Kinnate Biopharma (KNTE) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 09, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Document Transition Report	false
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	3611 Valley Centre Drive, Suite 175
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92130
City Area Code	858
Local Phone Number	299-4699
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	KNTE
Security Exchange Name	NASDAQ
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		43,696,095

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 135,009	$ 365,462
Cash at consolidated joint venture	34,308	0
Short-term investments	88,219	31,398
Prepaid expenses and other current assets	3,176	3,343
Total current assets	260,712	400,203
Property and equipment, net	291	368
Long-term investments	124,636	0
Restricted cash	371	0
Other non-current assets	319	0
Total assets	386,329	400,571
Current liabilities:
Accounts payable	2,724	3,940
Accrued expenses	7,575	3,364
Total current liabilities	10,299	7,304
Commitments and contingencies (See Note 12)
Redeemable convertible noncontrolling interests	35,000	0
Stockholders' equity:
Preferred stock, $0.0001 par value; 200,000,000 shares authorized at September 30, 2021 and December 31, 2020; 0 shares outstanding at September 30, 2021 and December 31, 2020	0	0
Common stock, $0.0001 par value; 1,000,000,000 shares authorized at September 30, 2021 and December 31, 2020; 43,682,671 and 43,477,439 shares issued and outstanding at September, 2021 and December 31, 2020, respectively	4	4
Additional paid-in capital	457,995	446,601
Accumulated other comprehensive loss	(36)	(9)
Accumulated deficit	(116,933)	(53,329)
Total stockholders' equity	341,030	393,267
Total liabilities and equity	$ 386,329	$ 400,571

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 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)	43,682,671	43,477,439
Common stock, shares outstanding (in shares)	43,682,671	43,477,439

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating expenses:
Research and development	$ 18,729	$ 8,484	$ 47,637	$ 17,261
General and administrative (includes related party amounts of $0 and $92 for the three and nine months ended September 30, 2020)	6,073	2,019	16,215	5,021
Total operating expenses	24,802	10,503	63,852	22,282
Loss from operations	(24,802)	(10,503)	(63,852)	(22,282)
Other income:
Interest income	640	4	1,715	228
Other expense, net	(540)	0	(1,467)	0
Total other income, net	100	4	248	228
Net loss	(24,702)	(10,499)	(63,604)	(22,054)
Net loss attributable to redeemable convertible noncontrolling interests	0	0	0	0
Net loss attributable to Kinnate	$ (24,702)	$ (10,499)	$ (63,604)	$ (22,054)
Weighted-average shares outstanding, basic (in shares)	43,663,985	3,748,324	43,559,787	3,709,020
Weighted-average shares outstanding, diluted (in shares)	43,663,985	3,748,324	43,559,787	3,709,020
Net loss per share, basic (in dollars per share)	$ (0.57)	$ (2.80)	$ (1.46)	$ (5.95)
Net loss per share, diluted (in dollars per share)	$ (0.57)	$ (2.80)	$ (1.46)	$ (5.95)
Comprehensive loss:
Net loss	$ (24,702)	$ (10,499)	$ (63,604)	$ (22,054)
Other comprehensive loss:
Unrealized income (loss) on investments	38	0	(27)	0
Total comprehensive loss	(24,664)	(10,499)	(63,631)	(22,054)
Comprehensive loss attributable to redeemable convertible noncontrolling interests	0	0	0	0
Comprehensive loss attributable to Kinnate	$ (24,664)	$ (10,499)	$ (63,631)	$ (22,054)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Operating expenses:
General and administrative, related party amounts	$ 0	$ 92

