Caribou Biosciences (CRBU) 10-Q 9 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 05, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Entity Registrant Name	Caribou Biosciences, Inc.
Entity Central Index Key	0001619856
Entity File Number	001-40631
Entity Tax Identification Number	45-3728228
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Address Address Line1	2929 7th Street
Entity Address, Address Line Two	Suite 105
Entity Address City Or Town	Berkeley
Entity Address, State and Province	CA
Entity Incorporation State Country Code	DE
Entity Address Postal Zip Code	94710
Local Phone Number	982-6030
City Area Code	510
Security12b Title	Common Stock, par value $0.0001 per share
Trading Symbol	CRBU
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		60,192,061

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 435,310	$ 15,953
Accounts receivable	578	150
Contract assets ($0 and $250 from related party, respectively)	1,853	1,328
Other receivables	5,354	3,682
Prepaid expenses and other current assets	5,952	3,193
Total current assets	449,047	24,306
INVESTMENTS IN EQUITY SECURITIES	7,626	7,626
PROPERTY AND EQUIPMENT - NET	4,477	3,502
OTHER ASSETS	810	612
TOTAL ASSETS	461,960	36,046
CURRENT LIABILITIES:
Accounts payable ($0 and $500 to related party, respectively)	3,482	2,601
Accrued expenses and other current liabilities	13,930	8,973
Promissory note - PPP Loan		654
Deferred revenue	8,746	161
Total current liabilities	26,158	12,389
LONG-TERM LIABILITIES
Deferred revenue, net of current portion ($100 and $50 from related party)	23,022	937
Deferred rent and lease incentive liability	1,833	925
Promissory note - PPP Loan, net of current portion		924
MSKCC success payments liability	6,238	2,654
Other liabilities	153	176
Deferred tax liabilities	155	155
Total liabilities	57,559	18,160
COMMITMENTS AND CONTINGENCIES (Note 9)
STOCKHOLDERS' EQUITY (DEFICIT)
Common stock, par value $0.0001 per share 300,000,000 and 28,933,380 shares authorized at September 30, 2021 and December 31, 2020, respectively; 60,021,319 and 9,710,830 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	6	1
Additional paid-in-capital	483,710	7,433
Accumulated deficit	(79,315)	(30,871)
Total stockholders' equity (deficit)	404,401	(23,437)
TOTAL LIABILITIES, CONVERTIBLE PREFERRED STOCK, AND STOCKHOLDERS' EQUITY (DEFICIT)	461,960	36,046
Convertible Preferred Stock
LONG-TERM LIABILITIES
CONVERTIBLE PREFERRED STOCK, par value $0.0001 per share; no shares authorized, issued, and outstanding at September 30, 2021; 7,766,582 shares authorized. issued, and outstanding at December 31, 2020		$ 41,323

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Contract assets related party	$ 0	$ 250
Accounts payable related parties, Current	0	500
Deferred revenue, net of current portion	$ 100	$ 50
Preferred stock, shares authorized		7,766,582
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0	7,766,582
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	28,933,380
Common stock, shares issued	60,021,319	9,710,830
Common Stock Shares Outstanding	60,021,319	9,710,830
Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	7,766,582
Convertible preferred stock, shares issued	0	7,766,582
Convertible preferred stock, shares outstanding	0	7,766,582

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Licensing and collaboration revenue	$ 3,977	$ 1,198	$ 7,039	$ 11,377
Operating expenses:
Research and development	15,833	6,180	37,144	22,401
General and administrative	6,760	3,247	16,469	9,887
Total operating expenses	22,593	9,427	53,613	32,288
Loss from operations	(18,616)	(8,229)	(46,574)	(20,911)
Other income (expense):
Interest income	22	4	72	157
Interest expense	0	(6)	(8)	(14)
Change in fair value of equity securities				(733)
Change in fair value of the MSKCC success payments liability	(2,403)		(3,584)
Gain on extinguishment of PPP Loan			1,584
Other income	23	85	66	431
Total other income (expense)	(2,358)	83	(1,870)	(159)
Net loss before provision for income taxes	(20,974)	(8,146)	(48,444)	(21,070)
Benefit from income taxes		213		1,465
Net loss and comprehensive loss	$ (20,974)	$ (7,933)	$ (48,444)	$ (19,605)
Net loss per share, basic and diluted	$ (0.46)	$ (0.93)	$ (2.20)	$ (2.31)
Weighted-average common shares outstanding, basic and diluted	45,889,646	8,537,965	22,052,944	8,470,019

Consdensed Consolidated Stateme

Consdensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue from related party	$ 0	$ 0	$ 0	$ 7,500

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)
Temporary Equity, Beginning Balance at Dec. 31, 2019		$ 41,323
Temporary Equity, Beginning Balance (in shares) at Dec. 31, 2019		7,766,582
Beginning Balance at Dec. 31, 2019	$ 7,463		$ 1	$ 4,025	$ 3,437
Beginning Balance (in shares) at Dec. 31, 2019			8,839,205
Stock-based compensation expense	237			237
Net loss and comprehensive loss	(9,800)				(9,800)
Temporary Equity, Ending Balance at Mar. 31, 2020		$ 41,323
Temporary Equity, Ending Balance (in shares) at Mar. 31, 2020		7,766,582
Ending Balance at Mar. 31, 2020	(2,100)		$ 1	4,262	(6,363)
Ending Balance (in shares) at Mar. 31, 2020			8,839,205
Temporary Equity, Beginning Balance at Dec. 31, 2019		$ 41,323
Temporary Equity, Beginning Balance (in shares) at Dec. 31, 2019		7,766,582
Beginning Balance at Dec. 31, 2019	7,463		$ 1	4,025	3,437
Beginning Balance (in shares) at Dec. 31, 2019			8,839,205
Net loss and comprehensive loss	(19,605)
Temporary Equity, Ending Balance at Sep. 30, 2020		$ 41,323
Temporary Equity, Ending Balance (in shares) at Sep. 30, 2020		7,766,582
Ending Balance at Sep. 30, 2020	(11,211)		$ 1	4,956	(16,168)
Ending Balance (in shares) at Sep. 30, 2020			8,969,576
Temporary Equity, Beginning Balance at Mar. 31, 2020		$ 41,323
Temporary Equity, Beginning Balance (in shares) at Mar. 31, 2020		7,766,582
Beginning Balance at Mar. 31, 2020	(2,100)		$ 1	4,262	(6,363)
Beginning Balance (in shares) at Mar. 31, 2020			8,839,205
Issuance of restricted stock awards (in shares)			4,545
Issuance of common stock on exercise of options	21			21
Issuance of common stock on exercise of stock options (in shares)			50,358
Stock-based compensation expense	286			286
Net loss and comprehensive loss	(1,872)				(1,872)
Temporary Equity, Ending Balance at Jun. 30, 2020		$ 41,323
Temporary Equity, Ending Balance (in shares) at Jun. 30, 2020		7,766,582
Ending Balance at Jun. 30, 2020	(3,665)		$ 1	4,569	(8,235)
Ending Balance (in shares) at Jun. 30, 2020			8,894,108
Issuance of common stock on exercise of options	139			139
Issuance of common stock on exercise of stock options (in shares)			75,468
Stock-based compensation expense	248			248
Net loss and comprehensive loss	(7,933)				(7,933)
Temporary Equity, Ending Balance at Sep. 30, 2020		$ 41,323
Temporary Equity, Ending Balance (in shares) at Sep. 30, 2020		7,766,582
Ending Balance at Sep. 30, 2020	(11,211)		$ 1	4,956	(16,168)
Ending Balance (in shares) at Sep. 30, 2020			8,969,576
Temporary Equity, Beginning Balance at Dec. 31, 2020	41,323	$ 41,323
Temporary Equity, Beginning Balance (in shares) at Dec. 31, 2020		7,766,582
Beginning Balance at Dec. 31, 2020	(23,437)		$ 1	7,433	(30,871)
Beginning Balance (in shares) at Dec. 31, 2020			9,710,830
Issuance of Series C convertible preferred stock, net of issuance costs of $6.2 million		$ 108,827
Issuance of Series C convertible preferred stock, net of issuance costs of $6.2 million (in shares)		6,663,940
Issuance of common stock on exercise of options	564			564
Issuance of common stock on exercise of stock options (in shares)			584,614
Stock-based compensation expense	343			343
Net loss and comprehensive loss	(13,159)				(13,159)
Temporary Equity, Ending Balance at Mar. 31, 2021		$ 150,150
Temporary Equity, Ending Balance (in shares) at Mar. 31, 2021		14,430,522
Ending Balance at Mar. 31, 2021	(35,689)		$ 1	8,340	(44,030)
Ending Balance (in shares) at Mar. 31, 2021			10,295,444
Temporary Equity, Beginning Balance at Dec. 31, 2020	41,323	$ 41,323
Temporary Equity, Beginning Balance (in shares) at Dec. 31, 2020		7,766,582
Beginning Balance at Dec. 31, 2020	$ (23,437)		$ 1	7,433	(30,871)
Beginning Balance (in shares) at Dec. 31, 2020			9,710,830
Issuance of common stock on exercise of stock options (in shares)	2,225,839
Net loss and comprehensive loss	$ (48,444)
Temporary Equity, Ending Balance at Sep. 30, 2021		$ 0
Temporary Equity, Ending Balance (in shares) at Sep. 30, 2021		0
Ending Balance at Sep. 30, 2021	404,401		$ 6	483,710	(79,315)
Ending Balance (in shares) at Sep. 30, 2021			60,021,323
Temporary Equity, Beginning Balance at Mar. 31, 2021		$ 150,150
Temporary Equity, Beginning Balance (in shares) at Mar. 31, 2021		14,430,522
Beginning Balance at Mar. 31, 2021	(35,689)		$ 1	8,340	(44,030)
Beginning Balance (in shares) at Mar. 31, 2021			10,295,444
Repayment of loan issued by stockholder	1,150			1,150
Issuance of common stock on exercise of options	566			566
Issuance of common stock on exercise of stock options (in shares)			1,037,979
Stock-based compensation expense	593			593
Net loss and comprehensive loss	(14,311)				(14,311)
Temporary Equity, Ending Balance at Jun. 30, 2021		$ 150,150
Temporary Equity, Ending Balance (in shares) at Jun. 30, 2021		14,430,522
Ending Balance at Jun. 30, 2021	(47,691)		$ 1	10,649	(58,341)
Ending Balance (in shares) at Jun. 30, 2021			11,333,423
Conversion of convertible preferred stock into common stock	150,150	$ (150,150)	$ 3	150,147
Conversion of convertible preferred stock into common stock (in shares)		(14,430,522)	26,234,654
Issuance of common stock upon initial public offering, net of issuance costs of $28.6 million	321,020		$ 2	321,018
Issuance of common stock upon initial public offering, net of issuance costs of $28.6 million (in shares)			21,850,000
Issuance of common stock on exercise of options	961			961
Issuance of common stock on exercise of stock options (in shares)			603,246
Stock-based compensation expense	935			935
Net loss and comprehensive loss	(20,974)				(20,974)
Temporary Equity, Ending Balance at Sep. 30, 2021		$ 0
Temporary Equity, Ending Balance (in shares) at Sep. 30, 2021		0
Ending Balance at Sep. 30, 2021	$ 404,401		$ 6	$ 483,710	$ (79,315)
Ending Balance (in shares) at Sep. 30, 2021			60,021,323

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2021	Mar. 31, 2021
Convertible Preferred Stock
Payments of stock issuance costs		$ 6.2
Common Stock
Payments of stock issuance costs	$ 28.6

Condensed Consolidated Statem_4

Condensed Consolidated Statement of Cash Flows (Unaudited) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (48,444)	$ (19,605)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	711	680
Loss on disposal of fixed assets	3	70
Change in fair value of equity securities		733
Non-cash consideration for licensing and collaboration revenue ($0 and $7,500 from related party, respectively)		(7,580)
Stock-based compensation expense	1,871	771
Change in fair value of MSKCC success payments liability	3,584
Acquired in-process research and development	1,000	425
Extinguishment of PPP Loan	(1,578)
Changes in operating assets and liabilities:
Accounts receivable	(428)	4
Contract assets	(525)	170
Other receivables	(1,673)	147
Prepaid expenses and other current assets	(2,759)	1,487
Other assets	(151)	(19)
Accounts payable	848	(1,907)
Accrued expenses and other current liabilities	4,855	1,112
Deferred revenue, current and long-term	30,669	(667)
Deferred rent and lease incentive liability	909	23
Other liabilities	(22)	(431)
Deferred tax liabilities		(552)
Net cash used in operating activities	(11,130)	(25,139)
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sale of equity securities		7,668
Purchases of property and equipment	(1,436)	(290)
Proceeds from sale of property and equipment		10
Payments to acquire in-process research and development	(1,000)	(425)
Net cash provided by (used in) investing activities	(2,436)	6,963
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from initial public offering of common stock, net of offering costs	321,020
Proceeds from issuance of Series C convertible preferred stock, net of issuance costs	108,827
Proceeds from exercise of stock options	2,091	160
Repayment of promissory note	1,150
Payments on capital lease	(119)	(81)
Proceeds from PPP Loan	0	1,574
Net cash provided by financing activities	432,969	1,653
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	419,403	(16,523)
CASH AND CASH EQUIVALENTS —Beginning of period	15,953	41,070
CASH AND CASH EQUIVALENTS —End of period	435,356	24,547
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	435,310	24,547
Restricted Cash	46
CASH. CASH EQUIVALENTS, AND RESTRICTED CASH ON THE BALANCE SHEET	435,356	24,547
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for income taxes	11	11
SUPPLEMENTAL SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITES:
Acquisition of property and equipment included in accrued expenses and other current liabilities	268	27
Extinguishment of PPP Loan	1,578
Non-cash consideration in exchange for licensing and collaboration revenue		$ 7,580
Conversion of convertible preferred stock to common stock at closing of initial public offering	$ 150,150

