Nkarta (NKTX) 10-Q 11 Aug 22 2022 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 08, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Entity File Number	001-39370
Entity Registrant Name	Nkarta, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-4515206
Entity Address, Address Line One	6000 Shoreline Court
Entity Address, Address Line Two	Suite 102
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	415
Local Phone Number	582-4923
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	NKTX
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	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		48,656,798
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001787400

CONDENSED BALANCE SHEETS (Unaud

CONDENSED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 131,646	$ 60,816
Short-term investments, available-for-sale	281,305	177,272
Prepaid expenses and other current assets	4,428	7,692
Total current assets	417,379	245,780
Restricted cash	2,098	2,098
Property and equipment, net	16,939	12,856
Operating lease right-of-use assets	66,030	11,678
Other long-term assets	1,195	1,491
Total assets	503,641	273,903
Current liabilities
Accounts payable	2,968	1,112
Operating lease liabilities, current portion	3,071	2,484
Accrued and other current liabilities	7,145	9,347
Total current liabilities	13,184	12,943
Operating lease liabilities, net of current portion	69,408	9,975
Other long-term liabilities	8	18
Total liabilities	82,600	22,936
Commitments and contingencies (Note 7)
Stockholders’ equity
Common stock	5	3
Additional paid-in capital	678,973	455,210
Accumulated other comprehensive loss	(931)	(150)
Accumulated deficit	(257,006)	(204,096)
Total stockholders’ equity	421,041	250,967
Total liabilities and stockholders’ equity	$ 503,641	$ 273,903

CONDENSED STATEMENTS OF OPERATI

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating expenses
Research and development	$ 21,049	$ 15,957	$ 40,617	$ 29,496
General and administrative	6,563	5,677	13,093	11,618
Total operating expenses	27,612	21,634	53,710	41,114
Loss from operations	(27,612)	(21,634)	(53,710)	(41,114)
Other income (expense), net:
Interest income	686	104	798	214
Other income (expense), net	3	(5)	2	(8)
Total other income (expense), net	689	99	800	206
Net loss	(26,923)	(21,535)	(52,910)	(40,908)
Comprehensive loss:
Net loss	(26,923)	(21,535)	(52,910)	(40,908)
Other comprehensive gain (loss)	(325)	(28)	(781)	3
Comprehensive loss	$ (27,248)	$ (21,563)	$ (53,691)	$ (40,905)
Net loss per share, basic	$ (0.61)	$ (0.66)	$ (1.38)	$ (1.25)
Net loss per share, diluted	$ (0.61)	$ (0.66)	$ (1.38)	$ (1.25)
Weighted average shares used to compute net loss per share, basic	43,841,392	32,827,365	38,446,956	32,783,730
Weighted average shares used to compute net loss per share, diluted	43,841,392	32,827,365	38,446,956	32,783,730

CONDENSED STATEMENTS OF STOCKHO

CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2020	$ 321,220	$ 3	$ 439,235	$ 3	$ (118,021)
Beginning Balance, Shares at Dec. 31, 2020		32,627,963
Vesting of shares of common stock subject to repurchase	9		9
Vesting of shares of common stock subject to repurchase, Shares		15,802
Issuance of common stock upon exercise of stock option, net of repurchase	756		756
Issuance of common stock upon exercise of stock option, net of repurchase, Shares		154,489
Share-based compensation expense	3,347		3,347
Unrealized gain (loss) on short-term investments	31			31
Net loss	(19,373)				(19,373)
Ending Balance at Mar. 31, 2021	305,990	$ 3	443,347	34	(137,394)
Ending Balance, Shares at Mar. 31, 2021		32,798,254
Beginning Balance at Dec. 31, 2020	321,220	$ 3	439,235	3	(118,021)
Beginning Balance, Shares at Dec. 31, 2020		32,627,963
Net loss	(40,908)
Ending Balance at Jun. 30, 2021	288,382	$ 3	447,302	6	(158,929)
Ending Balance, Shares at Jun. 30, 2021		32,852,861
Beginning Balance at Mar. 31, 2021	305,990	$ 3	443,347	34	(137,394)
Beginning Balance, Shares at Mar. 31, 2021		32,798,254
Vesting of shares of common stock subject to repurchase	9		9
Vesting of shares of common stock subject to repurchase, Shares		15,575
Issuance of common stock upon exercise of stock option, net of repurchase	256		256
Issuance of common stock upon exercise of stock option, net of repurchase, Shares		39,032
Share-based compensation expense	3,690		3,690
Unrealized gain (loss) on short-term investments	(28)			(28)
Net loss	(21,535)				(21,535)
Ending Balance at Jun. 30, 2021	288,382	$ 3	447,302	6	(158,929)
Ending Balance, Shares at Jun. 30, 2021		32,852,861
Beginning Balance at Dec. 31, 2021	250,967	$ 3	455,210	(150)	(204,096)
Beginning Balance, Shares at Dec. 31, 2021		32,971,107
Vesting of shares of common stock subject to repurchase	6		6
Vesting of shares of common stock subject to repurchase, Shares		10,924
Issuance of common stock upon exercise of stock option, net of repurchase	79		79
Issuance of common stock upon exercise of stock option, net of repurchase, Shares		21,067
Share-based compensation expense	4,097		4,097
Unrealized gain (loss) on short-term investments	(456)			(456)
Net loss	(25,987)				(25,987)
Ending Balance at Mar. 31, 2022	228,706	$ 3	459,392	(606)	(230,083)
Ending Balance, Shares at Mar. 31, 2022		33,003,098
Beginning Balance at Dec. 31, 2021	$ 250,967	$ 3	455,210	(150)	(204,096)
Beginning Balance, Shares at Dec. 31, 2021		32,971,107
Issuance of common stock upon exercise of stock option, net of repurchase, Shares	109,450
Net loss	$ (52,910)
Ending Balance at Jun. 30, 2022	421,041	$ 5	678,973	(931)	(257,006)
Ending Balance, Shares at Jun. 30, 2022		48,427,202
Beginning Balance at Mar. 31, 2022	228,706	$ 3	459,392	(606)	(230,083)
Beginning Balance, Shares at Mar. 31, 2022		33,003,098
Vesting of shares of common stock subject to repurchase	3		3
Vesting of shares of common stock subject to repurchase, Shares		2,387
Issuance of common stock upon exercise of stock option, net of repurchase	334		334
Issuance of common stock upon exercise of stock option, net of repurchase, Shares		88,383
Issuance of common stock upon secondary offering, net of issuance costs	215,334	$ 2	215,332
Issuance of common stock upon secondary offering, net of issuance costs, Shares		15,333,334
Share-based compensation expense	3,912		3,912
Unrealized gain (loss) on short-term investments	(325)			(325)
Net loss	(26,923)				(26,923)
Ending Balance at Jun. 30, 2022	$ 421,041	$ 5	$ 678,973	$ (931)	$ (257,006)
Ending Balance, Shares at Jun. 30, 2022		48,427,202