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' (DEFICIT) EQUITY - USD ($) $ in Thousands	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	$ 74,204	$ 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							$ 0	$ (17)	$ 0
Net loss							0	0	0
Balance at Mar. 31, 2020							$ 18,942	$ 74,187	$ 0
Balance (in shares) at Mar. 31, 2020							7,762,727	9,705,182	0
Balance at Dec. 31, 2019	$ 0	$ 82	$ 0	$ (17,568)	$ 0	$ (17,486)
Balance (in shares) at Dec. 31, 2019	3,665,020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 0	128	0	0	0	128
Exercise of stock options	$ 0	3	0	0	0	3
Exercise of stock options (in shares)	7,593
Net loss	$ 0	0	0	(3,941)	0	(3,941)
Balance at Mar. 31, 2020	$ 0	213	0	(21,509)	0	(21,296)
Balance (in shares) at Mar. 31, 2020	3,672,613
Balance at Dec. 31, 2019							$ 18,942	$ 74,204	$ 0
Balance (in shares) at Dec. 31, 2019							7,762,727	9,705,182	0
Balance at Sep. 30, 2020							$ 18,942	$ 74,187	$ 97,706
Balance (in shares) at Sep. 30, 2020							7,762,727	9,705,182	8,282,789
Balance at Dec. 31, 2019	$ 0	82	0	(17,568)	0	(17,486)
Balance (in shares) at Dec. 31, 2019	3,665,020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss						(22,054)
Balance at Sep. 30, 2020	$ 0	1,285	0	(39,622)	0	(38,337)
Balance (in shares) at Sep. 30, 2020	3,748,782
Balance at Mar. 31, 2020							$ 18,942	$ 74,187	$ 0
Balance (in shares) at Mar. 31, 2020							7,762,727	9,705,182	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Net loss							$ 0	$ 0	$ 0
Balance at Jun. 30, 2020							$ 18,942	$ 74,187	$ 0
Balance (in shares) at Jun. 30, 2020							7,762,727	9,705,182	0
Balance at Mar. 31, 2020	$ 0	213	0	(21,509)	0	(21,296)
Balance (in shares) at Mar. 31, 2020	3,672,613
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 0	410	0	0	0	410
Exercise of stock options	$ 0	18	0	0	0	18
Exercise of stock options (in shares)	101,167
Net loss	$ 0	0	0	(7,614)	0	(7,614)
Balance at Jun. 30, 2020	$ 0	641	0	(29,123)	0	(28,482)
Balance (in shares) at Jun. 30, 2020	3,773,780
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance costs for convertible preferred stock							$ 0	$ 0	$ 97,706
Issuance costs for convertible preferred stock (in shares)									8,282,789
Net loss							0	0	$ 0
Balance at Sep. 30, 2020							$ 18,942	$ 74,187	$ 97,706
Balance (in shares) at Sep. 30, 2020							7,762,727	9,705,182	8,282,789
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 0	714	0	0	0	714
Exercise of stock options	$ 0	5	0	0	0	5
Exercise of stock options (in shares)	4,218
Shares acquired upon forfeiture	$ 0	(75)	0	0	0	(75)
Shares acquired upon forfeiture (in shares)	(29,216)
Net loss	$ 0	0	0	(10,499)	0	(10,499)
Balance at Sep. 30, 2020	$ 0	1,285	0	(39,622)	0	(38,337)
Balance (in shares) at Sep. 30, 2020	3,748,782
Balance at Dec. 31, 2020	$ 4	446,601	(9)	(53,329)	0	393,267
Balance (in shares) at Dec. 31, 2020	43,477,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 0	2,793	0	0	0	2,793
Net loss	0	0	0	(17,457)	0	(17,457)
Other comprehensive income (loss)	0	0	(31)	0	0	(31)
Balance at Mar. 31, 2021	$ 4	449,394	(40)	(70,786)	0	378,572
Balance (in shares) at Mar. 31, 2021	43,477,439
Balance at Dec. 31, 2020	$ 4	446,601	(9)	(53,329)	0	393,267
Balance (in shares) at Dec. 31, 2020	43,477,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss						(63,604)
Balance at Sep. 30, 2021	$ 4	457,995	(36)	(116,933)	35,000	341,030
Balance (in shares) at Sep. 30, 2021	43,682,671
Balance at Mar. 31, 2021	$ 4	449,394	(40)	(70,786)	0	378,572
Balance (in shares) at Mar. 31, 2021	43,477,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 0	3,760	0	0	0	3,760
Exercise of stock options	$ 0	139	0	0	0	139
Exercise of stock options (in shares)	116,147
Shares issued under employee stock purchase plan	$ 0	495	0	0	0	495
Shares issued under employee stock purchase plan (in shares)	29,159
Contributions from redeemable convertible noncontrolling interest owners	$ 0	0	0	0	35,000	0
Issuance costs for Series A preferred stock to redeemable NCI	0	(147)	0	0	0	(147)
Net loss	0	0	0	(21,445)	0	(21,445)
Other comprehensive income (loss)	0	0	(34)	0	0	(34)
Balance at Jun. 30, 2021	$ 4	453,641	(74)	(92,231)	35,000	361,340
Balance (in shares) at Jun. 30, 2021	43,622,745
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 0	4,161	0	0	0	4,161
Exercise of stock options	$ 0	193	0	0	0	193
Exercise of stock options (in shares)	59,926
Net loss	$ 0	0	0	(24,702)	0	(24,702)
Other comprehensive income (loss)	0	0	38	0	0	38
Balance at Sep. 30, 2021	$ 4	$ 457,995	$ (36)	$ (116,933)	$ 35,000	$ 341,030
Balance (in shares) at Sep. 30, 2021	43,682,671

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (63,604)	$ (22,054)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	10,714	1,252
Depreciation	87	59
Amortization/accretion of investments	1,360	0
Loss on disposal of property and equipment	58	0
Changes in operating assets and liabilities:
Related party receivables, net	0	1,127
Prepaid expenses and other assets	(152)	(650)
Accounts payable and accrued expenses	2,995	3,861
Net cash used in operating activities	(48,542)	(16,405)
Cash flows from investing activities:
Purchases of short-term and long-term investments	(216,613)	0
Sales and maturities of short-term and long-term investments	33,769	0
Purchases of property and equipment	(68)	(359)
Net cash used in investing activities	(182,912)	(359)
Cash flows from financing activities:
Issuance costs for Series B convertible preferred stock	0	(17)
Proceeds from issuance of Series C convertible preferred stock, net of issuance costs	0	97,706
Payment of deferred offering costs	0	(470)
Contributions from redeemable convertible noncontrolling interest owners, net	34,853	0
Proceeds (payments) upon stock option exercises, net of shares acquired upon forfeiture	332	(49)
Proceeds from issuance of common stock under employee stock purchase plan	495	0
Net cash provided by financing activities	35,680	97,170
Net (decrease) increase in cash, cash equivalents and restricted cash	(195,774)	80,406
Cash, cash equivalents and restricted cash at the beginning of the period	365,462	76,453
Cash, cash equivalents and restricted cash at the end of the period	169,688	156,859
Supplemental non-cash investing and financing activity:
Property and equipment included in accounts payable and accrued expenses	0	16
Deferred offering costs included in accounts payable and accrued expenses	$ 0	$ 876