Description of the Business, Or

Description of the Business, Organization, and Liquidity	9 Months Ended
	Sep. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of the Business, Organization, and Liquidity	1. Description of the Business, Organization, and Liquidity Business and Organization Caribou Biosciences, Inc. (the “Company” or “we”) is a clinical-stage CRISPR genome-editing biotechnology company. We are developing an internal pipeline of off-the-shelf chimeric antigen receptor (“CAR”) T cell (“CAR-T”) and CAR-natural killer cell (“CAR-NK”) therapies. The Company was incorporated in October 2011 as a Delaware corporation and is headquartered in Berkeley, California. The Company has four wholly-owned subsidiaries: Antler Holdco, LLC, incorporated in Delaware in April 2019; Microbe Holdco, LLC, incorporated in Delaware in June 2020; Arboreal Holdco, LLC, incorporated in Delaware in November 2020; and Biloba Holdco, LLC, incorporated in Delaware in April 2021. Another subsidiary, Caribou Therapeutics Holdco, LLC, was incorporated in Delaware in July 2014 and dissolved in December 2020. The Company’s wholly-owned subsidiaries hold interests in our equity investments and do not have operating activities. Initial Public Offering On July 22, 2021, the Company’ s registration statement on Form S-1 (File No. 333-257604) relating to its initial public offering (“IPO”) of common stock became effective. The IPO closed on July 27, 2021, at which time we issued 19,000,000 shares of our common stock at a price of $ 16.00 per share. On August 9, 2021, we issued and sold an additional 2,850,000 shares of our common stock to the IPO underwriters pursuant to the full exercise of their over-allotment option to purchase additional shares at the public offering price of $ 16.00 per share . We received an aggregate of $ 349.6 million in gross proceeds and approximately $ 321.0 million in net proceeds from the IPO after deducting underwriting discounts and commissions and offering costs. Upon closing of the IPO, all outstanding shares of our convertible preferred stock converted into 26,234,654 shares of our common stock. In connection with the completion of our IPO, on July 27, 2021, our Certificate of Incorporation was amended and restated to provide for 300,000,000 authorized shares of common stock with a par value of $ 0.0001 per share and 10,000,000 authorized shares of preferred stock with a par value of $ 0.0001 per share. Forward Stock Split In July 2021, our board of directors (the “Board”) and stockholders approved an amendment to our Certificate of Incorporation to effect a forward split of the shares of our outstanding common stock at a ratio of 1.818 -for-1 (the “Forward Stock Split”) effective as of July 15, 2021. The number of authorized shares was increased as a result of the Forward Stock Split, but the par values of the common stock and preferred stock were not adjusted. All references to common stock, options to purchase common stock, common stock share data, per share data, and related information contained in the financial statements have been retrospectively adjusted to reflect the effect of the Forward Stock Split for all periods presented. Liquidity We have incurred net operating losses and negative cash flows from operations since our inception and we had an accumulated deficit of $ 79.3 million as of September 30, 2021. During the nine months ended September 30, 2021, we incurred a net loss of $ 48.4 million and used $ 11.1 million of cash in operating activities. We expect to continue to incur substantial losses, and our ability to achieve and sustain profitability will depend on the successful development, approval, and commercialization of our product candidates and on our achievement of sufficient revenue to support our cost structure. We may never achieve profitability and, unless and until we do, we will need to continue to raise additional capital. Our management expects that existing cash and cash equivalents of $ 435.3 million as of September 30, 2021, including the IPO net proceeds of $ 321.0 million, will be sufficient to fund our current operating plan for at least the next 12 months from the date of issuance of our condensed consolidated financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies There have been no changes to the significant accounting policies disclosed in Note 2 to the annual consolidated financial statements for the years ended December 31, 2019 and 2020 included in our final prospectus for our IPO (“Final Prospectus”) except as set forth below. Basis of Presentation and Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Caribou Biosciences, Inc. and its wholly-owned subsidiaries and have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and the requirements of the SEC for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP may be condensed or omitted. Our condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements included in our Final Prospectus, except as noted below. In the opinion of our management, the information furnished in our condensed consolidated financial statements reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the financial position and results of operations for the reported interim periods. We consider events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period. Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities; the disclosure of contingent assets and liabilities at the date of our condensed consolidated financial statements; and the reported amounts of revenue, income, and expenses during the reporting period. On an ongoing basis, we evaluate our estimates and assumptions, including those related to revenue recognition, common stock valuation, stock-based compensation expense, accrued expenses related to research and development activities, valuation of the MSKCC success payments liability, and income taxes. Our management bases its estimates on historical experience and on various other assumptions that they believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those estimates. Segments We operate and manage our business as one reportable and operating segment, which is the business of developing an internal pipeline of off-the-shelf CAR-T and CAR-NK cell therapies. Our chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating resources and evaluating financial performance. All long-lived assets are maintained in the United States. Concentrations of Credit Risk and Other Uncertainties Financial instruments that potentially subject us to concentration of credit risk consist of cash and cash equivalents, accounts receivable, contract assets, other receivables, and investments in equity securities. Substantially all our cash and cash equivalents were deposited in accounts at one financial institution, and account balances may at times exceed federally insured limits. We believe the financial institution to be of high credit quality. Licensees that represent 10% or more of our revenue and accounts receivable and contract assets were as follows: Revenue Revenue Accounts Receivable and Three Months Ended Nine Months Ended As of As of September 30, 2021 September 30, 2020 September 30, 2021 September 30, 2020 September 30, 2021 December 31, 2020 Licensee A 14.0 % 38.8 % 23.2 % 10.5 % 23.1 % 40.6 % Licensee B * * * * * 13.2 % Licensee C, related party * * * * * 16.9 % Licensee D * * * * * 10.1 % Licensee E 57.2 % * 39.5 % * 50.4 % * Licensee F, related party * * * 65.9 % * * Licensee G * 24.0 % * * * * Licensee H * 20.4 % * * * * Total 71.2 % 83.2 % 62.7 % 76.4 % 73.5 % 80.8 % *Less than 10% We monitor economic conditions to identify facts or circumstances that may indicate if any of our accounts receivable are not collectible or if the contract assets should be impaired. No allowance for doubtful accounts was recorded as of September 30, 2021 or December 31, 2020. Restricted Cash We define restricted cash as cash and cash equivalents that cannot be withdrawn or used for general operating activities. Our restricted cash consists of a letter of credit with a financial institution related to our workers’ compensation insurance, which renews annually. As of September 30, 2021, we had less than $ 0.1 million of restricted cash, which was recorded in other assets in our condensed consolidated balance sheets. We did no t have any restricted cash as of December 31, 2020. Patent Costs We expense costs as incurred for filing, prosecuting, and maintaining patents and patent applications, including certain of the patents and patent applications that we license from third parties. We classify such costs as general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. In addition, we are entitled to receive reimbursement from third parties for a portion of the filing, prosecution, and maintenance costs for certain patents and patent applications. We accrue for these reimbursements as the respective expenses are incurred, and we classify such reimbursements as a reduction of general and administrative expenses. During each of the three months ended September 30, 2021 and 2020, we incurred gross patent costs of $ 2.8 million. During the nine months ended September 30, 2021 and 2020, we incurred gross patent costs of $ 10.3 million and $ 7.3 million, respectively. During the three months ended September 30, 2021 and 2020, we recorded $ 1.6 million and $ 1.5 million, respectively, of patent cost reimbursements as a credit to general and administrative expenses. During the nine months ended September 30, 2021 and 2020, we recorded $ 6.1 million and $ 3.7 million, respectively, of patent cost reimbursements as a credit to general and administrative expenses. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “ FASB”) or other standard-setting bodies and adopted by us as of the specified effective date. New Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) . This ASU requires a lessee to recognize in its statement of financial position a liability to make lease payments (the lease liability) and a right-to-use asset representing its right to use the underlying asset for the lease term. We may elect not to apply Topic 842 to short-term leases with a term of 12 months or less. This ASU is effective for fiscal years beginning after December 15, 2021 and interim periods within fiscal years beginning after December 15, 2022, with early adoption permitted. We are in the process of completing a qualitative and quantitative assessment of our lease portfolio and implementing new processes and controls to account for leases in accordance with the new standard. We believe the most significant changes to our financial statements will relate to the recognition of right-of-use assets and offsetting lease liabilities for operating leases in the consolidated balance sheet. We do not expect the standard to have a material impact on cash flows or results of operations. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326) . This ASU provides guidance on the measurement of credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. ASU 2016-13 replaces the current incurred loss impairment approach with a methodology to reflect expected credit losses and requires consideration of a broader range of reasonable and supportable information to explain credit loss estimates. This ASU is to be applied on a modified retrospective approach and is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022, and interim reporting periods within fiscal years beginning after December 15, 2023. Early adoption is permitted for all entities for fiscal years beginning after December 15, 2018, and interim periods therein. We are currently evaluating the impact of adoption of this ASU on our condensed consolidated financial statements.

Fair Value Measurements and Fai

Fair Value Measurements and Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements and Fair Value of Financial Instruments	3. Fair Value Measurements and Fair Value of Financial Instruments The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1 —Quoted prices in active markets for identical assets or liabilities. Level 2 —Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Assets and liabilities measured at fair value are classified in their entireties based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires our management to make judgments and consider factors specific to the asset or liability. Our financial instruments consist of Level 1 and Level 3 financial instruments. Level 1 financial instruments are comprised of money market mutual funds. Level 3 financial instruments are comprised of the success payments liability related to the Exclusive License Agreement (the “MSKCC Agreement”), dated November 13, 2020, by and between us and Memorial Sloan Kettering Cancer Center (“MSKCC”). The following table sets forth our financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): Fair Value Measurements as of September 30, 2021 Total Level 1 Level 2 Level 3 Assets: Money market investments (included in cash and cash equivalents) $ 435,310 $ 435,310 $ - $ - Total $ 435,310 $ 435,310 $ - $ - Liabilities: MSKCC success payments liability $ 6,238 $ - $ - $ 6,238 Total $ 6,238 $ - $ - $ 6,238 Fair Value Measurements as of December 31, 2020 Total Level 1 Level 2 Level 3 Assets: Money market investments (included in cash and cash equivalents) $ 15,953 $ 15,953 $ - $ - Total $ 15,953 $ 15,953 $ - $ - Liabilities: MSKCC success payments liability $ 2,654 $ - $ - $ 2,654 Total $ 2,654 $ - $ - $ 2,654 The following table sets forth a summary of the changes in the fair value of our Level 3 financial liability (in thousands): MSKCC Success Payments Balance at December 31, 2020 $ 2,654 Change in fair value 3,584 Balance at September 30, 2021 $ 6,238 We recorded a $ 2.4 million change and a $ 3.6 million change in fair value of the MSKCC success payments liability in other income (expense) in our condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2021, respectively. Our liability for the MSKCC success payments is carried at fair value and changes are recognized as expense or income as part of “other income (expense)” until the success payments liability is paid or expires (Note 4). We utilize a Monte Carlo simulation model that models the future movement of stock prices based on several key variables. This model requires significant estimates and assumptions in determining the estimated success payments liability under the MSKCC Agreement and associated expense or income at each balance sheet date based on changes in the estimated success payments liability . The assumptions used to calculate the fair value of the MSKCC success payments are subject to a significant amount of judgment including the expected volatility that was estimated using available information about the historical volatility of stocks of publicly traded companies that are similar to us, the estimated term, and the estimated number and timing of valuation measurement dates. The table below summarizes key assumptions used in the valuation of MSKCC success payments liability: As of As of Fair value of common stock $ 23.870 $ 5.462 Risk-free interest rate 1.52 % 0.93 % Expected volatility 80 % 80 % Probability 11.9 % to 26.7 % 4.4 % to 13.4 % Expected term (years) 4.0 to 4.8 4.7 to 5.7 The computation of expected volatility was estimated using a combination of available information about the historical volatility of stocks of similar publicly traded companies for a period matching the expected term assumption and the historical and implied volatility of our stock. The risk-free interest rate, expected volatility, and expected term assumptions depend on the estimated timing of our phase 1 clinical trial and U.S. Food and Drug Administration (“FDA”) approval of one of our product candidates. In addition, we incorporated the estimated number and timing of valuation measurement dates in the calculation of the MSKCC success payments liability. A small change in the assumptions and other inputs, such as the fair value of our common stock, may have a relatively large change in the estimated valuation and associated liability and expense or income. The carrying value of the promissory note pursuant to the Paycheck Protection Program (“PPP”) administered by the Small Business Administration (the “SBA”) under the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) approximates its fair value (Note 8).

