Kinnate Biopharma (KNTE) 10-K 28 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	Mar. 25, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity File Number	001-39743
Entity Registrant Name	KINNATE BIOPHARMA INC.
Entity Central Index Key	0001797768
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-4566526
Entity Address, Address Line One	103 Montgomery Street, Suite 150
Entity Address, Address Line Two	The Presidio of San Francisco
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94129
City Area Code	858
Local Phone Number	299-4699
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	KNTE
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 634
Entity Common Stock, Shares Outstanding		43,949,284
Auditor Firm ID	185
Auditor Name	KPMG LLP
Auditor Location	San Diego, California

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 116,096	$ 365,462
Cash at consolidated joint venture	33,593	0
Short-term investments	103,362	31,398
Prepaid expenses and other current assets	5,639	3,343
Total current assets	258,690	400,203
Property and equipment, net	956	368
Long-term investments	105,449	0
Restricted cash	371	0
Deferred offering costs	641	0
Other non-current assets	757	0
Total assets	366,864	400,571
Current liabilities:
Accounts payable	3,148	3,940
Accrued expenses	9,239	3,364
Total current liabilities	12,387	7,304
Commitments and contingencies (See Note 13)
Redeemable convertible noncontrolling interests	35,000	0
Stockholders' equity:
Preferred stock, $0.0001 par value; 200,000,000 shares authorized at December 31, 2021 and 2020; 0 shares outstanding at December 31, 2021 and 2020	0	0
Common stock, $0.0001 par value; 1,000,000,000 shares authorized at December 31, 2021 and 2020; 43,855,944 and 43,477,439 shares issued and outstanding at December 31, 2021 and 2020, respectively	4	4
Additional paid-in capital	463,089	446,601
Accumulated other comprehensive loss	(524)	(9)
Accumulated deficit	(143,092)	(53,329)
Total stockholders' equity	319,477	393,267
Total liabilities, redeemable convertible noncontrolling interests and stockholders' equity	$ 366,864	$ 400,571

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	200,000,000	200,000,000
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	43,855,944	43,477,439
Common stock, shares outstanding (in shares)	43,855,944	43,477,439

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 67,166	$ 29,237
General and administrative	22,945	6,764
Total operating expenses	90,111	36,001
Loss from operations	(90,111)	(36,001)
Other income, net	348	240
Net loss	(89,763)	(35,761)
Net loss attributable to redeemable convertible noncontrolling interests	0	0
Net loss attributable to Kinnate	$ (89,763)	$ (35,761)
Weighted-average shares outstanding, basic (in shares)	43,601,162	6,767,591
Weighted-average shares outstanding, diluted (in shares)	43,601,162	6,767,591
Net loss per share, basic (in dollars per share)	$ (2.06)	$ (5.28)
Net loss per share, diluted (in dollars per share)	$ (2.06)	$ (5.28)
Comprehensive loss:
Net loss	$ (89,763)	$ (35,761)
Other comprehensive loss:
Unrealized loss on investments	(515)	(9)
Total comprehensive loss	(90,278)	(35,770)
Comprehensive loss attributable to redeemable convertible noncontrolling interests	0	0
Comprehensive loss attributable to Kinnate	$ (90,278)	$ (35,770)

CONSOLIDATED STATEMENTS OF CONV

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	Redeemable Convertible Noncontrolling Interests [Member]	Total	Series A Convertible Preferred Stock [Member]	Series B Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]
Balance at Dec. 31, 2019							$ 18,942,000	$ 74,204,000	$ 0
Balance (in shares) at Dec. 31, 2019							7,762,727	9,705,182	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance costs for convertible preferred stock								$ (17,000)	$ 97,707,000
Issuance costs for convertible preferred stock (in shares)									8,282,789
Conversion to common stock							$ (18,942,000)	$ (74,187,000)	$ (97,707,000)
Conversion to common stock (in shares)							(7,762,727)	(9,705,182)	(8,282,789)
Net loss	$ 0	$ 0	$ 0	$ (35,761,000)	$ 0	$ (35,761,000)
Balance at Dec. 31, 2020							$ 0	$ 0	$ 0
Balance (in shares) at Dec. 31, 2020							0	0	0
Balance at Dec. 31, 2019	$ 0	$ 82,000	0	(17,568,000)	0	(17,486,000)
Balance (in shares) at Dec. 31, 2019	3,665,020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in connection with initial public offering, net of underwriting discounts, commissions and offering costs	$ 1,000		0	0	0	253,314,000
Issuance of common stock in connection with initial public offering, net of underwriting discounts, commissions and offering costs (in shares)	13,800,000	253,313
Conversion to common stock	$ 3,000	$ 190,833,000	0	0	0	190,836,000
Conversion to common stock (in shares)	25,778,437
Stock-based compensation expense	$ 0	2,478,000	0	0	0	2,478,000
Exercise of stock options	$ 0	117,000	0	0	0	117,000
Exercise of stock options (in shares)	280,781
Issuance costs for Series A preferred stock to redeemable convertible NCI									$ (294,000)
Shares acquired upon forfeiture	$ 0	(222,000)	0	0	0	(222,000)
Shares acquired upon forfeiture (in shares)	(46,799)
Net loss						(35,761,000)
Other comprehensive loss	$ 0	$ 0	(9,000)	0	0	(9,000)
Balance at Dec. 31, 2020	$ 4,000		(9,000)	(53,329,000)	0	393,267,000
Balance (in shares) at Dec. 31, 2020	43,477,439	446,601
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 0	$ 15,016,000	0	0	0	15,016,000
Exercise of stock options	$ 0	730,000	0	0	0	730,000
Exercise of stock options (in shares)	328,238
Shares issued under employee stock purchase plan	$ 0	889,000	0	0	0	889,000
Shares issued under employee stock purchase plan (in shares)	50,267
Contributions from redeemable convertible noncontrolling interest owners	$ 0	0	0	0	35,000,000	0
Issuance costs for Series A preferred stock to redeemable convertible NCI	0	(147,000)	0	0	0	(147,000)
Net loss	0	0	0	(89,763,000)	0	(89,763,000)
Other comprehensive loss	0	0	(515,000)	0	0	(515,000)
Balance at Dec. 31, 2021	$ 4,000	$ 463,089,000	$ (524,000)	$ (143,092,000)	$ 35,000,000	$ 319,477,000
Balance (in shares) at Dec. 31, 2021	43,855,944

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, underwriting discounts, commissions and offering costs	$ 22,686
Series C Convertible Preferred Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock, issuance costs	$ 294

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (89,763,000)	$ (35,761,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	15,016,000	2,478,000
Depreciation	123,000	83,000
Amortization/accretion of investments	1,877,000	5,000
Loss on disposal of property and equipment	58,000	0
Changes in operating assets and liabilities:
Related party receivables, net	0	973,000
Prepaid expenses and other assets	(3,053,000)	(3,318,000)
Accounts payable and accrued expenses	4,677,000	5,359,000
Net cash used in operating activities	(71,065,000)	(30,181,000)
Cash flows from investing activities:
Purchases of short-term and long-term investments	(247,142,000)	(31,412,000)
Sales and maturities of short-term and long-term investments	67,337,000	0
Purchases of property and equipment	(769,000)	(297,000)
Net cash used in investing activities	(180,574,000)	(31,709,000)
Cash flows from financing activities:
Proceeds from issuance of common stock in initial public offering, net of issuance costs	0	253,314,000
Issuance costs for Series B convertible preferred stock	0	(17,000)
Proceeds from issuance of Series C convertible preferred stock, net of issuance costs	0	97,707,000
Payment of deferred offering costs	(235,000)	0
Contributions from redeemable convertible noncontrolling interest owners, net	34,853,000	0
Proceeds (payments) upon stock option exercises, net of shares acquired upon forfeiture	730,000	(105,000)
Proceeds from issuance of common stock under employee stock purchase plan	889,000	0
Net cash provided by financing activities	36,237,000	350,899,000
Net (decrease) increase in cash, cash equivalents and restricted cash	(215,402,000)	289,009,000
Cash, cash equivalents and restricted cash at the beginning of the period	365,462,000	76,453,000
Cash, cash equivalents and restricted cash at the end of the period	150,060,000	365,462,000
Supplemental non-cash investing and financing activity:
Deferred offering costs included in accounts payable and accrued expenses	$ 406,000	$ 149,000

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2021
Organization and Basis of Presentation [Abstract]
Organization and Basis of Presentation	1) Organization and Basis of Presentation a) Organization and Nature of Operations Kinnate Biopharma Inc. (Kinnate or the Company) was incorporated in the State of Delaware in January 2018 and is headquartered in San Francisco, California. The Company is a biopharmaceutical company focused on the discovery and development of small molecule kinase inhibitors for difficult-to-treat, genomically defined cancers. Since its inception, the Company has devoted substantially all of its resources to research and development activities, business planning, establishing and maintaining its intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these operations. It has incurred losses and negative cash flows from operations since commencement of its operations. The Company had an accumulated deficit of $143.1 million and cash and cash equivalents and short-term and long-term investments of $324.9 million as of December 31, 2021, exclusive of $33.6 million at its consolidated joint venture discussed in the paragraph below. From its inception through December 31, 2021, the Company has financed its operations primarily through issuances of common stock, including in the Company’s initial public offering (IPO), and private placements of convertible preferred stock. In May 2021, the Company announced the closing of a Series A preferred stock financing of a China joint venture, Kinnjiu Biopharma Inc. (Kinnjiu) to enable the potential development and commercialization of certain targeted oncology product candidates across Greater China. Contributions from noncontrolling interest members totaled $35.0 million before issuance costs of $0.2 million. As of December 31, 2021, the Company held a 54.9% equity interest in the joint venture. As the Company continues to pursue its business plan, it expects to finance its operations through the sale of equity, debt financings or other capital resources, which could include income from collaborations, strategic partnerships or marketing, distribution, licensing or other strategic arrangements with third parties, or from grants. However, there can be no assurance that any additional financing or strategic transactions will be available to the Company on acceptable terms, if at all. If events or circumstances occur such that the Company does not obtain additional funding, it may need to delay, reduce or eliminate its product development or future commercialization efforts, which could have a material adverse effect on the Company’s business, results of operations or financial condition. The accompanying consolidated financial statements do not include any adjustments that might be necessary if it were unable to continue as a going concern. Management believes that it has sufficient working capital on hand to fund operations through at least the next twelve months from the date these consolidated financial statements were available to be issued. b) Basis of Presentation The Company’s consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP). The accompanying consolidated financial statements include the accounts of the Company and its variable interest entity (VIE), Kinnjiu, for which the Company is the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. The accompanying consolidated financial statements include all known adjustments necessary for a fair presentation of the results as required by GAAP. These adjustments consist primarily of normal recurring accruals and estimates that impact the carrying value of assets and liabilities. Operating results presented in these consolidated financial statements are not necessarily indicative of future results, particularly in light of the COVID-19 pandemic and its impact on domestic and global economies. To limit the spread of the novel coronavirus that causes COVID-19, governments have taken various actions including the issuance of stay-at-home orders and physical distancing guidelines. Accordingly, businesses have adjusted, reduced or suspended operating activities. Between March 2020 and June 2021, the Company’s employees worked almost exclusively from home. Since June 2021, the Company’s employees have been working in a hybrid model both in the Company’s offices and also from home. Although some of the governmental orders and guidelines have terminated or are now less restrictive than when originally implemented, the Company continues to monitor and assess the spread of COVID-19 and may need to further adjust its working model from time to time. The ultimate impact of the COVID-19 pandemic is highly uncertain and subject to change, based, in part, on the length and severity of any additional restrictions and other limitations that may be imposed on the Company’s business. As a result, research and development expenses and general and administrative expenses may vary significantly if there is an increased impact from the COVID-19 pandemic on the costs and timing associated with the conduct of the clinical activities and other related business activities. The Company evaluates its ownership, contractual and other interests in entities that are not wholly-owned to determine if these entities are VIEs, and, if so, whether the Company is the primary beneficiary of the VIE. In determining whether the Company is the primary beneficiary of a VIE and therefore required to consolidate the VIE, the Company applies a qualitative approach that determines whether the Company has both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses of, or the rights to receive benefits from, the VIE that could potentially be significant to that VIE. As of December 31, 2021, the Company held a 54.9% equity interest in Kinnjiu. Based on the Company’s assessment, the Company concluded that Kinnjiu is a VIE and the Company is the primary beneficiary. The Company will continuously assess whether it is the primary beneficiary of a VIE, as changes to existing relationships or future transactions may result in the consolidation or deconsolidation of such VIE. During the periods presented, the Company has not provided any other financial or other support to the Company’s VIE that it was not contractually required to provide. c) Initial Public Offering On December 3, 2020, the Company completed its IPO selling 13,800,000 shares of common stock, which includes the full exercise by the underwriters of their option to purchase up to 1,800,000 additional shares, at a price of $20.00 per share resulting in gross proceeds of $276.0 million. After deducting underwriting discounts and commissions and other offering expenses related to the IPO of $22.7 million, the net proceeds to the Company from the transaction were $253.3 million. In connection with the IPO, all shares of convertible preferred stock outstanding at the time of the IPO converted into 25,778,437 shares of common stock. On November 25, 2020, the Company filed a certificate of amendment to its amended and restated certificate of incorporation effecting a 1-for-1.23453

