Document and Entity Information
| Document and Entity Information - shares | 9 Months Ended | |
| Sep. 30, 2023 | Nov. 06, 2023 | |
| Cover [Abstract] | ||
| Document Type | 10-Q | |
| Document Quarterly Report | true | |
| Document Period End Date | Sep. 30, 2023 | |
| 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 | 1150 Veterans Boulevard | |
| Entity Address, City or Town | South San Francisco | |
| Entity Address, State or Province | CA | |
| Entity Address, Postal Zip Code | 94080 | |
| City Area Code | 925 | |
| Local Phone Number | 407-1049 | |
| Title of 12(b) Security | Common Stock, $0.0001 par value per share | |
| Trading Symbol | NKTX | |
| Security Exchange Name | NASDAQ | |
| Entity Current Reporting Status | Yes | |
| Entity Interactive Data Current | Yes | |
| Entity Filer Category | Non-accelerated Filer | |
| Entity Small Business | true | |
| Entity Emerging Growth Company | true | |
| Entity Ex Transition Period | true | |
| Entity Shell Company | false | |
| Entity Common Stock, Shares Outstanding | 49,072,342 | |
| Amendment Flag | false | |
| Document Fiscal Year Focus | 2023 | |
| Document Fiscal Period Focus | Q3 | |
| Current Fiscal Year End Date | --12-31 | |
| Entity Central Index Key | 0001787400 |
CONDENSED BALANCE SHEETS (Unaud
| CONDENSED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022 |
| Current assets | ||
| Cash and cash equivalents | $ 38,262 | $ 37,494 |
| Short-term investments | 237,351 | 314,649 |
| Prepaid expenses and other current assets | 5,575 | 8,545 |
| Total current assets | 281,188 | 360,688 |
| Restricted cash | 2,743 | 2,743 |
| Property and equipment, net | 77,687 | 61,908 |
| Operating lease right-of-use assets | 40,519 | 45,749 |
| Other long-term assets | 3,727 | 1,850 |
| Total assets | 405,864 | 472,938 |
| Current liabilities | ||
| Accounts payable | 4,284 | 1,761 |
| Operating lease liabilities, current portion | 6,057 | 4,249 |
| Accrued and other current liabilities | 15,299 | 16,036 |
| Total current liabilities | 25,640 | 22,046 |
| Operating lease liabilities, net of current portion | 83,408 | 78,685 |
| Total liabilities | 109,048 | 100,731 |
| Commitments and contingencies (Note 7) | ||
| Stockholders’ equity | ||
| Common stock | 5 | 5 |
| Additional paid-in capital | 704,900 | 690,814 |
| Accumulated other comprehensive loss | (409) | (679) |
| Accumulated deficit | (407,680) | (317,933) |
| Total stockholders’ equity | 296,816 | 372,207 |
| Total liabilities and stockholders’ equity | $ 405,864 | $ 472,938 |
CONDENSED STATEMENTS OF OPERATI
| CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | |
| Operating expenses | ||||
| Research and development | $ 22,194 | $ 23,435 | $ 73,451 | $ 64,053 |
| General and administrative | 7,100 | 6,827 | 27,014 | 19,919 |
| Total operating expenses | 29,294 | 30,262 | 100,465 | 83,972 |
| Loss from operations | (29,294) | (30,262) | (100,465) | (83,972) |
| Other income, net: | ||||
| Interest income | 3,616 | 1,900 | 10,651 | 2,698 |
| Other income, net | 33 | 17 | 67 | 19 |
| Total other income, net | 3,649 | 1,917 | 10,718 | 2,717 |
| Net loss | (25,645) | (28,345) | (89,747) | (81,255) |
| Other comprehensive loss: | ||||
| Net unrealized gain (loss) on investments | 192 | (390) | 270 | (1,171) |
| Comprehensive loss | $ (25,453) | $ (28,735) | $ (89,477) | $ (82,426) |
| Net loss per share, basic | $ (0.52) | $ (0.58) | $ (1.83) | $ (1.94) |
| Net loss per share, diluted | $ (0.52) | $ (0.58) | $ (1.83) | $ (1.94) |
| Weighted average shares used to compute net loss per share, basic | 49,062,799 | 48,630,328 | 48,985,373 | 41,878,716 |
| Weighted average shares used to compute net loss per share, diluted | 49,062,799 | 48,630,328 | 48,985,373 | 41,878,716 |
CONDENSED STATEMENTS OF STOCKHO
| CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands | Total | Secondary Offering | At-The-Market Offering | Common Stock | Common Stock Secondary Offering | Common Stock At-The-Market Offering | Additional Paid-In Capital | Additional Paid-In Capital Secondary Offering | Additional Paid-In Capital At-The-Market Offering | Accumulated Other Comprehensive Gain/(Loss) | Accumulated Deficit |
| 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 options | 79 | 79 | |||||||||
| Issuance of common stock upon exercise of stock options, Shares | 21,067 | ||||||||||
| Share-based compensation expense | 4,097 | 4,097 | |||||||||
| Unrealized gain (loss) on 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 | ||||||||||
| Net loss | (81,255) | ||||||||||
| Ending Balance at Sep. 30, 2022 | 399,264 | $ 5 | 685,931 | (1,321) | (285,351) | ||||||
| Ending Balance, Shares at Sep. 30, 2022 | 48,807,705 | ||||||||||
| 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 options | 334 | 334 | |||||||||
| Issuance of common stock upon exercise of stock options, Shares | 88,383 | ||||||||||
| Issuance of common stock, net of issuance costs | $ 215,334 | $ 2 | $ 215,332 | ||||||||
| Issuance of common stock, net of issuance costs, Shares | 15,333,334 | ||||||||||
| Share-based compensation expense | 3,912 | 3,912 | |||||||||
| Unrealized gain (loss) on 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 | ||||||||||
| Vesting of shares of common stock subject to repurchase | 3 | 3 | |||||||||
| Vesting of shares of common stock subject to repurchase, Shares | 1,302 | ||||||||||
| Issuance of common stock upon exercise of stock options | 953 | 953 | |||||||||
| Issuance of common stock upon exercise of stock options, Shares | 265,988 | ||||||||||
| Issuance of common stock, net of issuance costs | $ 1,612 | $ 1,612 | |||||||||
| Issuance of common stock, net of issuance costs, Shares | 113,213 | ||||||||||
| Share-based compensation expense | 4,390 | 4,390 | |||||||||
| Unrealized gain (loss) on investments | (390) | (390) | |||||||||
| Net loss | (28,345) | (28,345) | |||||||||
| Ending Balance at Sep. 30, 2022 | 399,264 | $ 5 | 685,931 | (1,321) | (285,351) | ||||||
| Ending Balance, Shares at Sep. 30, 2022 | 48,807,705 | ||||||||||
| Beginning Balance at Dec. 31, 2022 | 372,207 | $ 5 | 690,814 | (679) | (317,933) | ||||||
| Beginning Balance, Shares at Dec. 31, 2022 | 48,877,806 | ||||||||||
| Vesting of shares of common stock subject to repurchase | 2 | 2 | |||||||||
| Vesting of shares of common stock subject to repurchase, Shares | 395 | ||||||||||
| Issuance of common stock upon exercise of stock options | 1 | 1 | |||||||||
| Issuance of common stock upon exercise of stock options, Shares | 253 | ||||||||||
| Issuance of common stock upon vesting of restricted stock units, Shares | 50,469 | ||||||||||
| Share-based compensation expense | 4,746 | 4,746 | |||||||||
| Unrealized gain (loss) on investments | 505 | 505 | |||||||||
| Net loss | (30,815) | (30,815) | |||||||||
| Ending Balance at Mar. 31, 2023 | 346,646 | $ 5 | 695,563 | (174) | (348,748) | ||||||
| Ending Balance, Shares at Mar. 31, 2023 | 48,928,923 | ||||||||||
| Beginning Balance at Dec. 31, 2022 | 372,207 | $ 5 | 690,814 | (679) | (317,933) | ||||||
| Beginning Balance, Shares at Dec. 31, 2022 | 48,877,806 | ||||||||||
| Issuance of common stock, net of issuance costs, Shares | 0 | ||||||||||
| Net loss | (89,747) | ||||||||||
| Ending Balance at Sep. 30, 2023 | 296,816 | $ 5 | 704,900 | (409) | (407,680) | ||||||
| Ending Balance, Shares at Sep. 30, 2023 | 49,068,234 | ||||||||||
| Beginning Balance at Mar. 31, 2023 | 346,646 | $ 5 | 695,563 | (174) | (348,748) | ||||||
| Beginning Balance, Shares at Mar. 31, 2023 | 48,928,923 | ||||||||||
| Vesting of shares of common stock subject to repurchase | 1 | 1 | |||||||||
| Vesting of shares of common stock subject to repurchase, Shares | 113 | ||||||||||
| Issuance of common stock upon exercise of stock options | 21 | 21 | |||||||||