CONDENSED STATEMENT OF CASH FLO

CONDENSED STATEMENT OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net loss	$ (52,910)	$ (40,908)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	8,009	7,037
Depreciation and amortization	1,243	667
Accretion and amortization of premiums and discounts on investments, net	1,110	1,576
Non-cash lease expense	2,019	231
Changes in operating assets and liabilities:
Prepaid expenses and other assets	3,282	(987)
Operating lease right-of-use assets	2,923
Operating lease liabilities	726
Accounts payable and accrued and other liabilities	(1,274)	285
Net cash used in operating activities	(34,872)	(32,099)
Cash flows from investing activities
Purchases of property and equipment	(4,399)	(2,411)
Purchases of short-term investments	(175,011)	(86,234)
Maturities of short-term investments	69,088	47,500
Net cash used in investing activities	(110,322)	(41,145)
Cash flows from financing activities
Proceeds from stock option exercises	413	1,012
Proceeds from secondary offering, net of issuance costs	215,611
Net cash provided by financing activities	216,024	1,012
Net increase (decrease) in cash and cash equivalents	70,830	(72,232)
Cash, cash equivalents, and restricted cash beginning of period	62,914	97,105
Cash, cash equivalents, and restricted cash end of period	133,744	24,873
Reconciliation of cash, cash equivalents and restricted cash to the balance sheet:
Cash and cash equivalents	131,646	24,421
Restricted cash	2,098	452
Total cash, cash equivalents and restricted cash	133,744	24,873
Supplemental disclosures of non-cash investing and financing activities:
Acquisitions of property and equipment	$ 926	$ 255

Organization and Description of

Organization and Description of Business	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Description of the Business Nkarta, Inc. (“Nkarta” or the “Company”) was incorporated in the State of Delaware in July 2015. The Company is a biopharmaceutical company developing engineered natural killer (“NK”) cells to treat cancer. The Company is focused on leveraging the natural potent power of NK cells to identify and kill abnormal cells and recruit adaptive immune effectors to generate responses that are specific and durable. Nkarta is combining its NK expansion platform technology with proprietary cell engineering technologies to generate an abundant supply of NK cells, engineer enhanced NK cell recognition of tumor targets, and improve persistence for sustained activity in the body for the treatment of cancer. Nkarta’s goal is to develop off-the-shelf NK cell therapy product candidates to improve outcomes for patients. The Company’s operations are based in South San Francisco, California, and it operates in one segment. Liquidity and Management Plans The accompanying unaudited condensed financial statements have been prepared assuming that the Company will continue as a going concern. However, since inception, the Company has devoted substantially all of its efforts to organizing and staffing, business planning, raising capital, conducting preclinical studies and initiating clinical studies, and has not realized substantial revenues from its planned principal operations. In addition, the Company has a limited operating history, has incurred operating losses since inception and expects that it will continue to incur net losses into the foreseeable future as it continues its research and development activities. As of June 30, 2022, the Company had an accumulated deficit of $ 257.0 million and cash, cash equivalents, restricted cash and short-term investments of $ 415.0 million. Management plans to continue to incur substantial costs in order to conduct research and development activities and additional capital will be needed to undertake these activities. The Company intends to raise such capital through debt or equity financings or other arrangements to fund operations. Management believes that the Company’s current cash, cash equivalents, restricted cash and short-term investments will provide sufficient funds to enable the Company to meet its obligations for at least twelve months from the filing date of this report. On April 28, 2022, the Company issued and sold 15,333,334 shares of its common stock, including 2,000,000 shares associated with the full exercise of the underwriters’ option to purchase additional shares, at a price to the public of $ 15.00 per share. The total net proceeds to the Company from the offering were approximately $ 215.3 million, after deducting underwriting discounts and commissions and offering expenses. The shares were issued pursuant to the Company’s Registration Statement on Form S-3.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	2. Basis of Presentation and Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed financial statements as of June 30, 2022 and for the three and six months ended June 30, 2022 and 2021 have been prepared in accordance with U.S. generally accepted accounting principle (“U.S. GAAP”) for interim financial information and pursuant to Article 10 of Regulation S-X of the Securities Act of 1933, as amended. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. These unaudited condensed financial statements include only normal and recurring adjustments that the Company believes are necessary to fairly state the Company’s financial position and the results of its operations and cash flows. The results for the three and six months ended June 30 , 2022 are not necessarily indicative of the results expected for the full year or any subsequent interim period. The condensed balance sheet at December 31, 2021 has been derived from the audited financial statements at that date but does not include all disclosures required by U.S. GAAP for complete financial statements. Because all of the disclosures required by U.S. GAAP for complete financial statements are not included herein, these unaudited condensed financial statements and the notes accompanying them should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2021, contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 filed by the Company with the Securities and Exchange Commission on March 17, 2022. COVID-19 Pandemic The COVID-19 pandemic has caused disruptions in the global economy and has affected and may affect the Company’s business and operations in the future. In response to the pandemic, the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was signed into law on March 27, 2020. The CARES Act, among other things, includes tax provisions relating to refundable payroll tax credits, deferment of employer’s social security payments, net operating loss utilization and carryback periods, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The CARES Act had no impact on the Company’s income tax provision for the year ended December 31, 2021 or the six months ended June 30, 2022. The Company continues to evaluate the impact of the CARES Act on its financial position, results of operations and cash flows. The Company currently does not expect to apply for loans or grants under the CARES Act. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to preclinical studies, fair value of assets and liabilities, share-based compensation and income taxes. Management bases its estimates on historical experience, knowledge of current events and actions it may undertake in the future that management believes to be reasonable under the circumstances. Actual results may differ from these estimates and assumptions. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration of potential dilutive securities. Diluted net loss per share is computed by dividing the net loss by the sum of the weighted average number of common shares plus the potential dilutive effects of potential dilutive securities outstanding during the period. Potential dilutive securities are excluded from diluted earnings or loss per share if the effect of such inclusion is antidilutive. The Company’s potentially dilutive securities, which include convertible preferred stock prior to the conversion of such shares to common stock, unvested common stock, and outstanding stock options under the Company’s equity incentive plan, have been excluded from the computation of diluted net loss per share as they would be anti-dilutive to the net loss per share. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position.