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2) Summary of Significant Accounting Policies a) Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP 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 consolidated financial statements and the reported amounts of expenses during the reporting period. Accounting estimates and management judgments reflected in the consolidated financial statements include: normal recurring accruals, including the accrual of research and development expenses; valuation of deferred tax assets; fair value of common stock and preferred stock and stock-based compensation. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions. Although the impact of the COVID-19 pandemic to the Company’s business and operating results presents additional uncertainty, the Company continues to use the best information available to update its critical accounting estimates. b) Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentration of credit risk, consist primarily of cash and cash equivalents and short-term and long-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company has not experienced any losses on deposits since inception. The Company’s short-term and long-term investments are invested in high grade securities with limited concentration in any one issuer, and as a result, the Company believes represent minimal credit risk. c) Fair Value of Financials Instruments The accounting guidance defines fair value, establishes a consistent framework for measuring fair value, and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The carrying amounts of cash, cash equivalents, prepaid expenses and other current assets, accounts payable and accrued expenses are reasonable estimates of their fair value because of the short maturity of these items. d) Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash equivalents primarily represent funds invested in readily available money market accounts. As of December 31, 2021 and 2020, the Company had cash and cash equivalents balances deposited at major financial institutions. e) Investments All investments have been classified as “available-for-sale” and are carried at fair value as determined based upon quoted market prices or pricing models for similar securities at period end. Investments with contractual maturities less than 12 months at the balance sheet date are considered short-term investments. Those investments with contractual maturities 12 months or greater at the balance sheet date are considered long-term investments. Dividend and interest income are recognized in the Company’s consolidated statements of operations and comprehensive loss when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of securities sold. Unrealized gains and losses are reported as a component of accumulated other comprehensive income (loss). The cost of the Company’s available-for-sale debt securities is adjusted for amortization of premium and accretion of discounts to maturity. The Company reviews its portfolio of available-for-sale debt securities, using both quantitative and qualitative factors, to determine if declines in fair value below cost have resulted from a credit-related loss or other factors. If the decline in fair value is due to credit-related factors, a loss is recognized in statements of operations, whereas if the decline in fair value is not due to credit-related factors, the loss is recorded in other comprehensive income f) Property and Equipment, Net Property and equipment, net are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which ranges between three g) Impairment of Property and Equipment The Company accounts for the impairment of long-lived assets by reviewing these assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted-cash-flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. The Company did not recognize impairment losses for the periods ended December 31, 2021 and 2020. h) Deferred Offering Costs Deferred offering costs are expenses directly related to an at-the-market offering of the Company’s common stock (ATM Offering) (see Note 15), which is pursuant to a prospectus supplement which is part of a shelf registration that was declared effective by the Securities and Exchange Commission (SEC) on January 3, 2022 (Shelf Registration). These costs consist of legal, accounting, printing and filing fees that the Company has capitalized. Deferred costs associated with the ATM Offering will be netted against proceeds, if any, from funds raised pursuant to the ATM Offering . i) Research and Development Research and development expenses are expensed in the periods in which they are incurred. External expenses consist primarily of payments to outside consultants and contract research organizations in connection with the Company’s clinical trials, discovery and preclinical activities, process development, manufacturing activities, regulatory and other services. External expenses are recognized based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its service providers or the estimate of the level of service that has been performed at each reporting date. The Company makes estimates of accrued expenses as of each balance sheet date based on facts and circumstances known at that time. The Company periodically confirms the accuracy of its estimates with the service providers and makes adjustments if necessary. The significant estimates in its accrued research and development expenses include the costs incurred for services performed by vendors in connection with research and development activities for which the Company has not yet been invoiced. j) Redeemable Convertible Noncontrolling Interests The shares third parties own in Kinnjiu represent an interest in the equity the Company does not control. The redeemable convertible noncontrolling interests attributable to other owners has been classified in temporary equity on the Consolidated Balance Sheets as the preferred stock is redeemable by the noncontrolling interests. Since the preferred stock held at Kinnjiu does not represent a residual equity interest, net losses of Kinnjiu are not allocated to the preferred shares. As a result, the balance of the preferred stock classified as a redeemable convertible noncontrolling interest equals its carrying value. k) Commitments and Contingencies The Company recognizes a liability with regard to loss contingencies when it believes it is probable a liability has been incurred, and the amount can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, the Company accrues that amount. When no amount within the range is a better estimate than any other amount the Company accrues the minimum amount in the range. The Company has not recorded any such liabilities as of December 31, 2021 and 2020. l) Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. As of December 31, 2021 and 2020, the Company maintained valuation allowances against its deferred tax assets as the Company concluded it had not met the “more likely than not” to be realized threshold. Changes in the valuation allowance when they are recognized in the provision for income taxes would result in a change in the estimated annual effective tax rate. m) Stock-Based Compensation Stock-based compensation expense represents the cost of the grant date fair value of employee, officer, director and non-employee stock option grants, estimated in accordance with the applicable accounting guidance, recognized on a straight-line basis over the vesting period. The vesting period generally approximates the expected service period of the awards. The Company recognizes forfeitures as they occur. The fair value of stock options is estimated using a Black-Scholes valuation model on the date of grant. This method requires certain assumptions be used as inputs, such as the fair value of the underlying common stock, expected term of the option before exercise, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend. Options granted have a maximum contractual term of ten years. The Company has limited historical stock option activity and therefore estimates the expected term of stock options granted using the simplified method, which represents the arithmetic average of the original contractual term of the stock option and its weighted-average vesting term. The expected volatility of stock options is based upon the historical volatility of a number of publicly traded companies in similar stages of clinical development. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. The risk-free interest rates used are based on the U.S. Treasury yield in effect at the time of grant for zero-coupon U.S. treasury notes with maturities approximately equal to the expected term of the stock options. The Company has historically not declared or paid any dividends and does not currently expect to do so in the foreseeable future, and therefore has estimated the dividend yield to be zero. n) Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized gains and losses on investments and foreign currency gains and losses. The unrealized losses on available-for-sale investments represent the only component of other comprehensive loss that is excluded from the reported net loss. o) Net Loss Per Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of 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 common shares and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, the Company’s common stock options are considered to be potentially dilutive securities. As the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods. The following table sets forth the computation of the basic and diluted net loss per share attributable to common stockholders (in thousands, except share and per share amounts). Years Ended December 31, 2021 2020 Numerator Net loss attributable to Kinnate $ (89,763 ) $ (35,761 ) Denominator Weighted-average shares outstanding used in computing net loss per share, basic and diluted 43,601,162 6,767,591 Net loss per share, basic and diluted $ (2.06 ) $ (5.28 ) The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: As of December 31, 2021 2020 Options to purchase common stock 7,477,568 6,265,409 p) Recently Issued Accounting Standards In In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) (ASC 326): Measurement of Credit Losses on Financial Instruments, which introduced the expected credit losses methodology for the measurement of credit losses on financial assets measured at amortized cost basis, replacing the previous incurred loss methodology. The amendments in Update 2016-13 added Topic 326, Financial Instruments—Credit Losses, made several consequential amendments to the Codification. Update 2016-13 also modified the accounting for available-for-sale debt securities, which must be individually assessed for credit losses when fair value is less than the amortized cost basis, in accordance with Subtopic 326-30, Financial Instruments— Credit Losses—Available-for-Sale Debt Securities. The guidance is effective for public business entities for annual periods beginning after December 15, 2019, including interim periods within those years. For all other entities, the standard is effective for annual periods beginning after December 15, 2022 and interim periods, therein. Early adoption is permitted. Since the Company has elected to use the extended transition period under the JOBS Act available to emerging growth companies (EGCs), the ASU is effective for the Company for fiscal years beginning after December 15, 2022. The Company does not expect the adoption to have a material impact on its consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes - Simplifying the Accounting for Income Taxes (ASU 2019-12). Among other items, the amendments in ASU 2019-12 simplify the accounting treatment of tax law changes and year-to-date losses in interim periods. An entity generally recognizes the effects of a change in tax law in the period of enactment; however, there is an exception for tax laws with delayed effective dates. Under current guidance, an entity may not adjust its annual effective tax rate for a tax law change until the period in which the law is effective. This exception was removed under ASU 2019-12, thereby providing that all effects of a tax law change are recognized in the period of enactment, including adjustment of the estimated annual effective tax rate. Regarding year-to-date losses in interim periods, an entity is required to estimate its annual effective tax rate for the full fiscal year at the end of each interim period and use that rate to calculate its income taxes on a year-to-date basis. However, current guidance provides an exception that when a loss in an interim period exceeds the anticipated loss for the year, the income tax benefit is limited to the amount that would be recognized if the year-to-date loss were the anticipated loss for the full year. ASU 2019-12 removes this exception and provides that, in this situation, an entity would compute its income tax benefit at each interim period based on its estimated annual effective tax rate. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, including interim periods within those annual periods. Early adoption is permitted. For EGCs, the standard is effective for fiscal years beginning after December 15, 2021. The Company does not expect the ASU to have a material impact on its consolidated financial statements and related disclosures.