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Organization and Basis of Presentation [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation 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 Diego, 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 $116.9 million and had cash and cash equivalents and short-term and long-term investments totaling $347.9 million as of September 30, 2021. From its inception through September 30, 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 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 September 30, 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 financial statements do not include any adjustments that might be necessary if the Company 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 this Quarterly Report on Form 10-Q is filed with the U.S. Securities and Exchange Commission (SEC). Basis of Presentation The Company’s condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of SEC Regulation S-X. Accordingly, since they are interim statements, the accompanying condensed consolidated financial statements do not include all of the information and notes required by GAAP for complete financial statements. The accompanying unaudited interim consolidated financial statements include all known adjustments which, in the opinion of management, are 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. The Condensed Consolidated Balance Sheet at December 31, 2020 has been derived from the audited financial statements at that date, but does not include all information and footnotes required by GAAP for complete financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2020 included in the Company’s Annual Report on Form 10-K filed with the SEC. The condensed consolidated financial statements include the accounts of the Company’s variable interest entity (VIE), the China joint venture, for which the Company is the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. 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 September 30, 2021, the Company held a 54.9% equity interest in the China joint venture. Based on the Company’s assessment, the Company concluded that the China joint venture 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. Operating results presented in these unaudited condensed 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. Initial Public Offering On December 3, 2020, the Company completed the IPO selling 13,800,000 shares of common stock, which included 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 reverse stock split of its issued and outstanding common stock and convertible preferred stock. The par value of the authorized stock was not adjusted as a result of the reverse stock split. Other than the par value, all share and per share data shown in the accompanying financial statements and related notes have been retroactively revised to reflect the reverse stock split.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Redeemable Convertible Noncontrolling Interests The shares third parties own in the China joint venture 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 Condensed Consolidated Balance Sheets as the preferred stock is redeemable by the noncontrolling interests. Since the preferred stock held at the China joint venture does not represent a residual equity interest, net losses of the China joint venture 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. Use of Estimates The preparation of 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 financial statements and the reported amounts of expenses during the reporting period. Accounting estimates and management judgments reflected in the financial statements include: normal recurring accruals, including the accrual of research and development expenses; valuation of deferred tax assets; 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. Net Loss Per Share Basic net loss per common share is calculated by dividing 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 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 outstanding convertible preferred stock and common stock options are considered to be potentially dilutive securities. Basic and diluted net loss attributable to common stockholders per share is presented in conformity with the two-class method required for participating securities as the convertible preferred stock is considered a participating security. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. 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 (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Numerator Net loss attributable to Kinnate $ (24,702 ) $ (10,499 ) $ (63,604 ) $ (22,054 ) Denominator Weighted-average shares outstanding used in computing net loss per share, basic and diluted 43,663,985 3,748,324 43,559,787 3,709,020 Net loss per share, basic and diluted $ (0.57 ) $ (2.80 ) $ (1.46 ) $ (5.95 ) The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Options to purchase common stock 7,677,795 5,700,149 7,677,795 5,700,149 Convertible preferred stock - 25,750,698 - 25,750,698 Total 7,677,795 31,450,847 7,677,795 31,450,847 Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board Accounting Standard Update 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 ASU No. 2016-13 added Topic 326, Financial Instruments—Credit Losses, made several consequential amendments to the Codification. ASU No. 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 financial statements. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes - Simplifying the Accounting for Income Taxes (ASU No. 2019-12). Among other items, the amendments in ASU No. 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 No. 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 No. 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 No. 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 financial statements and related disclosures.

Cash, cash equivalents and rest

Cash, cash equivalents and restricted cash	9 Months Ended
	Sep. 30, 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 Condensed Consolidated Statements of Cash Flows (in thousands): September 30, 2021 December 31, 2020 Cash and cash equivalents $ 135,009 $ 365,462 Cash at consolidated joint venture 34,308 - Restricted cash, non-current 371 - Total cash, cash equivalents and restricted cash reported in the Condensed Consolidated Statements of Cash Flows $ 169,688 $ 365,462 The cash at the consolidated joint venture represents cash held at the China joint venture and the use of such cash is limited to the operations of the China joint venture (see Note 11). The restricted cash balance relates to the Company’s office lease in San Diego, California (see Note 12).

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 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): September 30, 2021 December 31, 2020 Furniture and fixtures $ 4 $ 72 Computers and equipment 327 275 Computer software 104 104 Property and equipment 435 451 Less accumulated depreciation (144 ) (83 ) Property and equipment, net $ 291 $ 368

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2021
Accrued Expenses [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consisted of the following (in thousands): September 30, 2021 December 31, 2020 Accrued research and development $ 4,033 $ 1,580 Accrued compensation 2,862 1,388 Accrued legal fees 134 288 Other accruals 546 108 Total $ 7,575 $ 3,364

Investments

Investments	9 Months Ended
	Sep. 30, 2021
Investments [Abstract]
Investments	6. Investments The Company has invested its excess cash in marketable securities as of September 30, 2021 and December 31, 2020. The following is a summary by significant investment category (in thousands): September 30, 2021 Maturity in Years Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities less than 1 $ 41,372 $ 4 $ (6 ) $ 41,370 Commercial paper less than 1 11,000 - - 11,000 U.S. Treasury securities less than 1 30,368 10 - 30,378 Asset-backed securities less than 1 5,475 - (4 ) 5,471 Short-term investments $ 88,215 $ 14 $ (10 ) $ 88,219 Corporate debt securities 1 - 2 $ 4,739 $ - $ (1 ) $ 4,738 U.S. Treasury securities 1 - 2 105,469 7 (40 ) 105,436 Asset-backed securities 1 - 2 14,468 1 (7 ) 14,462 Long-term investments $ 124,676 $ 8 $ (48 ) $ 124,636 December 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 At September 30, 2021 and December 31, 2020, the Company did not have any securities in material unrealized loss positions. Further, 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. 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 September 30, 2021 and December 31, 2020.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 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 and the U.S. government are measured at fair value in accordance with the fair value hierarchy. The following tables present the hierarchy for assets measured at fair value on a recurring basis (in thousands): Fair Value Measurements at September 30, 2021 Level 1 Level 2 Level 3 Total Money market funds $ 134,000 $ - $ - $ 134,000 Corporate debt securities - 46,108 - 46,108 Commercial paper - 11,000 - 11,000 U.S. Treasury securities - 135,814 - 135,814 Asset-backed securities - 19,933 - 19,933 Total cash equivalents and investments $ 134,000 $ 212,855 $ - $ 346,855 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 balance sheets at September 30, 2021 and December 31, 2020.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 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.