| Issuance of common stock upon exercise of stock options, Shares | 5,892 | ||||||||||
| Issuance of common stock upon vesting of restricted stock units, Shares | 28,074 | ||||||||||
| Common stock issued under employee stock purchase plan | 374 | 374 | |||||||||
| Common stock issued under employee stock purchase plan, Shares | 95,232 | ||||||||||
| Share-based compensation expense | 4,650 | 4,650 | |||||||||
| Unrealized gain (loss) on investments | (427) | (427) | |||||||||
| Net loss | (33,287) | (33,287) | |||||||||
| Ending Balance at Jun. 30, 2023 | 317,978 | $ 5 | 700,609 | (601) | (382,035) | ||||||
| Ending Balance, Shares at Jun. 30, 2023 | 49,058,234 | ||||||||||
| Issuance of common stock upon vesting of restricted stock units, Shares | 10,000 | ||||||||||
| Share-based compensation expense | 4,291 | 4,291 | |||||||||
| Unrealized gain (loss) on investments | 192 | 192 | |||||||||
| Net loss | (25,645) | (25,645) | |||||||||
| Ending Balance at Sep. 30, 2023 | $ 296,816 | $ 5 | $ 704,900 | $ (409) | $ (407,680) | ||||||
| Ending Balance, Shares at Sep. 30, 2023 | 49,068,234 |
CONDENSED STATEMENT OF CASH FLO
| CONDENSED STATEMENT OF CASH FLOWS (Unaudited) | 9 Months Ended | |
| Sep. 30, 2023 USD ($) | Sep. 30, 2022 USD ($) | |
| Cash flows from operating activities | ||
| Net loss | $ (89,747,000) | $ (81,255,000) |
| Adjustments to reconcile net loss to net cash used in operating activities: | ||
| Share-based compensation expense | 13,687,000 | 12,399,000 |
| Depreciation and amortization | 3,618,000 | 1,908,000 |
| Accretion and amortization of premiums and discounts on investments, net | (6,915,000) | 763,000 |
| Realized gain on investments | (34,000) | 0 |
| Impairment of right-of-use assets | 4,100,000 | |
| Non-cash lease expense | 1,653,000 | 3,269,000 |
| Changes in operating assets and liabilities: | ||
| Prepaid expenses and other assets | 1,093,000 | (1,575,000) |
| Operating lease liabilities | 6,112,000 | 11,446,000 |
| Accounts payable and accrued and other liabilities | 3,627,000 | 3,376,000 |
| Net cash used in operating activities | (62,806,000) | (49,669,000) |
| Cash flows from investing activities | ||
| Purchases of property and equipment | (21,340,000) | (12,073,000) |
| Purchases of investments | (196,877,000) | (310,313,000) |
| Maturities of investments | 281,395,000 | 132,950,000 |
| Net cash provided by (used in) investing activities | 63,178,000 | (189,436,000) |
| Cash flows from financing activities | ||
| Proceeds from stock option exercises | 22,000 | 1,365,000 |
| Proceeds from ESPP purchases | 374,000 | |
| Proceeds from ATM offering, net of issuance costs | 1,612,000 | |
| Proceeds from secondary offering, net of issuance costs | 215,611,000 | |
| Net cash provided by financing activities | 396,000 | 218,588,000 |
| Net (decrease) increase in cash and cash equivalents | 768,000 | (20,517,000) |
| Cash, cash equivalents, and restricted cash beginning of period | 40,237,000 | 62,914,000 |
| Cash, cash equivalents, and restricted cash end of period | 41,005,000 | 42,397,000 |
| Reconciliation of cash, cash equivalents and restricted cash to the balance sheet: | ||
| Cash and cash equivalents | 38,262,000 | 39,654,000 |
| Restricted cash | 2,743,000 | 2,743,000 |
| Total cash, cash equivalents and restricted cash | 41,005,000 | 42,397,000 |
| Supplemental disclosures of non-cash investing activities: | ||
| Acquisitions of property and equipment in accounts payable and accrued and other current liabilities | $ 1,842,000 | $ 7,228,000 |
Organization and Description of
| Organization and Description of Business | 9 Months Ended |
| Sep. 30, 2023 | |
| 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") cell therapies. 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 therapeutic 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 therapeutic targets, and improve persistence for sustained activity in the body for the treatment of cancer and autoimmune disease. 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 September 30, 2023, the Company had an accumulated deficit of $ 407.7 million and cash, cash equivalents, restricted cash and investments of $ 278.4 million. Management plans to continue to incur substantial costs in order to conduct research and development activities for which additional capital will be needed. 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 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 March 17, 2023, the Company filed a Registration Statement on Form S-3, as amended by the Form S-3/A filed on April 24, 2023 (the "Shelf Registration Statement"), covering the offer and sale from time to time, pursuant to Rule 415 of the Securities Act of 1933, as amended (the "Securities Act"), of up to $ 350.0 million in aggregate offering price of shares of the Company’s common stock, shares of the Company’s preferred stock, debt securities, warrants, rights and/or units, including up to $ 120.0 million in aggregate offering price of shares of the Company’s common stock, shares of the Company’s preferred stock, debt securities, warrants, rights and/or units registered on the Company’s Registration Statement on Form S-3 declared effective by the Securities and Exchange Commission (the "SEC") on September 2, 2021 (the "Prior Registration Statement") that have not yet been sold. The Shelf Registration Statement was declared effective by the SEC on May 5, 2023. On August 12, 2021, the Company entered into a sales agreement with Cowen and Company, LLC, a sales agent, to provide for the offering, issuance and sale of up to an aggregate of $ 150.0 million of the Company’s common stock through an “at-the-market” equity offering program (the "ATM Offering Program") pursuant to the Prior Registration Statement and subject to the limitations thereof. For the nine months ended September 30, 2023, no sales of the Company’s common stock were made pursuant to the ATM Offering Program. |
Basis of Presentation and Signi
| Basis of Presentation and Significant Accounting Policies | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 September 30, 2023 and for the three and nine months ended September 30, 2023 and 2022 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, 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 for the periods presented. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of the results expected for the full year or any subsequent interim period. The condensed balance sheet at December 31, 2022 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, 2022, contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed by the Company with the SEC on March 16, 2023. 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, 2022 or the nine months ended September 30, 2023. The Company continues to evaluate the impact of the CARES Act on its financial position, results of operations and cash flows. 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, percentage of completion of manufacturing activities, fair value of assets and liabilities, impairment of assets, leases, 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 unvested common stock, outstanding stock options and restricted stock units under the Company’s equity incentive plans, 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. Long-Lived Asset Impairment The Company assesses the impairment of long-lived assets whenever events or changes in business circumstances indicate that the carrying amounts of the asset or group of assets may not be fully recoverable. In the case of property, plant and equipment and right-of-use assets for the Company's leases, the Company determines whether there has been an impairment by comparing the carrying value of the group of assets to the anticipated undiscounted net future cash flows associated with the group of assets. If such cash flows are less than the carrying value, the Company writes down the group of assets to its fair value, which may be measured as anticipated net cash flows associated with the group of assets, discounted at a rate that the Company believes a market participant would utilize to reflect the risks associated with the cash flows, such as credit risk. See Note 6 for additional information regarding the impairment charge the Company recorded in connection with its leased facilities. |