Cash, cash equivalents and rest

Cash, cash equivalents and restricted cash	12 Months Ended
	Dec. 31, 2021
Cash, cash equivalents and restricted cash [Abstract]
Cash, cash equivalents and restricted cash	3) Cash, cash equivalents and restricted cash The following table provides a reconciliation of the components of cash, cash equivalents and restricted cash reported in the Consolidated Statements of Cash Flows (in thousands): As of December 31, 2021 2020 Cash and cash equivalents $ 116,096 $ 365,462 Cash at consolidated joint venture 33,593 - Restricted cash, non-current 371 - Total cash, cash equivalents and restricted cash reported in the Consolidated Statements of Cash Flows $ 150,060 $ 365,462 The cash at the consolidated joint venture represents cash held at Kinnjiu with the use of such cash limited to the operations of Kinnjiu (see Note 11). The restricted cash balance relates to the Company's office lease in San Diego, California (see Note 13).

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2021
Property and Equipment, Net [Abstract]
Property and Equipment, Net	4) Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): As of December 31, 2021 2020 Furniture and fixtures $ 5 $ 72 Computers and equipment 381 275 Computer software 69 104 Leasehold improvements 638 - Property and equipment 1,093 451 Less accumulated depreciation (137 ) (83 ) Property and equipment, net $ 956 $ 368 Depreciation expense for the years ended December 31, 2021 and 2020 was $123,000 and $83,000, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2021
Accrued Expenses [Abstract]
Accrued Expenses	5) Accrued Expenses Accrued expenses consisted of the following (in thousands): As of December 31, 2021 2020 Accrued research and development $ 4,842 $ 1,580 Accrued compensation 3,344 1,388 Accrued legal fees 425 288 Other accruals 628 108 Total $ 9,239 $ 3,364

Investments

Investments	12 Months Ended
	Dec. 31, 2021
Investments [Abstract]
Investments	6) Investments The Company’s investment policy defines allowable investments and establishes guidelines relating to credit quality, diversification, and maturities of its investments to preserve principal and maintain liquidity. In accordance with the Company’s investment policy, it has The cost, gross unrealized holding gains, gross unrealized holding losses and fair value of available-for-sale investments by types and classes of security at December 31, 2021 and 2020 consisted of the following (in thousands): December 31, 2021 Maturity in Years Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities less than $ 27,450 $ - $ (25 ) $ 27,425 U.S. Treasury securities less than 60,226 - (67 ) 60,159 Asset-backed securities less than 15,798 - (20 ) 15,778 Short-term investments $ 103,474 $ - $ (112 ) $ 103,362 U.S. Treasury securities 1 - 105,861 - (412 ) 105,449 Long-term investments $ 105,861 $ - $ (412 ) $ 105,449 Decemb er 31, 2020 Maturity in Years Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities less than 1 $ 20,327 $ - $ (9 ) $ 20,318 Commercial paper less than 1 11,080 - - 11,080 Short-term investments $ 31,407 $ - $ (9 ) $ 31,398 The Company reviews its investments to identify and evaluate investments that have an indication of possible other-than-temporary impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. At December 31, 2020, the Company did not have any securities in material unrealized loss positions. At December 31, 2021, the Company held securities in a total unrealized loss position of $0.5 million. The Company generally does not intend to sell any investments prior to recovery of their amortized cost basis for any investment in an unrealized loss position. Further, such investments are invested in high grade securities. As such, the Company has classified these losses as temporary in nature. The Company has determined that there were no material declines in fair value of its investments due to credit-related factors as of December 31, 2021 and 2020.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Measurements [Abstract]
Fair Value Measurements	7) Fair Value Measurements The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets; Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The carrying amounts of the Company’s prepaid expenses and other current assets, accounts payable and accrued expenses are generally considered to be representative of their fair value because of the short-term nature of these instruments. The Company’s investments, which may include money market funds and available-for-sale investment securities consisting of high-quality, marketable debt instruments of corporations Following are the major categories of assets measured at fair value on a recurring basis as of December 31, 2021 and 2020 (in thousands): Fair Value Measurements at December 31, 2021 Level 1 Level 2 Level 3 Total Money market funds $ 115,049 $ - $ - $ 115,049 Corporate debt securities - 27,425 - 27,425 U.S. Treasury securities - 165,608 - 165,608 Asset-backed securities - 15,778 - 15,778 Total cash equivalents and investments $ 115,049 $ 208,811 $ - $ 323,860 Fair Value Measurements at December 31, 2020 Level 1 Level 2 Level 3 Total Money market funds $ 364,461 $ - $ - $ 364,461 Corporate debt securities - 20,318 - 20,318 Commercial paper - 11,080 - 11,080 Total cash equivalents and investments $ 364,461 $ 31,398 $ - $ 395,859 Money market funds are classified as cash and cash equivalents in the Company’s Consolidated Balance Sheets at December 31, 2021 and 2020.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity [Abstract]
Stockholders' Equity	8) Stockholders’ Equity Under its Amended and Restated Articles of Incorporation dated December 7, 2020, the Company had a total of 1,200,000,000 shares of capital stock authorized for issuance, consisting of 1,000,000,000 shares of common stock, par value of $0.0001 per share, and 200,000,000 shares of preferred stock, par value of $0.0001 per share. a) Convertible Preferred Stock Prior to 2020, the Company issued shares of Series A and Series B convertible preferred stock for total net proceeds of $93.1 million including issuance costs of $0.5 million. In July and August 2020, the Company issued an aggregate of 8,282,789 shares of its Series C convertible preferred stock at a price of $11.8317 per share, resulting in total net proceeds of approximately $97.7 million including issuance costs of $0.3 million. In connection with the Company’s IPO in December 2020, all outstanding shares of convertible preferred stock converted into 25,778,437 shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There were no shares of convertible preferred stock outstanding as of December 31, 2021 and 2020. b) Common Stock Common stock reserved for future issuance consisted of the following: As of December 31, 2021 2020 Common stock options granted and outstanding 7,477,568 6,265,409 Common stock reserved for future option grants 4,079,339 5,619,735 Total common stock reserved for future issuance 11,556,907 11,885,144

Equity Incentive Plans and Stoc

Equity Incentive Plans and Stock-Based Compensation	12 Months Ended
	Dec. 31, 2021
Equity Incentive Plans and Stock-Based Compensation [Abstract]
Equity Incentive Plans and Stock-Based Compensation	9) Equity Incentive Plans and Stock-Based Compensation a) Equity Incentive Plans I n December 2020, the Company adopted the 2020 Equity Incentive Plan (the 2020 Plan), which replaced the 2018 Equity Incentive Plan (the 2018 Plan). The 2020 Plan allows for the issuance of incentive stock options (ISOs), nonstatutory stock options (NSOs), stock appreciation rights (SARs), restricted stock and restricted stock units (RSUs). The 2020 Plan was established to enable the Company to attract and retain the best available personnel, to provide additional incentive to its employees, directors, and consultants of the Company and to promote the financial success and progress of the Company Under the 2020 and 2018 Plans, the exercise price of each share shall be established at the sole discretion of the Company’s board of directors (or any of the committees of the Company’s board of directors); provided, however, that the exercise price per share shall not be less than the fair market value for shares of the Company’s common stock on the date of grant. The exercise price per share of an ISO granted to an optionee who on the date of the grant owns stock possessing more than 10% of the total combined voting power of all classes of the Company’s stock shall not be less than 110% of the fair market value of a share of its common stock on the date of grant. The options that are granted under the 2020 and 2018 Plans are exercisable at various dates as determined upon grant and terminate within 10 years of the date of grant, unless the optionee owns 10% or more of the common shares at which point the expiration period is 5 years, or upon the employee’s termination (whereupon the terminated employee has thirty days after termination to exercise vested options from the date of termination). The vesting period generally occurs over two Stock option activity under the 2020 Plan is as follows: Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding at January 1, 2021 6,265,409 $ 4.12 9.3 $ 223,454 Granted 2,155,851 29.88 Exercised (328,238 ) 2.23 Forfeited (615,454 ) 10.43 Outstanding at December 31, 2021 7,477,568 $ 11.11 8.3 $ 74,268 Exercisable at December 31, 2021 2,594,363 $ 6.31 7.6 $ 33,261 All exercisable options are vested and all outstanding options are vested or expected to vest. Total intrinsic value of options exercised was $6.0 million and $2.0 million for the years ended December 31, 2021 and 2020, respectively. b) Kinnjiu Equity Incentive Plan In May 2021, Kinnjiu adopted the 2021 Equity Incentive Plan (2021 Plan) to attract and retain the best available personnel, to provide additional incentive to its employees, directors, and consultants of Kinnjiu and to promote the financial success and progress of Kinnjiu. The 2021 Plan allows for the issuance of ISOs, NSOs, SARs, restricted stock and RSUs. The 2021 Plan allows Kinnjiu to issue awards for shares of its common stock up to a total of 9,000,000 shares. Under the 2021 Plan, the exercise price of each share shall be established at the sole discretion of Kinnjiu’s board of directors (or any of the committees of Kinnjiu’s board of directors); provided, however, that the exercise price per share shall not be less than the fair market value for shares of Kinnjiu’s common stock on the date of grant. An independent valuation firm was engaged to provide a valuation report related to the fair market value of Kinnjiu’s shares, as Kinnjiu is not publicly traded, and the fair market was determined to be $0.34 per ordinary share Pursuant to the 2021 Plan, both SARs and NSOs were granted to employees and consultants to Kinnjiu. The NSOs generally vest over 4 years. The vesting provisions for SAR awards, which have been granted to Kinnjiu employees, include both a service-based vesting requirement and liquidity event requirement, each such vesting date, a Vesting Event. The service-based vesting is as follows: (i) 30% of the SAR shall vest on the two-year anniversary of the vesting commencement date, (ii) 30% of the SAR shall vest on the three-year anniversary of the vesting commencement date, and (iii) 40% of the SAR shall vest on the four-year anniversary of the vesting commencement date. The liquidity event requirement shall be satisfied upon the earlier of the expiration of a lock-up period following an IPO event or a change in control, subject to the holder of the SAR continuing to be a service provider through the date such earlier event occurs. The SARs shall automatically be exercised, to the extent vested, upon the occurrence of a Vesting Event. Unless otherwise determined by the administrator of the plan, the portion of the SAR that has not satisfied the service-based vesting requirement as of immediately prior to the liquidity event will terminate on the liquidity event without consideration. As the settlement of the SARs granted to Kinnjiu employees is contingent upon both a service condition and performance condition (liquidity event such as an IPO) that is not deemed probable, compensation cost for such awards will not be recognized until the event occurs. During the year ended December 31, 2021, equity award activity under the 2021 Plan is as follows: Stock Options Shares Weighted- Outstanding at January 1, 2021 - - Granted 3,087,500 $ 0.34 Exercised - - Forfeited (250,000 ) 0.34 Outstanding at December 31, 2021 2,837,500 $ 0.34 Exercisable at December 31, 2021 - - SARs Shares Weighted- Outstanding at January 1, 2021 - - Granted 325,000 0.34 Exercised - - Forfeited (25,000 ) 0.34 Outstanding at December 31, 2021 300,000 $ 0.34 Exercisable at December 31, 2021 - - c) Employee Stock Purchase Plan In December 2020, the Company’s board of directors approved and adopted the 2020 Employee Stock Purchase Plan (the ESPP). The ESPP became effective on the business day immediately prior to the effective date of the Company’s first registration statement. The ESPP permits eligible employees who elect to participate in an offering under the ESPP to have up to 15% of their eligible earnings withheld, subject to certain limitations, to purchase shares of common stock pursuant to the ESPP. The price of common stock purchased under the ESPP is equal to 85% of the lower of the fair market value of the common stock at the commencement date of each offering period or the relevant date of purchase. Each offering period is six months, with new offering periods commencing every six months on or about the dates of May 15 and November 15 of each year. A total of 435,000 shares of common stock were initially reserved. d) Stock-Based Compensation Expense The Company estimated the fair value of stock options using the Black-Scholes valuation model. The Company accounts for any forfeitures of options when they occur. Previously recognized compensation expense for an award is reversed in the period that the award is forfeited. The fair value of stock options was estimated using the following assumptions: Years Ended December 31, 2021 2020 Expected term (in years) 5 - 6 6 - 7 Expected volatility 85% - 89% 88% - 93% Risk-free interest rate 0.68% - 1.21% 0.37% - 1.57% Expected dividend 0% 0% The weighted-average grant-date fair value of options granted was $21.70 and $2.89 for the years ended December 31, 2021, and 2020, respectively. The assumptions used for the years ended December 31, 2021 and 2020 under the ESPP were as follows: Years Ended December 31, 2021 2020 Expected term (in years) 0.50 0.41 Expected volatility 50% - 68% 51% Risk-free interest rate 0.03% - 0.07% 0.09% Expected dividend 0% 0% Stock-based compensation expense related to the Company’s stock options and ESPP totaled the following (in thousands): Years Ended December 31, 2021 2020 Research and development $ 6,778 $ 1,404 General and administrative 8,238 1,074 Total stock-based compensation $ 15,016 $ 2,478 As of December 31, 2021, and 2020, there was approximately $45.0 million and $17.1 million of total unrecognized stock-based compensation expense related to nonvested stock-based compensation arrangements, which is expected to be recognized over a weighted-average period of approximately 2.58 years and 3.31 years, respectively. As of December 31, 2021 and 2020, there was approximately $0.1 million and $0.6 million of total unrecognized stock-based compensation expense related to the ESPP.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	10) Related Party Transactions Series A Preferred Stock Financing of Kinnjiu In connection with the Series A preferred stock financing of Kinnjiu, contributions from noncontrolling interest members totaled $35.0 million before issuance costs of $0.2 million. Such noncontrolling interest members are also investors or affiliates of investors in the Company and have representatives that serve on both the Company’s board of directors and the board of directors of Kinnjiu.