Equity Incentive Plans and Stoc

Equity Incentive Plans and Stock-Based Compensation	9 Months Ended
	Sep. 30, 2021
Equity Incentive Plans and Stock-Based Compensation [Abstract]
Equity Incentive Plans and Stock-Based Compensation	9. Equity Incentive Plans and Stock-Based Compensation 2020 Equity Incentive Plan In December 2020, the Company adopted the 2020 Equity Incentive Plan (2020 Plan), which replaced the 2018 Equity Incentive Plan (2018 Plan). The 2020 Plan allows the Company to issue options for shares of its common stock up to a total of 5,218,000 shares (Option Pool), subject to appropriate adjustments for stock splits, combinations and other similar events for issuance pursuant to awards made under the 2020 Plan. As of September 30, 2021, 4,031,277 shares of common stock remained available for future grants under the 2020 Plan. 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, 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 2,099,851 30.01 Exercised (176,073 ) 1.88 Forfeited (511,392 ) 9.59 Outstanding at September 30, 2021 7,677,795 $ 10.89 8.5 $ 107,061 Exercisable at September 30, 2021 2,278,793 $ 5.48 7.2 $ 41,712 All exercisable options are vested and all outstanding options are vested or expected to vest. Total intrinsic value of options exercised during the nine months ended September 2020 Employee Stock Purchase Plan The 2020 Employee Stock Purchase Plan (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 for issuance under the ESPP. As of September 2021 Equity Incentive Plan at China Joint Venture The China joint venture adopted the 2021 Equity Incentive Plan (2021 Plan), which allows for the issuance of options for shares of common stock and share appreciation rights up to a total of 9,000,000 shares subject to appropriate adjustments for stock splits, combinations and other similar events for issuance pursuant to awards made under the 2021 Plan. 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: Nine Months Ended September 30, 2021 2020 Expected term (in years) 5 - 6 6 - 7 Expected volatility 86% - 89% 88% - 89% Risk-free interest rate 0.68% - 1.17% 0.37% - 1.57% Expected dividend 0% 0% The weighted-average grant-date fair value of options granted was $21.80 and $2.58 for the nine months ended September 30, 2021 and 2020, respectively. The assumptions used for the nine months ended September 30, 2021 and the resulting estimates of weighted-average fair value per share for stock purchased under the ESPP were as follows: Nine Months Ended September 30, 2021 Expected term (in years) 0.41 - .50 Expected volatility 51% -68% Risk-free interest rate 0.03% - 0.09% Expected dividend 0% Stock-based compensation expense related to the Company’s stock options and ESPP totaled the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 1,768 $ 370 $ 4,958 $ 695 General and administrative 2,393 344 5,756 557 Total stock-based compensation $ 4,161 $ 714 $ 10,714 $ 1,252 As of September 30, 2021, there was approximately $49.0 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 2.78 years. As of September

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	10. Related Party Transactions a) Series A Preferred Stock Financing of China Joint Venture In connection with the Series A preferred stock financing of the China joint venture, contributions from noncontrolling interest members totaled $35.0 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 the China joint venture. b) Management Service Agreement with Fount Therapeutics, LLC and Fount Service Corp. Effective June 22, 2018, the Company entered into a Master Service Agreement with Fount Therapeutics, LLC (FTL) and Fount Service Corp. (FSC), a wholly owned subsidiary of FTL. Under this agreement, FTL and FSC agreed to perform various management and other services to the Company, either directly or via arrangements with third parties. These services included research and development and general and administrative functions, such as finance, audit, accounting, human resources, technology, facilities, and other management services necessary for the Company’s operations. After 2019, the Company no longer relied on FTL or FSC for such services and, in November 2020, the Company terminated its agreement with FTL and FSC. The Company recognized no management fee expenses for the three and nine months ended September 30, 2021. The Company recognized no management fee expenses for the three months ended September September c) Management Services Agreement with Subveho, LLC Effective March 21, 2018, FTL entered into a Management Service Agreement (Subveho MSA) with Subveho, LLC (Subveho), pursuant to which Subveho agreed to perform various services necessary for the operations of the Company. Total expenses paid to Subveho under the Subveho MSA for services provided to the Company were $75,000 for the nine months ended September September September .