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	3. Net Loss Per Share The following tables summarize the computation of the basic and diluted net loss per share (in thousands except share and per share data): Three Months Ended Six Months Ended 2022 2021 2022 2021 Numerator: Net loss $ ( 26,923 ) $ ( 21,535 ) $ ( 52,910 ) $ ( 40,908 ) Denominator: Weighted average common shares outstanding 43,844,869 32,879,406 38,452,511 32,843,343 Less: weighted average unvested common stock ( 3,477 ) ( 52,041 ) ( 5,555 ) ( 59,613 ) Weighted average shares used to compute net loss 43,841,392 32,827,365 38,446,956 32,783,730 Net loss per share, basic and diluted $ ( 0.61 ) $ ( 0.66 ) $ ( 1.38 ) $ ( 1.25 ) The following table summarizes the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive: As of June 30, 2022 2021 Common stock options 5,257,754 4,293,442 Restricted stock units 320,278 — Unvested common stock upon early exercise of common stock 2,475 46,849 5,580,507 4,340,291

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	4. Fair Value of Financial Instruments The following tables summarize the fair value of the Company’s financial instruments (in thousands): Fair Value Measurements Using June 30, Quoted Prices Significant Significant Assets: Cash equivalents: Money market funds $ 125,653 $ 125,653 $ — $ — Commercial paper 4,993 — 4,993 — Total cash equivalents $ 130,646 $ 125,653 $ 4,993 $ — Short-term investments: Corporate debt securities $ 112,634 $ — $ 112,634 — Commercial paper 64,153 — 64,153 — U.S. Government securities 104,518 — 104,518 — Total short-term investments 281,305 — 281,305 — Total $ 411,951 $ 125,653 $ 286,298 $ — Fair Value Measurements Using December 31, Quoted Prices Significant Significant Assets: Cash equivalents: Money market funds $ 57,018 $ 57,018 $ — $ — Short-term investments: Corporate debt securities $ 111,466 $ — $ 111,466 — Commercial paper 21,272 — 21,272 — U.S. Government securities 44,534 — 44,534 — Total short-term investments 177,272 — 177,272 — Total $ 234,290 $ 57,018 $ 177,272 $ — Cash Equivalents and Short-Term Investments Financial assets measured at fair value on a recurring basis consist of the Company’s cash equivalents and short-term investments. Cash equivalents consisted of money market funds and short-term investments consisted of commercial paper, U.S. Government securities and corporate bonds. The Company obtains pricing information from its investment manager and generally determines the fair value of investment securities using standard observable inputs, including reported trades, broker/dealer quotes, and bids and/or offers. Investments are classified as Level 1 within the fair value hierarchy if their quoted prices are available in active markets for identical securities. Investments in money market funds of $ 125.7 million and $ 57.0 million as of June 30, 2022 and December 31, 2021, respectively, were classified as Level 1 instruments and were included in cash and cash equivalents. Investments in marketable securities are valued using Level 2 inputs. Level 2 securities are initially valued at the transaction price and subsequently valued and reported upon utilizing inputs other than quoted prices that are observable either directly or indirectly, such as quotes from third-party pricing vendors. Fair values determined by Level 2 inputs, which utilize data points that are observable such as quoted prices, interest rates and yield curves, require the exercise of judgment and use of estimates, that if changed, could significantly affect the Company’s financial position and results of operations. The marketable securities of $ 286.3 million and $ 177.3 million as of June 30, 2022 and December 31, 2021, respectively, were classified as Level 2 instruments. As of June 30, 2022, marketable securities of $ 5.0 million and $ 281.3 million were included in cash and cash equivalents and short-term investments, respectively. As of December 31, 2021, marketable securities of $ 177.3 million were included in short-term investments. Accrued interest receivable related to short-term investments was $ 1.0 million as of both June 30, 2022 and December 31, 2021 and included as part of prepaid expenses and other current assets in the condensed balance sheets. The following tables summarize the Company’s short-term investments accounted for as available-for-sale securities as of June 30, 2022 and December 31, 2021 (in thousands): June 30, 2022 Maturity Amortized Unrealized Unrealized Estimated Corporate debt securities 1 year or less $ 113,037 $ ( 407 ) $ 4 $ 112,634 Commercial paper 1 year or less 69,146 — — 69,146 U.S. Government securities 1 year or less 105,046 ( 528 ) — 104,518 Total $ 287,229 $ ( 935 ) $ 4 $ 286,298 December 31, 2021 Maturity Amortized Unrealized Unrealized Estimated Corporate debt securities 1 year or less $ 111,548 $ ( 89 ) $ 7 $ 111,466 Commercial paper 1 year or less 21,272 — — 21,272 U.S. Government securities 1 year or less 44,602 ( 68 ) — $ 44,534 Total $ 177,422 $ ( 157 ) $ 7 $ 177,272 The Company has classified all of its available-for-sale investment securities as current assets on the condensed balance sheets based on the highly liquid nature of these investment securities and because these investment securities are considered available for use in current operations. The Company considers whether unrealized losses have resulted from a credit loss or other factors. The unrealized losses on the Company’s available-for-sale securities as of June 30, 2022 and December 31, 2021 were caused by fluctuations in market value and interest rates as a result of the economic environment and not credit risk. The Company concluded that an allowance for credit losses was unnecessary as of June 30, 2022 and December 31, 2021. It is neither management’s intention to sell nor is it more likely than not that the Company will be required to sell these investments prior to recovery of their cost basis or recovery of fair value. Unrealized gains and losses are included in accumulated other comprehensive loss. There was no realized gain or loss on available-for-sale securities in the periods presented. The Company uses the specific identification method to determine the cost basis of investments sold.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	5. Balance Sheet Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets are comprised of the following (in thousands): June 30, December 31, Prepaid expenses $ 2,343 $ 4,538 Other current assets 2,085 3,154 Total prepaid expenses and other current assets $ 4,428 $ 7,692 Property and Equipment, Net Property and equipment, net is comprised of the following (in thousands): June 30, December 31, Leasehold improvements $ 3,491 $ 3,462 Furniture and fixtures 543 544 Research equipment 11,466 9,633 Computers and software 130 130 Construction in progress 5,739 2,274 Total property and equipment 21,369 16,043 Less accumulated depreciation and amortization ( 4,430 ) ( 3,187 ) Total property and equipment, net $ 16,939 $ 12,856 Depreciation and amortization expense was $ 0.6 million and $ 1.2 million for the three and six months ended June 30, 2022, respectively, and $ 0.4 million and $0 .7 million for the three and six months ended June 30, 2021, respectively. Accrued and Other Current Liabilities Accrued other current liabilities are comprised of the following (in thousands): June 30, December 31, Accrued compensation $ 3,737 $ 5,453 Accrued research and development costs 2,510 2,280 Accrued property and equipment 177 96 Other accrued and current liabilities 721 1,518 Total accrued and other liabilities $ 7,145 $ 9,347