Net Loss Per Share
| Net Loss Per Share | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 Nine Months Ended 2023 2022 2023 2022 Numerator: Net loss $ ( 25,645 ) $ ( 28,345 ) $ ( 89,747 ) $ ( 81,255 ) Denominator: Weighted average common shares outstanding 49,062,799 48,631,941 48,985,448 41,882,929 Less: weighted average unvested common stock — ( 1,613 ) ( 75 ) ( 4,213 ) Weighted average shares used to compute net loss 49,062,799 48,630,328 48,985,373 41,878,716 Net loss per share, basic and diluted $ ( 0.52 ) $ ( 0.58 ) $ ( 1.83 ) $ ( 1.94 ) 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 September 30, 2023 2022 Common stock options 7,127,449 5,312,013 Restricted stock units 695,110 359,708 Unvested common stock upon early exercise of common stock — 1,173 7,822,559 5,672,894 |
Fair Value of Financial Instrum
| Fair Value of Financial Instruments | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 September 30, Quoted Prices Significant Significant Assets: Cash equivalents: Money market funds $ 17,437 $ 17,437 $ — $ — Short-term investments: Corporate debt securities $ 47,423 $ — $ 47,423 $ — Commercial paper 37,546 — 37,546 — U.S. Government securities 152,382 — 152,382 — Total short-term investments 237,351 — 237,351 — Total $ 254,788 $ 17,437 $ 237,351 $ — Fair Value Measurements Using December 31, Quoted Prices Significant Significant Assets: Cash equivalents: Money market funds $ 36,494 $ 36,494 $ — $ — Short-term investments: Corporate debt securities $ 88,681 $ — $ 88,681 $ — Commercial paper 65,409 — 65,409 — Government securities 160,559 — 160,559 — Total short-term investments 314,649 — 314,649 — Total $ 351,143 $ 36,494 $ 314,649 $ — Cash Equivalents and Investments Financial assets measured at fair value on a recurring basis consist of the Company’s cash equivalents and short-term and long-term investments. Cash equivalents consisted of money market funds and short-term and long-term investments consisted of commercial paper, 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 $ 17.4 million and $ 36.5 million as of September 30, 2023 and December 31, 2022, 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 $ 237.4 million and $ 314.6 million as of September 30, 2023 and December 31, 2022, respectively, were classified as Level 2 instruments and included in short-term investments. Accrued interest receivable related to investments was $ 0.9 million and $ 0.8 million as of September 30, 2023 and December 31, 2022, respectively, and included as part of prepaid expenses and other current assets in the condensed balance sheets. The following tables summarize the Company’s investments accounted for as available-for-sale securities as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 Maturity Amortized Unrealized Unrealized Estimated Corporate debt securities 1 year or less $ 47,507 $ ( 84 ) $ — $ 47,423 Commercial paper 1 year or less 37,663 ( 117 ) 37,546 U.S. Government securities 1 year or less 152,590 ( 210 ) 2 152,382 Total $ 237,760 $ ( 411 ) $ 2 $ 237,351 December 31, 2022 Maturity Amortized Unrealized Unrealized Estimated Corporate debt securities 1 year or less $ 88,995 $ ( 320 ) $ 6 $ 88,681 Commercial paper 1 year or less 65,532 ( 123 ) — 65,409 Government securities 1 year or less 160,801 ( 319 ) 77 160,559 Total $ 315,328 $ ( 762 ) $ 83 $ 314,649 The Company has classified its investment securities as current and non-current assets on the condensed balance sheets based on each security's contractual maturity date, and all investment securities are accounted for as available-for-sale 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 September 30, 2023 and December 31, 2022 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 September 30, 2023 and December 31, 2022. 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. During the nine months ended September 30, 2023, there were immaterial realized gains recognized on available-for-sale securities sold in the period. There was no realized gain or loss on available-for-sale securities for the nine months ended September 30, 2022. The Company uses the specific identification method to determine the cost basis of investments sold. |
Balance Sheet Components
| Balance Sheet Components | 9 Months Ended |
| Sep. 30, 2023 | |
| 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): September 30, December 31, Prepaid expenses $ 3,986 $ 5,616 Other current assets 1,589 2,929 Total prepaid expenses and other current assets $ 5,575 $ 8,545 Property and Equipment, Net Property and equipment, net is comprised of the following (in thousands): September 30, December 31, Leasehold improvements $ 66,619 $ 4,402 Furniture and fixtures 645 645 Research equipment 14,621 12,900 Computers and software 130 130 Construction in progress 5,114 49,655 Total property and equipment, gross 87,129 67,732 Less accumulated depreciation and amortization ( 9,442 ) ( 5,824 ) Total property and equipment, net $ 77,687 $ 61,908 Depreciation and amortization expense was $ 2.0 million and $ 3.6 million for the three and nine months ended September 30, 2023, respectively, and $ 0.7 million and $ 1.9 million for the three and nine months ended September 30, 2022, respectively. Accrued and Other Current Liabilities Accrued other current liabilities are comprised of the following (in thousands): September 30, December 31, Accrued compensation $ 6,021 $ 6,691 Accrued research and development costs 6,042 3,486 Accrued property and equipment 2,190 5,001 Other accrued and current liabilities 1,046 858 Total accrued and other liabilities $ 15,299 $ 16,036 |
Leases
| Leases | 9 Months Ended |
| Sep. 30, 2023 | |
| Leases [Abstract] | |
| Leases | 6. Leases The Company has operating leases for its current corporate offices, laboratories, manufacturing facilities, and dedicated space in a vivarium in South San Francisco, California. Rent expense was $ 2.7 million and $ 8.2 million for the three and nine months ended September 30, 2023, respectively, and $ 2.8 million and $ 8.2 million for the three and nine months ended September 30, 2022, respectively. The total cash paid for operating leases included in the operating cash flows was $ 0.5 million, inclusive of $ 8.3 million of rent payments less $ 7.8 million of cash received related to tenant improvement allowance reimbursement, for the nine months ended September 30, 2023. The total cash received for operating leases included in the operating cash flows was $ 6.6 million, inclusive of $ 9.5 million of cash received related to tenant improvement allowance reimbursement less $ 2.9 million of rent payments, for the nine months ended September 30, 2022. The weighted-average remaining lease term was 10.0 years for the corporate office, laboratory space leases, and additional facility as of September 30, 2023. The weighted-average discount rate was 9.8 % as of September 30, 2023. In May 2018, the Company entered into a lease agreement for 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 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 an additional 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 (the “Optional TIA”). 