Variable Interest Entity

Variable Interest Entity	12 Months Ended
	Dec. 31, 2021
Variable Interest Entity [Abstract]
Variable Interest Entity	11) Variable Interest Entity As disclosed above, in May 2021, the Company announced the closing of a Series A preferred stock financing of Kinnjiu to enable the potential development and commercialization of certain targeted oncology product candidates across Greater China. Contributions from noncontrolling interest members totaled $35.0 million before issuance costs of $0.2 million. As of December 31, 2021, the Company held a 54.9% equity interest in the joint venture. As the Company determined it was the primary beneficiary of this VIE, the VIE has been consolidated in the Company’s consolidated financial statements. The Company provides certain general and administrative and research and development services to Kinnjiu pursuant to intercompany agreements; however, the Company does not provide any financial support and has no obligation to fund operations of Kinnjiu. The following table summarizes the fair value of Kinnjiu, as of May 13, 2021 recorded upon initial consolidation in the Company’s Consolidated Balance Sheets and the carrying amount of such assets and liabilities as of December 31, 2021 (in thousands): December 31, 2021 May 13, 2021 Cash at consolidated joint venture $ 33,593 $ 35,011 Prepaid expenses and other current assets 215 - Accounts payable and accrued expenses 286 -

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Taxes [Abstract]
Income Taxes	12) Income Taxes Significant components of the Company’s provision for income taxes and income taxes computed using the U.S. federal statutory corporate tax rate were as follows (in thousands): Years Ended December 31, 2021 2020 Income taxes computed at the statutory rate $ (18,850 ) $ (7,510 ) State income taxes, net of federal benefit (4 ) - Permanent items 922 4 Stock-based compensation (280 ) 102 Research credits (1,306 ) - Other 548 (36 ) Change in valuation allowance 18,970 7,440 Provision for income taxes $ - $ - Significant components of the Company’s deferred taxes were as follows (in thousands): As of December 31, 2021 2020 Deferred tax assets: Net operating loss carryforward $ 28,054 $ 12,304 Research and development credit carryforwards 1,295 - Stock-based compensation 1,774 264 Accrued compensation 635 292 Other, net 144 23 Gross deferred tax assets: 31,902 12,883 Less valuation allowance (31,741 ) (12,883 ) Total deferred tax assets 161 - Deferred tax liabilities: Other (161 ) - Net deferred tax assets $ - $ - Deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The Company has established a valuation allowance against net deferred tax assets due to the uncertainty that such assets will be realized. The Company periodically evaluates the recoverability of its deferred tax assets. Due to the Company's history of losses management cannot conclude that the deferred tax asset will be realized. The change in the valuation allowance for the year ended December 31, 2021 was an increase of $18.9 million. At December 31, 2021, the Company has federal and California net operating loss carryforwards of approximately $127.1 million and $24.8 million, respectively. As a result of the Tax Cuts and Jobs Act of 2017, as amended by the Coronavirus Aid, Relief, and Economic Security Act, for U.S. income tax purposes, net operating losses generated in taxable years beginning after December 31, 2017 can be carried forward indefinitely, but for taxable years beginning after December 31, 2020 the deductibility of such NOLs is limited to 80% of current year taxable income. The California net operating losses will begin to expire in 2038 and the foreign losses carry forward indefinitely. Pursuant to the Internal Revenue Code, as amended (IRC) Sections 382 and 383, annual use of the Company's NOL and research and development credit carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year period. The Company has not completed an ownership change analysis pursuant to IRS Section 382. If ownership changes have occurred or occurs in the future, the amount of remaining tax attribute carryforwards available to offset taxable income and income tax expense in future years may be restricted or eliminated. If eliminated, the related asset would be removed from deferred tax assets with a corresponding reduction in the valuation allowance. Due to the existence of the valuation allowance, limitations created by future ownership changes, if any, will not impact the Company's effective tax rate. The Company conducted a study to document whether its research activities qualify for the research and development tax credit. Based on such study, the Company determined that certain research activities qualified for the research and development tax credit. As of December 31, 2021, the Company has federal and California research and development tax credit carryforwards of $1.0 million and $1.1 million, respectively, which begin to expire in 2040. Uncertain tax positions are evaluated based upon the facts and circumstances that exist at each reporting period. Subsequent changes in judgement based upon new information may lead to changes in recognition, derecognition, and measurement. Adjustment may result, for example, upon resolution of an issue with the taxing authorities or expiration of a statute of limitations barring an assessment for an issue. The Company recognizes a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination by tax authorities. As of December 31, 2021 and 2020, the Company did not have gross unrecognized tax benefits. The Company is subject to taxation in the United States and California. All of the Company’s tax years from inception are subject to examination by federal and state tax authorities. The Company’s practice is to recognize interest and penalties related to income tax matters in income tax expense. The Company had no accrued interest or penalties related to income tax matters in the Company’s balance sheets at December 31, 2021 and 2020 and has not recognized interest or penalties in the Company’s statements of operations and comprehensive loss for the years ended December 31, 2021 and 2020. Further, the Company is not currently under examination by any federal, state or local tax authority.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies [Abstract]
Commitments and Contingencies	13) Commitments and Contingencies Litigation T he Company, from time to time, is involved in legal proceedings, regulatory actions, claims and litigation arising in the ordinary course of business. The Company was not a defendant in any lawsuit for the years ending December 31, 2021 and 2020, that, in the opinion of Company’s management, is likely to have a material adverse effect on the Company’s business Leases In June 2021, the Company entered into an agreement to lease 8,088 rentable square feet of office space (SD Permanent Space) located in San Diego, California (SD Lease) for a period of five years and four months commencing in March 2022. Payments for the SD Permanent Space pursuant to the SD Lease commenced in the first quarter of 2022. Additionally, the Company has an option to extend the SD Lease for an additional five years at the end of the initial term. Under the SD Lease, the Company utilized temporary space in San Diego, California, which ended when payments for the SD Permanent Space commenced. In connection with the execution of the SD Lease, the Company provided a standby letter of credit for $0.4 million in lieu of a security deposit, which is classified as restricted cash on the Consolidated Balance Sheets. So long as the Company is not in default under the SD Lease, this amount will decrease after each of years three and four of the SD Lease term to $0.3 million. In May 2021, the Company entered into a lease for temporary office space in San Francisco, California, with a lease term that initially ran through December 31, 2021 and was extended to January 31, 2022. In August 2021, the Company entered into an agreement to lease 5,698 rentable square feet of office space located in San Francisco, California (SF Lease) for an initial term that commenced on January 1, 2022 June 30, 2026, and the Company has an option to extend the SF Lease for an additional three years at the end of the initial term. Future minimum lease payments under non-cancelable operating leases as of December 31, 2021 were as follows (in thousands): Year Ending December 31, Operating Leases 2022 $ 638 2023 1,045 2024 1,076 2025 1,108 2026 924 Thereafter 365 Total mimium lease payments $ 5,156 Rent expense was $0.2 million and $0.2 million for the years ended December 31, 2021 and 2020, respectively.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2021
Employee Benefit Plan [Abstract]
Employee Benefit Plan	14) Employee Benefit Plan The Company has a defined-contribution 401(k) plan for employees. Employees are eligible to participate in the plan beginning immediately following date of hire. Under the terms of the plan, employees may make voluntary contributions as a percentage of compensation and the Company may make a discretionary match or another contribution. The Company contributed $0.4 million to the plan during the year ended December 31, 2021. There were no employer contributions to the plan during the year ended December 31, 2020.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	15) Subsequent Events In January 2022, the Company filed a shelf registration with the SEC on Form S-3. The shelf registration statement included a prospectus for an ATM Offering to sell up to an aggregate of $150.0 million of shares of the Company’s common stock that may be issued and sold from time to time under a sales agreement with SVB Leerink LLC. To date, no shares have been issued and sold pursuant to the ATM Offering.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2021
Organization and Basis of Presentation [Abstract]
Organization and Nature of Operations	a) Organization and Nature of Operations Kinnate Biopharma Inc. (Kinnate or the Company) was incorporated in the State of Delaware in January 2018 and is headquartered in San Francisco, California. The Company is a biopharmaceutical company focused on the discovery and development of small molecule kinase inhibitors for difficult-to-treat, genomically defined cancers. Since its inception, the Company has devoted substantially all of its resources to research and development activities, business planning, establishing and maintaining its intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these operations. It has incurred losses and negative cash flows from operations since commencement of its operations. The Company had an accumulated deficit of $143.1 million and cash and cash equivalents and short-term and long-term investments of $324.9 million as of December 31, 2021, exclusive of $33.6 million at its consolidated joint venture discussed in the paragraph below. From its inception through December 31, 2021, the Company has financed its operations primarily through issuances of common stock, including in the Company’s initial public offering (IPO), and private placements of convertible preferred stock. In May 2021, the Company announced the closing of a Series A preferred stock financing of a China joint venture, Kinnjiu Biopharma Inc. (Kinnjiu) to enable the potential development and commercialization of certain targeted oncology product candidates across Greater China. Contributions from noncontrolling interest members totaled $35.0 million before issuance costs of $0.2 million. As of December 31, 2021, the Company held a 54.9% equity interest in the joint venture. As the Company continues to pursue its business plan, it expects to finance its operations through the sale of equity, debt financings or other capital resources, which could include income from collaborations, strategic partnerships or marketing, distribution, licensing or other strategic arrangements with third parties, or from grants. However, there can be no assurance that any additional financing or strategic transactions will be available to the Company on acceptable terms, if at all. If events or circumstances occur such that the Company does not obtain additional funding, it may need to delay, reduce or eliminate its product development or future commercialization efforts, which could have a material adverse effect on the Company’s business, results of operations or financial condition. The accompanying consolidated financial statements do not include any adjustments that might be necessary if it were unable to continue as a going concern. Management believes that it has sufficient working capital on hand to fund operations through at least the next twelve months from the date these consolidated financial statements were available to be issued.
Basis of Presentation	b) Basis of Presentation The Company’s consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP). The accompanying consolidated financial statements include the accounts of the Company and its variable interest entity (VIE), Kinnjiu, for which the Company is the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. The accompanying consolidated financial statements include all known adjustments necessary for a fair presentation of the results as required by GAAP. These adjustments consist primarily of normal recurring accruals and estimates that impact the carrying value of assets and liabilities. Operating results presented in these consolidated financial statements are not necessarily indicative of future results, particularly in light of the COVID-19 pandemic and its impact on domestic and global economies. To limit the spread of the novel coronavirus that causes COVID-19, governments have taken various actions including the issuance of stay-at-home orders and physical distancing guidelines. Accordingly, businesses have adjusted, reduced or suspended operating activities. Between March 2020 and June 2021, the Company’s employees worked almost exclusively from home. Since June 2021, the Company’s employees have been working in a hybrid model both in the Company’s offices and also from home. Although some of the governmental orders and guidelines have terminated or are now less restrictive than when originally implemented, the Company continues to monitor and assess the spread of COVID-19 and may need to further adjust its working model from time to time. The ultimate impact of the COVID-19 pandemic is highly uncertain and subject to change, based, in part, on the length and severity of any additional restrictions and other limitations that may be imposed on the Company’s business. As a result, research and development expenses and general and administrative expenses may vary significantly if there is an increased impact from the COVID-19 pandemic on the costs and timing associated with the conduct of the clinical activities and other related business activities. The Company evaluates its ownership, contractual and other interests in entities that are not wholly-owned to determine if these entities are VIEs, and, if so, whether the Company is the primary beneficiary of the VIE. In determining whether the Company is the primary beneficiary of a VIE and therefore required to consolidate the VIE, the Company applies a qualitative approach that determines whether the Company has both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses of, or the rights to receive benefits from, the VIE that could potentially be significant to that VIE. As of December 31, 2021, the Company held a 54.9% equity interest in Kinnjiu. Based on the Company’s assessment, the Company concluded that Kinnjiu is a VIE and the Company is the primary beneficiary. The Company will continuously assess whether it is the primary beneficiary of a VIE, as changes to existing relationships or future transactions may result in the consolidation or deconsolidation of such VIE. During the periods presented, the Company has not provided any other financial or other support to the Company’s VIE that it was not contractually required to provide.
Initial Public Offering	c) Initial Public Offering On December 3, 2020, the Company completed its IPO selling 13,800,000 shares of common stock, which includes the full exercise by the underwriters of their option to purchase up to 1,800,000 additional shares, at a price of $20.00 per share resulting in gross proceeds of $276.0 million. After deducting underwriting discounts and commissions and other offering expenses related to the IPO of $22.7 million, the net proceeds to the Company from the transaction were $253.3 million. In connection with the IPO, all shares of convertible preferred stock outstanding at the time of the IPO converted into 25,778,437 shares of common stock. On November 25, 2020, the Company filed a certificate of amendment to its amended and restated certificate of incorporation effecting a 1-for-1.23453