Leases

Leases	6 Months Ended
	Jun. 30, 2022
Leases [Abstract]
Leases	6. Leases The Company has operating leases for its current corporate offices, laboratory space, manufacturing facility, and dedicated space in a vivarium in South San Francisco, California, as well as for an additional facility in South San Francisco that the Company plans to use for corporate offices, laboratories and manufacturing. Rent expense, which is recognized on a straight-line basis over the term of each lease, was $ 2.8 million and $ 5.4 million for the three and six months ended June 30, 2022, respectively, and $ 0.7 million and $ 1.2 million for the three and six months ended June 30, 2021, respectively. The total cash paid for operating leases included in the operating cash flows was $ 1.9 million and $ 1.0 million for the six months ended June 30, 2022 and 2021, respectively. The weighted-average remaining lease term was 11.0 years for the corporate office, laboratory space leases, and additional facility as of June 30, 2022. The weighted-average discount rate was 8.9 % as of June 30, 2022. In May 2018, the Company entered into a lease agreement for its corporate office and laboratory space located in South San Francisco, California with an expiration date in May 2025 (the “Initial Lease Agreement”). In April 2019, the Company executed the first amendment to the Initial Lease Agreement for additional corporate space, laboratory space and manufacturing capabilities and an extension to the lease term through April 2026. In May 2020, the Company signed a second amendment to the Initial Lease Agreement . The amended lease provides for an eight-year non-cancelable lease of additional office and laboratory space in the same building. The lease amendment for additional office and laboratory space contains rent escalations during the term of the lease. The lease for this additional space commenced in January 2021 and expires in January 2029 . The lease amendment also includes an extension of the lease term for the existing office and laboratory space beginning on May 1, 2020 and expiring in January 2029. The amendment to the Initial Lease Agreement also includes an option to extend the lease for an additional seven-year term . In January 2021, the Company signed a third amendment to the Initial Lease Agreement which provides for lease of additional space in the same building. The lease amendment for this additional space commenced in April 2021 and expires in March 2024 . In October 2021, the Company signed a fourth amendment to the Initial Lease Agreement which provides for lease of additional space in the same building . The lease for additional office and laboratory space contains rent escalations during the term of the lease. The lease amendment of this additional space commenced in April 2022 and expires in January 2029 . The Company expects to pay base rent of approximately $ 4.6 million over the lease term. The lease amendment also includes this additional space in the Company’s option to extend the amended Initial Lease Agreement for an additional seven-year term. The other terms of the Initial Lease Agreement, as amended, remain unchanged. In July 2021, the Company entered into a lease agreement for corporate office, manufacturing and laboratory space located in South San Francisco, California with an expiration date approximately twelve years after the lease commencement date (the “Additional Lease Agreement”). The lease for this additional space and the Company's obligation to pay rent commenced in January 2022. In addition to ba se rent, the Company is responsible for payment of direct expenses, which include operating, insurance and tax expenses. The lease also provides for certain tenant improvement allowances of up to approximately $ 25.2 million for tenant improvements and certain infrastructure upgrades in connection with the initial buildout of the premises, approximately $ 4.4 million of which, if utilized, would need to be repaid by the Company over the lease term. In 2021, the Company delivered a security deposit in the form of a letter of credit of $ 1.6 million to the landlord in connection with the Additional Lease Agreement. In November 2021, the Company entered into an amendment to the Additional Lease Agreement. The lease amendment expressly includes manufacturing as a permitted use at the facility, clarifies that Silicon Valley Bank is an acceptable bank for purposes of issuing a letter of credit under the lease, revises the letter of credit transferability terms and replaces the form of letter of credit attached to the lease. Maturities of operating lease liabilities under existing operating leases as of June 30, 2022 were as follows (in thousands): Year ending December 31, Amount 2022 (remaining six months) $ 3,238 2023 9,899 2024 9,912 2025 10,199 2026 10,566 2027 and thereafter 75,067 Total undiscounted future minimum lease payments 118,881 Less imputed interest ( 45,676 ) Less tenant improvement receivable ( 726 ) Total operating lease liabilities $ 72,479 Operating lease liabilities: Current 3,071 Non-current 69,408 Total lease liability $ 72,479

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments & Contingencies Guarantee Agreement The Company has agreements whereby it indemnifies its officers and directors for certain events or occurrences while the officer or director is, or was, serving at the Company’s request in such capacity. The term of the indemnification period is for the officer’s or director’s lifetime. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited; however, the Company has a director and officer insurance policy that limits its exposure and enables the Company to recover a portion of any future amounts under certain circumstances and subject to deductibles and exclusions. The Company had no liabilities recorded for these agreements as of June 30, 2022 and December 31, 2021. Letters of Credit As of June 30, 2022, the Company had $ 2.1 million in letter of credit agreements with a financial institution that are used as collateral for the Company’s corporate headquarters’ operating lease and the additional facility in South San Francisco that the Company plans to use for corporate offices, laboratories and manufacturing. The letters of credit automatically renew annually without amendment unless cancelled by the financial institutions within 30 to 60 days of the annual expiration date.

CRISPR Collaboration Agreement

CRISPR Collaboration Agreement	6 Months Ended
	Jun. 30, 2022
Collaboration Agreement [Abstract]
CRISPR Collaboration Agreement	8. CRISPR Collaboration Agreement On May 5, 2021, the Company entered into a research collaboration agreement (as amended, the “CRISPR Agreement”) with CRISPR Therapeutics AG (“CRISPR”) to co-develop and co-commercialize an engineered CAR-NK product candidate targeting the CD70 tumor antigen and a second novel NK plus T cell (“NK+T”) product candidate. In addition, the Company has received licenses from CRISPR for two CRISPR-Cas9 gene editing targets and will receive a license from CRISPR for up to three more CRISPR-Cas9 gene editing targets that can be engineered into an unlimited number of its own NK cell products. CRISPR also has an option to co-develop and co-commercialize a future CAR-NK program. Under the terms of the CRISPR Agreement, the Company and CRISPR share equally in all research and development costs and potential profits worldwide related to the CD70 CAR-NK product candidate, NK+T product candidate, and the potential future CAR-NK program. For the NK+T program, CRISPR is responsible for gene-editing activities and T cell related activities, and Nkarta is responsible for NK cell related activities. The related impact of the cost sharing associated with the research and development activities is included in research and development expense on the condensed statements of operations. Expenses related to services performed by the Company are classified as research and development expense. Payments received from CRISPR for partial reimbursement of expenses are recorded as a reduction of research and development expense. As of June 30, 2022, the Company had a $ 0.7 million receivable under the research cost sharing provision, which is included as part of prepaid expenses and other current assets in the condensed balance sheet. For each non-collaboration product candidate incorporating a gene editing target licensed from CRISPR, the Company would retain worldwide rights and may be required to make potential future payments based on the achievement of development and regulatory approval milestones totaling less than mid-twenty million dollars for each non-collaboration product, as well as tiered royalties up to the mid-single digits on net product sales of such product. As of June 30, 2022, the Company has no t paid any amounts no r are any amounts owed by the Company under the CRISPR Agreement, and no milestones have been achieved.

