Ikena Oncology (IKNA) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Oct. 31, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Entity Registrant Name	IKENA ONCOLOGY, INC.
Entity Central Index Key	0001835579
Entity Incorporation, State or Country Code	DE
Entity File Number	001-40287
Entity Tax Identification Number	81-1697316
Entity Address, Address Line One	645 Summer Street
Entity Address, Address Line Two	Suite 101
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02210
City Area Code	857
Local Phone Number	273-8343
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Shell Company	false
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	IKNA
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		35,906,794

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 245,899	$ 162,491
Prepaid expenses and other current assets	5,966	3,478
Total current assets	251,865	165,969
Property and equipment, net	2,125	1,393
Right-of-use asset	6,843	170
Other assets	872	872
Total assets	261,705	168,404
Current liabilities:
Accounts payable	1,928	2,122
Accrued expenses and other current liabilities	4,232	5,402
Operating lease liability	1,838	186
Deferred revenue	22,574	20,622
Total current liabilities	30,572	28,332
Long-term portion of lease liabilities	5,449	0
Deferred revenue, net of current portion	22,421	35,141
Total liabilities	58,442	63,473
Commitments and contingencies (Note 13)
Redeemable convertible preferred stock (Series A, A-1 and B), $0.001 par value, No shares authorized, issued and outstanding as of September 30, 2021; 169,396,576 shares authorized, issued and outstanding as of December 31, 2020 (liquidation preference of $0 as of September 30, 2021 and $202.2 million as of December 31, 2020)	0	205,979
Stockholders’ equity (deficit):
Preferred Stock, $0.001 par value - 10,000,000 shares authorized as of September 30, 2021 and no shares authorized as of December 31, 2020; No shares issued and outstanding as of September 30, 2021 or December 31, 2020
Common stock, $0.001 par value, 150,000,000 shares authorized, 35,877,794 issued and outstanding as of September 30, 2021; 230,000,000 shares authorized, 3,096,903 issued and outstanding as of December 31, 2020	36	3
Additional paid-in capital	351,478	10,288
Accumulated deficit	(148,251)	(111,339)
Total stockholders’ equity (deficit)	203,263	(101,048)
Total liabilities, redeemable convertible preferred stock and stockholders’ equity (deficit)	$ 261,705	$ 168,404

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	0	169,396,576
Redeemable convertible preferred stock, shares issued	0	169,396,576
Redeemable convertible preferred stock, shares outstanding	0	169,396,576
Redeemable convertible preferred stock, liquidation preference	$ 0	$ 202.2
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	230,000,000
Common stock, shares issued	35,877,794	3,096,903
Common stock, shares outstanding	35,877,794	3,096,903

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Research and development revenue under collaboration agreement	$ 3,746	$ 2,829	$ 10,768	$ 9,129
Revenue from Contract with Customer, Product and Service [Extensible List]	Research And Development Member	Research And Development Member	Research And Development Member	Research And Development Member
Operating expenses:
Research and development	$ 13,375	$ 7,218	$ 34,770	$ 21,445
General and administrative	4,893	1,844	12,928	6,150
Total operating expenses	18,268	9,062	47,698	27,595
Loss from operations	(14,522)	(6,233)	(36,930)	(18,466)
Other income, net	7	11	18	261
Net loss and comprehensive loss	$ (14,515)	$ (6,222)	$ (36,912)	$ (18,205)
Net loss per share attributable to common stockholders basic and diluted	$ (0.40)	$ (2.34)	$ (1.46)	$ (6.85)
Weighted-average common stocks outstanding, basic and diluted	35,860,284	2,658,800	25,305,212	2,657,793