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 ("SVB") 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. In August 2022, the Company entered into fifth amendment to the Initial Lease Agreement and a second amendment to the Additional Lease Agreement for its existing facilities in South San Francisco, California. The fifth amendment to the Initial Lease Agreement includes an extension of the lease term for certain of the Company's existing facilities through July 31, 2030. The second amendment to the Additional Lease Agreement provides 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 Additional Lease Agreement, and increases the base rent payments over the existing term of the lease. In March 2023, the Company held $ 2.7 million in collateral money market accounts supporting letters of credit issued by SVB to the landlord in connection with the Initial Lease Agreement and Additional Lease Agreement. In April 2023, the Company replaced the $ 2.7 million in letters of credit issued by SVB with letters of credit in the same amount from a different financial institution, and the Company entered into a third amendment to the Additional Lease Agreement. The lease amendment clarifies the form of letter of credit. In June 2023, the Company entered into a fourth amendment to the Additional Lease Agreement. The lease amendment confirms that the Company utilized the Optional TIA in the amount of approximately $ 4.4 million and as a result the Company began repaying the “Optional TIA” on July 1, 2023. The other terms of the Additional Lease Agreement, as amended, remain unchanged. Maturities of operating lease liabilities under existing operating leases as of September 30, 2023 were as follows (in thousands): Year ending December 31, Amount 2023 (remaining three months) $ 3,364 2024 12,720 2025 13,027 2026 13,462 2027 13,912 2028 and thereafter 87,254 Total undiscounted future minimum lease payments 143,739 Less imputed interest ( 54,274 ) Total operating lease liabilities $ 89,465 Operating lease liabilities: Current 6,057 Non-current 83,408 Total lease liability $ 89,465 The Company tests long-lived assets for recoverability whenever events or changes in circumstances suggest that the carrying value of an asset or group of assets may not be recoverable. Beginning in the second quarter of 2023, the Company started to market for sublease portions of the Company's leased corporate office space in South San Francisco. As a result of these plans, the Company reviewed these spaces for impairment during the three months ended June 30, 2023. As part of the impairment evaluation of the spaces being marketed for sublease, the Company compared the estimated undiscounted income for the marketed sublease spaces to the net book value of the related long-term assets, which include right-of-use assets and certain property, plant and equipment, primarily for leasehold improvements (collectively, "Sublease Asset Group"). The Company estimated potential sublease income using market participant assumptions, which the Company evaluated based on current real estate trends and market conditions. For the Sublease Asset Group, the Company determined that the respective right-of-use assets had net carrying values that exceeded their estimated undiscounted future cash flows. Accordingly, the Company then estimated the fair value of the Sublease Asset Group based on its discounted cash flows. The carrying value of the Sublease Asset Group exceeded its fair values and, as a result, the Company recorded a right-of-use asset impairment of $ 4.1 million for the three months ended June 30, 2023. The impairment is recorded within general and administrative expenses in the condensed statements of operations and comprehensive loss. There was no additional impairment recorded for the three months ended September 30, 2023. |
Commitments and Contingencies
| Commitments and Contingencies | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 September 30, 2023 and December 31, 2022. Letters of Credit As of September 30, 2023 and December 31, 2022, the Company had $ 2.7 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. The letters of credit are presented as restricted cash in the condensed balance sheet. Contingencies The Company, from time to time, may be involved in litigation arising in the ordinary course of business . The Company assesses its potential liability in such situations by analyzing potential outcomes, assuming various litigation, regulatory and settlement strategies. If the Company determines a loss is probable and its amount can be reasonably estimated, the Company accrues an amount equal to the estimated loss. No losses and no provision for a loss contingency have been recorded to date. Purchase Commitments The Company enters into contracts in the normal course of business for clinical trials, preclinical studies, manufacturing and other services and products for operating purposes. These contracts generally provide for termination following a certain period after notice and therefore the Company believes that non-cancelable obligations under these agreements are not material. |
CRISPR Collaboration Agreement
| CRISPR Collaboration Agreement | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 allogeneic, off-the-shelf chimeric antigen receptor-natural killer ("CAR NK") product candidate targeting the CD70 tumor antigen ("NKX070") and an allogeneic, off-the-shelf product candidate that comprises both engineered NK cells and engineered T cells ("NK+T"). In May 2022, the CRISPR Agreement was amended to revise the transfer of materials and nomination provisions. On March 8, 2023, the CRISPR Agreement was further amended to permit Nkarta's advancement of CRISPR-licensed product candidates targeting a specified tumor antigen (the "Specified TA") and incorporate associated development and regulatory approval milestones and sales based royalties. In addition, the Company has received licenses from CRISPR for four CRISPR-Cas9 gene editing targets and will receive a license from CRISPR for up to one more CRISPR-Cas9 gene editing target 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 NKX070 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 and comprehensive loss. 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. Reduction of research and development expense resulting from partial reimbursement from CRISPR was $ 0.3 million and $ 1.4 million for the three and nine months ended September 30, 2023, respectively, and $ 1.0 million and $ 2.8 million for the three and nine months ended September 30, 2022, respectively. As of September 30, 2023, the Company had a $ 0.3 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 genome editing target licensed from CRISPR (a "CRISPR-Licensed Product Candidate"), other than those targeting the Specified TA, 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 , as well as tiered royalties up to the mid-single digits on net product sales of such product candidate. For each CRISPR-Licensed Product Candidate targeting the Specified TA, 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 high-forty million dollars , as well as tiered royalties up to the mid-single digits on net product sales of such product candidate. As of September 30, 2023, 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 | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 in July 2020 ("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 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. As of September 30, 2023, a total of 8,388,917 shares of the Company’s common stock were authorized for issuance with respect to awards granted under the 2020 Plan (this number of shares gives effect to the annual increases in the 2020 Plan share limit, as described in the next sentence, through that date). 