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	9. Share-Based Compensation Equity Incentive Plan The Company’s 2020 Performance Incentive Plan (the “2020 Plan”), which was adopted by the Company’s board of directors in June 2020 and approved by the Company’s stockholders in July 2020, became effective upon the consummation of the Company’s initial public offering (“IPO”). Upon the effectiveness of the 2020 Plan, no further grants may be made under the Company’s 2015 Equity Incentive Plan (the “2015 Plan”). The Company’s 2020 Plan allows for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, stock bonuses, restricted stock, stock units and other forms of awards including cash awards to its officers, directors, employees, consultants and advisors. A total of 5,945,002 shares of the Company’s common stock is authorized for issuance with respect to awards granted under the 2020 Plan. The share limit will automatically increase on the first trading day in January of each year by an amount equal to the lesser of (1) 5 % of the total number of outstanding shares of the Company’s common stock on the last trading day in December in the prior year, or (2) such lesser number as determined by the Company’s board of directors. Any shares subject to awards granted under the 2020 Plan or the 2015 Plan that are not paid, delivered or exercised before they expire or are canceled or terminated, or otherwise fail to vest, as well as shares used to pay the purchase or exercise price of such awards or related tax withholding obligations, will become available for new award grants under the 2020 Plan. The following table summarizes the option activity under the 2020 Plan and 2015 Plan during the six months ended June 30, 2022: Number of shares Weighted- Weighted- Outstanding at December 31, 2021 4,204,686 $ 19.19 8.2 Granted 1,642,598 12.51 Exercised ( 109,450 ) 3.76 Forfeited ( 480,080 ) 20.47 Outstanding at June 30, 2022 5,257,754 $ 17.31 8.0 Exercisable at June 30, 2022 2,078,037 $ 16.32 6.8 Vested and expected to vest at June 30, 2022 5,257,754 $ 17.31 8. 0 The weighted-average grant date fair value of stock option grants was $ 8.49 per share for the six months ended June 30, 2022. The following table summarizes the restricted stock unit activity under the 2020 Plan during the six months ended June 30, 2022: Number of shares Weighted-average Outstanding at December 31, 2021 — $ — Granted 356,908 12.18 Forfeited ( 36,630 ) 12.14 Vested — — Outstanding at June 30, 2022 320,278 $ 12.18 Employee Stock Purchase Plan The Company’s 2020 Employee Stock Purchase Plan (the “ESPP”), which was adopted by the Company’s board of directors in June 2020 and approved by the Company’s stockholders in July 2020, became effective upon the consummation of the IPO. A total of 952,524 shares of the Company’s common stock is available for issuance under the ESPP. The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15 % of their eligible compensation, subject to any plan limitations. The ESPP provides for six-month offering periods, and at the end of each offering period, employees are able to purchase shares at 85 % of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the last trading day of the offering period. As of June 30 , 2022 , no shares had been issued under the ESPP, and the full number of shares authorized under the ESPP was available for issuance purposes. Liability for Early Exercise of Restricted Stock Options Shares subject to repurchase by the Company were 2,475 shares and 16,181 shares, and the related liability recorded under other long-term liabilities in the condensed balance sheets was insignificant as of June 30, 2022 and December 31, 2021, respectively. Share-Based Compensation Expense Share-based compensation expense for the three and six months ended June 30, 2022 and 2021 was as follows (in thousands): Three Months Ended Six Months Ended 2022 2021 2022 2021 Research and development $ 1,602 $ 1,744 $ 3,457 $ 3,314 General and administrative 2,310 1,946 4,552 3,723 Total share-based compensation $ 3,912 $ 3,690 $ 8,009 $ 7,037 The total unrecognized compensation cost related to unvested stock options was $ 44.5 million, which is expected to be recognized over a weighted-average remaining service period of 2.60 years as of June 30, 2022. The total unrecognized compensation cost related to unvested restricted stock units was $ 3.9 million, which is expected to be recognized over a weighted-average remaining service period of 3.69 years as of June 30, 2022.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes There was no provision for income taxes recorded during the three and six months ended June 30, 2022 and 2021. The Company’s deferred tax assets continue to be fully offset by a valuation allowance .

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	11. Subsequent Events In August 2022, the Company signed amendment lease agreements for its future cell therapy manufacturing facility and company headquarters and for its existing facilities in South San Francisco, California. The amendments provide for approximately $ 15.0 million of additional tenant improvement allowances, in addition to the tenant improvement allowances of $ 25.2 million included in the original lease agreement. Additionally, the amendments increase the rent and term of the lease for some of the Company's existing facilities. As a result of the amendments, the Company expects the lease liability and corresponding right-of-use-asset to increase based on the present value of the remaining minimum rental payments using discount rates as of the effective date of the amendments. At this time, the amount of the increase to the lease liability and corresponding right-of-use-asset has not been determined but will be reflected in the condensed balance sheet as of September 30, 2022.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements as of June 30, 2022 and for the three and six months ended June 30, 2022 and 2021 have been prepared in accordance with U.S. generally accepted accounting principle (“U.S. GAAP”) for interim financial information and pursuant to Article 10 of Regulation S-X of the Securities Act of 1933, as amended. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. These unaudited condensed financial statements include only normal and recurring adjustments that the Company believes are necessary to fairly state the Company’s financial position and the results of its operations and cash flows. The results for the three and six months ended June 30 , 2022 are not necessarily indicative of the results expected for the full year or any subsequent interim period. The condensed balance sheet at December 31, 2021 has been derived from the audited financial statements at that date but does not include all disclosures required by U.S. GAAP for complete financial statements. Because all of the disclosures required by U.S. GAAP for complete financial statements are not included herein, these unaudited condensed financial statements and the notes accompanying them should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2021, contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 filed by the Company with the Securities and Exchange Commission on March 17, 2022.
COVID-19 Pandemic	COVID-19 Pandemic The COVID-19 pandemic has caused disruptions in the global economy and has affected and may affect the Company’s business and operations in the future. In response to the pandemic, the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was signed into law on March 27, 2020. The CARES Act, among other things, includes tax provisions relating to refundable payroll tax credits, deferment of employer’s social security payments, net operating loss utilization and carryback periods, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The CARES Act had no impact on the Company’s income tax provision for the year ended December 31, 2021 or the six months ended June 30, 2022. The Company continues to evaluate the impact of the CARES Act on its financial position, results of operations and cash flows. The Company currently does not expect to apply for loans or grants under the CARES Act.
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 amounts reported in the Company’s financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to preclinical studies, fair value of assets and liabilities, share-based compensation and income taxes. Management bases its estimates on historical experience, knowledge of current events and actions it may undertake in the future that management believes to be reasonable under the circumstances. Actual results may differ from these estimates and assumptions.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration of potential dilutive securities. Diluted net loss per share is computed by dividing the net loss by the sum of the weighted average number of common shares plus the potential dilutive effects of potential dilutive securities outstanding during the period. Potential dilutive securities are excluded from diluted earnings or loss per share if the effect of such inclusion is antidilutive. The Company’s potentially dilutive securities, which include convertible preferred stock prior to the conversion of such shares to common stock, unvested common stock, and outstanding stock options under the Company’s equity incentive plan, have been excluded from the computation of diluted net loss per share as they would be anti-dilutive to the net loss per share. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position.

