31, 2021
Debt Instrument [Line Items]
Aggregate loan proceeds	$ 356,000
Gain on extinguishment of debt		$ 355,515
Paycheck Protection Program Loan
Debt Instrument [Line Items]
Gain on extinguishment of debt		$ 356,000

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Conversion of convertible affiliated note, shares	5,451,958
Promissory note principal balance		$ 36.1
Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of note		$ 43.8

Benefit Plans - Additional Info

Benefit Plans - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Expense related to discretionary contribution to the Plans	$ 86,000	$ 84,000