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Summary of Significant Accounting Policies [Abstract]
Use of Estimates	a) Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP 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 consolidated financial statements and the reported amounts of expenses during the reporting period. Accounting estimates and management judgments reflected in the consolidated financial statements include: normal recurring accruals, including the accrual of research and development expenses; valuation of deferred tax assets; fair value of common stock and preferred stock and stock-based compensation. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions. Although the impact of the COVID-19 pandemic to the Company’s business and operating results presents additional uncertainty, the Company continues to use the best information available to update its critical accounting estimates.
Concentration of Credit Risk	b) Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentration of credit risk, consist primarily of cash and cash equivalents and short-term and long-term investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company has not experienced any losses on deposits since inception. The Company’s short-term and long-term investments are invested in high grade securities with limited concentration in any one issuer, and as a result, the Company believes represent minimal credit risk.
Fair Value of Financials Instruments	c) Fair Value of Financials Instruments The accounting guidance defines fair value, establishes a consistent framework for measuring fair value, and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The carrying amounts of cash, cash equivalents, prepaid expenses and other current assets, accounts payable and accrued expenses are reasonable estimates of their fair value because of the short maturity of these items.
Cash and Cash Equivalents	d) Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash equivalents primarily represent funds invested in readily available money market accounts. As of December 31, 2021 and 2020, the Company had cash and cash equivalents balances deposited at major financial institutions.
Investments	e) Investments All investments have been classified as “available-for-sale” and are carried at fair value as determined based upon quoted market prices or pricing models for similar securities at period end. Investments with contractual maturities less than 12 months at the balance sheet date are considered short-term investments. Those investments with contractual maturities 12 months or greater at the balance sheet date are considered long-term investments. Dividend and interest income are recognized in the Company’s consolidated statements of operations and comprehensive loss when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of securities sold. Unrealized gains and losses are reported as a component of accumulated other comprehensive income (loss). The cost of the Company’s available-for-sale debt securities is adjusted for amortization of premium and accretion of discounts to maturity. The Company reviews its portfolio of available-for-sale debt securities, using both quantitative and qualitative factors, to determine if declines in fair value below cost have resulted from a credit-related loss or other factors. If the decline in fair value is due to credit-related factors, a loss is recognized in statements of operations, whereas if the decline in fair value is not due to credit-related factors, the loss is recorded in other comprehensive income
Property and Equipment, Net	f) Property and Equipment, Net Property and equipment, net are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which ranges between three
Impairment of Property and Equipment	g) Impairment of Property and Equipment The Company accounts for the impairment of long-lived assets by reviewing these assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted-cash-flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. The Company did not recognize impairment losses for the periods ended December 31, 2021 and 2020.
Deferred Offering Costs	h) Deferred Offering Costs Deferred offering costs are expenses directly related to an at-the-market offering of the Company’s common stock (ATM Offering) (see Note 15), which is pursuant to a prospectus supplement which is part of a shelf registration that was declared effective by the Securities and Exchange Commission (SEC) on January 3, 2022 (Shelf Registration). These costs consist of legal, accounting, printing and filing fees that the Company has capitalized. Deferred costs associated with the ATM Offering will be netted against proceeds, if any, from funds raised pursuant to the ATM Offering .
Research and Development	i) Research and Development Research and development expenses are expensed in the periods in which they are incurred. External expenses consist primarily of payments to outside consultants and contract research organizations in connection with the Company’s clinical trials, discovery and preclinical activities, process development, manufacturing activities, regulatory and other services. External expenses are recognized based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its service providers or the estimate of the level of service that has been performed at each reporting date. The Company makes estimates of accrued expenses as of each balance sheet date based on facts and circumstances known at that time. The Company periodically confirms the accuracy of its estimates with the service providers and makes adjustments if necessary. The significant estimates in its accrued research and development expenses include the costs incurred for services performed by vendors in connection with research and development activities for which the Company has not yet been invoiced.
Redeemable Convertible Noncontrolling Interests	j) Redeemable Convertible Noncontrolling Interests The shares third parties own in Kinnjiu represent an interest in the equity the Company does not control. The redeemable convertible noncontrolling interests attributable to other owners has been classified in temporary equity on the Consolidated Balance Sheets as the preferred stock is redeemable by the noncontrolling interests. Since the preferred stock held at Kinnjiu does not represent a residual equity interest, net losses of Kinnjiu are not allocated to the preferred shares. As a result, the balance of the preferred stock classified as a redeemable convertible noncontrolling interest equals its carrying value.
Commitments and Contingencies	k) Commitments and Contingencies The Company recognizes a liability with regard to loss contingencies when it believes it is probable a liability has been incurred, and the amount can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, the Company accrues that amount. When no amount within the range is a better estimate than any other amount the Company accrues the minimum amount in the range. The Company has not recorded any such liabilities as of December 31, 2021 and 2020.
Income Taxes	l) Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. As of December 31, 2021 and 2020, the Company maintained valuation allowances against its deferred tax assets as the Company concluded it had not met the “more likely than not” to be realized threshold. Changes in the valuation allowance when they are recognized in the provision for income taxes would result in a change in the estimated annual effective tax rate.
Stock-Based Compensation	m) Stock-Based Compensation Stock-based compensation expense represents the cost of the grant date fair value of employee, officer, director and non-employee stock option grants, estimated in accordance with the applicable accounting guidance, recognized on a straight-line basis over the vesting period. The vesting period generally approximates the expected service period of the awards. The Company recognizes forfeitures as they occur. The fair value of stock options is estimated using a Black-Scholes valuation model on the date of grant. This method requires certain assumptions be used as inputs, such as the fair value of the underlying common stock, expected term of the option before exercise, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend. Options granted have a maximum contractual term of ten years. The Company has limited historical stock option activity and therefore estimates the expected term of stock options granted using the simplified method, which represents the arithmetic average of the original contractual term of the stock option and its weighted-average vesting term. The expected volatility of stock options is based upon the historical volatility of a number of publicly traded companies in similar stages of clinical development. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. The risk-free interest rates used are based on the U.S. Treasury yield in effect at the time of grant for zero-coupon U.S. treasury notes with maturities approximately equal to the expected term of the stock options. The Company has historically not declared or paid any dividends and does not currently expect to do so in the foreseeable future, and therefore has estimated the dividend yield to be zero.
Comprehensive Loss	n) Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized gains and losses on investments and foreign currency gains and losses. The unrealized losses on available-for-sale investments represent the only component of other comprehensive loss that is excluded from the reported net loss.
Net Loss Per Share	o) Net Loss Per Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of 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 common shares and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, the Company’s common stock options are considered to be potentially dilutive securities. As the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods. The following table sets forth the computation of the basic and diluted net loss per share attributable to common stockholders (in thousands, except share and per share amounts). Years Ended December 31, 2021 2020 Numerator Net loss attributable to Kinnate $ (89,763 ) $ (35,761 ) Denominator Weighted-average shares outstanding used in computing net loss per share, basic and diluted 43,601,162 6,767,591 Net loss per share, basic and diluted $ (2.06 ) $ (5.28 ) The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: As of December 31, 2021 2020 Options to purchase common stock 7,477,568 6,265,409
Recently Issued Accounting Standards	p) Recently Issued Accounting Standards In In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) (ASC 326): Measurement of Credit Losses on Financial Instruments, which introduced the expected credit losses methodology for the measurement of credit losses on financial assets measured at amortized cost basis, replacing the previous incurred loss methodology. The amendments in Update 2016-13 added Topic 326, Financial Instruments—Credit Losses, made several consequential amendments to the Codification. Update 2016-13 also modified the accounting for available-for-sale debt securities, which must be individually assessed for credit losses when fair value is less than the amortized cost basis, in accordance with Subtopic 326-30, Financial Instruments— Credit Losses—Available-for-Sale Debt Securities. The guidance is effective for public business entities for annual periods beginning after December 15, 2019, including interim periods within those years. For all other entities, the standard is effective for annual periods beginning after December 15, 2022 and interim periods, therein. Early adoption is permitted. Since the Company has elected to use the extended transition period under the JOBS Act available to emerging growth companies (EGCs), the ASU is effective for the Company for fiscal years beginning after December 15, 2022. The Company does not expect the adoption to have a material impact on its consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes - Simplifying the Accounting for Income Taxes (ASU 2019-12). Among other items, the amendments in ASU 2019-12 simplify the accounting treatment of tax law changes and year-to-date losses in interim periods. An entity generally recognizes the effects of a change in tax law in the period of enactment; however, there is an exception for tax laws with delayed effective dates. Under current guidance, an entity may not adjust its annual effective tax rate for a tax law change until the period in which the law is effective. This exception was removed under ASU 2019-12, thereby providing that all effects of a tax law change are recognized in the period of enactment, including adjustment of the estimated annual effective tax rate. Regarding year-to-date losses in interim periods, an entity is required to estimate its annual effective tax rate for the full fiscal year at the end of each interim period and use that rate to calculate its income taxes on a year-to-date basis. However, current guidance provides an exception that when a loss in an interim period exceeds the anticipated loss for the year, the income tax benefit is limited to the amount that would be recognized if the year-to-date loss were the anticipated loss for the full year. ASU 2019-12 removes this exception and provides that, in this situation, an entity would compute its income tax benefit at each interim period based on its estimated annual effective tax rate. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, including interim periods within those annual periods. Early adoption is permitted. For EGCs, the standard is effective for fiscal years beginning after December 15, 2021. The Company does not expect the ASU to have a material impact on its consolidated financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Summary of Significant Accounting Policies [Abstract]
Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the basic and diluted net loss per share attributable to common stockholders (in thousands, except share and per share amounts). Years Ended December 31, 2021 2020 Numerator Net loss attributable to Kinnate $ (89,763 ) $ (35,761 ) Denominator Weighted-average shares outstanding used in computing net loss per share, basic and diluted 43,601,162 6,767,591 Net loss per share, basic and diluted $ (2.06 ) $ (5.28 )
Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share	The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive: As of December 31, 2021 2020 Options to purchase common stock 7,477,568 6,265,409