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss Per Share	The following tables summarize the computation of the basic and diluted net loss per share (in thousands except share and per share data): Three Months Ended Six Months Ended 2022 2021 2022 2021 Numerator: Net loss $ ( 26,923 ) $ ( 21,535 ) $ ( 52,910 ) $ ( 40,908 ) Denominator: Weighted average common shares outstanding 43,844,869 32,879,406 38,452,511 32,843,343 Less: weighted average unvested common stock ( 3,477 ) ( 52,041 ) ( 5,555 ) ( 59,613 ) Weighted average shares used to compute net loss 43,841,392 32,827,365 38,446,956 32,783,730 Net loss per share, basic and diluted $ ( 0.61 ) $ ( 0.66 ) $ ( 1.38 ) $ ( 1.25 )
Summarizes the Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share	The following table summarizes the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive: As of June 30, 2022 2021 Common stock options 5,257,754 4,293,442 Restricted stock units 320,278 — Unvested common stock upon early exercise of common stock 2,475 46,849 5,580,507 4,340,291

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables) - Short-term investments	6 Months Ended
	Jun. 30, 2022
Summary of Fair Value of Financial Instrument	The following tables summarize the fair value of the Company’s financial instruments (in thousands): Fair Value Measurements Using June 30, Quoted Prices Significant Significant Assets: Cash equivalents: Money market funds $ 125,653 $ 125,653 $ — $ — Commercial paper 4,993 — 4,993 — Total cash equivalents $ 130,646 $ 125,653 $ 4,993 $ — Short-term investments: Corporate debt securities $ 112,634 $ — $ 112,634 — Commercial paper 64,153 — 64,153 — U.S. Government securities 104,518 — 104,518 — Total short-term investments 281,305 — 281,305 — Total $ 411,951 $ 125,653 $ 286,298 $ — Fair Value Measurements Using December 31, Quoted Prices Significant Significant Assets: Cash equivalents: Money market funds $ 57,018 $ 57,018 $ — $ — Short-term investments: Corporate debt securities $ 111,466 $ — $ 111,466 — Commercial paper 21,272 — 21,272 — U.S. Government securities 44,534 — 44,534 — Total short-term investments 177,272 — 177,272 — Total $ 234,290 $ 57,018 $ 177,272 $ —
Schedule of Short-term Investments	The following tables summarize the Company’s short-term investments accounted for as available-for-sale securities as of June 30, 2022 and December 31, 2021 (in thousands): June 30, 2022 Maturity Amortized Unrealized Unrealized Estimated Corporate debt securities 1 year or less $ 113,037 $ ( 407 ) $ 4 $ 112,634 Commercial paper 1 year or less 69,146 — — 69,146 U.S. Government securities 1 year or less 105,046 ( 528 ) — 104,518 Total $ 287,229 $ ( 935 ) $ 4 $ 286,298 December 31, 2021 Maturity Amortized Unrealized Unrealized Estimated Corporate debt securities 1 year or less $ 111,548 $ ( 89 ) $ 7 $ 111,466 Commercial paper 1 year or less 21,272 — — 21,272 U.S. Government securities 1 year or less 44,602 ( 68 ) — $ 44,534 Total $ 177,422 $ ( 157 ) $ 7 $ 177,272

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets are comprised of the following (in thousands): June 30, December 31, Prepaid expenses $ 2,343 $ 4,538 Other current assets 2,085 3,154 Total prepaid expenses and other current assets $ 4,428 $ 7,692
Schedule of Property and Equipment, Net	Property and equipment, net is comprised of the following (in thousands): June 30, December 31, Leasehold improvements $ 3,491 $ 3,462 Furniture and fixtures 543 544 Research equipment 11,466 9,633 Computers and software 130 130 Construction in progress 5,739 2,274 Total property and equipment 21,369 16,043 Less accumulated depreciation and amortization ( 4,430 ) ( 3,187 ) Total property and equipment, net $ 16,939 $ 12,856
Schedule of Accrued Other Current Liabilities	Accrued other current liabilities are comprised of the following (in thousands): June 30, December 31, Accrued compensation $ 3,737 $ 5,453 Accrued research and development costs 2,510 2,280 Accrued property and equipment 177 96 Other accrued and current liabilities 721 1,518 Total accrued and other liabilities $ 7,145 $ 9,347

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2022
Leases [Abstract]
Schedule of Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities under existing operating leases as of June 30, 2022 were as follows (in thousands): Year ending December 31, Amount 2022 (remaining six months) $ 3,238 2023 9,899 2024 9,912 2025 10,199 2026 10,566 2027 and thereafter 75,067 Total undiscounted future minimum lease payments 118,881 Less imputed interest ( 45,676 ) Less tenant improvement receivable ( 726 ) Total operating lease liabilities $ 72,479 Operating lease liabilities: Current 3,071 Non-current 69,408 Total lease liability $ 72,479