Significant Agreements

Significant Agreements	9 Months Ended
	Sep. 30, 2021
Significant Agreements [Abstract]
Significant Agreements	4. Significant Agreements The Regents of the University of California/University of Vienna We entered into an Exclusive License Agreement, dated April 16, 2013, as amended (the “UC/Vienna Agreement”) with The Regents of the University of California (“UC”) and the University of Vienna (“Vienna”) (together, “UC/Vienna”) wherein UC/Vienna granted us an exclusive worldwide license, with the right to sublicense, in all fields to the foundational CRISPR-Cas9 patent family co-owned by UC, Vienna, and Dr. Emmanuelle Charpentier (the “CVC IP”). Dr. Charpentier has not granted us any rights, either directly or indirectly. The UC/Vienna Agreement continues until the last-to-expire patent or last-to-be-abandoned patent application within the CVC IP; provided, however, that UC/Vienna may terminate the UC/Vienna Agreement upon the occurrence of certain events and we may terminate the UC/Vienna Agreement at our sole discretion upon written notice. Without patent term adjustment or patent term extension, the CVC IP will expire in 2033. The UC/Vienna Agreement includes certain diligence milestones that we must meet. For products and services sold by us that are covered by the CVC IP, we will owe low- to mid-single-digit percent royalties on net sales, subject to a minimum annual royalty. Prior to the time that we are selling products, we owe UC/Vienna an annual license maintenance fee. We may owe UC/Vienna up to $ 3.4 million in certain regulatory and clinical milestone payments in the field of human therapeutics and diagnostics for products that are covered by the CVC IP and developed by us, an affiliate, or a sublicensee. Additionally, we pay UC/Vienna a specified percentage of sublicensing revenue, including cash and equity, we receive from sublicensing the CVC IP, subject to certain exceptions. If we include intellectual property owned or controlled by us in a sublicense to the CVC IP, we pay UC/Vienna a low double-digit percentage of sublicensing revenues received under the sublicense. If we do not include intellectual property owned or controlled by us in a sublicense to the CVC IP, we pay UC/Vienna 50% of sublicensing revenues received under the sublicense. To date, we have entered into over 20 sublicensing agreements in a variety of fields such as human therapeutics, forestry, agriculture, research reagents, transgenic animals, certain livestock targets, internal research, bioproduction, cell lines, and microbial applications that include the CVC IP as well as other Cas9 intellectual property owned or controlled by us. We are obligated to reimburse UC for its prosecution and maintenance costs of the CVC IP. For the three months ended September 30, 2021 and 2020, we incurred $ 0.3 million and $ 0.1 million, respectively, for payments we owe to UC related to sublicensing revenues, which were recorded in research and development expenses in our condensed consolidated statements of operations and comprehensive loss. For the nine months ended September 30, 2021 and 2020, we incurred $ 1.3 million and $ 0.6 million, respectively, for payments we owe to UC related to sublicensing revenues, which were recorded in research and development expenses in our condensed consolidated statements of operations and comprehensive loss. For the three months ended September 30, 2021 and 2020, we reimbursed UC $ 2.4 million and $ 2.3 million, respectively, for prosecution and maintenance costs of the CVC IP, which were recorded in general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. For the nine months ended September 30, 2021 and 2020, we reimbursed UC $ 8.9 million and $ 6.0 million, respectively, for prosecution and maintenance costs of the CVC IP, which were recorded in general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. On December 15, 2016, we entered into a Consent to Assignments, Licensing and Common Ownership and Invention Management Agreement (“IMA”) relating to the CVC IP. Under the IMA, CRISPR Therapeutics AG (“CRISPR”) reimburses us 50 % of the amounts we reimburse UC for patent prosecution and maintenance costs of the CVC IP. For the three months ended September 30, 2021 and 2020, CRISPR reimbursed us $ 1.2 million and $ 1.1 million, respectively, which were recorded as reductions of general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. For the nine months ended September 30, 2021 and 2020, CRISPR reimbursed us $ 4.4 million and $ 2.6 million, respectively, which were recorded as reductions of general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. Memorial Sloan Kettering Cancer Center Under the MSKCC Agreement, we exclusively licensed know-how, biological materials, and intellectual property relating to humanized single-chain variable fragments targeting CD371 for use in T cells, NK cells, and genome-edited induced pluripotent stem cells for allogeneic CD371-targeted cell therapy (currently used in our CB-012 product candidate). We paid MSKCC an upfront payment of $ 0.5 million in cash and $ 2.1 million in stock. For each licensed CD371 product, we may owe potential clinical, regulatory, and commercial milestone payments totaling $ 112.0 million. In addition, in the event we, our affiliates, or sublicensees, receive regulatory approval for a licensed CD371 product, we will owe low- to mid-single-digit percent royalties on net sales by us, our affiliates, and our sublicensees. Our license from MSKCC includes the right to sublicense through multiple tiers and we will owe MSKCC a percentage of upfront cash or equity received from our sublicensees. The percentage owed decreases as our licensed CD371 product candidate moves through development, starting at a low-double-digit percentage if clinical trials have not yet begun and decreasing to a mid-single-digit percentage if our licensed CD371 product candidate is in later clinical trial stages. We are also responsible for paying a percentage of licensed patent costs. The MSKCC Agreement includes certain diligence milestones that we must meet by specified dates, which dates may be extended upon payment of additional fees. MSKCC is entitled to certain success payments if our common stock fair value increases by certain multiples of increasing value based on a comparison of the fair market value of our common stock with the split-adjusted initial stock price of our Series B convertible preferred stock financing of $ 5.1914 per share, as adjusted for any future stock splits (the “Initial Share Price”), during a specified time interval. Under the MSKCC Agreement, as a publicly traded company, our common stock fair value is determined by any given 45-day volume-weighted average trading price. At our option, success payments to MSKCC may be made in cash or common stock. The relevant time interval commences when the first patient is dosed with a licensed CD371 product candidate in the first phase 1 clinical trial and ends upon the earlier of the third anniversary from the approval of our, or our affiliate’s, or sublicensee’s, biologics license application by the FDA or 10 years from the date the first patient was dosed with a licensed CD371 product candidate in the first phase 1 clinical trial. The aggregate success payments will not exceed $ 35.0 million. Additionally, if we undergo a change of control during the specified time interval, we may owe a change of control payment, depending upon the increase in our stock price due to the change of control and also to what extent success payments have already been paid by us to MSKCC. In no event will the combination of success payments and the change of control payment owed to MSKCC exceed $ 35.0 million. The following table summarizes the amounts of the MSKCC success payments: Multiple of Initial Share Price giving rise to a success payment 5 x 10 x 15 x MSKCC success payments (in millions) $ 10.0 $ 10.0 $ 15.0 We may terminate the MSKCC Agreement upon 90 calendar days’ prior written notice to MSKCC. MSKCC may terminate in the event of our uncured material breach, bankruptcy, or criminal activity. In the event that MSKCC materially breaches the MSKCC Agreement in certain circumstances ( e.g ., granting a third party a license in our field) then, during the time of such uncured breach, MSKCC will not be entitled to receive any success payments or any change of control payment. As of September 30, 2021, the estimated fair value of the total success payments obligation to MSKCC was $ 6.2 million, which was included in long-term liabilities in our condensed consolidated balance sheets. For the three and nine months ended September 30, 2021, we recognized $ 2.4 million and $ 3.6 million, respectively, of change in fair value of the MSKCC success payments liability, which were recorded in other income (expense) in our condensed consolidated statements of operations and comprehensive loss. Intellia Therapeutics, Inc. On July 16, 2014, we entered into a License Agreement, as amended (the “Intellia License Agreement”) and a Services Agreement with Intellia, LLC, to which Intellia Therapeutics, Inc. (“Intellia”) is a successor in interest. Under the Intellia License Agreement, we granted Intellia an exclusive worldwide license, with the right to sublicense, to certain CRISPR-Cas9 technology for a defined field of human therapeutics, including a license to certain of our future CRISPR-Cas9 intellectual property until our direct or indirect percentage of Intellia’s common stock dropped below 10 % (the “IP Cut-off Date”). Intellia granted us an exclusive worldwide license, with the right to sublicense, to certain of its CRISPR-Cas9 technology for all fields outside of the defined field of human therapeutics, including a license to certain of Intellia’s future CRISPR-Cas9 intellectual property until the IP Cut-off Date. Each party had the right to opt-in to any licenses in its field of use entered into by the other party prior to the IP Cut-off Date, subject to the terms and conditions of such license. The IP Cut-off Date occurred on January 30, 2018. Under the Intellia License Agreement, each party is responsible for 30 % of the other party’s expenses for prosecution and maintenance of the licensed intellectual property. For each of the three and nine months ended September 30, 2021 and 2020, we reimbursed Intellia less than $ 0.1 million, which was recorded as general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. During each of the three months ended September 30, 2021 and 2020, Intellia reimbursed us $ 0.4 million (including reimbursement for a portion of the patent prosecution and maintenance costs of the CVC IP paid to UC), which was recorded as reductions of general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. During the nine months ended September 30, 2021 and 2020, Intellia reimbursed us $ 1.7 million and $ 1.1 million, respectively (including reimbursement for a portion of patent prosecution and maintenance costs of the CVC IP paid to UC), which were recorded as reductions of general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. The term of the Intellia License Agreement continues for the life of the licensed patents and patent applications; provided, however, either party may terminate upon the occurrence of certain events. On June 16, 2021, we and Intellia entered into a leaseback agreement (the “Leaseback Agreement”), which resolved the arbitration dispute between the parties (Note 9). Pursuant to the Leaseback Agreement, in exchange for Intellia’s grant to us of an exclusive license to certain intellectual property relating to CRISPR-Cas9, including Cas9 chRDNAs, for use solely in the manufacture of our CB-010 product candidate, we agreed to make certain payments to Intellia, including $ 1.0 million paid to Intellia in July 2021. We are also obligated to pay up to $ 23.0 million in potential future regulatory and sales milestones for our CB-010 product candidate if and when such milestones are achieved. We will also pay Intellia low- to mid-single-digit percent royalties on net sales of our CB-010 product candidate sold by us, our affiliates, and sublicensees until the expiration, abandonment, or invalidation of the last patent within the intellectual property relating to certain CRISPR-Cas9, including those relating to Cas9 chRDNAs. Pioneer Hi-Bred International, Inc. (now Corteva Agriscience) On July 13, 2015, we and Pioneer Hi-Bred International, Inc. (“Pioneer”) (now Corteva Agriscience), then a DuPont company (“DuPont”), entered into an Amended and Restated Collaboration and License Agreement, as amended (the “Pioneer Agreement”). Under the terms of the Pioneer Agreement, we and Pioneer cross-licensed CRISPR intellectual property portfolios. Pioneer granted us an exclusive worldwide license, with the right to sublicense, to its CRISPR intellectual property in the field of research tools, as well as a non-exclusive worldwide license to such intellectual property in human and animal therapeutics, industrial biotechnology, certain agriculture segments, and other fields; and we granted Pioneer an exclusive worldwide license, with the right to sublicense, to our CRISPR intellectual property, including the CVC IP, in a defined field of agriculture relating to specified row crops, as well as a non-exclusive worldwide license to such intellectual property in other agricultural applications, industrial biotechnology, nutrition and health, and other fields. The Pioneer Agreement continues until the expiration, abandonment, or invalidation of the last patent or patent application within the licensed intellectual property; provided, however, that the parties may terminate the Pioneer Agreement by mutual consent or either party may unilaterally terminate the Pioneer Agreement in the event of an uncured breach of a payment obligation, bankruptcy, or failure to maintain or own licensed intellectual property by the other party in the event the non-breaching party is materially adversely affected by such failure. We are obligated to pay low-single-digit percent royalties to Pioneer for the sales of our products in the research tools field as well as certain sublicensing revenues in that field. We are eligible to receive milestone payments from Pioneer in the event certain regulatory and commercial milestones are met related to specified row crops, for a total of up to $ 22.4 million, as well as to receive low-single-digit percent royalties for sales of defined agricultural products and certain sublicensing revenues in that field. In March 2021, we received a milestone payment of $ 0.3 million from Pioneer. Under the Pioneer Agreement, we and Pioneer also entered into a three-year collaboration, funded by Pioneer, which ended in 2016. Initially, Pioneer owned the patents and patent applications developed under the collaboration, including the chRDNA patent family, and granted us an exclusive license to these patents and patent applications in the fields of research tools and therapeutics. In December 2020, we and Pioneer entered into an amendment to the Pioneer Agreement under which Pioneer assigned to us the chRDNA patent family developed under the research collaboration, and we paid Pioneer an upfront payment of $ 0.5 million. We considered the payment to Pioneer in accordance with revenue recognition guidance and accounted for it as a reduction of the licensing and collaboration revenue in our condensed consolidated statements of operations and comprehensive loss. In addition to the upfront payment, we are now obligated to pay all patent prosecution and maintenance costs for the chRDNA patent family; up to $ 2.8 million in regulatory milestone payments for therapeutic products developed by us, our affiliates, or licensees that are covered by the chRDNA patent family; up to $ 20.0 million in sales milestones over a total of four therapeutics products sold by us, our affiliates, or licensees that are covered by the chRDNA patent family; and a low-single-digit percentage of licensing revenues received by us for licensing the chRDNA patent family after December 2020. During the nine months ended September 30, 2021, we incurred $ 0.8 million for payments we owe to Pioneer related to licensing revenues, which were recorded as a research and development expense in our condensed consolidated statements of operations and comprehensive loss. No licensing fees payments were incurred to Pioneer during the three months ended September 30, 2021 no r during the three and nine months ended September 30, 2020. Genus plc On May 12, 2016, we entered into a Research Collaboration and License Agreement, as amended (the “Genus Agreement”) with Genus plc (“Genus”) under which we granted Genus an exclusive worldwide license to certain CRISPR-Cas9 technology for the introduction of genetic traits into cattle and pigs raised to produce protein primarily for human consumption; provided, however, that at the end of the four-year research collaboration, Genus was required to select a specified number of licensed products and our license to Genus is now limited to those particular products. The Genus Agreement continues until the expiration, abandonment, or invalidation of the last patent or patent application within the licensed patent rights; provided, however, that each party may terminate the Genus Agreement upon the occurrence of certain events, and Genus may terminate the Genus Agreement at its sole discretion upon written notice to us. In addition to an upfront payment we received, we are eligible to receive milestone payments from Genus in the event certain regulatory and commercial milestones are met, for the selected licensed products, up to a total of $ 10.0 million. We will also be eligible to receive either low- to mid-single-digit percent royalties or low-single to low-double-digit percent royalties on net sales of the licensed products. Under the Genus Agreement, we and Genus entered into a four-year research collaboration, which was funded by Genus. The collaboration ended in May 2020. We did no t recognize any revenue in connection with the Genus Agreement for the three and nine months ended September 30, 2021. During the three months ended September 30, 2020, we did no t recognize any revenue related to the Genus Agreement. During the nine months ended September 30, 2020, we recognized revenue of $ 0.8 million related to the Genus Agreement. Related Party Private Company On May 15, 2020, we entered into an Exclusive License Agreement, as amended, with a related party private company (the “Private Company License Agreement”), under which we granted the private company an exclusive worldwide license to certain CRISPR intellectual property rights and know-how in a defined field. We are eligible to receive milestone payments for licensed products following the first commercial sale of each licensed product in each of the United States and the first European country in which each licensed product is sold by the private company. The private company may select one of several milestone payment amounts for each licensed product, which selection then dictates the applicable royalty rate for net sales of licensed products. We are also eligible to receive a percentage of sublicensing revenues in the event the private company sublicenses the CRISPR intellectual property that we licensed to the private company. The Private Company License Agreement will continue in force and effect until the expiration, abandonment, or invalidation of the last patent or patent application within the licensed patent rights. The Private Company License Agreement may be terminated during the term by either party for an uncured material breach or bankruptcy. Additionally, the private company may terminate the Private Company License Agreement upon 90 days’ written notice to us. As consideration for the exclusive license, the private company issued to us 7,500,000 shares of convertible preferred stock with an estimated fair value of $ 7.5 million, which was the price paid for similar shares by another investor, and which was an arm’s length transaction. We accounted for the grant of the license as a contract with a customer under Accounting Standards Codification (“ASC”) 606 and recognized $ 7.5 million as license and collaboration revenue in our condensed consolidated statements of operations and comprehensive loss for the nine months ended September 30, 2020. We did no t recognize any revenue in connection with the Private Company License Agreement for the three and nine months ended September 30, 2021 nor for the three months ended September 30, 2020. On May 15, 2020, we entered into a separate option agreement under which we granted the same private company a three-year option to negotiate an exclusive, royalty-bearing, worldwide license in a defined field to the CVC IP and certain other CRISPR-Cas9 patent rights controlled by us. Through September 2021 , we received a total of $ 100,000 in upfront option payments and may receive an additional annual option fee and an option exercise fee. We recorded the upfront payments received in long-term deferred revenue in our condensed consolidated balance sheets as of September 30, 2021 and December 31, 2020. AbbVie Manufacturing Management Unlimited Company On February 9, 2021, we entered into a Collaboration and License Agreement (the “AbbVie Agreement”) with AbbVie Manufacturing Management Unlimited Company (“AbbVie”). Pursuant to the AbbVie Agreement, AbbVie selects one target or, for a dual CAR-T product, two targets (each selection, a “Program Slot”) to develop collaboration CAR-T products (and corresponding licensed products). For each of AbbVie’s two Program Slots (or up to four Program Slots, if AbbVie elects to expand the number as set forth below), we will collaborate to develop one or more collaboration allogeneic CAR-T products directed toward the single cancer target or target combination chosen by AbbVie as described in an applicable research plan, utilizing our Cas12a chRDNA genome-editing and cell therapy technologies. We granted AbbVie an exclusive (even as to us), royalty-bearing, worldwide license, with the right to grant sublicenses, under our Cas12a chRDNA and cell therapy intellectual property, as well as certain genome-editing technology that we may gain rights to in the future and intellectual property that may be developed under the collaboration, solely for AbbVie to develop, commercialize, manufacture, and otherwise exploit the collaboration CAR-T products in the field of human diagnostics, prophylactics, and therapeutics. Under the terms of the AbbVie Agreement, we will conduct certain preclinical research, development, and manufacturing activities under the collaboration, including certain activities for the manufacture and supply of licensed product for AbbVie’s phase 1 clinical studies. AbbVie will reimburse us for all such activities, including reimbursement for time spent by employees at a designated FTE rate. The duration of the collaboration is not fixed. Under the terms of the AbbVie Agreement, AbbVie has selected its initial Program Slot and has reserved six additional targets, which AbbVie may choose to be used or substituted into the two Program Slots or used for the third or fourth Program Slots if AbbVie expands the number of Program Slots during the collaboration. During the collaboration, AbbVie may expand from two Program Slots to a total of four Program Slots by paying us an additional $ 15.0 million for each Program Slot , provided that AbbVie must make such payment within the earlier of (a) 60 calendar days following completion of the phase 1 clinical studies for the initial collaboration CAR-T and (b) December 31, 2025. Under the terms of the AbbVie Agreement, we are eligible to receive up to $ 150.0 million in future developmental and regulatory milestone payments for each Program Slot and up to $ 200.0 million in sales-based milestones for each Program Slot. We are also eligible to receive global royalties on net sales of licensed products sold by AbbVie, its affiliates, and sublicensees in the high-single-digit to low-teens percent range, subject, in certain instances, to various reductions. The term of the AbbVie Agreement will continue in force and effect until the date of expiration of the last royalty term of the last country in which a licensed product is exploited. On a licensed product-by-licensed product and country-by-country basis, the royalty term is the period of time beginning on the first commercial sale of a licensed product in a country and ending on the latest of the following three dates: (a) the expiration, invalidation, revocation, cancellation, or abandonment date of the last patent that includes a valid claim to either (i) the collaboration CAR-T product in the licensed product or (ii) the method of making the collaboration CAR-T product in the licensed product in such country (in the case of (ii), only for so long as no biosimilar product is commercially available in such country); (b) 10 years from the date of the first commercial sale of such licensed product in such country; and (c) the expiration date of regulatory exclusivity for such licensed product in such country. The AbbVie Agreement may be terminated during the term by either party for an uncured material breach or bankruptcy by the other party. Additionally, AbbVie may terminate the AbbVie Agreement, in its entirety or on a licensed product-by-licensed product basis, effective immediately upon written notice to us, if AbbVie in good faith believes that it is not advisable for AbbVie to continue to exploit the collaboration CAR-T products or licensed products as a result of a perceived serious safety issue. AbbVie may also terminate the AbbVie Agreement in its entirety at its sole discretion upon 90 days’ prior written notice to us. The transaction price we received under the AbbVie Agreement associated with the first two Program Slots consisted of the $ 30.0 million upfront cash payment and the estimated variable consideration related to our performance of preclinical, development, and manufacturing activities under the collaboration and the developmental and regulatory milestone payments. We constrain the estimated variable consideration if we assess that it is probable that a significant reversal in the amount of cumulative revenue recognized may occur in future periods. We constrained all developmental and regulatory milestone payments as of September 30, 2021. The transaction price will be reevaluated in each reporting period and as changes in circumstances occur. We determined that the licenses we granted to AbbVie and our participation in the joint governance committee are not capable of being distinct from the preclinical research, development, and manufacturing activities and therefore are combined into one performance obligation. We recognize revenue based on the measure of progress using an estimated cost-based input method each reporting period. We received an upfront cash payment of $ 30.0 million from AbbVie on March 11, 2021. We recognized short-term deferred revenue in the amount of $ 8.3 million and long-term deferred revenue in the amount of $ 20.1 million related to this upfront cash payment in our condensed consolidated balance sheets as of September 30, 2021. We recognized $ 2.3 million and $ 2.8 million in revenue for the three and nine months ended September 30, 2021, respectively, in relation to the AbbVie Agreement.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2021
Revenue From Contract With Customer [Abstract]
Revenue	5. Revenue Disaggregation of Revenue We disaggregate revenue by geographical market based on the location of research and development activities of our licensees and collaborators. The following is a summary of revenue by geographic location for the three and nine months ended September 30, 2021 and 2020 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United States $ 3,507 $ 953 $ 6,483 $ 10,946 Rest of world 470 245 556 431 Total $ 3,977 $ 1,198 $ 7,039 $ 11,377 During the three months ended September 30, 2021, we recognized $ 1.7 million of revenue related to performance obligations satisfied at a point in time, and we recognized $ 2.3 million of revenue related to performance obligations satisfied over time. During the three months ended September 30, 2020, we recognized $ 1.2 million of revenue related to performance obligations satisfied at a point in time, and we did no t recognize any revenue related to performance obligations satisfied over time. During the nine months ended September 30, 2021, we recognized $ 4.2 million of revenue related to performance obligations satisfied at a point in time, and we recognized $ 2.8 million of revenue related to performance obligations satisfied over time. During the nine months ended September 30, 2020, we recognized $ 10.5 million of revenue related to performance obligations satisfied at a point in time, and we recognized $ 0.9 million of revenue related to performance obligations satisfied over time. Contract Balances Accounts receivable relate to our right to consideration for performance obligations completed (or partially completed) for which we have an unconditional right to consideration. Our accounts receivable balances represent amounts that we billed to licensees with invoices outstanding as of the period end. Contract assets are rights to consideration in exchange for a license that we have granted to a licensee when such right is conditional on something other than the passage of time. Our contract asset balances represent royalties, milestone payments, and research costs related to the AbbVie Agreement that are unbilled as of the period end. Contract liabilities consist of deferred revenue and relate to amounts invoiced to, or advance consideration received from, licensees, which precede our satisfaction of the associated performance obligations. Our deferred revenue primarily results from upfront payments received relating to performance obligations that are satisfied over time under the AbbVie Agreement. The remaining deferred revenue relates to upfront payments received under license agreements that also include non-refundable annual license fees, which are accounted for as material rights for license renewals and are recognized at the point in time the annual license fee is paid by the licensee and the renewal period begins. The following table presents changes in our contract assets and liabilities during the nine months ended September 30, 2021 (in thousands): Balance as of Additions Deductions Balance as of Accounts receivable $ 150 $ 7,220 $ ( 6,792 ) $ 578 Contract assets: Unbilled accounts receivable $ 1,328 $ 3,656 $ ( 3,131 ) $ 1,853 Contract liabilities: Deferred revenue, current and long-term $ 1,098 $ 34,826 $ ( 4,156 ) $ 31,768 Unbilled accounts receivable increased during the nine months ended September 30, 2021, primarily due to unbilled research costs under the AbbVie Agreement in the amount of $ 1.0 million. Deferred revenue increased during the nine months ended September 30, 2021, primarily due to recognition of $ 30.0 million in deferred revenue related to the AbbVie Agreement (Note 4). During the nine months ended September 30, 2021 and 2020, we recognized $ 0.1 million and $ 1.0 million of revenue, respectively, which were included in the opening contract liabilities balances as of December 31, 2020 and 2019, respectively. Transaction Prices Allocated to the Remaining Performance Obligations Remaining unsatisfied performance obligations represent in aggregate the amount of a transaction price that has been allocated to performance obligations not delivered, or only partially delivered, as of the end of a reporting period. The value of transaction prices allocated to remaining unsatisfied performance obligations as of September 30, 2021 was approximately $ 54.0 million. We expect to recognize approximately $ 8.7 million of remaining performance obligations as revenue in the next 12 months , and the remainder thereafter. Capitalized Contract Acquisition Costs and Fulfillment Costs We did not incur any expenses to obtain license and collaboration agreements, and costs to fulfill those contracts do not generate or enhance our resources. As such, no costs to obtain or fulfill a contract have been capitalized in any period.