Cash, cash equivalents and re_2

Cash, cash equivalents and restricted cash (Tables)	12 Months Ended
	Dec. 31, 2021
Cash, cash equivalents and restricted cash [Abstract]
Components of cash, cash equivalents and restricted cash	The following table provides a reconciliation of the components of cash, cash equivalents and restricted cash reported in the Consolidated Statements of Cash Flows (in thousands): As of December 31, 2021 2020 Cash and cash equivalents $ 116,096 $ 365,462 Cash at consolidated joint venture 33,593 - Restricted cash, non-current 371 - Total cash, cash equivalents and restricted cash reported in the Consolidated Statements of Cash Flows $ 150,060 $ 365,462

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2021
Property and Equipment, Net [Abstract]
Property and Equipment, Net	Property and equipment, net, consisted of the following (in thousands): As of December 31, 2021 2020 Furniture and fixtures $ 5 $ 72 Computers and equipment 381 275 Computer software 69 104 Leasehold improvements 638 - Property and equipment 1,093 451 Less accumulated depreciation (137 ) (83 ) Property and equipment, net $ 956 $ 368

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2021
Accrued Expenses [Abstract]
Accrued Expenses	Accrued expenses consisted of the following (in thousands): As of December 31, 2021 2020 Accrued research and development $ 4,842 $ 1,580 Accrued compensation 3,344 1,388 Accrued legal fees 425 288 Other accruals 628 108 Total $ 9,239 $ 3,364

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2021
Investments [Abstract]
Investments by Type and Classes of Security	The cost, gross unrealized holding gains, gross unrealized holding losses and fair value of available-for-sale investments by types and classes of security at December 31, 2021 and 2020 consisted of the following (in thousands): December 31, 2021 Maturity in Years Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities less than $ 27,450 $ - $ (25 ) $ 27,425 U.S. Treasury securities less than 60,226 - (67 ) 60,159 Asset-backed securities less than 15,798 - (20 ) 15,778 Short-term investments $ 103,474 $ - $ (112 ) $ 103,362 U.S. Treasury securities 1 - 105,861 - (412 ) 105,449 Long-term investments $ 105,861 $ - $ (412 ) $ 105,449 Decemb er 31, 2020 Maturity in Years Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities less than 1 $ 20,327 $ - $ (9 ) $ 20,318 Commercial paper less than 1 11,080 - - 11,080 Short-term investments $ 31,407 $ - $ (9 ) $ 31,398

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Measurements [Abstract]
Major Categories of Assets Measured at Fair Value on a Recurring Basis	Following are the major categories of assets measured at fair value on a recurring basis as of December 31, 2021 and 2020 (in thousands): Fair Value Measurements at December 31, 2021 Level 1 Level 2 Level 3 Total Money market funds $ 115,049 $ - $ - $ 115,049 Corporate debt securities - 27,425 - 27,425 U.S. Treasury securities - 165,608 - 165,608 Asset-backed securities - 15,778 - 15,778 Total cash equivalents and investments $ 115,049 $ 208,811 $ - $ 323,860 Fair Value Measurements at December 31, 2020 Level 1 Level 2 Level 3 Total Money market funds $ 364,461 $ - $ - $ 364,461 Corporate debt securities - 20,318 - 20,318 Commercial paper - 11,080 - 11,080 Total cash equivalents and investments $ 364,461 $ 31,398 $ - $ 395,859

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity [Abstract]
Common Stock Reserved for Future Issuance	Common stock reserved for future issuance consisted of the following: As of December 31, 2021 2020 Common stock options granted and outstanding 7,477,568 6,265,409 Common stock reserved for future option grants 4,079,339 5,619,735 Total common stock reserved for future issuance 11,556,907 11,885,144

Equity Incentive Plans and St_2

Equity Incentive Plans and Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option Activity	Stock option activity under the 2020 Plan is as follows: Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding at January 1, 2021 6,265,409 $ 4.12 9.3 $ 223,454 Granted 2,155,851 29.88 Exercised (328,238 ) 2.23 Forfeited (615,454 ) 10.43 Outstanding at December 31, 2021 7,477,568 $ 11.11 8.3 $ 74,268 Exercisable at December 31, 2021 2,594,363 $ 6.31 7.6 $ 33,261
Equity Award Activity	During the year ended December 31, 2021, equity award activity under the 2021 Plan is as follows: Stock Options Shares Weighted- Outstanding at January 1, 2021 - - Granted 3,087,500 $ 0.34 Exercised - - Forfeited (250,000 ) 0.34 Outstanding at December 31, 2021 2,837,500 $ 0.34 Exercisable at December 31, 2021 - - SARs Shares Weighted- Outstanding at January 1, 2021 - - Granted 325,000 0.34 Exercised - - Forfeited (25,000 ) 0.34 Outstanding at December 31, 2021 300,000 $ 0.34 Exercisable at December 31, 2021 - -
Stock-Based Compensation Expense	Stock-based compensation expense related to the Company’s stock options and ESPP totaled the following (in thousands): Years Ended December 31, 2021 2020 Research and development $ 6,778 $ 1,404 General and administrative 8,238 1,074 Total stock-based compensation $ 15,016 $ 2,478
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value of Stock Assumptions	The assumptions used for the years ended December 31, 2021 and 2020 under the ESPP were as follows: Years Ended December 31, 2021 2020 Expected term (in years) 0.50 0.41 Expected volatility 50% - 68% 51% Risk-free interest rate 0.03% - 0.07% 0.09% Expected dividend 0% 0%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value of Stock Assumptions	The fair value of stock options was estimated using the following assumptions: Years Ended December 31, 2021 2020 Expected term (in years) 5 - 6 6 - 7 Expected volatility 85% - 89% 88% - 93% Risk-free interest rate 0.68% - 1.21% 0.37% - 1.57% Expected dividend 0% 0%

Variable Interest Entity (Table

Variable Interest Entity (Tables)	12 Months Ended
	Dec. 31, 2021
Variable Interest Entity [Abstract]
Carrying Amount of Assets and Liabilities	The following table summarizes the fair value of Kinnjiu, as of May 13, 2021 recorded upon initial consolidation in the Company’s Consolidated Balance Sheets and the carrying amount of such assets and liabilities as of December 31, 2021 (in thousands): December 31, 2021 May 13, 2021 Cash at consolidated joint venture $ 33,593 $ 35,011 Prepaid expenses and other current assets 215 - Accounts payable and accrued expenses 286 -