Share-Based Compensation (Table

Share-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Activity	The following table summarizes the option activity under the 2020 Plan and 2015 Plan during the six months ended June 30, 2022: Number of shares Weighted- Weighted- Outstanding at December 31, 2021 4,204,686 $ 19.19 8.2 Granted 1,642,598 12.51 Exercised ( 109,450 ) 3.76 Forfeited ( 480,080 ) 20.47 Outstanding at June 30, 2022 5,257,754 $ 17.31 8.0 Exercisable at June 30, 2022 2,078,037 $ 16.32 6.8 Vested and expected to vest at June 30, 2022 5,257,754 $ 17.31 8. 0
Summary of Restricted Stock Unit Activity	The following table summarizes the restricted stock unit activity under the 2020 Plan during the six months ended June 30, 2022: Number of shares Weighted-average Outstanding at December 31, 2021 — $ — Granted 356,908 12.18 Forfeited ( 36,630 ) 12.14 Vested — — Outstanding at June 30, 2022 320,278 $ 12.18
Summary of Share-based Compensation Expense	Share-based compensation expense for the three and six months ended June 30, 2022 and 2021 was as follows (in thousands): Three Months Ended Six Months Ended 2022 2021 2022 2021 Research and development $ 1,602 $ 1,744 $ 3,457 $ 3,314 General and administrative 2,310 1,946 4,552 3,723 Total share-based compensation $ 3,912 $ 3,690 $ 8,009 $ 7,037

Organization and Description _2

Organization and Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands		3 Months Ended	6 Months Ended
	Apr. 28, 2022 USD ($) $ / shares shares	Jun. 30, 2022 USD ($) shares	Jun. 30, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)
Class Of Stock [Line Items]
Number of operating segments | Segment			1
Accumulated deficit		$ 257,006	$ 257,006	$ 204,096
Cash, cash equivalents restricted cash and short-term investments		$ 415,000	$ 415,000
Common Stock
Class Of Stock [Line Items]
Common stock shares issued and sold | shares	15,333,334	15,333,334
Stock public offering price | $ / shares	$ 15
Common Stock | Underwriters Option to Purchase Additional Shares
Class Of Stock [Line Items]
Common stock shares issued and sold | shares	2,000,000
Common Stock | Follow On Offering of Stock
Class Of Stock [Line Items]
Net proceeds from public offering	$ 215,300

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Net loss	$ (26,923)	$ (25,987)	$ (21,535)	$ (19,373)	$ (52,910)	$ (40,908)
Denominator:
Weighted average common shares outstanding	43,844,869		32,879,406		38,452,511	32,843,343
Less: weighted average unvested common stock issued upon early exercise of common stock options	(3,477)		(52,041)		(5,555)	(59,613)
Weighted average shares used to compute net loss per share, basic	43,841,392		32,827,365		38,446,956	32,783,730
Weighted average shares used to compute net loss per share, diluted	43,841,392		32,827,365		38,446,956	32,783,730
Net loss per share, basic	$ (0.61)		$ (0.66)		$ (1.38)	$ (1.25)
Net loss per share, diluted	$ (0.61)		$ (0.66)		$ (1.38)	$ (1.25)

Net Loss Per Share - Summarizes

Net Loss Per Share - Summarizes the Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share (Details) - shares	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,580,507	4,340,291
Common Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,257,754	4,293,442
Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	320,278
Unvested Common Stock Upon Early Exercise of Common Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	2,475	46,849

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Summary of Fair Value of Financial Instrument (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Assets:
Money market funds	$ 125,653	$ 57,018
Commercial paper	4,993
Total cash equivalents	130,646
Total short-term investments	281,305	177,272
Total	411,951	234,290
Commercial Paper
Assets:
Total short-term investments	64,153	21,272
Corporate Debt Securities
Assets:
Total short-term investments	112,634	111,466
U.S. Government Securities
Assets:
Total short-term investments	104,518	44,534
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Money market funds	125,653	57,018
Total cash equivalents	125,653
Total	125,653	57,018
Significant Other Observable Inputs (Level 2)
Assets:
Commercial paper	4,993
Total cash equivalents	4,993
Total short-term investments	281,305	177,272
Total	286,298	177,272
Significant Other Observable Inputs (Level 2) | Commercial Paper
Assets:
Total short-term investments	64,153	21,272
Significant Other Observable Inputs (Level 2) | Corporate Debt Securities
Assets:
Total short-term investments	112,634	111,466
Significant Other Observable Inputs (Level 2) | U.S. Government Securities
Assets:
Total short-term investments	$ 104,518	$ 44,534

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Realized gain or loss on available-for-sale securities	$ 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money Market Funds
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Investments	125,700,000	$ 57,000,000
Significant Other Observable Inputs (Level 2)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Marketable securities	286,300,000	177,300,000
Significant Other Observable Inputs (Level 2) | Short-term investments
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Marketable securities	281,300,000	177,300,000
Accrued interest receivable	1,000,000	$ 1,000,000
Significant Other Observable Inputs (Level 2) | Cash and Cash Equivalents
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Marketable securities	$ 5,000,000

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Schedule of Short-term Investments Accounted as Available-for-sale Securities (Details) - Short-term investments - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available for sale securities, Amortized Cost	$ 287,229	$ 177,422
Available for sale securities, Unrealized Losses	(935)	(157)
Available for sale securities, Unrealized Gains	4	7
Available for sale securities,Estimated Fair Value	286,298	177,272
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available for sale securities, Amortized Cost	69,146	21,272
Available for sale securities,Estimated Fair Value	$ 69,146	$ 21,272
Commercial Paper | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Maturity (in years)	1 year	1 year
U.S. Government Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available for sale securities, Amortized Cost	$ 105,046	$ 44,602
Available for sale securities, Unrealized Losses	(528)	(68)
Available for sale securities,Estimated Fair Value	$ 104,518	$ 44,534
U.S. Government Securities | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Maturity (in years)	1 year	1 year
Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available for sale securities, Amortized Cost	$ 113,037	$ 111,548
Available for sale securities, Unrealized Losses	(407)	(89)
Available for sale securities, Unrealized Gains	4	7
Available for sale securities,Estimated Fair Value	$ 112,634	$ 111,466
Corporate Debt Securities | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Maturity (in years)	1 year	1 year

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Prepaid expenses	$ 2,343	$ 4,538
Other current assets	2,085	3,154
Total prepaid expenses and other current assets	$ 4,428	$ 7,692

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total property and equipment	$ 21,369	$ 16,043
Less accumulated depreciation and amortization	(4,430)	(3,187)
Total property and equipment, net	16,939	12,856
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	3,491	3,462
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	543	544
Research Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	11,466	9,633
Computers and Software
Property Plant And Equipment [Line Items]
Total property and equipment	130	130
Construction in Progress
Property Plant And Equipment [Line Items]
Total property and equipment	$ 5,739	$ 2,274

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization expense	$ 0.6	$ 0.4	$ 1.2	$ 0.7

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accrued compensation	$ 3,737	$ 5,453
Accrued research and development costs	2,510	2,280
Accrued property and equipment	177	96
Other accrued and current liabilities	721	1,518
Total accrued and other liabilities	$ 7,145	$ 9,347