Balance Sheet Items

Balance Sheet Items	9 Months Ended
	Sep. 30, 2021
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Items	6. Balance Sheet Items Other receivables consisted of the following as of September 30, 2021 and December 31, 2020, respectively (in thousands): September 30, December 31, Patent cost reimbursements $ 4,890 $ 3,672 Other 464 10 Total $ 5,354 $ 3,682 Prepaid expenses and other current assets consisted of the following as of September 30, 2021 and December 31, 2020, respectively (in thousands): September 30, December 31, Prepaid income taxes $ 1,490 $ 1,479 Prepaid insurance 2,646 - Prepaid contract manufacturing and clinical costs 609 954 Prepaid rent 444 337 Other 763 423 Total $ 5,952 $ 3,193 Property and equipment, net, consisted of the following as of September 30, 2021 and December 31, 2020, respectively (in thousands): September 30, December 31, Furniture and equipment $ 128 $ 117 Computer equipment 273 263 Lab equipment 6,245 5,038 Leasehold improvements 1,636 1,180 Total property and equipment, gross 8,282 6,598 Less: accumulated depreciation and amortization ( 3,805 ) ( 3,096 ) Property and equipment, net $ 4,477 $ 3,502 Depreciation and amortization expenses related to property and equipment were $ 0.3 million for each of the three months ended September 30, 2021 and 2020. Depreciation and amortization expenses related to property and equipment were $ 0.7 million for each of the nine months ended September 30, 2021 and 2020. Accrued expenses and other current liabilities consisted of the following as of September 30, 2021 and December 31, 2020, respectively (in thousands): September 30, December 31, Accrued patent expenses $ 5,633 $ 5,087 Accrued employee compensation and related expenses 2,948 2,081 Accrued research and development expenses 2,822 581 Credit card liability 871 193 Accrued sublicensing fees 478 402 Accrued legal expenses 407 - Other 771 629 Total $ 13,930 $ 8,973