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Taxes [Abstract]
Provision for Income Taxes	Significant components of the Company’s provision for income taxes and income taxes computed using the U.S. federal statutory corporate tax rate were as follows (in thousands): Years Ended December 31, 2021 2020 Income taxes computed at the statutory rate $ (18,850 ) $ (7,510 ) State income taxes, net of federal benefit (4 ) - Permanent items 922 4 Stock-based compensation (280 ) 102 Research credits (1,306 ) - Other 548 (36 ) Change in valuation allowance 18,970 7,440 Provision for income taxes $ - $ -
Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred taxes were as follows (in thousands): As of December 31, 2021 2020 Deferred tax assets: Net operating loss carryforward $ 28,054 $ 12,304 Research and development credit carryforwards 1,295 - Stock-based compensation 1,774 264 Accrued compensation 635 292 Other, net 144 23 Gross deferred tax assets: 31,902 12,883 Less valuation allowance (31,741 ) (12,883 ) Total deferred tax assets 161 - Deferred tax liabilities: Other (161 ) - Net deferred tax assets $ - $ -

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies [Abstract]
Future Minimum Lease Payments Under Non-Cancelable Operating Leases	Future minimum lease payments under non-cancelable operating leases as of December 31, 2021 were as follows (in thousands): Year Ending December 31, Operating Leases 2022 $ 638 2023 1,045 2024 1,076 2025 1,108 2026 924 Thereafter 365 Total mimium lease payments $ 5,156

Organization and Basis of Pre_3

Organization and Basis of Presentation (Details) $ / shares in Units, $ in Thousands	May 31, 2021USD ($)	Dec. 03, 2020USD ($)$ / sharesshares	Nov. 25, 2020	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)shares
Organization and Nature of Operations [Abstract]
Accumulated deficit				$ (143,092)	$ (53,329)
Cash and cash equivalents and short-term and long-term investments				324,900
Contributions from redeemable convertible noncontrolling interest owners, net	$ 35,000			34,853	0
Contributions from noncontrolling interest owners, issuance cost	$ 200			200
Initial Public Offering [Abstract]
Underwriting discounts and commissions and other offering expenses				0	17
Net proceeds from issuance of stock				0	$ 253,314
Reverse stock split			0.81003
Common Stock [Member]
Initial Public Offering [Abstract]
Convertible preferred stock converted to common stock (in shares) | shares					25,778,437
IPO [Member]
Initial Public Offering [Abstract]
Issuance of common stock, net (in shares) | shares		13,800,000
Common stock sold to underwriters (in shares) | shares		1,800,000
Share price (in dollars per share) | $ / shares		$ 20
Gross proceeds from issuance of stock		$ 276,000
Underwriting discounts and commissions and other offering expenses		22,700
Net proceeds from issuance of stock		$ 253,300
IPO [Member] | Common Stock [Member]
Initial Public Offering [Abstract]
Convertible preferred stock converted to common stock (in shares) | shares		25,778,437
China Joint Venture [Member]
Organization and Nature of Operations [Abstract]
Cash and cash equivalents and short-term and long-term investments				$ 33,600
Equity interest held in joint venture				54.90%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies, Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Minimum [Member]
Property and Equipment [Abstract]
Estimated useful life	3 years
Maximum [Member]
Property and Equipment [Abstract]
Estimated useful life	5 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies, Impairment of Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Impairment of Property and Equipment [Abstract]
Impairment losses	$ 0	$ 0

Summary of Significant Accoun_6

Summary of Significant Accounting Policies, Research and Development (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Research and Development [Abstract]
Research and development	$ 67,166	$ 29,237

Summary of Significant Accoun_7

Summary of Significant Accounting Policies, Commitments and Contingencies (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Commitments and Contingencies [Abstract]
Commitments and contingencies	$ 0	$ 0

Summary of Significant Accoun_8

Summary of Significant Accounting Policies, Stock-Based Compensation (Details) - Stock Options [Member]	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Stock-Based Compensation [Abstract]
Expected term	10 years
Expected dividend yield	0.00%	0.00%

Summary of Significant Accoun_9

Summary of Significant Accounting Policies, Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Numerator [Abstract]
Net loss attributable to Kinnate	$ (89,763)	$ (35,761)
Denominator [Abstract]
Weighted-average shares outstanding used in computing net loss per share, basic (in shares)	43,601,162	6,767,591
Weighted-average shares outstanding used in computing net loss per share, diluted (in shares)	43,601,162	6,767,591
Net loss per share, basic (in dollars per share)	$ (2.06)	$ (5.28)
Net loss per share, diluted (in dollars per share)	$ (2.06)	$ (5.28)
Options to Purchase Common Stock [Member]
Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share [Abstract]
Dilutive securities excluded from computation of diluted net loss per share (in shares)	7,477,568	6,265,409

Summary of Significant Accou_10

Summary of Significant Accounting Policies, Recently Issued Accounting Standards (Details) $ in Millions	Dec. 31, 2021USD ($)
Recently Issued Accounting Standards [Abstract]
Expected operating lease liability	$ 4.2
Expected operating lease ROU assets	$ 3.7

Cash, cash equivalents and re_3

Cash, cash equivalents and restricted cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash, cash equivalents and restricted cash [Abstract]
Cash and cash equivalents	$ 116,096	$ 365,462
Cash at consolidated joint venture	33,593	0
Restricted cash, non-current	371	0
Total cash, cash equivalents and restricted cash reported in the Condensed Consolidated Statements of Cash Flows	$ 150,060	$ 365,462	$ 76,453

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property and Equipment [Abstract]
Property and equipment	$ 1,093,000	$ 451,000
Less accumulated depreciation	(137,000)	(83,000)
Property and equipment, net	956,000	368,000
Depreciation expense	123,000	83,000
Furniture and Fixtures [Member]
Property and Equipment [Abstract]
Property and equipment	5,000	72,000
Computers and Equipment [Member]
Property and Equipment [Abstract]
Property and equipment	381,000	275,000
Computer Software [Member]
Property and Equipment [Abstract]
Property and equipment	69,000	104,000
Leasehold Improvements [Member]
Property and Equipment [Abstract]
Property and equipment	$ 638,000	$ 0

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accrued Expenses [Abstract]
Accrued research and development	$ 4,842	$ 1,580
Accrued compensation	3,344	1,388
Accrued legal fees	425	288
Other accruals	628	108
Total	$ 9,239	$ 3,364

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Available-for-sale Investments by Types and Classes of Security [Abstract]
Securities in material unrealized loss positions	$ 500	$ 0
Fair value of investments due to credit-related factors	0	0
Short-term Investments [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	103,474	31,407
Unrealized Gains	0	0
Unrealized Losses	(112)	(9)
Estimated Fair Value	103,362	31,398
Short-term Investments [Member] | Corporate Debt Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	27,450	20,327
Unrealized Gains	0	0
Unrealized Losses	(25)	(9)
Estimated Fair Value	$ 27,425	$ 20,318
Short-term Investments [Member] | Corporate Debt Securities [Member] | Maximum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years	1 year	1 year
Short-term Investments [Member] | US Treasury Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	$ 60,226
Unrealized Gains	0
Unrealized Losses	(67)
Estimated Fair Value	$ 60,159
Short-term Investments [Member] | US Treasury Securities [Member] | Maximum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years	1 year
Short-term Investments [Member] | Asset-backed Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	$ 15,798
Unrealized Gains	0
Unrealized Losses	(20)
Estimated Fair Value	$ 15,778
Short-term Investments [Member] | Asset-backed Securities [Member] | Maximum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years	1 year
Short-term Investments [Member] | Commercial Paper [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost		$ 11,080
Unrealized Gains		0
Unrealized Losses		0
Estimated Fair Value		$ 11,080
Short-term Investments [Member] | Commercial Paper [Member] | Maximum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years		1 year
Long-term Investments [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	$ 105,861
Unrealized Gains	0
Unrealized Losses	(412)
Estimated Fair Value	105,449
Long-term Investments [Member] | US Treasury Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	105,861
Unrealized Gains	0
Unrealized Losses	(412)
Estimated Fair Value	$ 105,449
Long-term Investments [Member] | US Treasury Securities [Member] | Minimum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years	1 year
Long-term Investments [Member] | US Treasury Securities [Member] | Maximum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years	2 years

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	$ 323,860	$ 395,859
Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	115,049	364,461
Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	27,425	20,318
U.S. Treasury Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	165,608
Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	15,778
Commercial Paper [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments		11,080
Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	115,049	364,461
Level 1 [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	115,049	364,461
Level 1 [Member] | Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0	0
Level 1 [Member] | U.S. Treasury Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0
Level 1 [Member] | Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0
Level 1 [Member] | Commercial Paper [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments		0
Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	208,811	31,398
Level 2 [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0	0
Level 2 [Member] | Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	27,425	20,318
Level 2 [Member] | U.S. Treasury Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	165,608
Level 2 [Member] | Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	15,778
Level 2 [Member] | Commercial Paper [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments		11,080
Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0	0
Level 3 [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0	0
Level 3 [Member] | Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0	0
Level 3 [Member] | U.S. Treasury Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0
Level 3 [Member] | Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	$ 0
Level 3 [Member] | Commercial Paper [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments		$ 0

Stockholders' Equity, Shares Au

Stockholders' Equity, Shares Authorized and Par Value (Details) - $ / shares	Dec. 31, 2021	Dec. 31, 2020	Dec. 07, 2020
Stockholders' Equity [Abstract]
Capital shares authorized (in shares)			1,200,000,000
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000	1,000,000,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	200,000,000	200,000,000	200,000,000
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001

Stockholders' Equity, Convertib

Stockholders' Equity, Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Aug. 31, 2020	Jul. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Preferred Stock [Abstract]
Proceeds from issuance of preference share (in shares)			$ 0	$ 97,707
Share issuance cost			$ 0	$ 17
Convertible preferred stock outstanding (in shares)			0	0
Series A Convertible Preferred Stock [Member]
Preferred Stock [Abstract]
Proceeds from issuance of preference share (in shares)					$ 93,100
Share issuance cost					500
Series B Convertible Preferred Stock [Member]
Preferred Stock [Abstract]
Proceeds from issuance of preference share (in shares)					93,100
Share issuance cost					$ 500
Series C Convertible Preferred Stock [Member]
Preferred Stock [Abstract]
Proceeds from issuance of preference share (in shares)	$ 97,700	$ 97,700
Share issuance cost	$ 300	$ 300
Temporary equity, shares issued (in shares)	8,282,789	8,282,789
Temporary equity, value per share (in dollars per share)	$ 11.8317	$ 11.8317
Common Stock [Member]
Preferred Stock [Abstract]
Convertible preferred stock (in shares)				25,778,437

Stockholders' Equity, Common St

Stockholders' Equity, Common Stock (Details) - shares	Dec. 31, 2021	Dec. 31, 2020
Common Stock Sales [Abstract]
Common stock options granted and outstanding (in shares)	7,477,568	6,265,409
Common stock reserved for future option grants (in shares)	4,079,339	5,619,735
Total common stock reserved for future issuance (in shares)	11,556,907	11,885,144