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended					3 Months Ended		6 Months Ended
	Oct. 31, 2021	Jul. 31, 2021	Jan. 31, 2021	May 31, 2020	May 31, 2018	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Lessee Lease Description [Line Items]
Rent expense						$ 2.8	$ 0.7	$ 5.4	$ 1.2
Weighted-average remaining lease term						11 years		11 years
Cash paid for operating leases								$ 1.9	$ 1
Weighted-average discount rate						8.90%		8.90%
Lessee, operating lease, term of contract		12 years
Cash received for tenant improvement allowances to be repaid		$ 4.4
Maximum
Lessee Lease Description [Line Items]
Tenant improvement allowances yet to receive		$ 25.2
Letter of Credit
Lessee Lease Description [Line Items]
Security deposit						$ 1.6		$ 1.6
Third amendment
Lessee Lease Description [Line Items]
Lessee option to extend description								The lease amendment for this additional space commenced in April 2021 and expires in March 2024
Lease expiration month and year			2024-03
Initial Lease Agreement
Lessee Lease Description [Line Items]
Lease expiration year	2029			2029
Operating lease, existence of option to extend	true			true
Lessee option to extend description	The lease amendment of this additional space commenced in April 2022 and expires in January 2029. The Company expects to pay base rent of approximately $4.6 million over the lease term. The lease amendment also includes this additional space in the Company’s option to extend the amended Initial Lease Agreement for an additional seven-year term.							The lease amendment also includes an extension of the lease term for the existing office and laboratory space beginning on May 1, 2020 and expiring in January 2029. The amendment to the Initial Lease Agreement also includes an option to extend the lease for an additional seven-year term
Lease term				8 years
Expects to pay base rent over the lease term	$ 4.6
Corporate Office and Laboratory Space | Initial Lease Agreement
Lessee Lease Description [Line Items]
Lease expiration year					2025
Operating lease, existence of option to extend					true
Lessee option to extend description								In April 2019, the Company executed the first amendment to the Initial Lease Agreement for additional corporate space, laboratory space and manufacturing capabilities and an extension to the lease term through April 2026.
Renewal term				7 years

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Leases [Abstract]
2022 (remaining six months)	$ 3,238
2023	9,899
2024	9,912
2025	10,199
2026	10,566
2027 and thereafter	75,067
Total undiscounted future minimum lease payments	118,881
Less imputed interest	(45,676)
Tenant improvement receivable	(726)
Total operating lease liabilities	72,479
Operating lease liabilities:
Operating lease liabilities, current portion	3,071	$ 2,484
Operating lease liabilities, net of current portion	69,408	$ 9,975
Total lease liability	$ 72,479

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Liabilities recorded for agreements	$ 0	$ 0
Agreement with Financial Institution
Loss Contingencies [Line Items]
Letters of credit outstanding amount	$ 2,100,000
Agreement with Financial Institution | Minimum [Member]
Loss Contingencies [Line Items]
Letter of credit notice period by financial institution before annual expiration date	30 days
Agreement with Financial Institution | Maximum
Loss Contingencies [Line Items]
Letter of credit notice period by financial institution before annual expiration date	60 days

CRISPR Collaboration Agreement

CRISPR Collaboration Agreement - Additional Information (Details) - Research Collaboration Agreement		6 Months Ended
	May 05, 2021 CrisprCas9	Jun. 30, 2022 USD ($)
Development and Regulatory Approval Milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Receivable under research cost sharing provision		$ 700,000
Potential future payments		totaling less than mid-twenty million dollars
Amount paid under the agreement		$ 0
Amounts owed under the agreement		$ 0
NK Cell Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of non-exclusive rights to gene editing targets licenses received | CrisprCas9	2
NK Cell Products | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of non-exclusive rights to gene editing targets | CrisprCas9	3

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value of stock option	$ 8.49
Unrecognized compensation cost	$ 44.5
Unrecognized compensation cost, expected to be recognized over weighted average remaining service period	2 years 7 months 6 days
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares subject to repurchase	2,475	16,181
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost	$ 3.9
Unrecognized compensation cost, expected to be recognized over weighted average remaining service period	3 years 8 months 8 days
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock available for issuance	952,524
Maximum percentage of employee compensation eligible for plan	15%
Offering period	6 months
Commons stock purchase price as percentage of fair value	85%
Shares issued	0
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock authorized for issuance	5,945,002
Increase in share limit as percentage of outstanding shares of common stock on last trading day in prior year	5%

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Stock Option Activity (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2022 $ / shares shares	Dec. 31, 2021 $ / shares shares
Share-Based Payment Arrangement [Abstract]
Number of shares, outstanding beginning balance | shares	4,204,686
Number of shares, granted | shares	1,642,598
Number of shares, exercised | shares	(109,450)
Number of shares, forfeited | shares	(480,080)
Number of shares, outstanding ending balance | shares	5,257,754	4,204,686
Number of shares, exercisable | shares	2,078,037
Number of shares, vested and expected to vest | shares	5,257,754
Weighted-average exercise price, outstanding beginning balance | $ / shares	$ 19.19
Weighted-average exercise price, granted | $ / shares	12.51
Weighted-average exercise price, exercised | $ / shares	3.76
Weighted-average exercise price, forfeited | $ / shares	20.47
Weighted-average exercise price, outstanding ending balance | $ / shares	17.31	$ 19.19
Weighted-average exercise price, exercisable | $ / shares	16.32
Weighted-average exercise price, vested and expected to vest | $ / shares	$ 17.31
Weighted-average remaining contractual term (in years), outstanding balance	8 years	8 years 2 months 12 days
Weighted-average remaining contractual term (in years), exercisable	6 years 9 months 18 days
Weighted-average remaining contractual term (in years), vested and expected to vest	8 years

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Unit Activity	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares, outstanding beginning balance | shares	0
Number of shares, granted | shares	356,908
Number of shares, forfeited | shares	(36,630)
Number of shares, outstanding ending balance | shares	320,278
Weighted-average grant date fair value per share, outstanding beginning balance | $ / shares	$ 0
Weighted-average grant date fair value per share, granted | $ / shares	12.18
Weighted-average grant date fair value per share, Forfeited | $ / shares	12.14
Weighted-average grant date fair value per share, outstanding ending balance | $ / shares	$ 12.18

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 3,912	$ 3,690	$ 8,009	$ 7,037
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	1,602	1,744	3,457	3,314
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 2,310	$ 1,946	$ 4,552	$ 3,723

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 0	$ 0	$ 0	$ 0

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Scenario Forecast - Amendment of Lease Agreements $ in Millions	1 Months Ended
	Aug. 31, 2022 USD ($)
Subsequent Event [Line Items]
Additional tenant improvement allowances	$ 15
Tenant improvement allowances yet to receive	$ 25.2