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. A total of 2,177,773 shares were available for issuance under the 2020 Plan as of September 30, 2023. The following table summarizes the option activity under the 2020 Plan and 2015 Plan during the nine months ended September 30, 2023: Number of shares Weighted- Weighted- Outstanding at December 31, 2022 5,519,275 $ 17.17 8.1 Granted 2,338,828 4.39 Exercised ( 6,145 ) 3.61 Forfeited ( 724,509 ) 16.18 Outstanding at September 30, 2023 7,127,449 $ 13.09 8.0 Exercisable at September 30, 2023 3,257,376 $ 16.28 7.0 Vested and expected to vest at September 30, 2023 7,127,449 $ 13.09 8.0 The weighted-average grant date fair value of stock option grants was $ 3.35 per share for the nine months ended September 30, 2023. The following table summarizes the restricted stock unit activity under the 2020 Plan during the nine months ended September 30, 2023: Number of shares Weighted-average Outstanding at December 31, 2022 356,728 $ 12.66 Granted 503,639 5.57 Vested ( 88,543 ) 12.66 Forfeited ( 76,714 ) 7.79 Outstanding at September 30, 2023 695,110 $ 8.06 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 1,441,307 shares of the Company’s common stock were authorized 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. The six-month offering periods extend from June to November and December to May. As of September 30, 2023, 156,986 shares had been issued under the ESPP, and 1,284,321 shares remained available for issuance under the ESPP (after giving effect to share purchases under the ESPP through and including the offering period on May 31, 2023). As of September 30, 2023, employee contributions to the ESPP were $ 0.3 million and included as part of accrued and other current liabilities in the condensed balance sheets. Share-Based Compensation Expense Share-based compensation expense for the three and nine ended September 30, 2023 and 2022 was as follows (in thousands): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Research and development $ 2,077 $ 1,947 $ 6,283 $ 5,404 General and administrative 2,214 2,443 7,404 6,995 Total share-based compensation $ 4,291 $ 4,390 $ 13,687 $ 12,399 The total unrecognized compensation cost related to unvested stock options was $ 26.4 million, which is expected to be recognized over a weighted-average remaining service period of 2.7 years as of September 30, 2023. The total unrecognized compensation cost related to unvested restricted stock units was $ 4.7 million, which is expected to be recognized over a weighted-average remaining service period of 3.0 years as of September 30, 2023. Liability for Early Exercise of Restricted Stock Options There were no shares subject to repurchase by the Company as of September 30, 2023. Shares subject to repurchase by the Company were 508 shares as of December 31, 2022, and the related liability recorded under other accrued and other current liabilities in the condensed balance sheet was insignificant. |
Income Taxes
| Income Taxes | 9 Months Ended |
| Sep. 30, 2023 | |
| Income Tax Disclosure [Abstract] | |
| Income Taxes | 10. Income Taxes There was no provision for income taxes recorded during the three and nine months ended September 30, 2023 and 2022. The Company’s deferred tax assets continue to be fully offset by a valuation allowance . |
Subsequent Events
| Subsequent Events | 9 Months Ended |
| Sep. 30, 2023 | |
| Subsequent Events [Abstract] | |
| Subsequent Events | 11. Subsequent Events On October 16, 2023 , the Company committed to cost saving measures, including a reduction in force (the "Reduction") that resulted in a reduction of 18 positions, representing approximately 10 % of the Company’s workforce. The Company undertook the Reduction to decrease its costs and create a more streamlined organization to support its operations through multiple clinical data updates expected in 2024. In connection with the implementation of the Reduction, the Company currently estimates it will incur approximately $ 1 million to $ 1.5 million in costs, consisting primarily of cash severance costs and transition support services for impacted employees, which the Company expects to recognize in the fourth quarter of 2023. |
Basis of Presentation and Sig_2
| Basis of Presentation and Significant Accounting Policies (Policies) | 9 Months Ended |
| Sep. 30, 2023 | |
| Accounting Policies [Abstract] | |
| Basis of Presentation | Basis of Presentation The accompanying unaudited condensed financial statements as of September 30, 2023 and for the three and nine months ended September 30, 2023 and 2022 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, 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 for the periods presented. The results for the three and nine months ended September 30, 2023 are not necessarily indicative of the results expected for the full year or any subsequent interim period. The condensed balance sheet at December 31, 2022 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, 2022, contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed by the Company with the SEC on March 16, 2023. |
| 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, 2022 or the nine months ended September 30, 2023. The Company continues to evaluate the impact of the CARES Act on its financial position, results of operations and cash flows. |
| 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, percentage of completion of manufacturing activities, fair value of assets and liabilities, impairment of assets, leases, 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 unvested common stock, outstanding stock options and restricted stock units under the Company’s equity incentive plans, 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. |
| Long-Lived Asset Impairment | Long-Lived Asset Impairment The Company assesses the impairment of long-lived assets whenever events or changes in business circumstances indicate that the carrying amounts of the asset or group of assets may not be fully recoverable. In the case of property, plant and equipment and right-of-use assets for the Company's leases, the Company determines whether there has been an impairment by comparing the carrying value of the group of assets to the anticipated undiscounted net future cash flows associated with the group of assets. If such cash flows are less than the carrying value, the Company writes down the group of assets to its fair value, which may be measured as anticipated net cash flows associated with the group of assets, discounted at a rate that the Company believes a market participant would utilize to reflect the risks associated with the cash flows, such as credit risk. See Note 6 for additional information regarding the impairment charge the Company recorded in connection with its leased facilities. |
Net Loss Per Share (Tables)
| Net Loss Per Share (Tables) | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 Nine Months Ended 2023 2022 2023 2022 Numerator: Net loss $ ( 25,645 ) $ ( 28,345 ) $ ( 89,747 ) $ ( 81,255 ) Denominator: Weighted average common shares outstanding 49,062,799 48,631,941 48,985,448 41,882,929 Less: weighted average unvested common stock — ( 1,613 ) ( 75 ) ( 4,213 ) Weighted average shares used to compute net loss 49,062,799 48,630,328 48,985,373 41,878,716 Net loss per share, basic and diluted $ ( 0.52 ) $ ( 0.58 ) $ ( 1.83 ) $ ( 1.94 ) |
| 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 September 30, 2023 2022 Common stock options 7,127,449 5,312,013 Restricted stock units 695,110 359,708 Unvested common stock upon early exercise of common stock — 1,173 7,822,559 5,672,894 |
Fair Value of Financial Instr_2