Variable Interest Entity

Variable Interest Entity	9 Months Ended
	Sep. 30, 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 the China joint venture 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 September 30, 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 condensed consolidated financial statements. The following table summarizes the fair value of the China joint venture as of May 13, 2021 recorded upon initial consolidation in the Company's Condensed Consolidated Balance Sheets and the carrying amount of such assets and liabilities as of September 30, 2021, before intercompany eliminations (in thousands): September 30, 2021 May 13, 2021 Cash at consolidated joint venture $ 34,308 $ 35,011 Accounts payable and accrued expenses 175 -

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies [Abstract]
Commitments and Contingencies	12. Commitments and Contingencies Litigation The 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 nine months ended September 30, 2021 and 2020. 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. Payments for the SD Permanent Space pursuant to the SD Lease are expected to commence in the first half 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 utilizes temporary space in San Diego, California, which is expected to end when payments for the SD Permanent Space commence. 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 Condensed 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 through December 31, 2021. 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 commencing on the later of (i) December 1, 2021 and (ii) the date that is four calendar months following the date the premises are delivered to the Company as required under the SF Lease. The initial term of the SF Lease expires 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 September 30, 2021 were as follows (in thousands): Year Ending December 31, Operating Leases 2021 (Remaining period) $ 71 2022 806 2023 1,048 2024 1,079 2025 1,112 2026 927 Thereafter 246 Total mimium lease payments $ 5,289

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events On October 28, 2021, the Company announced that on December 3, 2021 Eric Murphy, Ph.D. will transition from the Company’s Chief Scientific Officer to a member of its Scientific Advisory Board.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2021
Organization and Basis of Presentation [Abstract]
Organization and Nature of Operations	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 Diego, 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 $116.9 million and had cash and cash equivalents and short-term and long-term investments totaling $347.9 million as of September 30, 2021. From its inception through September 30, 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 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 September 30, 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 financial statements do not include any adjustments that might be necessary if the Company 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 this Quarterly Report on Form 10-Q is filed with the U.S. Securities and Exchange Commission (SEC).
Basis of Presentation	Basis of Presentation The Company’s condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of SEC Regulation S-X. Accordingly, since they are interim statements, the accompanying condensed consolidated financial statements do not include all of the information and notes required by GAAP for complete financial statements. The accompanying unaudited interim consolidated financial statements include all known adjustments which, in the opinion of management, are 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. The Condensed Consolidated Balance Sheet at December 31, 2020 has been derived from the audited financial statements at that date, but does not include all information and footnotes required by GAAP for complete financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2020 included in the Company’s Annual Report on Form 10-K filed with the SEC. The condensed consolidated financial statements include the accounts of the Company’s variable interest entity (VIE), the China joint venture, for which the Company is the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. 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 September 30, 2021, the Company held a 54.9% equity interest in the China joint venture. Based on the Company’s assessment, the Company concluded that the China joint venture 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. Operating results presented in these unaudited condensed 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.
Initial Public Offering	Initial Public Offering On December 3, 2020, the Company completed the IPO selling 13,800,000 shares of common stock, which included 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 reverse stock split of its issued and outstanding common stock and convertible preferred stock. The par value of the authorized stock was not adjusted as a result of the reverse stock split. Other than the par value, all share and per share data shown in the accompanying financial statements and related notes have been retroactively revised to reflect the reverse stock split.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Summary of Significant Accounting Policies [Abstract]
Redeemable Convertible Noncontrolling Interests [Policy Text Block]	Redeemable Convertible Noncontrolling Interests The shares third parties own in the China joint venture 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 Condensed Consolidated Balance Sheets as the preferred stock is redeemable by the noncontrolling interests. Since the preferred stock held at the China joint venture does not represent a residual equity interest, net losses of the China joint venture 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.
Use of Estimates	Use of Estimates The preparation of 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 financial statements and the reported amounts of expenses during the reporting period. Accounting estimates and management judgments reflected in the financial statements include: normal recurring accruals, including the accrual of research and development expenses; valuation of deferred tax assets; 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.
Net Loss Per Share	Net Loss Per Share Basic net loss per common share is calculated by dividing 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 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 outstanding convertible preferred stock and common stock options are considered to be potentially dilutive securities. Basic and diluted net loss attributable to common stockholders per share is presented in conformity with the two-class method required for participating securities as the convertible preferred stock is considered a participating security. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. 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 (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Numerator Net loss attributable to Kinnate $ (24,702 ) $ (10,499 ) $ (63,604 ) $ (22,054 ) Denominator Weighted-average shares outstanding used in computing net loss per share, basic and diluted 43,663,985 3,748,324 43,559,787 3,709,020 Net loss per share, basic and diluted $ (0.57 ) $ (2.80 ) $ (1.46 ) $ (5.95 ) The following outstanding shares of potentially dilutive securities were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Options to purchase common stock 7,677,795 5,700,149 7,677,795 5,700,149 Convertible preferred stock - 25,750,698 - 25,750,698 Total 7,677,795 31,450,847 7,677,795 31,450,847
Recently Issued Accounting Standards	Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board Accounting Standard Update 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 ASU No. 2016-13 added Topic 326, Financial Instruments—Credit Losses, made several consequential amendments to the Codification. ASU No. 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 financial statements. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes - Simplifying the Accounting for Income Taxes (ASU No. 2019-12). Among other items, the amendments in ASU No. 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 No. 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 No. 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 No. 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 financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 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 (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Numerator Net loss attributable to Kinnate $ (24,702 ) $ (10,499 ) $ (63,604 ) $ (22,054 ) Denominator Weighted-average shares outstanding used in computing net loss per share, basic and diluted 43,663,985 3,748,324 43,559,787 3,709,020 Net loss per share, basic and diluted $ (0.57 ) $ (2.80 ) $ (1.46 ) $ (5.95 )
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 for the periods presented because including them would have been anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Options to purchase common stock 7,677,795 5,700,149 7,677,795 5,700,149 Convertible preferred stock - 25,750,698 - 25,750,698 Total 7,677,795 31,450,847 7,677,795 31,450,847