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Redeemable Convertible Preferred Stock
Beginning Balance, Shares at Dec. 31, 2019					75,727,268
Beginning Balance at Dec. 31, 2019					$ 78,867
Beginning Balance, Shares at Dec. 31, 2019		2,651,333
Beginning Balance at Dec. 31, 2019	$ (61,463)	$ 3	$ 5,617	$ (67,083)
Exercise of stock options	21		21
Exercise of stock options, Shares		7,461
Stock-based compensation	375		375
Net loss and comprehensive loss	(6,945)			(6,945)
Ending Balance, Shares at Mar. 31, 2020					75,727,268
Ending Balance at Mar. 31, 2020					$ 78,867
Ending Balance, Shares at Mar. 31, 2020		2,658,794
Ending Balance at Mar. 31, 2020	(68,012)	$ 3	6,013	(74,028)
Beginning Balance, Shares at Dec. 31, 2019					75,727,268
Beginning Balance at Dec. 31, 2019					$ 78,867
Beginning Balance, Shares at Dec. 31, 2019		2,651,333
Beginning Balance at Dec. 31, 2019	(61,463)	$ 3	5,617	(67,083)
Net loss and comprehensive loss	(18,205)
Ending Balance, Shares at Sep. 30, 2020					75,727,268
Ending Balance at Sep. 30, 2020					$ 78,867
Ending Balance, Shares at Sep. 30, 2020		2,658,794
Ending Balance at Sep. 30, 2020	(78,500)	$ 3	6,785	(85,288)
Beginning Balance, Shares at Mar. 31, 2020					75,727,268
Beginning Balance at Mar. 31, 2020					$ 78,867
Beginning Balance, Shares at Mar. 31, 2020		2,658,794
Beginning Balance at Mar. 31, 2020	(68,012)	$ 3	6,013	(74,028)
Stock-based compensation	354		354
Net loss and comprehensive loss	(5,038)			(5,038)
Ending Balance, Shares at Jun. 30, 2020					75,727,268
Ending Balance at Jun. 30, 2020					$ 78,867
Ending Balance, Shares at Jun. 30, 2020		2,658,794
Ending Balance at Jun. 30, 2020	(72,696)	$ 3	6,367	(79,066)
Stock-based compensation	418		418
Net loss and comprehensive loss	(6,222)			(6,222)
Ending Balance, Shares at Sep. 30, 2020					75,727,268
Ending Balance at Sep. 30, 2020					$ 78,867
Ending Balance, Shares at Sep. 30, 2020		2,658,794
Ending Balance at Sep. 30, 2020	$ (78,500)	$ 3	6,785	(85,288)
Beginning Balance, Shares at Dec. 31, 2020	169,396,576				169,396,576
Beginning Balance at Dec. 31, 2020	$ 205,979				$ 205,979
Beginning Balance, Shares at Dec. 31, 2020		3,096,903
Beginning Balance at Dec. 31, 2020	(101,048)	$ 3	10,288	(111,339)
Initial public offering, net of issuance costs	131,302	$ 9	131,293
Initial public offering, net of issuance costs, Shares		8,984,375
Conversion of convertible preferred stock into common stock	205,979	$ 24	205,955
Conversion of convertible preferred stock into common stock, Shares					(169,396,576)
Conversion of convertible preferred stock into common stock					$ (205,979)
Conversion of convertible preferred stock into common stock, Shares		23,678,568
Exercise of stock options	242		242
Exercise of stock options, Shares		91,395
Stock-based compensation	885		885
Net loss and comprehensive loss	(9,716)			(9,716)
Ending Balance, Shares at Mar. 31, 2021		35,851,241
Ending Balance at Mar. 31, 2021	$ 227,644	$ 36	348,663	(121,055)
Beginning Balance, Shares at Dec. 31, 2020	169,396,576				169,396,576
Beginning Balance at Dec. 31, 2020	$ 205,979				$ 205,979
Beginning Balance, Shares at Dec. 31, 2020		3,096,903
Beginning Balance at Dec. 31, 2020	$ (101,048)	$ 3	10,288	(111,339)
Exercise of stock options, Shares	117,948
Net loss and comprehensive loss	$ (36,912)
Ending Balance, Shares at Sep. 30, 2021	0
Ending Balance at Sep. 30, 2021	$ 0
Ending Balance, Shares at Sep. 30, 2021		35,877,794
Ending Balance at Sep. 30, 2021	203,263	$ 36	351,478	(148,251)
Beginning Balance, Shares at Mar. 31, 2021		35,851,241
Beginning Balance at Mar. 31, 2021	227,644	$ 36	348,663	(121,055)
Exercise of stock options	35		35
Exercise of stock options, Shares		7,878
Stock-based compensation	1,262		1,262
Net loss and comprehensive loss	(12,681)			(12,681)
Ending Balance, Shares at Jun. 30, 2021		35,859,119
Ending Balance at Jun. 30, 2021	216,260	$ 36	349,960	(133,736)
Exercise of stock options	69		69
Exercise of stock options, Shares		18,675
Stock-based compensation	1,449		1,449
Net loss and comprehensive loss	$ (14,515)			(14,515)
Ending Balance, Shares at Sep. 30, 2021	0
Ending Balance at Sep. 30, 2021	$ 0
Ending Balance, Shares at Sep. 30, 2021		35,877,794
Ending Balance at Sep. 30, 2021	$ 203,263	$ 36	$ 351,478	$ (148,251)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Initial Public Offering
Issuance costs	$ 2,400

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net loss	$ (36,912)	$ (18,205)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	381	225
Stock-based compensation	3,596	1,147
Non-cash operating lease expense	868	713
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(3,118)	341
Accounts payable	(94)	89
Accrued expenses and other current liabilities	(397)	266
Lease liability	(440)	(703)
Deferred revenue	(10,768)	(9,129)
Net cash flows used in operating activities	(46,884)	(25,256)
Cash flows from investing activities
Purchases of property and equipment	(1,210)	(116)
Net cash flows used in investing activities	(1,210)	(116)
Cash flows from financing activities
Proceeds from initial public offering, net of offering costs	131,302
Payment of preferred issuance costs	(146)
Proceeds from exercise of stock options	346	21
Net cash flows provided by financing activities	131,502	21
Net increase (decrease) in cash and cash equivalents and restricted cash	83,408	(25,351)
Cash, cash equivalents and restricted cash, beginning of period	163,363	82,083
Cash, cash equivalents and restricted cash, end of period	246,771	56,732
Cash and cash equivalents	245,899	55,860
Restricted cash included in other assets	872	872
Cash, cash equivalents and restricted cash, end of period	246,771	56,732
Supplemental disclosure of non-cash activities
Purchases of property and equipment in accrued expense	86	128
Right-of-use assets recognized upon adoption of ASC 842		956
Right-of-use asset obtained in exchange for operating lease liability		178
Right-of-use assets and lease liabilities recognized upon lease inception	$ 7,541
Deferred transaction costs in accounts payable and accrued expenses		$ 133