| Fair Value of Financial Instruments (Tables) | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 September 30, Quoted Prices Significant Significant Assets: Cash equivalents: Money market funds $ 17,437 $ 17,437 $ — $ — Short-term investments: Corporate debt securities $ 47,423 $ — $ 47,423 $ — Commercial paper 37,546 — 37,546 — U.S. Government securities 152,382 — 152,382 — Total short-term investments 237,351 — 237,351 — Total $ 254,788 $ 17,437 $ 237,351 $ — Fair Value Measurements Using December 31, Quoted Prices Significant Significant Assets: Cash equivalents: Money market funds $ 36,494 $ 36,494 $ — $ — Short-term investments: Corporate debt securities $ 88,681 $ — $ 88,681 $ — Commercial paper 65,409 — 65,409 — Government securities 160,559 — 160,559 — Total short-term investments 314,649 — 314,649 — Total $ 351,143 $ 36,494 $ 314,649 $ — |
| Short-term investments | |
| Schedule of Short-term Investments | The following tables summarize the Company’s investments accounted for as available-for-sale securities as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 Maturity Amortized Unrealized Unrealized Estimated Corporate debt securities 1 year or less $ 47,507 $ ( 84 ) $ — $ 47,423 Commercial paper 1 year or less 37,663 ( 117 ) 37,546 U.S. Government securities 1 year or less 152,590 ( 210 ) 2 152,382 Total $ 237,760 $ ( 411 ) $ 2 $ 237,351 December 31, 2022 Maturity Amortized Unrealized Unrealized Estimated Corporate debt securities 1 year or less $ 88,995 $ ( 320 ) $ 6 $ 88,681 Commercial paper 1 year or less 65,532 ( 123 ) — 65,409 Government securities 1 year or less 160,801 ( 319 ) 77 160,559 Total $ 315,328 $ ( 762 ) $ 83 $ 314,649 |
Balance Sheet Components (Table
| Balance Sheet Components (Tables) | 9 Months Ended |
| Sep. 30, 2023 | |
| Balance Sheet Related Disclosures [Abstract] | |
| Schedule of Prepaid Expenses and Other Current Assets | Prepaid expenses and other current assets are comprised of the following (in thousands): September 30, December 31, Prepaid expenses $ 3,986 $ 5,616 Other current assets 1,589 2,929 Total prepaid expenses and other current assets $ 5,575 $ 8,545 |
| Schedule of Property and Equipment, Net | Property and equipment, net is comprised of the following (in thousands): September 30, December 31, Leasehold improvements $ 66,619 $ 4,402 Furniture and fixtures 645 645 Research equipment 14,621 12,900 Computers and software 130 130 Construction in progress 5,114 49,655 Total property and equipment, gross 87,129 67,732 Less accumulated depreciation and amortization ( 9,442 ) ( 5,824 ) Total property and equipment, net $ 77,687 $ 61,908 |
| Schedule of Accrued Other Current Liabilities | Accrued other current liabilities are comprised of the following (in thousands): September 30, December 31, Accrued compensation $ 6,021 $ 6,691 Accrued research and development costs 6,042 3,486 Accrued property and equipment 2,190 5,001 Other accrued and current liabilities 1,046 858 Total accrued and other liabilities $ 15,299 $ 16,036 |
Leases (Tables)
| Leases (Tables) | 9 Months Ended |
| Sep. 30, 2023 | |
| Leases [Abstract] | |
| Schedule of Maturities of Operating Lease Liabilities | Maturities of operating lease liabilities under existing operating leases as of September 30, 2023 were as follows (in thousands): Year ending December 31, Amount 2023 (remaining three months) $ 3,364 2024 12,720 2025 13,027 2026 13,462 2027 13,912 2028 and thereafter 87,254 Total undiscounted future minimum lease payments 143,739 Less imputed interest ( 54,274 ) Total operating lease liabilities $ 89,465 Operating lease liabilities: Current 6,057 Non-current 83,408 Total lease liability $ 89,465 |
Share-Based Compensation (Table
| Share-Based Compensation (Tables) | 9 Months Ended |
| Sep. 30, 2023 | |
| 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 nine months ended September 30, 2023: Number of shares Weighted- Weighted- Outstanding at December 31, 2022 5,519,275 $ 17.17 8.1 Granted 2,338,828 4.39 Exercised ( 6,145 ) 3.61 Forfeited ( 724,509 ) 16.18 Outstanding at September 30, 2023 7,127,449 $ 13.09 8.0 Exercisable at September 30, 2023 3,257,376 $ 16.28 7.0 Vested and expected to vest at September 30, 2023 7,127,449 $ 13.09 8.0 |
| Summary of Restricted Stock Unit Activity | The following table summarizes the restricted stock unit activity under the 2020 Plan during the nine months ended September 30, 2023: Number of shares Weighted-average Outstanding at December 31, 2022 356,728 $ 12.66 Granted 503,639 5.57 Vested ( 88,543 ) 12.66 Forfeited ( 76,714 ) 7.79 Outstanding at September 30, 2023 695,110 $ 8.06 |
| Summary of Share-based Compensation Expense | Share-based compensation expense for the three and nine ended September 30, 2023 and 2022 was as follows (in thousands): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Research and development $ 2,077 $ 1,947 $ 6,283 $ 5,404 General and administrative 2,214 2,443 7,404 6,995 Total share-based compensation $ 4,291 $ 4,390 $ 13,687 $ 12,399 |
Organization and Description _2
| Organization and Description of Business - Additional Information (Details) $ in Thousands | 9 Months Ended | ||||
| May 17, 2023 USD ($) | Sep. 02, 2021 USD ($) | Aug. 12, 2021 USD ($) | Sep. 30, 2023 USD ($) Segment shares | Dec. 31, 2022 USD ($) | |
| Class Of Stock [Line Items] | |||||
| Number of operating segments | Segment | 1 | ||||
| Accumulated deficit | $ 407,680 | $ 317,933 | |||
| Cash, cash equivalents restricted cash and short-term investments | $ 278,400 | ||||
| Maximum | |||||
| Class Of Stock [Line Items] | |||||
| Proceeds from issuance initial public offering | $ 150,000 | ||||
| IPO | Maximum | |||||
| Class Of Stock [Line Items] | |||||
| Aggregate offering price | $ 350,000 | $ 120,000 | |||
| Common Stock | |||||
| Class Of Stock [Line Items] | |||||
| Common stock shares issued and sold | shares | 0 |
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 | 9 Months Ended | ||||||
| Sep. 30, 2023 | Jun. 30, 2023 | Mar. 31, 2023 | Sep. 30, 2022 | Jun. 30, 2022 | Mar. 31, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | |
| Numerator: | ||||||||
| Net loss | $ (25,645) | $ (33,287) | $ (30,815) | $ (28,345) | $ (26,923) | $ (25,987) | $ (89,747) | $ (81,255) |
| Denominator: | ||||||||
| Weighted average common shares outstanding | 49,062,799 | 48,631,941 | 48,985,448 | 41,882,929 | ||||
| Less: weighted average unvested common stock issued upon early exercise of common stock options | (1,613) | (75) | (4,213) | |||||
| Weighted average shares used to compute net loss per share, basic | 49,062,799 | 48,630,328 | 48,985,373 | 41,878,716 | ||||
| Weighted average shares used to compute net loss per share, diluted | 49,062,799 | 48,630,328 | 48,985,373 | 41,878,716 | ||||
| Net loss per share, basic | $ (0.52) | $ (0.58) | $ (1.83) | $ (1.94) | ||||
| Net loss per share, diluted | $ (0.52) | $ (0.58) | $ (1.83) | $ (1.94) | ||||
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 | 9 Months Ended | |
| Sep. 30, 2023 | Sep. 30, 2022 | |
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
| Antidilutive securities excluded from computation of earnings per share | 7,822,559 | 5,672,894 |
| Common Stock Options | ||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
| Antidilutive securities excluded from computation of earnings per share | 7,127,449 | 5,312,013 |
| Restricted Stock Units | ||
| Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
| Antidilutive securities excluded from computation of earnings per share | 695,110 | 359,708 |
| 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 | 1,173 | |
Fair Value of Financial Instr_3
| Fair Value of Financial Instruments - Summary of Fair Value of Financial Instrument (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022 |
| Assets: | ||