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	7. Related Party Transactions Related Party Private Company On May 15, 2020, we received 7,500,000 shares of convertible preferred stock with an estimated fair value of $ 7.5 million as consideration for the Private Company License Agreement (Note 4). This represents a material voting interest in the private company and entitles us to hold one of the four private company’s board of director seats and to jointly vote with another stockholder on a second board of director ’ s seat. To date, we have appointed one of the three directors on the private company board of directors. We concluded that the private company is a variable interest entity and that we are not its primary beneficiary based on our representation on its board of directors. As the private company’s convertible preferred stock is not in substance common stock, we record this investment using the measurement alternative in accordance with ASC 321. Under the measurement alternative, our investment in the private company’s convertible preferred stock was initially recorded at its estimated fair value, but the carrying value may be adjusted through earnings upon an impairment or when there is an observable price change involving the same or a similar investment with the private company. As of each of September 30, 2021 and December 31, 2020, the carrying value of investment was $ 7.5 million. There have been no changes to the carrying value of the investment during the nine months ended September 30, 2021. Amended and Restated Collaboration and License Agreement with Pioneer As of September 30, 2020, DuPont held a greater than 10 % voting interest in the Company and Pioneer, then a DuPont company, was considered a related party (Note 4). Scientific Advisory Board Payments Dr. Jennifer A. Doudna, a co-founder and significant stockholder of the Company, receives compensation for participating on our scientific advisory board (the “SAB”) . During each of the three and nine months ended September 30, 2021 and 2020, we paid Dr. Doudna less than $ 0.1 million for her participation on our SAB. Officer Promissory Note In November 2018, our president and chief executive officer entered into a promissory note with us for $ 1.1 million, as a means to provide liquidity without triggering a taxable event. The note bore interest at a rate of 3.04 %, compounded annually, and was payable in five year s, together with principal and accrued interest. The promissory note was secured by 409,795 shares of our common stock owned by our president and chief executive officer and was determined to be non-recourse for accounting purposes. As such, the issuance of the promissory note was effectively the grant of a new share option. A one-time stock compensation charge of $ 0.7 million was recorded as a general and administrative expenses during the year ended December 31, 2018. The promissory note was repaid in full amount in June 2021 by our president and chief executive officer, and recognized as an increase in additional paid in capital of $ 1.2 million.

Paycheck Protection Program Loa

Paycheck Protection Program Loan	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Paycheck Protection Program Loan	8. Paycheck Protection Program Loan On May 6, 2020, we entered into a promissory note with WebBank (the “Lender”) pursuant to the Paycheck Protection Program for a total amount of $ 1.6 million (the “PPP Loan”). Our PPP Loan had a two-year term and bore interest at a stated rate of 1.0 % per annum, accrued monthly, beginning on the date our PPP Loan was issued by the Lender. No monthly principal and interest payments were required under our PPP Loan. We did not provide any collateral or guarantees for our PPP Loan, nor did we pay any facility charge to obtain our PPP Loan. Our PPP Loan provided for customary events of default, including those relating to failure to make payment, bankruptcy, breaches of representations, and material adverse effects. We could have prepaid the principal of our PPP Loan at any time without incurring any prepayment charges. A PPP loan can be partially or fully forgiven if a borrower complies with the provisions of the CARES Act, including the use of PPP loan proceeds for payroll costs, rent, utilities, and certain other expenses, and at least 60 % of the PPP loan proceeds must be used for payroll costs as defined by the CARES Act. Any forgiveness of a PPP loan is subject to approval by the SBA. On May 22, 2021, our PPP Loan was forgiven in full by the SBA and, at that time, we recognized a PPP Loan extinguishment gain of $ 1.6 million in our condensed consolidated statements of operations and comprehensive loss.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies Facility Lease Agreements We lease laboratory and office space under non-cancellable operating agreements. On March 31, 2021, we entered into a ten-year lease agreement, which superseded and replaced our prior lease, as amended, and the lease included additional office and laboratory space located within the same building in Berkeley, California. Our lease agreement contains a renewal option for an additional term of five year s . Monthly base rent under our lease agreement amounts to $ 0.3 million, subject to annual escalation from 3.1 % to 3.5 %. We record rent expense on a straight-line basis over the term of our leases. For tenant improvement allowances funded by landlord incentives, we record a deferred lease incentive liability in accrued expenses and other liabilities and amortize the deferred lease incentive liability as a reduction to rent expense on our condensed consolidated statements of operations and comprehensive loss over the term of the applicable lease. As of September 30, 2021 and December 31, 2020, we recorded $ 0.8 million and $ 0.6 million, respectively, related to the required security deposits in other assets, long-term, in our condensed consolidated balance sheets. As of September 30, 2021, future minimum lease payments under the leases were as follows (in thousands): Remainder of 2021 $ 845 2022 3,485 2023 3,596 2024 3,708 2025 3,627 Thereafter 27,379 Total $ 42,640 Rent expense was $ 2.9 million and $ 2.2 million for the nine months ended September 30, 2021 and 2020, respectively. Capital Lease We accounted for certain leased equipment as a capital lease due to the ownership of such equipment transferring to us at the end of the lease term. As of September 30, 2021, the capital lease obligation was repaid in full and we do no t have any remaining future minimum lease payments related to this capital lease. As of December 31, 2020, the total capital lease obligation amounted to $ 0.1 million, which was included in the current portion of the capital lease obligation in the accrued expenses and other current liabilities and the non-current portion of the capital lease in other liabilities in our condensed consolidated balance sheets. Research and Development Agreements We enter into various agreements in the ordinary course of business, such as those with suppliers, contract research organizations, contract manufacturing organizations, clinical trial sites, and the like. These agreements provide for termination at the request of either party, generally with less than one-year notice and are, therefore, cancellable contracts and, if cancelled, are not anticipated to have a material effect on our condensed consolidated financial condition, results of operations, or cash flows. Guarantees and Indemnifications In the normal course of business, we enter into agreements that contain a variety of representations and warranties and provide for certain indemnifications by us. Our exposure under these agreements is unknown because claims may be made against us in the future. To date, we have not paid any claims or been required to defend any action related to our indemnification obligations. As of each of September 30, 2021 and December 31, 2020, we did not have any material indemnification claims that were probable or reasonably possible, and consequently, we have not recorded related liabilities. Intellia Arbitration On October 16, 2018, Intellia initiated an arbitration proceeding with JAMS, asserting that we had violated the terms and conditions of the Intellia License Agreement (the “Intellia Arbitration”). The Intellia Arbitration involved whether two patent families controlled by us and respectively, to CRISPR-Cas9 chRDNAs and Cas9 scaffolds are included in the Intellia License Agreement. On September 19, 2019, the parties received an interim award from the arbitration panel ruling that the two patent families are included in the Intellia License Agreement, but the arbitration panel granted us an exclusive leaseback to Cas9 chRDNAs under economic terms to be negotiated by the parties. On February 6, 2020, the arbitration panel clarified that the leaseback relates solely to our CB-010 program and instructed the parties to negotiate economic terms based on a leaseback of that scope (Note 4). On June 16, 2021, the parties entered into the Leaseback Agreement, which resolved the dispute and, on July 21, 2021, the arbitration panel dismissed the Intellia Arbitration with prejudice.

Convertible Preferred Stock

Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Convertible Preferred Stock	10. Convertible Preferred Stock The authorized, issued, and outstanding shares of our convertible preferred stock and liquidation preferences as of December 31, 2020 were as follows (in thousands, except for share amounts): Series Authorized Outstanding Liquidation Carrying Series A 1,576,342 1,576,342 $ 3,550 $ 3,452 Series A-1 3,004,124 3,004,124 8,000 7,901 Series B 3,186,116 3,186,116 30,070 29,970 7,766,582 7,766,582 $ 41,620 $ 41,323 Upon the closing of our IPO on July 27, 2021, all outstanding shares of convertible preferred stock, including the Series C preferred stock issued in March 2021, were converted into shares of common stock. Our Amended and Restated Certificate of Incorporation, which was approved by our Board and stockholders in connection with the IPO, authorizes the issuance of 10,000,000 shares of preferred stock upon the closing of the IPO, no ne of which was issued and outstanding as of September 30, 2021.

Common Stock

Common Stock	9 Months Ended
	Sep. 30, 2021
Common Stock Number Of Shares Par Value And Other Disclosures [Abstract]
Common Stock	11. Common Stock Common stock reserved for future issuance, on an as converted basis, consists of the following: As of As of Preferred stock, issued and outstanding - 14,119,631 Stock options, issued and outstanding 4,965,952 4,520,551 Stock options, authorized for future issuance 5,782,814 582,340 Stock available under the Employee Stock Purchase Plan 511,000 - Restricted stock awards - 5,999 11,259,766 19,228,521

Stock Option Plans

Stock Option Plans	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Option Plans	12. Stock Option Plans In July 2021, our Board adopted and our stockholders approved the 2021 Equity Incentive Plan (the “2021 Plan“) that became effective on July 22, 2021. We reserved 5,200,000 shares of common stock for issuance under the 2021 Plan. In addition, 934,562 shares available for issuance under the 2013 Equity Incentive Plan, adopted in 2013 and amended and restated in 2019, were transferred into the 2021 Plan. Furthermore, any shares subject to awards under the 2013 Plan that terminate, expire, or lapse for any reason without the delivery of shares, or are reacquired or withheld (or not issued) to satisfy a tax withholding obligation or the purchase or exercise price, are added to the 2021 Plan. The 2021 Plan also provides that the number of shares initially reserved and available for issuance will automatically increase each January 1, beginning on January 1, 2022 and ending in January 1, 2031, by 5 % of the outstanding number of shares of our common stock as of the last day of the immediately preceding fiscal year, or such lesser number of shares as determined by our Board. No more than 56,000,000 shares of stock may be issued upon the exercise of incentive stock options under the 2021 Plan . Options under the 2021 Plan may be granted for periods of up to 10 years at exercise prices no less than the fair market value of our common stock on the date of grant; provided, however, that the exercise price of an incentive stock option granted to a 10 % stockholder may not be less than 110 % of the fair market value of the shares on the date of grant and such option may not be exercisable after the expiration of five years from the date of grant. The grant date fair market value of all awards made under our 2021 Plan and all cash compensation paid by us to any non-employee director for services as a director in any fiscal year may not exceed $ 750,000 , increased to $ 1,000,000 in the fiscal year of their initial service as a non-employee director. As of September 30, 2021, we had 5,782,814 shares available for issuance under our 2021 Plan. The following table summarizes stock option activity under our equity incentive plans during the nine months ended September 30, 2021: Shares Available Stock Options Weighted- Weighted- Aggregate Outstanding at December 31, 2020 582,340 4,520,551 $ 1.64 5.3 $ 6,929 Addition to option pool 7,871,714 Options granted ( 2,809,660 ) 2,809,660 $ 6.99 9.6 Options exercised - ( 2,225,839 ) $ 0.94 4.0 Options cancelled or forfeited 138,420 ( 138,420 ) $ 2.07 - Exercisable at September 30, 2021 5,782,814 4,965,952 $ 4.97 8.3 $ 94,075 Vested and expected to vest at September 30, 2021 4,965,952 $ 4.97 8.3 $ 94,075 (a) The aggregate intrinsic value is calculated as the difference between the stock option exercise price and the estimated fair value of the underlying common stock as of September 30, 2021. Grant Date Fair Value During the three months ended September 30, 2021, we granted 351,750 stock options to employees ( no stock options were granted to non-employees) with a weighted average grant date fair value of $ 16.64 . During the nine months ended September 30, 2021, we granted 2,809,660 stock options to employees and non-employees with a weighted average grant date fair value of $ 4.70 . During the three months ended September 30, 2020, no stock options were granted to employees or non-employees. During the nine months ended September 30, 2020, we granted 379,761 stock options to employees and non-employees with a weighted average grant date fair value of $ 1.82 . We estimated the fair value of each employee and non-employee stock option award on the grant date using the Black-Scholes option-pricing model based on the following assumptions for the three and nine months ended September 30, 2021 and 2020: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Volatility 74.8 % N/A 74.8 % to 76.5 % 74.9 % to 77.4 % Expected term (in years) 7 N/A 5.5 to 7.0 5.5 to 6.0 Risk-free interest rate 1.1 % N/A 0.9 % to 1.2 % 0.4 % to 0.7 % Expected dividend yield 0.0 % N/A 0.0 % 0.0 % As of September 30, 2021, there was $ 7.7 million of unrecognized stock-based compensation expense related to employee and non-employee stock options that is expected to be recognized over a weighted-average period of 9.3 years. Employee Stock Purchase Plan In July 2021, our Board adopted and our stockholders approved the 2021 Employee Stock Purchase Plan (“2021 ESPP”), which became effective on July 22, 2021. The 2021 ESPP is intended to qualify as an employee stock purchase plan under Section 423 of the Internal Revenue Code of 1986, as amended ( “Tax Code”) . We reserved 511,000 shares of our common stock for employees’ purchases under the 2021 ESPP. The number of shares of common stock reserved for issuance under the 2021 ESPP will be automatically increased each year for ten calendar years beginning in 2022 by the number of shares equal to 1 % of the total number of shares of common stock outstanding as of the last day of the immediately preceding fiscal year; provided that the maximum number of shares that may be issued under the ESPP is 10,000,000 shares. The 2021 ESPP allows an eligible employee to purchase shares of our common stock at a discount through payroll deductions of up to 15 % of the employee’s eligible compensation. At the end of each offering period, employees are able to purchase shares at 85 % of the lower of the fair market value of our common stock at the beginning of the offering period or at the end of each applicable offering period. The first offering period commenced on August 16, 2021 and will end on February 15, 2022. We recorded $ 0.1 million in accrued liabilities related to the amounts withheld as of September 30, 2021. Stock-Based Compensation Expense We recorded stock-based compensation expense related to employee and non-employee stock options grants in our condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2021 and 2020 as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 484 $ 173 $ 970 $ 526 General and administrative 451 75 901 245 Total $ 935 $ 248 $ 1,871 $ 771 The above stock-based compensation expense related to the following equity-based awards (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Stock options $ 894 $ 248 $ 1,830 $ 771 ESPP 41 - 41 - Total $ 935 $ 248 $ 1,871 $ 771 Stock-based compensation expense related to employees was $ 0.9 million and $ 0.2 million for the three months ended September 30, 2021 and 2020, respectively. Stock-based compensation expense related to employees was $ 1.9 million and $ 0.8 million for the nine months ended September 30, 2021 and 2020, respectively. Stock-based compensation expense related to non-employees was less than $ 0.1 million for each of the three and nine months ended September 30, 2021 and 2020.