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Note 1. Organization and Basis of Presentation The Company is a targeted oncology company developing novel therapies targeting key cancer signaling pathways. By leveraging the Company’s deep understanding of discovery chemistry, translational science, and patient-centric drug development, the Company has built a deep pipeline of programs, both wholly owned and partnered, focused on genetically defined or biomarker-driven cancers. This enables it to target specific patient populations that are in need of new treatment options and the Company believes are most likely to respond to treatment with its product candidates. Since the Company commenced operations in 2016, it has advanced multiple product candidates to Investigational New Drug Application, or IND, acceptance and clinical development. In addition, the Company has a robust pipeline of early stage programs. On March 22, 2021, ahead of the initial public offering, the Company effected a one-for-7.154 reverse stock split of the Company’s common stock. All share and per share amounts in the condensed consolidated financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to this reverse stock split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital. Shares of common stock underlying outstanding stock options and other equity instruments were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased in accordance with the terms of the appropriate securities agreements. Shares of common stock reserved for issuance upon the conversion of the Company’s convertible preferred stock were proportionately reduced and the respective conversion prices were proportionately increased. Stockholders entitled to fractional shares as a result of the reverse stock split received a cash payment in lieu of receiving fractional shares. On March 25, 2021, the Company’s registration statement on Form S-1 relating to its initial public offering of its common stock was declared effective by the Securities and Exchange Commission (“SEC”). In the IPO, which closed on March 30, 2021, the Company issued and sold 8,984,375 shares of common stock, including full exercise of the underwriters’ over-allotment option to purchase an additional 1,171,875 shares, at a public offering price of $ 16.00 per share and the aggregate gross proceeds before deducting underwriting discounts and commissions, and other estimated offering expenses payable by the Company, were approximately $ 143.8 million. Basis of Presentation: The Company’s condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the ASC and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). The accompanying condensed consolidated financial statements and footnotes to the financial statements have been prepared on the same basis as the most recently audited annual financial statements and, in the opinion of management, reflect all normal recurring adjustments necessary for the fair presentation of the Company’s financial position as of September 30, 2021 and the results of its operations and its cash flows for the three and nine months ended September 30, 2021. The results for the three and nine months ended September 30, 2021 are not necessarily indicative of results to be expected for the year ending December 31, 2021, any other interim periods, or any future year or period. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2020 included in the Company’s final prospectus for its IPO filed pursuant to Rule 424(b)(4) under the Securities Act of 1933, as amended (the “Securities Act”), with the Securities and Exchange Commission (the “SEC”) on March 25, 2021.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. Summary of Significant Accounting Policies Principles of Consolidation: The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Arrys Therapeutics, Inc. (“Arrys”), Ikena Oncology Securities Corporation and Amplify Medicines, Inc, (“Amplify”). All intercompany balances and transactions have been eliminated in consolidation. Use of Estimates: The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Estimates and judgments are based on historical information and other market-specific or various relevant assumptions, including in certain circumstances, future projections, that management believes to be reasonable under the circumstances. Actual results could differ materially from estimates. Significant estimates and assumptions are used for, but not limited to the accruals for research and development expenses, research and development revenue under a collaboration agreement, the determination of fair value of equity instruments and intangible assets acquired in an asset acquisition and, for periods prior to the completion of the IPO, stock based compensation expense. Summary of Significant Accounting Policies: The significant accounting policies and estimates used in the preparation of the accompanying consolidated financial statements are described in the Company’s audited consolidated financial statements for the year ended December 31, 2020 included in the Company’s final Prospectus for its IPO filed pursuant to Rule 424(b)(4) under the Securities Act with the SEC on March 25, 2021. There have been no material changes in the Company’s significant accounting policies during the nine months ended September 30, 2021 . Concentration of Credit Risk and of Significant Suppliers: Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents. As of September 30, 2021 substantially all of the Company’s cash and cash equivalents were deposited at two highly rated financial institutions. The Company maintains balances in operating accounts above federally insured limits. The Company has not experienced any losses on such accounts and does not believe it is exposed to any significant credit risk on cash and cash equivalents. The Company is dependent on third-party manufacturers and clinical research organizations to supply products and provide services for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs. In the second quarter 2021, we were notified that a key component required in the manufacturing of IK-412, our novel kynurenine-degrading enzyme, is similarly essential to the manufacturing of COVID-19 vaccines and therapies. As such, the availability of the component has been delayed as resources have been allocated towards vaccine production in the near-term. Deferred Issuance Costs: On March 30, 2021, the Company completed its IPO. Accordingly, the Company recognized offering costs of approximately $ 2.4 million as a reduction from the gross proceeds associated with the closing of the IPO through additional paid-in capital in the accompanying condensed consolidated balance sheet. The Company incurred deferred offering costs of $ 0.5 million as of December 31, 2020 which were included in prepaid expenses and other current assets. Recent Accounting Pronouncements: From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by us as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on our consolidated financial statements and disclosures.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3. Fair Value Measurements The following table presents information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): As of September 30, Quoted Prices in Active Markets Significant Observable Inputs Significant Unobservable Inputs Cash equivalents: Money market funds (included in cash equivalents) $ 245,699 $ 245,699 $ — $ — Total $ 245,699 $ 245,699 $ — $ — As of December 31, Quoted Prices in Active Markets Significant Observable Inputs Significant Unobservable Inputs Cash equivalents: Money market funds (included in cash equivalents) $ 162,290 $ 162,290 $ — $ — Total $ 162,290 $ 162,290 $ — $ — During the nine months ended September 30, 2021 and year ended December 31, 2020 , there were no transfers between Level 1, Level 2 and Level 3.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2021
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid Expenses and Other Current Assets	Note 4. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): As of September 30, 2021 As of December 31, 2020 Clinical, manufacturing and scientific development $ 3,276 $ 1,917 Prepaid Insurance 1,662 23 Other 1,028 1,538 Total $ 5,966 $ 3,478

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Note 5. Property and Equipment, net Property and equipment, net consist of the following (in thousands): As of September 30, 2021 As of December 31, 2020 Property and equipment: Lab equipment $ 1,384 $ 1,071 Leasehold improvements 860 939 Electronic equipment and software 407 71 Furniture and fixtures 384 — Total property and equipment 3,035 2,081 Less: accumulated depreciation ( 910 ) ( 688 ) Property and equipment, net $ 2,125 $ 1,393 Depreciation expense for the three months ended September 30, 2021 and 2020 was $ 0.1 million and $ 0.1 million , respectively. Depreciation expense for the nine months ended September 30, 2021 and 2020 was $ 0.4 million and $ 0.2 million , respectively. There were no impairments for the nine months ended September 30, 2021 and 2020 .