| Money market funds | $ 17,437 | $ 36,494 |
| Total short-term investments | 237,351 | 314,649 |
| Total | 254,788 | 351,143 |
| Commercial Paper | ||
| Assets: | ||
| Total short-term investments | 37,546 | 65,409 |
| Corporate Debt Securities | ||
| Assets: | ||
| Total short-term investments | 47,423 | 88,681 |
| U.S. Government securities | ||
| Assets: | ||
| Total short-term investments | 152,382 | 160,559 |
| Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
| Assets: | ||
| Money market funds | 17,437 | 36,494 |
| Total | 17,437 | 36,494 |
| Significant Other Observable Inputs (Level 2) | ||
| Assets: | ||
| Total short-term investments | 237,351 | 314,649 |
| Total | 237,351 | 314,649 |
| Significant Other Observable Inputs (Level 2) | Commercial Paper | ||
| Assets: | ||
| Total short-term investments | 37,546 | 65,409 |
| Significant Other Observable Inputs (Level 2) | Corporate Debt Securities | ||
| Assets: | ||
| Total short-term investments | 47,423 | 88,681 |
| Significant Other Observable Inputs (Level 2) | U.S. Government securities | ||
| Assets: | ||
| Total short-term investments | $ 152,382 | $ 160,559 |
Fair Value of Financial Instr_4
| Fair Value of Financial Instruments - Additional Information (Details) - USD ($) | 9 Months Ended | ||
| Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2022 | |
| Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |||
| Realized gain or loss on available-for-sale securities | $ 34,000 | $ 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 | 17,400,000 | $ 36,500,000 | |
| Significant Other Observable Inputs (Level 2) | |||
| Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |||
| Accrued interest receivable | 900,000 | 800,000 | |
| Significant Other Observable Inputs (Level 2) | Short-term investments | |||
| Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |||
| Marketable securities | $ 237,400,000 | $ 314,600,000 | |
Fair Value of Financial Instr_5
| Fair Value of Financial Instruments - Schedule of Short-term Investments Accounted as Available-for-sale Securities (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022 |
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Available for sale securities, Amortized Cost | $ 237,760 | $ 315,328 |
| Available for sale securities, Unrealized Losses | (411) | (762) |
| Available for sale securities, Unrealized Gains | 2 | 83 |
| Available for sale securities,Estimated Fair Value | 237,351 | 314,649 |
| Corporate Debt Securities | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Available for sale securities, Amortized Cost | 47,507 | 88,995 |
| Available for sale securities, Unrealized Losses | (84) | (320) |
| Available for sale securities, Unrealized Gains | 6 | |
| Available for sale securities,Estimated Fair Value | $ 47,423 | $ 88,681 |
| 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 |
| Commercial Paper | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Available for sale securities, Amortized Cost | $ 37,663 | $ 65,532 |
| Available for sale securities, Unrealized Losses | (117) | (123) |
| Available for sale securities,Estimated Fair Value | $ 37,546 | $ 65,409 |
| 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 | $ 152,590 | $ 160,801 |
| Available for sale securities, Unrealized Losses | (210) | (319) |
| Available for sale securities, Unrealized Gains | 2 | 77 |
| Available for sale securities,Estimated Fair Value | $ 152,382 | $ 160,559 |
| 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 |
Balance Sheet Components - Sche
| Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022 |
| Balance Sheet Related Disclosures [Abstract] | ||
| Prepaid expenses | $ 3,986 | $ 5,616 |
| Other current assets | 1,589 | 2,929 |
| Total prepaid expenses and other current assets | $ 5,575 | $ 8,545 |
Balance Sheet Components - Sc_2
| Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022 |
| Property Plant And Equipment [Line Items] | ||
| Total property and equipment, gross | $ 87,129 | $ 67,732 |
| Less accumulated depreciation and amortization | (9,442) | (5,824) |
| Total property and equipment, net | 77,687 | 61,908 |
| Leasehold Improvements | ||
| Property Plant And Equipment [Line Items] | ||
| Total property and equipment, gross | 66,619 | 4,402 |
| Furniture and Fixtures | ||
| Property Plant And Equipment [Line Items] | ||
| Total property and equipment, gross | 645 | 645 |
| Research Equipment | ||
| Property Plant And Equipment [Line Items] | ||
| Total property and equipment, gross | 14,621 | 12,900 |
| Computers and Software | ||
| Property Plant And Equipment [Line Items] | ||
| Total property and equipment, gross | 130 | 130 |
| Construction in Progress | ||
| Property Plant And Equipment [Line Items] | ||
| Total property and equipment, gross | $ 5,114 | $ 49,655 |
Balance Sheet Components - Addi
| Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | |
| Balance Sheet Related Disclosures [Abstract] | ||||
| Depreciation and amortization expense | $ 2 | $ 0.7 | $ 3.6 | $ 1.9 |
Balance Sheet Components - Sc_3
| Balance Sheet Components - Schedule of Accrued Other Current Liabilities (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022 |
| Balance Sheet Related Disclosures [Abstract] | ||
| Accrued compensation | $ 6,021 | $ 6,691 |
| Accrued research and development costs | 6,042 | 3,486 |
| Accrued property and equipment | 2,190 | 5,001 |
| Other accrued and current liabilities | 1,046 | 858 |
| Total accrued and other liabilities | $ 15,299 | $ 16,036 |
Leases - Additional Information
| Leases - Additional Information (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 9 Months Ended | |||||||||||
| Jun. 30, 2023 | Aug. 31, 2022 | Oct. 31, 2021 | Jul. 31, 2021 | Jan. 31, 2021 | May 31, 2020 | May 31, 2018 | Sep. 30, 2023 | Jun. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Apr. 30, 2023 | Mar. 31, 2023 | |
| Lessee Lease Description [Line Items] | ||||||||||||||
| Rent expense | $ 2,700,000 | $ 2,800,000 | $ 8,200,000 | $ 8,200,000 | ||||||||||
| Weighted-average remaining lease term | 10 years | 10 years | ||||||||||||
| Cash paid for operating leases | $ 500,000 | |||||||||||||
| Weighted-average discount rate | 9.80% | 9.80% | ||||||||||||
| Lessee, operating lease, term of contract | 12 years | |||||||||||||
| Cash received for tenant improvement allowances to be repaid | $ 4,400,000 | $ 4,400,000 | ||||||||||||
| Cash received for operating leases | 6,600,000 | |||||||||||||
| Cash received related to tenant improvement allowance reimbursement | $ 7,800,000 | 9,500,000 | ||||||||||||
| Right-of-use asset impairment | $ 0 | $ 4,100,000 | 4,100,000 | |||||||||||
| Rent payments | 8,300,000 | $ 2,900,000 | ||||||||||||
| Maximum | ||||||||||||||
| Lessee Lease Description [Line Items] | ||||||||||||||
| Tenant improvement allowances yet to receive | $ 25,200,000 | |||||||||||||
| Letter of Credit | ||||||||||||||
| Lessee Lease Description [Line Items] | ||||||||||||||
| Security deposit | $ 1,600,000 | $ 1,600,000 | ||||||||||||
| Letter of credit | $ 2,700,000 | |||||||||||||
| Third amendment | ||||||||||||||
| Lessee Lease Description [Line Items] | ||||||||||||||
| Operating lease, 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 And Additional Lease Agreement | ||||||||||||||
| Lessee Lease Description [Line Items] | ||||||||||||||
| Amount held as collateral for letters of credit issued to landlord | $ 2,700,000 | |||||||||||||
| Second Amendment Of Additional Lease Agreement | ||||||||||||||
| Lessee Lease Description [Line Items] | ||||||||||||||
| Additional tenant improvement allowances | $ 15,000,000 | |||||||||||||
| Tenant improvement allowances yet to receive | $ 25,200,000 | |||||||||||||
| 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 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 | |||||||||||||