401(k) Savings Plan

401(k) Savings Plan	9 Months Ended
	Sep. 30, 2021
Compensation And Retirement Disclosure [Abstract]
401(K) Savings plan	13. 401(k) Savings Plan In 2017, we established a defined-contribution savings plan under Section 401(k) of the Tax Code. Our 401(k) plan is available to all employees and allows participants to defer a portion of their annual compensation on a pretax basis subject to applicable laws. We also provide a 4 % match for employee contributions up to a certain limit. During the nine months ended September 30, 2021 and 2020, we contributed $ 0.3 million and $ 0.2 million, respectively, to our 401(k) plan.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes No income tax benefit was recorded during the three and nine months ended September 30, 2021 due to our operating losses. During the three and nine months ended September 30, 2020, we recorded income tax benefit of $ 0.2 million and $ 1.5 million, respectively. The income tax benefit was primarily related to the recognition of net operating loss carrybacks under the CARES Act, which generated a refund of taxes paid for the year ended December 31, 2018.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	15. Net Loss Per Share The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Numerator: Net loss $ ( 20,974 ) $ ( 7,933 ) $ ( 48,444 ) $ ( 19,605 ) Denominator: Weighted-average common shares outstanding used to compute net loss per share, basic and diluted 45,889,646 8,537,965 22,052,944 8,470,019 Net loss per share, basic and diluted $ ( 0.46 ) $ ( 0.93 ) $ ( 2.20 ) $ ( 2.31 ) Because we were in a net loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods, as the inclusion of all common stock equivalents outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were, as of September 30, 2021 and September 30, 2020 , as follows: As of As of Convertible preferred stock - 14,119,631 Stock options outstanding 4,965,952 4,759,953 Shares committed under ESPP 18,804 - Common shares subject to nonrecourse notes - 409,795 4,984,756 19,289,379

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	16. Subsequent Events The Company did not have any subsequent events as of the filing date of this Quarterly Report on Form 10-Q.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis Of Presentation and Principles of Consolidations	Basis of Presentation and Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Caribou Biosciences, Inc. and its wholly-owned subsidiaries and have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and the requirements of the SEC for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP may be condensed or omitted. Our condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements included in our Final Prospectus, except as noted below. In the opinion of our management, the information furnished in our condensed consolidated financial statements reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the financial position and results of operations for the reported interim periods. We consider events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period.
Use Of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities; the disclosure of contingent assets and liabilities at the date of our condensed consolidated financial statements; and the reported amounts of revenue, income, and expenses during the reporting period. On an ongoing basis, we evaluate our estimates and assumptions, including those related to revenue recognition, common stock valuation, stock-based compensation expense, accrued expenses related to research and development activities, valuation of the MSKCC success payments liability, and income taxes. Our management bases its estimates on historical experience and on various other assumptions that they believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those estimates.
Segments	Segments We operate and manage our business as one reportable and operating segment, which is the business of developing an internal pipeline of off-the-shelf CAR-T and CAR-NK cell therapies. Our chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating resources and evaluating financial performance. All long-lived assets are maintained in the United States.
Concentration of Credit Risk and Other Uncertainties	Concentrations of Credit Risk and Other Uncertainties Financial instruments that potentially subject us to concentration of credit risk consist of cash and cash equivalents, accounts receivable, contract assets, other receivables, and investments in equity securities. Substantially all our cash and cash equivalents were deposited in accounts at one financial institution, and account balances may at times exceed federally insured limits. We believe the financial institution to be of high credit quality. Licensees that represent 10% or more of our revenue and accounts receivable and contract assets were as follows: Revenue Revenue Accounts Receivable and Three Months Ended Nine Months Ended As of As of September 30, 2021 September 30, 2020 September 30, 2021 September 30, 2020 September 30, 2021 December 31, 2020 Licensee A 14.0 % 38.8 % 23.2 % 10.5 % 23.1 % 40.6 % Licensee B * * * * * 13.2 % Licensee C, related party * * * * * 16.9 % Licensee D * * * * * 10.1 % Licensee E 57.2 % * 39.5 % * 50.4 % * Licensee F, related party * * * 65.9 % * * Licensee G * 24.0 % * * * * Licensee H * 20.4 % * * * * Total 71.2 % 83.2 % 62.7 % 76.4 % 73.5 % 80.8 % *Less than 10% We monitor economic conditions to identify facts or circumstances that may indicate if any of our accounts receivable are not collectible or if the contract assets should be impaired. No allowance for doubtful accounts was recorded as of September 30, 2021 or December 31, 2020. Restricted Cash We define restricted cash as cash and cash equivalents that cannot be withdrawn or used for general operating activities. Our restricted cash consists of a letter of credit with a financial institution related to our workers’ compensation insurance, which renews annually. As of September 30, 2021, we had less than $ 0.1 million of restricted cash, which was recorded in other assets in our condensed consolidated balance sheets. We did no t have any restricted cash as of December 31, 2020. Patent Costs We expense costs as incurred for filing, prosecuting, and maintaining patents and patent applications, including certain of the patents and patent applications that we license from third parties. We classify such costs as general and administrative expenses in our condensed consolidated statements of operations and comprehensive loss. In addition, we are entitled to receive reimbursement from third parties for a portion of the filing, prosecution, and maintenance costs for certain patents and patent applications. We accrue for these reimbursements as the respective expenses are incurred, and we classify such reimbursements as a reduction of general and administrative expenses. During each of the three months ended September 30, 2021 and 2020, we incurred gross patent costs of $ 2.8 million. During the nine months ended September 30, 2021 and 2020, we incurred gross patent costs of $ 10.3 million and $ 7.3 million, respectively. During the three months ended September 30, 2021 and 2020, we recorded $ 1.6 million and $ 1.5 million, respectively, of patent cost reimbursements as a credit to general and administrative expenses. During the nine months ended September 30, 2021 and 2020, we recorded $ 6.1 million and $ 3.7 million, respectively, of patent cost reimbursements as a credit to general and administrative expenses.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “ FASB”) or other standard-setting bodies and adopted by us as of the specified effective date.
New Accounting Pronouncements Not Yet Adopted	New Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) . This ASU requires a lessee to recognize in its statement of financial position a liability to make lease payments (the lease liability) and a right-to-use asset representing its right to use the underlying asset for the lease term. We may elect not to apply Topic 842 to short-term leases with a term of 12 months or less. This ASU is effective for fiscal years beginning after December 15, 2021 and interim periods within fiscal years beginning after December 15, 2022, with early adoption permitted. We are in the process of completing a qualitative and quantitative assessment of our lease portfolio and implementing new processes and controls to account for leases in accordance with the new standard. We believe the most significant changes to our financial statements will relate to the recognition of right-of-use assets and offsetting lease liabilities for operating leases in the consolidated balance sheet. We do not expect the standard to have a material impact on cash flows or results of operations. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326) . This ASU provides guidance on the measurement of credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. ASU 2016-13 replaces the current incurred loss impairment approach with a methodology to reflect expected credit losses and requires consideration of a broader range of reasonable and supportable information to explain credit loss estimates. This ASU is to be applied on a modified retrospective approach and is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022, and interim reporting periods within fiscal years beginning after December 15, 2023. Early adoption is permitted for all entities for fiscal years beginning after December 15, 2018, and interim periods therein. We are currently evaluating the impact of adoption of this ASU on our condensed consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary Of Provision For Credit Losses and other Uncertainties	Licensees that represent 10% or more of our revenue and accounts receivable and contract assets were as follows: Revenue Revenue Accounts Receivable and Three Months Ended Nine Months Ended As of As of September 30, 2021 September 30, 2020 September 30, 2021 September 30, 2020 September 30, 2021 December 31, 2020 Licensee A 14.0 % 38.8 % 23.2 % 10.5 % 23.1 % 40.6 % Licensee B * * * * * 13.2 % Licensee C, related party * * * * * 16.9 % Licensee D * * * * * 10.1 % Licensee E 57.2 % * 39.5 % * 50.4 % * Licensee F, related party * * * 65.9 % * * Licensee G * 24.0 % * * * * Licensee H * 20.4 % * * * * Total 71.2 % 83.2 % 62.7 % 76.4 % 73.5 % 80.8 % *Less than 10%

Fair Value Measurements and F_2

Fair Value Measurements and Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Financial Instruments Measured on Recurring Basis	The following table sets forth our financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): Fair Value Measurements as of September 30, 2021 Total Level 1 Level 2 Level 3 Assets: Money market investments (included in cash and cash equivalents) $ 435,310 $ 435,310 $ - $ - Total $ 435,310 $ 435,310 $ - $ - Liabilities: MSKCC success payments liability $ 6,238 $ - $ - $ 6,238 Total $ 6,238 $ - $ - $ 6,238 Fair Value Measurements as of December 31, 2020 Total Level 1 Level 2 Level 3 Assets: Money market investments (included in cash and cash equivalents) $ 15,953 $ 15,953 $ - $ - Total $ 15,953 $ 15,953 $ - $ - Liabilities: MSKCC success payments liability $ 2,654 $ - $ - $ 2,654 Total $ 2,654 $ - $ - $ 2,654
Schedule of Change in Fair Value of Financial Liability	The following table sets forth a summary of the changes in the fair value of our Level 3 financial liability (in thousands): MSKCC Success Payments Balance at December 31, 2020 $ 2,654 Change in fair value 3,584 Balance at September 30, 2021 $ 6,238
Schedule of Assumptions Used in Valuation of MSKCC Success Payments Liability	The table below summarizes key assumptions used in the valuation of MSKCC success payments liability: As of As of Fair value of common stock $ 23.870 $ 5.462 Risk-free interest rate 1.52 % 0.93 % Expected volatility 80 % 80 % Probability 11.9 % to 26.7 % 4.4 % to 13.4 % Expected term (years) 4.0 to 4.8 4.7 to 5.7

Significant Agreements (Tables)

Significant Agreements (Tables)	9 Months Ended
	Sep. 30, 2021
Significant Agreements [Abstract]
Summary of Amounts of Success Payments MSKCC	The following table summarizes the amounts of the MSKCC success payments: Multiple of Initial Share Price giving rise to a success payment 5 x 10 x 15 x MSKCC success payments (in millions) $ 10.0 $ 10.0 $ 15.0

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue From Contract With Customer [Abstract]
Schedule of Disaggregation of Revenue	The following is a summary of revenue by geographic location for the three and nine months ended September 30, 2021 and 2020 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United States $ 3,507 $ 953 $ 6,483 $ 10,946 Rest of world 470 245 556 431 Total $ 3,977 $ 1,198 $ 7,039 $ 11,377
Schedule of Changes in Company's Contract Assets and Liabilities	The following table presents changes in our contract assets and liabilities during the nine months ended September 30, 2021 (in thousands): Balance as of Additions Deductions Balance as of Accounts receivable $ 150 $ 7,220 $ ( 6,792 ) $ 578 Contract assets: Unbilled accounts receivable $ 1,328 $ 3,656 $ ( 3,131 ) $ 1,853 Contract liabilities: Deferred revenue, current and long-term $ 1,098 $ 34,826 $ ( 4,156 ) $ 31,768

Balance Sheet Items (Tables)

Balance Sheet Items (Tables)	9 Months Ended
	Sep. 30, 2021
Balance Sheet Related Disclosures [Abstract]
Schedule of Other Receivables	Other receivables consisted of the following as of September 30, 2021 and December 31, 2020, respectively (in thousands): September 30, December 31, Patent cost reimbursements $ 4,890 $ 3,672 Other 464 10 Total $ 5,354 $ 3,682
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following as of September 30, 2021 and December 31, 2020, respectively (in thousands): September 30, December 31, Prepaid income taxes $ 1,490 $ 1,479 Prepaid insurance 2,646 - Prepaid contract manufacturing and clinical costs 609 954 Prepaid rent 444 337 Other 763 423 Total $ 5,952 $ 3,193
Schedule of Property and Equipment	Property and equipment, net, consisted of the following as of September 30, 2021 and December 31, 2020, respectively (in thousands): September 30, December 31, Furniture and equipment $ 128 $ 117 Computer equipment 273 263 Lab equipment 6,245 5,038 Leasehold improvements 1,636 1,180 Total property and equipment, gross 8,282 6,598 Less: accumulated depreciation and amortization ( 3,805 ) ( 3,096 ) Property and equipment, net $ 4,477 $ 3,502
Summary of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following as of September 30, 2021 and December 31, 2020, respectively (in thousands): September 30, December 31, Accrued patent expenses $ 5,633 $ 5,087 Accrued employee compensation and related expenses 2,948 2,081 Accrued research and development expenses 2,822 581 Credit card liability 871 193 Accrued sublicensing fees 478 402 Accrued legal expenses 407 - Other 771 629 Total $ 13,930 $ 8,973