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2021
Accrued Expenses And Other Current Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	Note 6. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): As of September 30, 2021 As of December 31, 2020 Employee compensation $ 1,940 $ 1,816 Research and development expenses 1,746 2,251 Professional fees 533 955 Other current liabilities 13 380 Total $ 4,232 $ 5,402

Collaboration Agreement and Sto

Collaboration Agreement and Stock Purchase Agreement with BMS	9 Months Ended
	Sep. 30, 2021
Collaboration And Stock Purchase Agreement [Abstract]
Collaboration Agreement and Stock Purchase Agreement with BMS	Note 7. Collaboration Agreement and Stock Purchase Agreement with BMS In January 2019, the Company entered into the BMS Collaboration Agreement with Celgene Corporation, which was acquired by BMS in November 2019, whereby the Company will carry out initial research and development activities with the goal of identifying and developing drug candidates for certain cancer types. Concurrent with execution of the BMS Collaboration Agreement, the Company entered into a stock purchase agreement with BMS, which resulted in the issuance of 14,545,450 shares of Series A-1 Preferred Stock (the “Stock Purchase Agreement”). Agreement Structure Under the BMS Collaboration Agreement, the Company will conduct exploratory and discovery activities, with the goal of identifying product candidates for certain targets, which are in the kynurenine pathway, which the Company is developing as IK-412, and the aryl hydrocarbon receptor (“AHR”), which the Company is developing as IK-175. The Company is obligated to complete research and development activities through completion of a Phase 1b clinical trial for each program. BMS has the option to receive a global-development, manufacture and commercialization license for the product candidate, which expires in January 2024. Subsequent to the delivery of a license, BMS is responsible for the worldwide development, manufacturing and commercialization of these product candidates. BMS paid the Company a total of $ 95.0 million in aggregate upfront consideration related to the BMS Collaboration Agreement and Stock Purchase Agreement. The Company is eligible to receive $ 50.0 million, in case of an exercise of its option with respect to IK-175, and $ 40.0 million, in case of an exercise of its option with respect to IK-412. If the Company does not complete a Phase 1b clinical trial by the end of the research term, the Company may provide a data package to BMS to support the decision to exercise the option for an additional $ 0.25 million. Upon the exercise of the delivery of each license, the Company becomes eligible to receive up to $ 450 million in milestone payments as well as a tiered royalty on worldwide sales from the high single to low teen digits. Accounting Considerations of the Agreement The BMS Collaboration Agreement and the Stock Purchase Agreement were executed concurrently and in contemplation of each other. The issuance of Series A-1 Preferred Stock was initially accounted for at fair value. The purchase price for the Series A-1 Preferred Stock was considered to be at a discount from fair value, and therefore $ 1.8 million of the upfront from the BMS Collaboration Agreement was allocated to the equity arrangement. The Company determined that the BMS Collaboration Agreement represented a contract with a customer and should be accounted for in accordance with ASC 606. The Company identified the two performance obligations, which are research and development services for IK-175 and IK-412. The options to receive worldwide development and commercialization licenses for the two targets and the option to receive manufacturing services in the future were determined to not provide any material rights to the customer and are therefore not considered to be performance obligations. The arrangement also contains certain di minimis items, including participation on joint oversight committees. The Company identified $ 78.7 million of total transaction price which represents the upfront consideration allocated to the revenue arrangement. Additional consideration to be paid to the Company upon exercise of a right to receive a license or potential milestone and royalty payments are excluded from the transaction price as they relate to amounts that can only be achieved subsequent to the exercise of an options and are outside of the initial contact term. Based on the distinct performance obligations identified above, the Company allocated the $ 78.7 million transaction price based on relative estimated standalone selling prices of each of its performance obligations as follows:  $ 41.2 million for research and development services for IK-175; and  $ 37.5 million for research and development services for IK-412. The Company determined the estimated standalone selling price for the research and development services based on internal estimates of the costs to perform the services, including expected internal expenses and expenses with third parties, marked up to include a reasonable profit margin. Significant inputs used to determine the total expense of the research and development activities include the length of time required and the number and cost of various studies that will be performed to complete the applicable development plan. The Company is recognizing revenue related to each of its performance obligations as the research and development services are performed through January 2024. The Company recognizes revenue related to research and development services performed using an input method by calculating costs incurred at each period end relative to total costs expected to be incurred. The Company recognized revenue of $ 3.7 million and $ 2.8 million in the three months ended September 30, 2021 and 2020, respectively, and revenue of $ 10.8 million and $ 9.1 million during the nine months ended September 30, 2021 and 2020, respectively, from the BMS Collaboration Agreement, that in each case was previously included in deferred revenue at the beginning of the respective period. The condensed consolidated balance sheet as of September 30, 2021 includes deferred revenue of $ 45.0 million related this agreement, of which $ 22.6 million and $ 22.4 million were classified as current and non-current, respectively. This amount is expected to be recognized as performance obligations are satisfied through the completion of the research and development services for IK-175 and IK-412 .