| Corporate Office and Laboratory Space | ||||||||||||||
| Lessee Lease Description [Line Items] | ||||||||||||||
| Lease expiration year | 2025 | |||||||||||||
| Corporate Office and Laboratory Space | Initial Lease Agreement | ||||||||||||||
| Lessee Lease Description [Line Items] | ||||||||||||||
| 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 | Sep. 30, 2023 | Dec. 31, 2022 |
| Leases [Abstract] | ||
| 2023 (remaining three months) | $ 3,364 | |
| 2024 | 12,720 | |
| 2025 | 13,027 | |
| 2026 | 13,462 | |
| 2027 | 13,912 | |
| 2028 and thereafter | 87,254 | |
| Total undiscounted future minimum lease payments | 143,739 | |
| Less imputed interest | (54,274) | |
| Total operating lease liabilities | 89,465 | |
| Operating lease liabilities: | ||
| Operating lease liabilities, current portion | 6,057 | $ 4,249 |
| Operating lease liabilities, net of current portion | 83,408 | $ 78,685 |
| Total lease liability | $ 89,465 |
Commitments and Contingencies -
| Commitments and Contingencies - Additional Information (Details) - USD ($) | 9 Months Ended | |
| Sep. 30, 2023 | Dec. 31, 2022 | |
| Loss Contingencies [Line Items] | ||
| Liabilities recorded for agreements | $ 0 | $ 0 |
| Contingency loss | 0 | |
| Provision for contingency loss | 0 | |
| Agreement with Financial Institution | ||
| Loss Contingencies [Line Items] | ||
| Letters of credit outstanding amount | $ 2,700,000 | $ 2,700,000 |
| 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 | 3 Months Ended | 9 Months Ended | |||
| May 05, 2021 CrisprCas9 | Sep. 30, 2023 USD ($) | Sep. 30, 2022 USD ($) | Sep. 30, 2023 USD ($) | Sep. 30, 2022 USD ($) | |
| Development and Regulatory Approval Milestones | |||||
| Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | |||||
| Reduction of research and development expense resulting from partial reimbursement | $ 300,000 | $ 1,000,000 | $ 1,400,000 | $ 2,800,000 | |
| Receivable under research cost sharing provision | $ 300,000 | $ 300,000 | |||
| 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 | 4 | ||||
| NK Cell Products | Minimum | |||||
| Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | |||||
| Number of non-exclusive rights to gene editing targets | CrisprCas9 | 1 | ||||
| Specified TA | Development and Regulatory Approval Milestones | |||||
| Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | |||||
| Potential future payments | totaling less than high-forty million dollars | ||||
Share-Based Compensation - Addi
| Share-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions | 9 Months Ended | |
| Sep. 30, 2023 | Dec. 31, 2022 | |
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Weighted average grant date fair value of stock option | $ 3.35 | |
| Unrecognized compensation cost | $ 26.4 | |
| Unrecognized compensation cost, expected to be recognized over weighted average remaining service period | 2 years 8 months 12 days | |
| Restricted Stock | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Shares subject to repurchase | 0 | 508 |
| Restricted Stock Units | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Unrecognized compensation cost | $ 4.7 | |
| Unrecognized compensation cost, expected to be recognized over weighted average remaining service period | 3 years | |
| 2020 Employee Stock Purchase Plan | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Number of common stock authorized for issuance | 1,441,307 | |
| Number of common stock available for issuance | 1,284,321 | |
| Maximum percentage of employee compensation eligible for plan | 15% | |
| Commons stock purchase price as percentage of fair value | 85% | |
| Shares issued | 156,986 | |
| 2020 Employee Stock Purchase Plan | Accrued and Other Current Liabilities | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Employee contributions to ESPP | $ 0.3 | |
| 2020 Plan | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Number of common stock authorized for issuance | 8,388,917 | |
| Increase in share limit as percentage of outstanding shares of common stock on last trading day in prior year | 5% | |
| Number of common stock available for issuance | 2,177,773 |
Share-Based Compensation - Summ
| Share-Based Compensation - Summary of Stock Option Activity (Details) - 2020 Plan and 2015 Plan - $ / shares | 9 Months Ended | 12 Months Ended |
| Sep. 30, 2023 | Dec. 31, 2022 | |
| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | ||
| Number of shares, outstanding beginning balance | 5,519,275 | |
| Number of shares, granted | 2,338,828 | |
| Number of shares, exercised | (6,145) | |
| Number of shares, forfeited | (724,509) | |
| Number of shares, outstanding ending balance | 7,127,449 | 5,519,275 |
| Number of shares, exercisable | 3,257,376 | |
| Number of shares, vested and expected to vest | 7,127,449 | |
| Weighted-average exercise price, outstanding beginning balance | $ 17.17 | |
| Weighted-average exercise price, granted | 4.39 | |
| Weighted-average exercise price, exercised | 3.61 | |
| Weighted-average exercise price, forfeited | 16.18 | |
| Weighted-average exercise price, outstanding ending balance | 13.09 | $ 17.17 |
| Weighted-average exercise price, exercisable | 16.28 | |
| Weighted-average exercise price, vested and expected to vest | $ 13.09 | |
| Weighted-average remaining contractual term (in years), outstanding balance | 8 years | 8 years 1 month 6 days |
| Weighted-average remaining contractual term (in years), exercisable | 7 years | |
| 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 | 9 Months Ended |
| Sep. 30, 2023 $ / shares shares | |
| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | |
| Number of shares, outstanding beginning balance | shares | 356,728 |
| Number of shares, granted | shares | 503,639 |
| Number of shares, Vested | shares | (88,543) |
| Number of shares, forfeited | shares | (76,714) |
| Number of shares, outstanding ending balance | shares | 695,110 |
| Weighted-average grant date fair value per share, outstanding beginning balance | $ / shares | $ 12.66 |
| Weighted-average grant date fair value per share, granted | $ / shares | 5.57 |
| Weighted-average grant date fair value per share, Vested | $ / shares | 12.66 |
| Weighted-average grant date fair value per share, Forfeited | $ / shares | 7.79 |
| Weighted-average grant date fair value per share, outstanding ending balance | $ / shares | $ 8.06 |
Share-Based Compensation - Su_3
| Share-Based Compensation - Summary of Share-based Compensation Expense (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | |
| Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
| Share-based compensation expense | $ 4,291 | $ 4,390 | $ 13,687 | $ 12,399 |
| Research and Development | ||||
| Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
| Share-based compensation expense | 2,077 | 1,947 | 6,283 | 5,404 |
| General and Administrative | ||||
| Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
| Share-based compensation expense | $ 2,214 | $ 2,443 | $ 7,404 | $ 6,995 |
Income Taxes - Additional Infor
| Income Taxes - Additional Information (Details) - USD ($) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | |
| Income Tax Disclosure [Abstract] | ||||
| Provision for income taxes | $ 0 | $ 0 | $ 0 | $ 0 |
Subsequent Events - Additional
| Subsequent Events - Additional Information (Details) - Subsequent Event $ in Millions | Oct. 16, 2023 USD ($) Employee |
| Subsequent Event [Line Items] | |
| Reduction initiation date | Oct. 16, 2023 |
| Number of position reduced | Employee | 18 |
| Percentage of reduction | 10% |
| Maximum | |
| Subsequent Event [Line Items] | |
| Reduction costs | $ 1.5 |
| Minimum | |
| Subsequent Event [Line Items] | |
| Reduction costs | $ 1 |