Cash, cash equivalents and re_2

Cash, cash equivalents and restricted cash (Tables)	9 Months Ended
	Sep. 30, 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 Condensed Consolidated Statements of Cash Flows (in thousands): September 30, 2021 December 31, 2020 Cash and cash equivalents $ 135,009 $ 365,462 Cash at consolidated joint venture 34,308 - Restricted cash, non-current 371 - Total cash, cash equivalents and restricted cash reported in the Condensed Consolidated Statements of Cash Flows $ 169,688 $ 365,462

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Property and Equipment, Net [Abstract]
Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): September 30, 2021 December 31, 2020 Furniture and fixtures $ 4 $ 72 Computers and equipment 327 275 Computer software 104 104 Property and equipment 435 451 Less accumulated depreciation (144 ) (83 ) Property and equipment, net $ 291 $ 368

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2021
Accrued Expenses [Abstract]
Accrued Expenses	Accrued expenses consisted of the following (in thousands): September 30, 2021 December 31, 2020 Accrued research and development $ 4,033 $ 1,580 Accrued compensation 2,862 1,388 Accrued legal fees 134 288 Other accruals 546 108 Total $ 7,575 $ 3,364

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2021
Investments [Abstract]
Investments by Type and Classes of Security	The Company has invested its excess cash in marketable securities as of September 30, 2021 and December 31, 2020. The following is a summary by significant investment category (in thousands): September 30, 2021 Maturity in Years Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities less than 1 $ 41,372 $ 4 $ (6 ) $ 41,370 Commercial paper less than 1 11,000 - - 11,000 U.S. Treasury securities less than 1 30,368 10 - 30,378 Asset-backed securities less than 1 5,475 - (4 ) 5,471 Short-term investments $ 88,215 $ 14 $ (10 ) $ 88,219 Corporate debt securities 1 - 2 $ 4,739 $ - $ (1 ) $ 4,738 U.S. Treasury securities 1 - 2 105,469 7 (40 ) 105,436 Asset-backed securities 1 - 2 14,468 1 (7 ) 14,462 Long-term investments $ 124,676 $ 8 $ (48 ) $ 124,636 December 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)	9 Months Ended
	Sep. 30, 2021
Fair Value Measurements [Abstract]
Major Categories of Assets Measured at Fair Value on a Recurring Basis	The following tables present the hierarchy for assets measured at fair value on a recurring basis (in thousands): Fair Value Measurements at September 30, 2021 Level 1 Level 2 Level 3 Total Money market funds $ 134,000 $ - $ - $ 134,000 Corporate debt securities - 46,108 - 46,108 Commercial paper - 11,000 - 11,000 U.S. Treasury securities - 135,814 - 135,814 Asset-backed securities - 19,933 - 19,933 Total cash equivalents and investments $ 134,000 $ 212,855 $ - $ 346,855 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

Equity Incentive Plans and St_2

Equity Incentive Plans and Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option Activity	Stock option activity, 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 2,099,851 30.01 Exercised (176,073 ) 1.88 Forfeited (511,392 ) 9.59 Outstanding at September 30, 2021 7,677,795 $ 10.89 8.5 $ 107,061 Exercisable at September 30, 2021 2,278,793 $ 5.48 7.2 $ 41,712
Stock-Based Compensation Expense	Stock-based compensation expense related to the Company’s stock options and ESPP totaled the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 1,768 $ 370 $ 4,958 $ 695 General and administrative 2,393 344 5,756 557 Total stock-based compensation $ 4,161 $ 714 $ 10,714 $ 1,252
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: Nine Months Ended September 30, 2021 2020 Expected term (in years) 5 - 6 6 - 7 Expected volatility 86% - 89% 88% - 89% Risk-free interest rate 0.68% - 1.17% 0.37% - 1.57% Expected dividend 0% 0%
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 nine months ended September 30, 2021 and the resulting estimates of weighted-average fair value per share for stock purchased under the ESPP were as follows: Nine Months Ended September 30, 2021 Expected term (in years) 0.41 - .50 Expected volatility 51% -68% Risk-free interest rate 0.03% - 0.09% Expected dividend 0%

Variable Interest Entity (Table

Variable Interest Entity (Tables)	9 Months Ended
	Sep. 30, 2021
Variable Interest Entity [Abstract]
Carrying Amount of Assets and Liabilities	The following table summarizes the fair value of the China joint venture as of May 13, 2021 recorded upon initial consolidation in the Company's Condensed Consolidated Balance Sheets and the carrying amount of such assets and liabilities as of September 30, 2021, before intercompany eliminations (in thousands): September 30, 2021 May 13, 2021 Cash at consolidated joint venture $ 34,308 $ 35,011 Accounts payable and accrued expenses 175 -

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2021 were as follows (in thousands): Year Ending December 31, Operating Leases 2021 (Remaining period) $ 71 2022 806 2023 1,048 2024 1,079 2025 1,112 2026 927 Thereafter 246 Total mimium lease payments $ 5,289