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Redeemable Convertible Preferred Stock	Note 8. Redeemable Convertible Preferred Stock In connection with the closing of the Company’s IPO on March 30, 2021, all issued and outstanding Redeemable Convertible Preferred Stock of 169,396,576 were converted to 23,678,568 shares of the Company’s common stock and are no longer issued.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Note 9. Stock-Based Compensation In March 2016, the Company’s board of directors and stockholders adopted the 2016 Stock Incentive Plan which was amended and restated in December 2020, (as so amended and restated, the “2016 Plan”) which permits the granting of (1) options to purchase common stock intended to qualify as incentive stock options under Section 422 of the Code, and (2) options that do not so qualify. On March 19, 2021, the Company’s board of directors approved, and on March 20, 2021, the Company’s stockholders approved the 2021 Stock Incentive Plan (the “2021 Plan”), which became effective on March 30, 2021 . The 2021 Plan replaced the 2016 Plan as the board of directors had determined it would not to make additional awards under the 2016 Plan following the closing of the initial public offering. However, the 2016 Plan will continue to govern outstanding equity awards granted thereunder. The 2021 Plan allows the Company to make equity-based and cash-based incentive awards to officers, employees, directors and consultants. As of the effective date of the 2021 Plan, no further awards will be made under the 2016 Plan. Any options or awards outstanding under the 2016 Plan remain outstanding and effective and are governed by their existing terms. The shares of the Company’s common stock subject to outstanding awards under the 2016 Plan that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right will be added back to the shares of common stock available for issuance under the 2021 Plan. No more than 3,263,664 shares of the Company’s common stock may be granted subject to incentive stock options under the 2021 Plan. In addition, the 2021 Plan contains an “evergreen” provision, which allows for an annual increase in the number of shares of common stock available for issuance under the 2021 Plan on the first day of each fiscal year during the period beginning in fiscal year 2022. The annual increase in the number of shares shall be equal to 4 % of the number of shares of common stock outstanding on the immediately preceding December 31; and such lesser number of shares as determined by the Administrator as provided in the 2021 Plan. As of September 30, 2021 , 2,661,608 shares of common stock remain available for future issuance under the 2021 Plan. The Plan provides that equity awards may be granted to employees and nonemployees. The vesting periods for equity awards, which generally is four years , are determined by the Board of Directors. The contractual term for stock option awards is ten years . The total compensation expense recognized in the statements of operations associated with all the stock-based compensation awards granted by the Company is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 672 $ 202 $ 1,621 $ 506 General and administrative 777 216 1,975 641 Total $ 1,449 $ 418 $ 3,596 $ 1,147 The weighted-average fair value of the stock options granted during the nine months ended September 30, 2021 was $ 5.78 . As of September 30, 2021, the total unrecognized stock-based compensation expense for unvested options was $ 17.1 million which is expected to be recognized over 3.0 years. The following table summarizes stock option activity under the Plan for the nine months ended September 30, 2021: Number of Weighted- Weighted- Aggregate Outstanding as of December 31, 2020 2,650,396 $ 3.45 8.01 $ 5,463 Granted 2,998,224 9.14 Exercised ( 117,948 ) 2.93 Cancelled or forfeited ( 22,188 ) 5.78 Outstanding as of September 30, 2021 5,508,484 $ 6.55 8.46 $ 34,867 Vested or expected to vest as of September 30, 2021 5,508,484 $ 6.55 8.46 $ 34,867 Options exercisable as of September 30, 2021 1,788,373 $ 3.26 7.06 $ 16,747 The aggregate intrinsic value of options exercised for the nine months ended September 30, 2021 and 2020 was $ 0.7 million and $ 13 thousand , respectively. The fair value of each option award granted is estimated on the date of grant using the Black-Scholes option pricing model and the weighted average assumptions. The underlying assumptions used to value stock options granted to participants using the Black-Scholes option-pricing were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Risk-free interest rate range 0.81 % to 1.07 % 0.36 % to 0.47 % 0.68 % to 1.07 % 0.27 % to 0.47 % Expected dividend yield 0 % 0 % 0 % 0 % Expected option term (in years) 6.08 5.00 to 6.08 6.00 to 6.08 5.00 to 6.08 Expected stock price volatility range 69.61 % to 69.74 % 73.15 % to 74.89 % 69.61 % to 73.30 % 73.15 % to 74.89 % Employee Stock Purchase Plan On March 20, 2021, the Company’s stockholders approved the 2021 Employee Stock Purchase Plan (the “ESPP”), which became effective on March 30, 2021 . The ESPP initially provides participating employees with the opportunity to purchase up to an aggregate of 346,613 shares of the Company’s common stock. An annual increase in the number of shares of common stock reserved and available for issuance under the ESPP shall be equal to 1 % of the number of shares of common stock outstanding on the immediately preceding December 31; and such lesser number of shares as determined by the Administrator as provided in the ESPP. As of September 30, 2021 , no shares have been purchased by employees under the ESPP.

Research License Agreements

Research License Agreements	9 Months Ended
	Sep. 30, 2021
Research and Development [Abstract]
Research License Agreements	Note 10. Research License Agreements During 2015, the Company entered into an exclusive patent license agreement (the “UT Austin License”) to license certain technologies and intellectual property rights from the University of Texas at Austin (the “University”), an entity affiliated with a director of the Company at the time of the agreement. The UT Austin License shall remain in effect until the expiration or abandonment of the last to expire technologies and intellectual property rights. The Company shall pay License Maintenance fees annually of $ 40 thousand. Additionally, the Company shall make additional milestone payments to the University upon meeting certain development milestones in the aggregate of $ 4.7 million upon meeting certain development milestones during the term of the UT Austin License. The Company will pay the University royalties as defined in the UT Austin License on any commercialized product sales related to the licensed technology in a percentage in the low single digits. The Company will also be responsible for reimbursing the University for certain patent-related costs incurred on its behalf. In 2018, the Company acquired IPR&D on an Arrys’ immune-oncology candidate based on the intellectual property associated with Arrys’ AskAt License as part of the acquisition of Arrys. Total consideration allocated to the technology was $ 28.5 million and was recognized as research and development expense upon the acquisition. The AskAt License is intended to be used by the Company in its future development of therapeutic drug candidates for eventual clinical development and commercialization. The Company shall make additional milestone payments to AskAt upon meeting certain development milestones totaling $ 4 million, as well as certain sales event milestones ranging from $ 50 million to $ 250 million contingent on sales in a calendar year, during the term of the AskAt License. The Company will pay the AskAt royalties a percentage in the low single digits as defined in the AskAt License on any commercialized product sales related to the licensed technology.

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	Note 11. Leases On July 21, 2020, the Company entered into an operating lease agreement for 20,752 square feet of office, lab and animal care facility space located in Boston, Massachusetts for the Company’s new corporate headquarters. The commencement date of the lease was February 19, 2021 and the lease term is 63 months. The lease provides a three-month free rent period, which commenced on the lease commencement date. The base rent at commencement is $ 145 thousand per month and escalates by 3 % annually for total lease payments during the term of $ 9.3 million. The Company provided a letter of credit to secure their obligations under the lease in the initial amount of $ 0.9 million. This balance is included in other assets on the accompanying condensed consolidated balance sheets. The Company recognized a right of use asset of $ 7.5 million and an operating lease liability of $ 7.5 million upon the commencement of the lease. The future lease payments for the Company’s operating lease as of September 30, 2021, were as follows (in thousands): Fiscal Year Operating 2021 (excluding the nine months ended September 30, 2021) $ 436 2022 1,774 2023 1,827 2024 1,882 2025 1,938 Thereafter 817 Total minimum lease payments 8,674 Less amounts representing interest or imputed interest 1,387 Present value of lease liabilities $ 7,287

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 12. Commitments and Contingencies The Company is also party to various agreements, principally relating to licensed technology, that require future payments relating to milestones not met as of September 30, 2021 or royalties on future sales of specified products that have not yet occurred as of September 30, 2021 .