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Summary of Future Minimum Lease Payment Under Leases	As of September 30, 2021, future minimum lease payments under the leases were as follows (in thousands): Remainder of 2021 $ 845 2022 3,485 2023 3,596 2024 3,708 2025 3,627 Thereafter 27,379 Total $ 42,640

Convertible Preferred Stock (Ta

Convertible Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2021
Temporary Equity Disclosure [Abstract]
Schedule of Convertible Preferred Stock and Liquidation Preference	The authorized, issued, and outstanding shares of our convertible preferred stock and liquidation preferences as of December 31, 2020 were as follows (in thousands, except for share amounts): Series Authorized Outstanding Liquidation Carrying Series A 1,576,342 1,576,342 $ 3,550 $ 3,452 Series A-1 3,004,124 3,004,124 8,000 7,901 Series B 3,186,116 3,186,116 30,070 29,970 7,766,582 7,766,582 $ 41,620 $ 41,323

Common Stock (Tables)

Common Stock (Tables)	9 Months Ended
	Sep. 30, 2021
Common Stock Number Of Shares Par Value And Other Disclosures [Abstract]
Schedule of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance, on an as converted basis, consists of the following: As of As of Preferred stock, issued and outstanding - 14,119,631 Stock options, issued and outstanding 4,965,952 4,520,551 Stock options, authorized for future issuance 5,782,814 582,340 Stock available under the Employee Stock Purchase Plan 511,000 - Restricted stock awards - 5,999 11,259,766 19,228,521

Stock Option Plans (Tables)

Stock Option Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Stock Option Activity	The following table summarizes stock option activity under our equity incentive plans during the nine months ended September 30, 2021: Shares Available Stock Options Weighted- Weighted- Aggregate Outstanding at December 31, 2020 582,340 4,520,551 $ 1.64 5.3 $ 6,929 Addition to option pool 7,871,714 Options granted ( 2,809,660 ) 2,809,660 $ 6.99 9.6 Options exercised - ( 2,225,839 ) $ 0.94 4.0 Options cancelled or forfeited 138,420 ( 138,420 ) $ 2.07 - Exercisable at September 30, 2021 5,782,814 4,965,952 $ 4.97 8.3 $ 94,075 Vested and expected to vest at September 30, 2021 4,965,952 $ 4.97 8.3 $ 94,075 (a) The aggregate intrinsic value is calculated as the difference between the stock option exercise price and the estimated fair value of the underlying common stock as of September 30, 2021.
Schedule of Estimated Fair Value of Stock Options on the Grant Date Using Black-Scholes Option-Pricing Model	We estimated the fair value of each employee and non-employee stock option award on the grant date using the Black-Scholes option-pricing model based on the following assumptions for the three and nine months ended September 30, 2021 and 2020: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Volatility 74.8 % N/A 74.8 % to 76.5 % 74.9 % to 77.4 % Expected term (in years) 7 N/A 5.5 to 7.0 5.5 to 6.0 Risk-free interest rate 1.1 % N/A 0.9 % to 1.2 % 0.4 % to 0.7 % Expected dividend yield 0.0 % N/A 0.0 % 0.0 %
Schedule of Stock-Based Compensation Expenses Recorded in the Condensed Consolidated Statements of Operations and Comprehensive Loss	We recorded stock-based compensation expense related to employee and non-employee stock options grants in our condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2021 and 2020 as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 484 $ 173 $ 970 $ 526 General and administrative 451 75 901 245 Total $ 935 $ 248 $ 1,871 $ 771
Schedule of Stock-Based Compensation Expense Related to Equity-Based Awards	The above stock-based compensation expense related to the following equity-based awards (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Stock options $ 894 $ 248 $ 1,830 $ 771 ESPP 41 - 41 - Total $ 935 $ 248 $ 1,871 $ 771

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Basic and Diluted Net Income Per Share	The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Numerator: Net loss $ ( 20,974 ) $ ( 7,933 ) $ ( 48,444 ) $ ( 19,605 ) Denominator: Weighted-average common shares outstanding used to compute net loss per share, basic and diluted 45,889,646 8,537,965 22,052,944 8,470,019 Net loss per share, basic and diluted $ ( 0.46 ) $ ( 0.93 ) $ ( 2.20 ) $ ( 2.31 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Because we were in a net loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods, as the inclusion of all common stock equivalents outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were, as of September 30, 2021 and September 30, 2020 , as follows: As of As of Convertible preferred stock - 14,119,631 Stock options outstanding 4,965,952 4,759,953 Shares committed under ESPP 18,804 - Common shares subject to nonrecourse notes - 409,795 4,984,756 19,289,379

Description of the Business, _2

Description of the Business, Organization, and Liquidity - Additional Information (Details) $ / shares in Units, $ in Thousands	Aug. 27, 2021USD ($)	Aug. 09, 2021$ / sharesshares	Jul. 27, 2021$ / sharesshares	Jul. 31, 2021	Sep. 30, 2021USD ($)$ / sharesshares	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)$ / sharesshares
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Common stock, par value | $ / shares					$ 0.0001						$ 0.0001		$ 0.0001
Proceeds from initial public offering, gross | $											$ 321,020
Common stock, shares authorized | shares					300,000,000						300,000,000		28,933,380
Preferred stock, shares authorized | shares			10,000,000										7,766,582
Forward stock split, conversion ratio				1.818
Accumulated deficit | $					$ (79,315)						$ (79,315)		$ (30,871)
Net loss and comprehensive loss | $					(20,974)	$ (14,311)	$ (13,159)	$ (7,933)	$ (1,872)	$ (9,800)	(48,444)	$ (19,605)
Cash generated in operating activities | $											(11,130)	(25,139)
Cash and cash equivalents | $					$ 435,310			$ 24,547			$ 435,310	$ 24,547	$ 15,953
IPO
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Common stock shares issued | shares			19,000,000
Share price | $ / shares			$ 16
Common stock, par value | $ / shares			$ 0.0001
Common stock issued to underwriters | shares		2,850,000
Offering price per share | $ / shares		$ 16
Proceeds from initial public offering, gross | $	$ 349,600
Proceeds from initial public offering, net | $	$ 321,000
Preferred stock shares issued | shares			26,234,654
Common stock, shares authorized | shares			300,000,000
Preferred stock, shares authorized | shares			10,000,000
Preferred stock par value per share | $ / shares			$ 0.0001

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)Segment	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Concentration Risk [Line Items]
Number of reportable segment | Segment			1
Number of operating segment | Segment			1
Allowance for doubtful accounts	$ 0		$ 0		$ 0
Restricted Cash	100,000		100,000		$ 0
Patent costs gross	2,800,000	$ 2,800,000	10,300,000	$ 7,300,000
General and Administrative Expense
Concentration Risk [Line Items]
Patent cost reimbursements	$ 1,600,000	$ 1,500,000	$ 6,100,000	$ 3,700,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Concentration of Credit Risk and other Uncertainties (Details) - Customer Concentration Risk	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenue Benchmark | Total
Concentration Risk [Line Items]
Total	71.20%	83.20%	62.70%	76.40%
Revenue Benchmark | Licensee A [Member]
Concentration Risk [Line Items]
Total	14.00%	38.80%	23.20%	10.50%
Revenue Benchmark | Licensee E [Member]
Concentration Risk [Line Items]
Total	57.20%		39.50%
Revenue Benchmark | Licensee F Related Party [Member]
Concentration Risk [Line Items]
Total				65.90%
Revenue Benchmark | Licensee G [Member]
Concentration Risk [Line Items]
Total		24.00%
Revenue Benchmark | License H [Member]
Concentration Risk [Line Items]
Total		20.40%
Accounts Receivable | Total
Concentration Risk [Line Items]
Total			73.50%		80.80%
Accounts Receivable | Licensee A [Member]
Concentration Risk [Line Items]
Total			23.10%		40.60%
Accounts Receivable | Licensee B [Member]
Concentration Risk [Line Items]
Total					13.20%
Accounts Receivable | Licensee C Related Party [Member]
Concentration Risk [Line Items]
Total					16.90%
Accounts Receivable | Licensee D [Member]
Concentration Risk [Line Items]
Total					10.10%
Accounts Receivable | Licensee E [Member]
Concentration Risk [Line Items]
Total			50.40%

Fair Value Measurements and F_3

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Financial Instruments Measured on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets:
Assets fair value	$ 435,310	$ 15,953
Liabilities:
Liabilities fair value	6,238	2,654
Money Market Investments (Included in Cash and Cash Equivalents)
Assets:
Assets fair value	435,310	15,953
MSKCC Success Payments Liability
Liabilities:
Liabilities fair value	6,238	2,654
Level 1
Assets:
Assets fair value	435,310	15,953
Level 1 | Money Market Investments (Included in Cash and Cash Equivalents)
Assets:
Assets fair value	435,310	15,953
Level 3
Liabilities:
Liabilities fair value	6,238	2,654
Level 3 | MSKCC Success Payments Liability
Liabilities:
Liabilities fair value	$ 6,238	$ 2,654

Fair Value Measurements and F_4

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Change in Fair Value of Financial Liability (Details) - MSKCC Success Payments Liability - Level 3 $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance at December 31, 2020	$ 2,654
Change in fair value	3,584
Balance at September 30, 2021	$ 6,238

Fair Value Measurements and F_5

Fair Value Measurements and Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
MSKCC Success Payments Liability | Research and Development Expense
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Change in fair value	$ 2.4	$ 3.6

Fair Value Measurements and F_6

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Assumptions Used in Valuation of MSKCC Success Payments Liability (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Fair Value of Common Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumption	$ 23,870	$ 5,462
Risk Free Interest Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumption	0.0152	0.0093
Expected Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumption	0.80	0.80
Probability | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumption	0.119	0.044
Probability | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumption	0.267	0.134
Expected Term (Years) | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumptions term	4 years	4 years 8 months 12 days
Expected Term (Years) | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumptions term	4 years 9 months 18 days	5 years 8 months 12 days

Significant Agreements - Additi

Significant Agreements - Additional Information (Details) - USD ($)	Jun. 16, 2021	Feb. 09, 2021	May 15, 2020	May 12, 2016	Jul. 13, 2015	Jul. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Mar. 11, 2021	Nov. 13, 2020	Dec. 15, 2016	Jul. 16, 2014
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
General and administrative							$ 6,760,000	$ 3,247,000		$ 16,469,000	$ 9,887,000
Research collaboration agreement, period										4 years
Upfront cash payment received													$ 30,000,000
Deferred revenue, net of current portion							100,000			$ 100,000		$ 50,000
Deferred revenue, net of current portion ($100 and $50 from related party)							23,022,000			23,022,000		937,000
Regulatory Milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential milestone payment												2,800,000
Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Future development, regulatory, and product launch milestones payment received			$ 200,000,000
The Regents of the University of California/University of Vienna
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Clinical milestone payment										3,400,000
Reimbursement percentage															50.00%
Reduction in general and administrative expenses							1,200,000	1,100,000		4,400,000	2,600,000
The Regents of the University of California/University of Vienna | Research and Development Expense
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Sublicensing expenses							300,000	100,000		1,300,000	600,000
The Regents of the University of California/University of Vienna | General and Administrative Expense
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Patent prosecution and maintenance costs							2,400,000	2,300,000		8,900,000	6,000,000
Memorial Sloan Kettering Cancer Center
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment fee														$ 500,000
Commercial milestones														112,000,000
Aggregate success payment							35,000,000			35,000,000
Maximum value of success payments and control payment							35,000,000			35,000,000
Fair value of success payments liability							6,200,000			6,200,000
Increase decrease in fair value of success payments liability							$ 2,400,000			$ 3,600,000
Memorial Sloan Kettering Cancer Center | Series B Convertible Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Share price							$ 5.1914			$ 5.1914
Memorial Sloan Kettering Cancer Center | Common Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment fee														$ 2,100,000
Intellia Therapeutics, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Ownership percentage																10.00%
Percentage of other party's expenses																30.00%
Payments						$ 1,000,000
Potential future milestone payments	$ 23,000,000
Intellia Therapeutics, Inc. | General and Administrative Expense | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Expenses incurred from transactions with related parties							$ 100,000	100,000		$ 100,000	100,000
Intellia Therapeutics, Inc. | General and Administrative Expense | Patents
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Expenses incurred from transactions with related parties							400,000	400,000		1,700,000	1,100,000
Pioneer Hi-Bred International, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment												500,000
Future contingent milestone payments					$ 22,400,000
Milestone Revenue					$ 300,000
Research collaboration agreement, period					3 years
Pioneer Hi-Bred International, Inc. | Sales Milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential milestone payment												$ 20,000,000
Pioneer Hi-Bred International, Inc. | Research and Development Expense
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment for licensing revenue							0	0		800,000	0
Genus plc
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research collaboration agreement, period				4 years
Regulatory and commercial milestone payments received				$ 10,000,000
Revenues							0		$ 0	0	800,000
Private Company License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenues							0	$ 0		0
Period for option			3 years
Upfront option payment			$ 100,000
Private Company License Agreement | License and Collaboration Revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License and collaboration revenue											$ 7,500,000
Private Company License Agreement | Convertible Preferred Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Convertible preferred stock issued			7,500,000
Fair value of convertible preferred stock			$ 7,500,000
Collaboration and License Agreement with AbbVie
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenues							2,300,000			2,800,000
Future development, regulatory, and product launch milestones payment received		$ 15,000,000	$ 150,000,000
Upfront cash payment received							30,000,000			30,000,000
Deferred revenue, net of current portion							8,300,000			8,300,000
Deferred revenue, net of current portion ($100 and $50 from related party)							$ 20,100,000			$ 20,100,000