Organization and Basis of Pre_3

Organization and Basis of Presentation (Details) $ / shares in Units, $ in Thousands	Dec. 03, 2020USD ($)$ / sharesshares	Nov. 25, 2020	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Organization and Nature of Operations [Abstract]
Accumulated deficit			$ (116,933)		$ (53,329)
Cash and cash equivalents and short-term and long-term investments			347,900
Contributions from redeemable convertible noncontrolling interest owners, net			34,853	$ 0
Contributions from noncontrolling interest owners, issuance cost			200
Initial Public Offering [Abstract]
Underwriting discounts and commissions and other offering expenses			$ 0	$ 17
Reverse stock split		1
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]
Equity interest held in joint venture			54.90%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies, Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator [Abstract]
Net loss attributable to Kinnate	$ (24,702)	$ (10,499)	$ (63,604)	$ (22,054)
Denominator [Abstract]
Weighted-average shares outstanding used in computing net loss per share, basic (in shares)	43,663,985	3,748,324	43,559,787	3,709,020
Weighted-average shares outstanding used in computing net loss per share, diluted (in shares)	43,663,985	3,748,324	43,559,787	3,709,020
Net loss per share, basic (in dollars per share)	$ (0.57)	$ (2.80)	$ (1.46)	$ (5.95)
Net loss per share, diluted (in dollars per share)	$ (0.57)	$ (2.80)	$ (1.46)	$ (5.95)
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)	7,677,795	31,450,847	7,677,795	31,450,847
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)	7,677,795	5,700,149	7,677,795	5,700,149
Convertible Preferred 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)	0	25,750,698	0	25,750,698

Cash, cash equivalents and re_3

Cash, cash equivalents and restricted cash (Details) - USD ($) $ in Thousands	Sep. 30, 2021	May 13, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cash, cash equivalents and restricted cash [Abstract]
Cash and cash equivalents	$ 135,009		$ 365,462
Cash at consolidated joint venture	34,308	$ 35,011	0
Restricted cash, non-current	371		0
Total cash, cash equivalents and restricted cash reported in the Condensed Consolidated Statements of Cash Flows	$ 169,688		$ 365,462	$ 156,859	$ 76,453

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property and Equipment [Abstract]
Property and equipment	$ 435	$ 451
Less accumulated depreciation	(144)	(83)
Property and equipment, net	291	368
Furniture and Fixtures [Member]
Property and Equipment [Abstract]
Property and equipment	4	72
Computers and Equipment [Member]
Property and Equipment [Abstract]
Property and equipment	327	275
Computer Software [Member]
Property and Equipment [Abstract]
Property and equipment	$ 104	$ 104

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accrued Expenses [Abstract]
Accrued research and development	$ 4,033	$ 1,580
Accrued compensation	2,862	1,388
Accrued legal fees	134	288
Other accruals	546	108
Total	$ 7,575	$ 3,364

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Available-for-sale Investments by Types and Classes of Security [Abstract]
Securities in material unrealized loss positions	$ 0	$ 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	88,215	31,407
Unrealized Gains	14	0
Unrealized Losses	(10)	(9)
Estimated Fair Value	88,219	31,398
Short-term Investments [Member] | Corporate Debt Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	41,372	20,327
Unrealized Gains	4	0
Unrealized Losses	(6)	(9)
Estimated Fair Value	$ 41,370	$ 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] | Commercial Paper [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	$ 11,000	$ 11,080
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	$ 11,000	$ 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	1 year
Short-term Investments [Member] | US Treasury Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	$ 30,368
Unrealized Gains	10
Unrealized Losses	0
Estimated Fair Value	$ 30,378
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	$ 5,475
Unrealized Gains	0
Unrealized Losses	(4)
Estimated Fair Value	$ 5,471
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
Long-term Investments [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	$ 124,676
Unrealized Gains	8
Unrealized Losses	(48)
Estimated Fair Value	124,636
Long-term Investments [Member] | Corporate Debt Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	4,739
Unrealized Gains	0
Unrealized Losses	(1)
Estimated Fair Value	$ 4,738
Long-term Investments [Member] | Corporate Debt Securities [Member] | Minimum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years	1 year
Long-term Investments [Member] | Corporate Debt Securities [Member] | Maximum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years	2 years
Long-term Investments [Member] | US Treasury Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	$ 105,469
Unrealized Gains	7
Unrealized Losses	(40)
Estimated Fair Value	$ 105,436
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
Long-term Investments [Member] | Asset-backed Securities [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Amortized Cost	$ 14,468
Unrealized Gains	1
Unrealized Losses	(7)
Estimated Fair Value	$ 14,462
Long-term Investments [Member] | Asset-backed Securities [Member] | Minimum [Member]
Available-for-sale Investments by Types and Classes of Security [Abstract]
Maturity in Years	1 year
Long-term Investments [Member] | Asset-backed 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	Sep. 30, 2021	Dec. 31, 2020
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	$ 346,855	$ 395,859
Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	134,000	364,461
Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	46,108	20,318
Commercial Paper [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	11,000	11,080
U.S. Treasury Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	135,814
Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	19,933
Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	134,000	364,461
Level 1 [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	134,000	364,461
Level 1 [Member] | Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	0	0
Level 1 [Member] | Commercial Paper [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 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	212,855	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	46,108	20,318
Level 2 [Member] | Commercial Paper [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	11,000	11,080
Level 2 [Member] | U.S. Treasury Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	135,814
Level 2 [Member] | Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Total cash equivalents and investments	19,933
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] | Commercial Paper [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

Stockholders' Equity (Details)

Stockholders' Equity (Details) - $ / shares	Sep. 30, 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