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Note 13. Related Party Transactions The Company entered into several agreements with a director and an entity affiliated with a director: 1) As discussed in Note 10 above, the Company has entered into a license agreement with the University, which was affiliated with a director of the Company at the time of the license agreement. During the three and nine months ended September 30, 2021 the Company recorded expenses in connection with University license fees and certain patent-related costs incurred on its behalf of $ 32 thousand and $ 126 thousand, respectively. University license fees and certain patent-related costs incurred during the three and nine months ended September 30, 2020 were $ 22 thousand and $ 95 thousand, respectively. 2) Certain entities affiliated with directors purchased shares in the IPO.

Net Loss per Share Attributable

Net Loss per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Common Stockholders	Note 14. Net Loss per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock and potentially dilutive securities outstanding during the period determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, convertible preferred stock, restricted common stock, restricted stock units and stock options are considered to be potentially dilutive securities, but are excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive and therefore basic and diluted net loss per share were the same for all periods presented. The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because to do so would be anti-dilutive: Nine Months Ended September 30, 2021 2020 Redeemable Convertible Preferred Stock — 75,727,268 Options to purchase Common Stock 5,508,484 2,662,359 Total 5,508,484 78,389,627

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation: The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Arrys Therapeutics, Inc. (“Arrys”), Ikena Oncology Securities Corporation and Amplify Medicines, Inc, (“Amplify”). All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates: The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Estimates and judgments are based on historical information and other market-specific or various relevant assumptions, including in certain circumstances, future projections, that management believes to be reasonable under the circumstances. Actual results could differ materially from estimates. Significant estimates and assumptions are used for, but not limited to the accruals for research and development expenses, research and development revenue under a collaboration agreement, the determination of fair value of equity instruments and intangible assets acquired in an asset acquisition and, for periods prior to the completion of the IPO, stock based compensation expense.
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies: The significant accounting policies and estimates used in the preparation of the accompanying consolidated financial statements are described in the Company’s audited consolidated financial statements for the year ended December 31, 2020 included in the Company’s final Prospectus for its IPO filed pursuant to Rule 424(b)(4) under the Securities Act with the SEC on March 25, 2021. There have been no material changes in the Company’s significant accounting policies during the nine months ended September 30, 2021 .
Concentration of Credit Risk and of Significant Suppliers	Concentration of Credit Risk and of Significant Suppliers: Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents. As of September 30, 2021 substantially all of the Company’s cash and cash equivalents were deposited at two highly rated financial institutions. The Company maintains balances in operating accounts above federally insured limits. The Company has not experienced any losses on such accounts and does not believe it is exposed to any significant credit risk on cash and cash equivalents. The Company is dependent on third-party manufacturers and clinical research organizations to supply products and provide services for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs. In the second quarter 2021, we were notified that a key component required in the manufacturing of IK-412, our novel kynurenine-degrading enzyme, is similarly essential to the manufacturing of COVID-19 vaccines and therapies. As such, the availability of the component has been delayed as resources have been allocated towards vaccine production in the near-term.
Deferred Issuance Costs	Deferred Issuance Costs: On March 30, 2021, the Company completed its IPO. Accordingly, the Company recognized offering costs of approximately $ 2.4 million as a reduction from the gross proceeds associated with the closing of the IPO through additional paid-in capital in the accompanying condensed consolidated balance sheet. The Company incurred deferred offering costs of $ 0.5 million as of December 31, 2020 which were included in prepaid expenses and other current assets.
Recent Accounting Pronouncements	Recent Accounting Pronouncements: From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by us as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on our consolidated financial statements and disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value On Recurring Basis	The following table presents information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): As of September 30, Quoted Prices in Active Markets Significant Observable Inputs Significant Unobservable Inputs Cash equivalents: Money market funds (included in cash equivalents) $ 245,699 $ 245,699 $ — $ — Total $ 245,699 $ 245,699 $ — $ — As of December 31, Quoted Prices in Active Markets Significant Observable Inputs Significant Unobservable Inputs Cash equivalents: Money market funds (included in cash equivalents) $ 162,290 $ 162,290 $ — $ — Total $ 162,290 $ 162,290 $ — $ —

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands): As of September 30, 2021 As of December 31, 2020 Clinical, manufacturing and scientific development $ 3,276 $ 1,917 Prepaid Insurance 1,662 23 Other 1,028 1,538 Total $ 5,966 $ 3,478

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment, Net	Property and equipment, net consist of the following (in thousands): As of September 30, 2021 As of December 31, 2020 Property and equipment: Lab equipment $ 1,384 $ 1,071 Leasehold improvements 860 939 Electronic equipment and software 407 71 Furniture and fixtures 384 — Total property and equipment 3,035 2,081 Less: accumulated depreciation ( 910 ) ( 688 ) Property and equipment, net $ 2,125 $ 1,393

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Accrued Expenses And Other Current Liabilities [Abstract]
Summary of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): As of September 30, 2021 As of December 31, 2020 Employee compensation $ 1,940 $ 1,816 Research and development expenses 1,746 2,251 Professional fees 533 955 Other current liabilities 13 380 Total $ 4,232 $ 5,402