Equity Incentive Plans and St_3

Equity Incentive Plans and Stock-Based Compensation, Equity Incentive Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
2020 Equity Incentive Plan [Member]
Share-based Payment Arrangement, Disclosure [Abstract]
Number of shares of common stock options authorized to issue (in shares)	5,218,000
2020 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Payment Arrangement, Disclosure [Abstract]
Percentage of combined voting power held by optionee	10.00%
Percentage of fair market value of common stock	110.00%
Grant expiration period	5 years
Vesting period	2 years
2020 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Payment Arrangement, Disclosure [Abstract]
Grant expiration period	10 years
Employee's exercise period for vesting shares after termination	30 days
Vesting period	4 years
2018 Equity Incentive Plan [Member]
Share-based Payment Arrangement, Disclosure [Abstract]
Common stock remained available for issuance of shares (in shares)	588,039
2018 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Payment Arrangement, Disclosure [Abstract]
Percentage of combined voting power held by optionee	10.00%
Percentage of fair market value of common stock	110.00%
Grant expiration period	5 years
Vesting period	2 years
2018 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Payment Arrangement, Disclosure [Abstract]
Grant expiration period	10 years
Employee's exercise period for vesting shares after termination	30 days
Vesting period	4 years
Stock Options [Member]
Aggregate Intrinsic Value [Abstract]
Total intrinsic value of options exercised	$ 6,000,000	$ 2,000
Stock Options [Member] | 2020 Equity Incentive Plan [Member]
Options [Roll Forward]
Outstanding at beginning of period (in shares)	6,265,409
Granted (in shares)	2,155,851
Exercised (in shares)	(328,238)
Forfeited (in shares)	(615,454)
Outstanding at end of period (in shares)	7,477,568	6,265,409
Exercisable at end of period (in shares)	2,594,363
Weighted-Average Exercise Price [Abstract]
Outstanding at beginning of period (in dollars per share)	$ 4.12
Granted (in dollars per share)	29.88
Exercised (in dollars per share)	2.23
Forfeited (in dollars per share)	10.43
Outstanding at end of period (in dollars per share)	11.11	$ 4.12
Exercisable at end of period (in dollars per share)	$ 6.31
Weighted-Average Remaining Contractual Term [Abstract]
Outstanding at beginning of period	8 years 3 months 18 days	9 years 3 months 18 days
Outstanding (in years)	8 years 3 months 18 days	9 years 3 months 18 days
Exercisable (in years)	7 years 7 months 6 days
Aggregate Intrinsic Value [Abstract]
Outstanding at end of period	$ 74,268,000	$ 223,454,000
Exercisable amount	$ 33,261,000

Equity Incentive Plans and St_4

Equity Incentive Plans and Stock-Based Compensation, Kinnjiu Equity Incentive Plan (Details) - 2021 Equity Incentive Plan [Member] - $ / shares	12 Months Ended
	Dec. 31, 2021	May 31, 2021
Kinnjiu Equity Incentive Plan [Abstract]
Number of shares of common stock options authorized to issue (in shares)		9,000,000
Fair market value of ordinary share (in dollars per share)		$ 0.34
Stock Options [Member]
Options [Roll Forward]
Outstanding at beginning of period (in shares)	0
Granted (in shares)	3,087,500
Exercised (in shares)	0
Forfeited (in shares)	(250,000)
Outstanding at end of period (in shares)	2,837,500
Exercisable at end of period (in shares)	0
Weighted-Average Exercise Price [Abstract]
Outstanding at beginning of period (in dollars per share)	$ 0
Granted (in dollars per share)	0.34
Exercised (in dollars per share)	0
Forfeited (in dollars per share)	0.34
Outstanding at end of period (in dollars per share)	0.34
Exercisable at end of period (in dollars per share)	$ 0
Nonstatutory Stock Options (NSOs) [Member]
Kinnjiu Equity Incentive Plan [Abstract]
Vesting period	4 years
Stock Appreciation Rights (SARs) [Member]
SARs [Roll Forward]
Outstanding, beginning balance (in shares)	0
Granted (in shares)	325,000
Exercised (in shares)	0
Forfeited (in shares)	(25,000)
Outstanding, ending balance (in shares)	300,000
Exercisable, ending balance (in shares)	0
Weighted-Average Award Price [Roll Forward]
Outstanding, beginning balance (in dollars per share)	$ 0
Granted (in dollars per share)	0.34
Exercised (in dollars per share)	0
Forfeited (in dollars per share)	0.34
Outstanding, ending balance (in dollars per share)	0.34
Exercisable, ending balance (in dollars per share)	$ 0
Stock Appreciation Rights (SARs) [Member] | Two-Year Anniversary [Member]
Kinnjiu Equity Incentive Plan [Abstract]
Percentage of vesting rights	30.00%
Vesting period	2 years
Stock Appreciation Rights (SARs) [Member] | Three-Year Anniversary [Member]
Kinnjiu Equity Incentive Plan [Abstract]
Percentage of vesting rights	30.00%
Vesting period	3 years
Stock Appreciation Rights (SARs) [Member] | Four-Year Anniversary [Member]
Kinnjiu Equity Incentive Plan [Abstract]
Percentage of vesting rights	40.00%
Vesting period	4 years

Equity Incentive Plans and St_5

Equity Incentive Plans and Stock-Based Compensation, Employee Stock Purchase Plan (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2021
Employee Stock Purchase Plan [Abstract]
Common stock reserved for future issuance (in shares)	11,885,144	11,556,907
Employee Stock Purchase Plan [Member]
Employee Stock Purchase Plan [Abstract]
Percentage of purchase date	85.00%
Offering period	6 months
New offering period	6 months
Common stock reserved for future issuance (in shares)	435,000
Employee Stock Purchase Plan [Member] | Maximum [Member]
Employee Stock Purchase Plan [Abstract]
Percentage of offering date	15.00%

Equity Incentive Plans and St_6

Equity Incentive Plans and Stock-Based Compensation, Stock-Based Compensation Expense (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value of Stock Assumptions [Abstract]
Unrecognized stock-based compensation expense	$ 45,000	$ 17,100
Weighted-average period of nonvested stock-based compensation	2 years 6 months 29 days	3 years 3 months 21 days
Share-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 15,016	$ 2,478
Employee Stock Purchase Plan [Member]
Fair Value of Stock Assumptions [Abstract]
Expected term (in years)	6 months	4 months 28 days
Expected volatility		51.00%
Risk-free interest rate		0.09%
Expected dividend	0.00%	0.00%
Unrecognized stock-based compensation expense	$ 100	$ 600
Employee Stock Purchase Plan [Member] | Minimum [Member]
Fair Value of Stock Assumptions [Abstract]
Expected volatility	50.00%
Risk-free interest rate	0.03%
Employee Stock Purchase Plan [Member] | Maximum [Member]
Fair Value of Stock Assumptions [Abstract]
Expected volatility	68.00%
Risk-free interest rate	0.07%
Research and Development [Member]
Share-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 6,778	1,404
General and Administrative [Member]
Share-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 8,238	$ 1,074
Stock Options [Member]
Fair Value of Stock Assumptions [Abstract]
Expected term (in years)	10 years
Expected dividend	0.00%	0.00%
Weighted-average grant-date fair value of options granted (in dollars per share)	$ 21.70	$ 2.89
Stock Options [Member] | Minimum [Member]
Fair Value of Stock Assumptions [Abstract]
Expected term (in years)	5 years	6 years
Expected volatility	85.00%	88.00%
Risk-free interest rate	0.68%	0.37%
Stock Options [Member] | Maximum [Member]
Fair Value of Stock Assumptions [Abstract]
Expected term (in years)	6 years	7 years
Expected volatility	89.00%	93.00%
Risk-free interest rate	1.21%	1.57%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	May 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Related Party Transactions [Abstract]
Contributions from redeemable convertible noncontrolling interest owners, net	$ 35,000	$ 34,853	$ 0
Contributions from noncontrolling interest owners, issuance cost	$ 200	$ 200

Variable Interest Entity (Detai

Variable Interest Entity (Details) - USD ($) $ in Thousands	May 31, 2021	Dec. 31, 2021	Dec. 31, 2020	May 13, 2021
Information of Variable Interest Entity [Abstract]
Contributions from redeemable convertible noncontrolling interest owners, net	$ 35,000	$ 34,853	$ 0
Contributions from noncontrolling interest owners, issuance cost	$ 200	200
Assets and Liabilities [Abstract]
Cash at consolidated joint venture		33,593	0
Prepaid expenses and other current assets		$ 5,639	$ 3,343
China Joint Venture [Member]
Information of Variable Interest Entity [Abstract]
Equity interest held in joint venture		54.90%
Assets and Liabilities [Abstract]
Cash at consolidated joint venture		$ 33,593		$ 35,011
Prepaid expenses and other current assets		215		0
Accounts payable and accrued expenses		$ 286		$ 0

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Provision for Income Taxes [Abstract]
Income taxes computed at the statutory rate	$ (18,850)	$ (7,510)
State income taxes, net of federal benefit	(4)	0
Permanent items	922	4
Stock-based compensation	(280)	102
Research credits	(1,306)	0
Other	548	(36)
Change in valuation allowance	18,970	7,440
Provision for income taxes	0	0
Deferred tax assets [Abstract]
Net operating loss carryforward	28,054	12,304
Research and development credit carryforwards	1,295	0
Stock-based compensation	1,774	264
Accrued compensation	635	292
Other, net	144	23
Gross deferred tax assets	31,902	12,883
Less valuation allowance	(31,741)	(12,883)
Total deferred tax assets	161	0
Deferred tax liabilities [Abstract]
Other	(161)	0
Net deferred tax assets	0	0
Deferred tax asset, change in valuation allowance	18,900
Operating Loss Carryforwards [Abstract]
Gross unrecognized tax benefits	0	0
Accrued interest or penalties	0	0
Recognized interest or penalties	0	$ 0
Federal [Member]
Operating Loss Carryforwards [Abstract]
Operating loss carryforwards	127,100
Research and development credit carryforwards	1,000
California [Member]
Operating Loss Carryforwards [Abstract]
Operating loss carryforwards	24,800
Research and development credit carryforwards	$ 1,100

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Aug. 31, 2021ft²	Jun. 30, 2021ft²	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Commitments and Contingencies [Abstract]
Area of office space under lease agreement | ft²	5,698	8,088
Period of lease agreement			5 years 4 months
Option to extend lease agreement	3 years	5 years
Standby letter of credit as security deposit			$ 400
Standby letter of credit, decrease in amount after each three and four year of lease term if no default			300
Future minimum lease payments under non-cancelable operating leases [Abstract]
2022			638
2023			1,045
2024			1,076
2025			1,108
2026			924
Thereafter			365
Total minimum lease payments			5,156
Rent expense			$ 200	$ 200

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Employee Benefit Plan [Abstract]
Employer contribution	$ 0.4	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] - ATM Offering [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 28, 2022	Jan. 31, 2022
Subsequent Events Disclosure [Abstract]
Aggregate value of common stock authorized to be issued and sold		$ 150
Common stock share issued and sold (in shares)	0