Equity Incentive Plans and St_3

Equity Incentive Plans and Stock-Based Compensation, Equity Incentive Plans (Details) - 2020 Equity Incentive Plan [Member] - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Share-based Payment Arrangement, Disclosure [Abstract]
Common stock remained available for issuance of shares (in shares)	4,031,277
Options termination life	10
Expiration period	5 years
Period of exercise vested options of terminated employees	30 days
Minimum [Member]
Share-based Payment Arrangement, Disclosure [Abstract]
Percentage of common shares owned by optionee	10.00%
Vesting period	2 years
Maximum [Member]
Share-based Payment Arrangement, Disclosure [Abstract]
Number of shares of common stock options issued (in shares)	5,218,000
Vesting period	4 years
Stock Options [Member]
Options [Roll Forward]
Outstanding at beginning of period (in shares)	6,265,409
Granted (in shares)	2,099,851
Exercised (in shares)	(176,073)
Forfeited (in shares)	(511,392)
Outstanding at end of period (in shares)	7,677,795	6,265,409
Exercisable at end of period (in shares)	2,278,793
Weighted-Average Exercise Price [Abstract]
Outstanding at beginning of period (in dollars per share)	$ 4.12
Granted (in dollars per share)	30.01
Exercised (in dollars per share)	1.88
Forfeited (in dollars per share)	9.59
Outstanding at end of period (in dollars per share)	10.89	$ 4.12
Exercisable at end of period (in dollars per share)	$ 5.48
Weighted-Average Remaining Contractual Term [Abstract]
Outstanding (in years)	8 years 6 months	9 years 3 months 18 days
Exercisable (in years)	7 years 2 months 12 days
Aggregate Intrinsic Value [Abstract]
Outstanding amount	$ 107,061	$ 223,454
Exercisable amount	41,712
Total intrinsic value of options exercised	$ 1,100		$ 300

Equity Incentive Plans and St_4

Equity Incentive Plans and Stock-Based Compensation, Employee Stock Purchase Plan (Details) - 2020 Employee Stock Purchase Plan [Member]	9 Months Ended
	Sep. 30, 2021shares
Employee Stock Purchase Plan [Abstract]
Percentage of offering date	15.00%
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
Common stock remained available for issuance of shares (in shares)	405,841

Equity Incentive Plans and St_5

Equity Incentive Plans and Stock-Based Compensation, Equity Incentive Plan at China Joint Venture (Details)	Sep. 30, 2021shares
2021 Equity Incentive Plan [Member] | Maximum [Member]
Equity Incentive Plan at China Joint Venture [Abstract]
Number of shares of common stock options issued (in shares)	9,000,000

Equity Incentive Plans and St_6

Equity Incentive Plans and Stock-Based Compensation, Stock-Based Compensation Expense (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Expense
Stock-based compensation expense	$ 4,161	$ 714	$ 10,714	$ 1,252
Employee Stock Purchase Plan [Member]
Fair Value of Stock Assumptions [Abstract]
Expected dividend			0.00%
Unrecognized stock-based compensation expense	100		$ 100
Employee Stock Purchase Plan [Member] | Minimum [Member]
Fair Value of Stock Assumptions [Abstract]
Expected term (in years)			4 months 28 days
Expected volatility			51.00%
Risk-free interest rate			0.03%
Employee Stock Purchase Plan [Member] | Maximum [Member]
Fair Value of Stock Assumptions [Abstract]
Expected term (in years)			6 months
Expected volatility			68.00%
Risk-free interest rate			0.09%
Research and Development [Member]
Share-based Compensation Expense
Stock-based compensation expense	1,768	370	$ 4,958	695
General and Administrative [Member]
Share-based Compensation Expense
Stock-based compensation expense	2,393	$ 344	$ 5,756	$ 557
Stock Options [Member]
Fair Value of Stock Assumptions [Abstract]
Expected dividend			0.00%	0.00%
Weighted-average grant-date fair value of options granted (in dollars per share)			$ 21.80	$ 2.58
Unrecognized stock-based compensation expense	$ 49,000		$ 49,000
Weighted-average period of nonvested stock-based compensation			2 years 9 months 10 days
Stock Options [Member] | Minimum [Member]
Fair Value of Stock Assumptions [Abstract]
Expected term (in years)			5 years	6 years
Expected volatility			86.00%	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%	89.00%
Risk-free interest rate			1.17%	1.57%

Related Party Transactions, Ser

Related Party Transactions, Series A Financing of Joint Venture in China (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Related Party Transactions [Abstract]
Contributions from redeemable convertible noncontrolling interest owners, net	$ 34,853	$ 0

Related Party Transactions, Man

Related Party Transactions, Management Service Agreement with Fount Therapeutics, LLC and Fount Service Corp (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Management Service Agreement [Abstract]
Management fee expenses		$ 0		$ 92,000
Fount Therapeutics, LLC and Fount Service Corp. [Member]
Management Service Agreement [Abstract]
Management fee expenses	$ 0	$ 0	$ 0	$ 92,000

Related Party Transactions, M_2

Related Party Transactions, Management Services Agreement with Subveho, LLC (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Management Service Agreement [Abstract]
Management fee expenses		$ 0		$ 92,000
Subveho, LLC [Member]
Management Service Agreement [Abstract]
Management fee expenses	$ 0	$ 0	$ 0	$ 75,000

Variable Interest Entity (Detai

Variable Interest Entity (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	May 13, 2021	Dec. 31, 2020
Information of Variable Interest Entity [Abstract]
Contributions from redeemable convertible noncontrolling interest owners, net	$ 34,853	$ 0
Contributions from noncontrolling interest owners, issuance cost	200
Assets and Liabilities [Abstract]
Cash at consolidated joint venture	34,308		$ 35,011	$ 0
Accounts payable and accrued expenses	$ 175		$ 0
China Joint Venture [Member]
Information of Variable Interest Entity [Abstract]
Equity interest held in joint venture	54.90%

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Thousands	1 Months Ended
	Aug. 16, 2021ft²	Jun. 30, 2021ft²	Sep. 30, 2021USD ($)
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]
2021 (Remaining period)			71
2022			806
2023			1,048
2024			1,079
2025			1,112
2026			927
Thereafter			246
Total minimum lease payments			$ 5,289