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Total Compensation Expense	The total compensation expense recognized in the statements of operations associated with all the stock-based compensation awards granted by the Company is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 672 $ 202 $ 1,621 $ 506 General and administrative 777 216 1,975 641 Total $ 1,449 $ 418 $ 3,596 $ 1,147
Summary of Stock Option Activity	The following table summarizes stock option activity under the Plan for the nine months ended September 30, 2021: Number of Weighted- Weighted- Aggregate Outstanding as of December 31, 2020 2,650,396 $ 3.45 8.01 $ 5,463 Granted 2,998,224 9.14 Exercised ( 117,948 ) 2.93 Cancelled or forfeited ( 22,188 ) 5.78 Outstanding as of September 30, 2021 5,508,484 $ 6.55 8.46 $ 34,867 Vested or expected to vest as of September 30, 2021 5,508,484 $ 6.55 8.46 $ 34,867 Options exercisable as of September 30, 2021 1,788,373 $ 3.26 7.06 $ 16,747
Summary of Assumptions Used to Value Stock Options Granted to Participants Using Black-Scholes Option-Pricing	The fair value of each option award granted is estimated on the date of grant using the Black-Scholes option pricing model and the weighted average assumptions. The underlying assumptions used to value stock options granted to participants using the Black-Scholes option-pricing were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Risk-free interest rate range 0.81 % to 1.07 % 0.36 % to 0.47 % 0.68 % to 1.07 % 0.27 % to 0.47 % Expected dividend yield 0 % 0 % 0 % 0 % Expected option term (in years) 6.08 5.00 to 6.08 6.00 to 6.08 5.00 to 6.08 Expected stock price volatility range 69.61 % to 69.74 % 73.15 % to 74.89 % 69.61 % to 73.30 % 73.15 % to 74.89 %

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Summary of Future Lease Payments for Operating Lease	The future lease payments for the Company’s operating lease as of September 30, 2021, were as follows (in thousands): Fiscal Year Operating 2021 (excluding the nine months ended September 30, 2021) $ 436 2022 1,774 2023 1,827 2024 1,882 2025 1,938 Thereafter 817 Total minimum lease payments 8,674 Less amounts representing interest or imputed interest 1,387 Present value of lease liabilities $ 7,287

Net Loss per Share Attributab_2

Net Loss per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share	The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because to do so would be anti-dilutive: Nine Months Ended September 30, 2021 2020 Redeemable Convertible Preferred Stock — 75,727,268 Options to purchase Common Stock 5,508,484 2,662,359 Total 5,508,484 78,389,627

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Millions	Mar. 30, 2021USD ($)$ / sharesshares	Mar. 22, 2021	Sep. 30, 2021
Subsidiary Sale Of Stock [Line Items]
Reverse stock split			one-for-7.154 reverse stock split
Stock split, conversion ratio		0.1397
Public offering price | $ / shares	$ 16
Gross proceeds from initial public offering | $	$ 143.8
IPO
Subsidiary Sale Of Stock [Line Items]
Company issued and sold shares of common stock	8,984,375
Over-allotment Option to Purchase
Subsidiary Sale Of Stock [Line Items]
Company issued and sold shares of common stock	1,171,875

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions	Mar. 30, 2021USD ($)	Sep. 30, 2021FinancialInstitution	Dec. 31, 2020USD ($)
Subsidiary Sale Of Stock [Line Items]
Concentration of credit risk, number of financial institutions | FinancialInstitution		2
IPO
Subsidiary Sale Of Stock [Line Items]
Offering costs recognized	$ 2.4
Deferred offering costs			$ 0.5

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value On Recurring Basis (Details) - Fair Value On Recurring Basis - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	$ 245,699	$ 162,290
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	245,699	162,290
Money Market Funds (Included in Cash Equivalents)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	245,699	162,290
Money Market Funds (Included in Cash Equivalents) | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	$ 245,699	$ 162,290

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Prepaid Expense and Other Assets, Current [Abstract]
Clinical, manufacturing and scientific development	$ 3,276	$ 1,917
Prepaid Insurance	1,662	23
Other	1,028	1,538
Total	$ 5,966	$ 3,478

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property and equipment:
Total property and equipment, gross	$ 3,035	$ 2,081
Less: accumulated depreciation	(910)	(688)
Property and equipment, net	2,125	1,393
Lab Equipment
Property and equipment:
Total property and equipment, gross	1,384	1,071
Leasehold Improvements
Property and equipment:
Total property and equipment, gross	860	939
Electronic Equipment and Software
Property and equipment:
Total property and equipment, gross	407	$ 71
Furniture and Fixtures
Property and equipment:
Total property and equipment, gross	$ 384

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Depreciation	$ 100,000	$ 100,000	$ 381,000	$ 225,000
Impairment of property and equipment			$ 0	$ 0

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accrued Expenses And Other Current Liabilities [Abstract]
Employee compensation	$ 1,940	$ 1,816
Research and development expenses	1,746	2,251
Professional fees	533	955
Other current liabilities	13	380
Total	$ 4,232	$ 5,402

Collaboration Agreement and S_2

Collaboration Agreement and Stock Purchase Agreement with BMS - Additional Information (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Preferred stock, shares issued		0		0		0
Deferred revenue current		$ 22,574		$ 22,574		$ 20,622
Deferred revenue non-current		22,421		22,421		$ 35,141
Stock Purchase Agreement with BMS | Series A-1 Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Preferred stock, shares issued	14,545,450
BMS Collaboration Agreement and Stock Purchase Agreement | BMS
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront consideration payment	$ 95,000
Option to exercise additional consideration if clinical trial not completed within research term	250
Milestone payments eligible to receive	450,000
BMS Collaboration Agreement and Stock Purchase Agreement | BMS | IK-175
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive in case of exercise of options	50,000
BMS Collaboration Agreement and Stock Purchase Agreement | BMS | IK-412
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive in case of exercise of options	40,000
BMS Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront amount allocated to equity arrangements	1,800
Transaction price allocated to revenue arrangement	78,700
Revenue recognized which were previously included in deferred revenue		3,700	$ 2,800	10,800	$ 9,100
Deferred revenue		45,000		45,000
Deferred revenue current		22,600		22,600
Deferred revenue non-current		$ 22,400		$ 22,400
BMS Collaboration Agreement | IK-175
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated to revenue arrangement	41,200
BMS Collaboration Agreement | IK-412
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated to revenue arrangement	$ 37,500

Redeemable Convertible Prefer_2

Redeemable Convertible Preferred Stock - Additional Information (Details) - shares	Mar. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Redeemable convertible preferred stock, shares issued			0	169,396,576
Redeemable convertible preferred stock, shares outstanding			0	169,396,576
Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Redeemable convertible preferred stock, shares outstanding				169,396,576	75,727,268	75,727,268	75,727,268	75,727,268
Shares converted		(169,396,576)
Redeemable Convertible Preferred Stock | IPO
Class Of Stock [Line Items]
Redeemable convertible preferred stock, shares issued	169,396,576		0
Redeemable convertible preferred stock, shares outstanding	169,396,576
Shares converted	23,678,568

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 30, 2021	Mar. 20, 2021	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average fair value of the stock options granted			$ 5.78
Number of shares granted			2,998,224
Total unrecognized stock-based compensation balance for unvested options			$ 17,100
Total unrecognized stock-based compensation balance for unvested options expected to be recognized period			3 years
Aggregate intrinsic value of options exercised			$ 700	$ 13
2021 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Plan effective date		Mar. 30, 2021
Number of stock granted	3,263,664
Available for issuance percentage of annual increase in number of common stock outstanding	4.00%
Number of shares reserved for issuance			2,661,608
Vesting period			4 years
Stock option contractual term			10 years
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Plan effective date	Mar. 30, 2021
Increase in number of shares reserved and available for issuance as percentage on common stock outstanding			1.00%
Number of shares purchased by employees			0
2021 Employee Stock Purchase Plan | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares issued for purchase			346,613

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Total Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 1,449	$ 418	$ 3,596	$ 1,147
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	672	202	1,621	506
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total	$ 777	$ 216	$ 1,975	$ 641

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Share-based Payment Arrangement [Abstract]
Number of Options, Outstanding | shares	2,650,396
Number of Options, Granted | shares	2,998,224
Number of Options, Exercised | shares	(117,948)
Number of Options, Cancelled or forfeited | shares	(22,188)
Number of Options, Outstanding | shares	5,508,484	2,650,396
Number of Options, Vested or expected to vest | shares	5,508,484
Number of Options, Options exercisable | shares	1,788,373
Weighted- Average Exercise Price, Outstanding | $ / shares	$ 3.45
Weighted- Average Exercise Price, Granted | $ / shares	9.14
Weighted- Average Exercise Price, Exercised | $ / shares	2.93
Weighted- Average Exercise Price, Cancelled or forfeited | $ / shares	5.78
Weighted- Average Exercise Price, Outstanding | $ / shares	6.55	$ 3.45
Weighted- Average Exercise Price, Vested or expected to vest | $ / shares	6.55
Weighted- Average Exercise Price, Options exercisable | $ / shares	$ 3.26
Weighted- Average Remaining Contractual Term, Outstanding	8 years 5 months 15 days	8 years 3 days
Weighted- Average Remaining Contractual Term, Vested or expected to vest	8 years 5 months 15 days
Weighted- Average Remaining Contractual Term, Option exercisable	7 years 21 days
Aggregate Intrinsic Value, Outstanding | $	$ 34,867	$ 5,463
Aggregate Intrinsic Value, Vested or expected to vest | $	34,867
Aggregate Intrinsic Value, Options exercisable as of September 30, 2021 | $	$ 16,747

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Assumptions Used to Value Stock Options Granted to Participants Using Black-Scholes Option-Pricing (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate minimum	0.81%	0.36%	0.68%	0.27%
Risk-free interest rate maximum	1.07%	0.47%	1.07%	0.47%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Expected option term (in years)	6 years 29 days
Expected stock price volatility minimum	69.61%	73.15%	69.61%	73.15%
Expected stock price volatility maximum	69.74%	74.89%	73.30%	74.89%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term (in years)		6 years 29 days	6 years 29 days	6 years 29 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option term (in years)		5 years	6 years	5 years

Research License Agreements - A

Research License Agreements - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2018	Dec. 31, 2015
UT Austin License | University
Research And Development Arrangement Contract To Perform For Others [Line Items]
License maintenance fees			$ 40
Additional milestone payments payable upon meeting certain development milestones			$ 4,700
Royalties terms	The Company will pay the University royalties as defined in the UT Austin License on any commercialized product sales related to the licensed technology in a percentage in the low single digits.
AskAt License
Research And Development Arrangement Contract To Perform For Others [Line Items]
Additional milestone payments payable upon meeting certain development milestones		$ 4,000
Royalties terms	The Company will pay the AskAt royalties a percentage in the low single digits as defined in the AskAt License on any commercialized product sales related to the licensed technology.
Total consideration allocated to technology recognized as research and development expense		28,500
AskAt License | Minimum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestones payable contingent on sales in calendar year		50,000
AskAt License | Maximum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestones payable contingent on sales in calendar year		$ 250,000

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	Jul. 21, 2020USD ($)ft²	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Lessee Lease Description [Line Items]
Total lease rent payments		$ 868	$ 713
Right-of-use asset		6,843		$ 170
Present value of lease liabilities		$ 7,287
Boston, Massachusetts
Lessee Lease Description [Line Items]
Area of leased property | ft²	20,752
Lease commencement date	Feb. 19, 2021
Lease term	63 months
Monthly base rent	$ 145
Percentage escalation in annual base rent	3.00%
Total lease rent payments	$ 9,300
Letter of credit to secure lease	900
Right-of-use asset	7,500
Present value of lease liabilities	$ 7,500

Leases - Summary of Future Leas

Leases - Summary of Future Lease Payments for Operating Lease (Details) $ in Thousands	Sep. 30, 2021USD ($)
Operating Lease Liabilities Payments Due Abstract
2021 (excluding the nine months ended September 30, 2021)	$ 436
2022	1,774
2023	1,827
2024	1,882
2025	1,938
Thereafter	817
Total minimum lease payments	8,674
Less amounts representing interest or imputed interest	1,387
Present value of lease liabilities	$ 7,287

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
UT Austin License | University | Affiliated to Director
Related Party Transaction [Line Items]
University license fees and certain-patent related costs	$ 32	$ 22	$ 126	$ 95

Net Loss per Share Attributab_3

Net Loss per Share Attributable to Common Stockholders - Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	5,508,484	78,389,627
Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		75,727,268
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	5,508,484	2,662,359