Significant Agreements - Summar

Significant Agreements - Summary Of MSKCC Success Payments Amounts (Details) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)$ / shares
5x
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Multiple of Initial Share Price giving rise to a success payment | $ / shares	$ 5
MSKCC Success payments (in millions) | $	$ 10
10x
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Multiple of Initial Share Price giving rise to a success payment | $ / shares	$ 10
MSKCC Success payments (in millions) | $	$ 10
15x
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Multiple of Initial Share Price giving rise to a success payment | $ / shares	$ 15
MSKCC Success payments (in millions) | $	$ 15

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Licensing and collaboration revenue	$ 3,977	$ 1,198	$ 7,039	$ 11,377
United States
Disaggregation Of Revenue [Line Items]
Licensing and collaboration revenue	3,507	953	6,483	10,946
Rest of World
Disaggregation Of Revenue [Line Items]
Licensing and collaboration revenue	$ 470	$ 245	$ 556	$ 431

Revenue - Additional Informatio

Revenue - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Increase in unbilled accounts receivable			$ 525,000	$ (170,000)
Revenue recognized included in the opening contract liabilities balance			100,000	1,000,000
Transaction price allocated to the remaining performance obligations	$ 54,000,000		54,000,000
AbbVie Agreement
Disaggregation Of Revenue [Line Items]
Increase in unbilled accounts receivable			1,000,000
Deferred revenue, recognized			30,000,000
Point in Time
Disaggregation Of Revenue [Line Items]
Revenue recognized, performance obligation, amount	1,700,000	$ 1,200,000	4,200,000	10,500,000
Over Time
Disaggregation Of Revenue [Line Items]
Revenue recognized, performance obligation, amount	$ 2,300,000	$ 0	$ 2,800,000	$ 900,000

Revenue - Schedule of Changes i

Revenue - Schedule of Changes in Company's Contract Assets and Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Accounts receivable
Accounts receivable, Beginning Balance	$ 150
Accounts receivable, Additions	7,220
Accounts receivable, Deductions	(6,792)
Accounts receivable, Ending Balance	578
Contract assets:
Unbilled accounts receivable, Beginning Balance	1,328
Unbilled accounts receivable, Additions	3,656
Unbilled accounts receivable, Deductions	(3,131)
Unbilled accounts receivable, Ending Balance	1,853
Contract liabilities:
Deferred revenue, current and long-term, Beginning Balance	1,098
Deferred revenue, current and long-term, Additions	34,826
Deferred revenue, current and long-term, Deductions	(4,156)
Deferred revenue, current and long-term, Ending Balance	$ 31,768

Revenue - Additional Informat_2

Revenue - Additional Information (Details1) $ in Millions	Sep. 30, 2021USD ($)
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	$ 54
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	$ 8.7
Remaining performance obligation, expected timing of satisfaction, period	12 months

Balance Sheet Items - Schedule

Balance Sheet Items - Schedule of Other Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Patent cost reimbursements	$ 4,890	$ 3,672
Other	464	10
Total	$ 5,354	$ 3,682

Balance Sheet Items - Schedul_2

Balance Sheet Items - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Prepaid income taxes	$ 1,490	$ 1,479
Prepaid directors' and officers' insurance	2,646
Prepaid contract manufacturing and clinical costs	609	954
Prepaid rent	444	337
Other	763	423
Total	$ 5,952	$ 3,193

Balance Sheet Items - Schedul_3

Balance Sheet Items - Schedule of Property And Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property and equipment, gross	$ 8,282	$ 6,598
Less: accumulated depreciation and amortization	(3,805)	(3,096)
Property and equipment, net	4,477	3,502
Furniture and Equipment [Member]
Property and equipment, gross	128	117
Computer Equipment [Member]
Property and equipment, gross	273	263
Lab Equipment [Member]
Property and equipment, gross	6,245	5,038
Leasehold Improvements [Member]
Property and equipment, gross	$ 1,636	$ 1,180

Balance Sheet Items - Additiona

Balance Sheet Items - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization expense related to property and equipment	$ 0.3	$ 0.3	$ 0.7	$ 0.7

Balance Sheet Items - Summary o

Balance Sheet Items - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Accrued patent expenses	$ 5,633	$ 5,087
Accrued employee compensation and related expenses	2,948	2,081
Accrued research and development expenses	2,822	581
Credit card liability	871	193
Accrued sublicensing fees	478	402
Accrued legal expenses	407
Other	771	629
Total	$ 13,930	$ 8,973

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	May 15, 2020	Nov. 30, 2018	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2018	Dec. 31, 2020
Related Party Transaction [Line Items]
Carrying value of investment			$ 7,626			$ 7,626			$ 7,626
Debt instrument, face amount		$ 1,100
Debt instrument, interest rate		3.04%
Debt instrument Term, Description								The promissory note was repaid in full amount in June 2021 by our president and chief executive officer,
Common stock shares held collateral for debt		409,795
Stock-based compensation expense						1,871	$ 771	$ 700
Increase in additional paid-in capital					$ 1,200
Debt Instrument Term		5 years
DuPont
Related Party Transaction [Line Items]
Voting interest							10.00%
Dr. Jennifer A. Doudna
Related Party Transaction [Line Items]
Payment for participation			100	$ 100		100	$ 100
Convertible Preferred Stock | Private Company License Agreement
Related Party Transaction [Line Items]
Convertible preferred stock issued	7,500,000
Fair value of convertible preferred stock	$ 7,500
Carrying value of investment			$ 7,500			$ 7,500			$ 7,500

Paycheck Protection Program L_2

Paycheck Protection Program Loan - Additional Information (Details) - USD ($) $ in Thousands	May 22, 2021	May 06, 2020	Nov. 30, 2018	Sep. 30, 2021
Line Of Credit Facility [Line Items]
Debt instrument, face amount			$ 1,100
Loan, term			5 years
Debt instrument, interest rate			3.04%
Gain on extinguishment of PPP Loan				$ 1,584
PPP Loan
Line Of Credit Facility [Line Items]
Gain on extinguishment of PPP Loan	$ 1,600
PPP Loan | CARES Act | Minimum
Line Of Credit Facility [Line Items]
Percentage of proceeds from loan		60.00%
Web Bank | PPP Loan
Line Of Credit Facility [Line Items]
Loan, term		2 years
Debt instrument, interest rate		1.00%
Web Bank | PPP Loan | CARES Act
Line Of Credit Facility [Line Items]
Debt instrument, face amount		$ 1,600

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended
	Mar. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Commitment And Contingencies [Line Items]
Lease initial term	10 years
Lease option to renew term description		lease laboratory and office space under non-cancellable operating agreements. On March 31, 2021, we entered into a ten-year lease agreement, which superseded and replaced our prior lease, as amended, and the lease included additional office and laboratory space located within the same building in Berkeley, California. Our lease agreement contains a renewal option for an additional term of five years.
Lease existence of option to renew term	true
Lease renewal term	5 years
Monthly base rent	$ 300,000
Rent expense		$ 2,900,000	$ 2,200,000
Future minimum lease payments related to capital lease		0
Capital lease obligation				$ 100,000
Other Assets [Member]
Commitment And Contingencies [Line Items]
Security deposit		$ 800,000		$ 600,000
Minimum
Commitment And Contingencies [Line Items]
Payment annual escalation	3.10%
Maximum
Commitment And Contingencies [Line Items]
Payment annual escalation	3.50%

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Commitments Under Lease Contracts (Details) $ in Thousands	Sep. 30, 2021USD ($)
Commitments And Contingencies Disclosure [Abstract]
Remainder of 2021	$ 845
2022	3,485
2023	3,596
2024	3,708
2025	3,627
Thereafter	27,379
Total	$ 42,640

Convertible Preferred Stock - S

Convertible Preferred Stock - Schedule of Convertible Preferred Stock and Liquidation Preference (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jul. 27, 2021	Dec. 31, 2020
Temporary Equity [Line Items]
Preferred Stock Shares Authorized		10,000,000	7,766,582
Preferred Stock Shares Outstanding	0		7,766,582
Preferred Stock, Liquidation Preference, Value			$ 41,620
Temporary Equity Carrying Amount Attributable To Parent			$ 41,323
Series A [Member]
Temporary Equity [Line Items]
Preferred Stock Shares Authorized			1,576,342
Preferred Stock Shares Outstanding			1,576,342
Preferred Stock, Liquidation Preference, Value			$ 3,550
Temporary Equity Carrying Amount Attributable To Parent			$ 3,452
Series A-1 [Member]
Temporary Equity [Line Items]
Preferred Stock Shares Authorized			3,004,124
Preferred Stock Shares Outstanding			3,004,124
Preferred Stock, Liquidation Preference, Value			$ 8,000
Temporary Equity Carrying Amount Attributable To Parent			$ 7,901
Series B [Member]
Temporary Equity [Line Items]
Preferred Stock Shares Authorized			3,186,116
Preferred Stock Shares Outstanding			3,186,116
Preferred Stock, Liquidation Preference, Value			$ 30,070
Temporary Equity Carrying Amount Attributable To Parent			$ 29,970

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Details) - shares	Sep. 30, 2021	Jul. 27, 2021	Dec. 31, 2020
Equity [Abstract]
Preferred stock, shares authorized		10,000,000	7,766,582
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0		7,766,582

Common Stock - Schedule of Comm

Common Stock - Schedule of Common Stock Reserved for Future Issuance (Details) - shares	Sep. 30, 2021	Dec. 31, 2020
Common stock reserved for future issuance	11,259,766	19,228,521
Preferred Stock, Issued and Outstanding
Common stock reserved for future issuance	0	14,119,631
Stock Options, Issued and Outstanding
Common stock reserved for future issuance	4,965,952	4,520,551
Stock Options, Authorized for Future Issuance
Common stock reserved for future issuance	5,782,814	582,340
Stock Available Under the Employee Stock Purchase Plan
Common stock reserved for future issuance	511,000	0
Restricted Stock Awards
Common stock reserved for future issuance	0	5,999

Stock Option Plans - Additional

Stock Option Plans - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jul. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jul. 22, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted during period				2,809,660
Percentage of price of shares granted at fair value	85.00%
Shares available for issuance							582,340
Common stock, shares authorized		300,000,000		300,000,000			28,933,380
Common stock reserved for future issuance		11,259,766		11,259,766			19,228,521
Unrecognized stock based-compensation expenses		$ 7,700,000		$ 7,700,000
Weighted-average period				9 years 3 months 18 days
Stock-based compensation expense		935,000	$ 248,000	$ 1,871,000	$ 771,000
Accrued liabilities		$ 100		100
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of price of shares granted at fair value	110.00%
Cash based compensation	$ 750,000,000
Employee [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted during period		351,750
Weighted average grant date fair value		$ 16.64
Stock-based compensation expense		$ 900,000	200,000	1,900,000	800,000
Non-Employee [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted during period		0
Stock-based compensation expense		$ 100,000	$ 100,000	$ 100,000	$ 100,000
Cash based compensation	$ 1,000,000,000
Employee and Non-Employee [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted during period			0	2,809,660	379,761
Common stock reserved for future issuance	511,000
Weighted average grant date fair value				$ 4.70	$ 1.82
Employee Stock Purchase Plan 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares issued	10,000,000
Stok option expiration period				10 years
Common stock outstanding percentage	1.00%
Stock option plan description	No more than 56,000,000 shares of stock may be issued upon the exercise of incentive stock options under the 2021 Plan
Common stock reserved for future issuance		5,782,814		5,782,814		5,200,000
Percentage of eligible employee to purchase shares of common stock discount	15.00%
Incentive Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of price of shares granted at fair value	10.00%			5.00%

Stock Option Plans - Schedule o

Stock Option Plans - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Shares Available to Grant
Outstanding, Beginning Balance	582,340
Addition to option pool	7,871,714
Options granted	2,809,660
Options cancelled or forfeited	138,420
Outstanding, Ending Balance		582,340
Exercisable at September 30, 2021	5,782,814
Stock Options
Outstanding, Beginning Balance	4,520,551
Options granted	2,809,660
Options exercised	(2,225,839)
Options cancelled or forfeited	(138,420)
Outstanding, Ending Balance		4,520,551
Exercisable at September 30, 2021	4,965,952
Vested and expected to vest at September 30, 2021	4,965,952
Weighted-Average Exercise Price
Outstanding, Beginning Balance	$ 1.64
Options granted	6.99
Options exercised	0.94
Options cancelled or forfeited	2.07
Outstanding, Ending Balance		$ 1.64
Exercisable at September 30, 2021	4.97
Vested and expected to vest at September 30, 2021	$ 4.97
Weighted-Average Remaining Contractual Term (years)
Outstanding		5 years 3 months 18 days
Options granted	9 years 7 months 6 days
Options exercised	4 years
Exercisable at September 30, 2021	8 years 3 months 18 days
Vested and expected to vest at September 30, 2021	8 years 3 months 18 days
Aggregate Intrinsic Value
Outstanding		$ 6,929
Exercisable at September 30, 2021	$ 94,075
Vested and expected to vest at September 30, 2021	$ 94,075

Stock Option Plans - Schedule_2

Stock Option Plans - Schedule of Estimated Fair Value of Stock Options on the Grant Date Using Black-Scholes Option-Pricing Model (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	74.80%
Contractual term	7 years
Risk free interest rate	1.10%
Expected dividend yield	0.00%	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility		74.80%	74.90%
Contractual term		5 years 6 months	5 years 6 months
Risk free interest rate		0.90%	0.40%
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility		76.50%	77.40%
Contractual term		7 years	6 years
Risk free interest rate		1.20%	0.70%

Stock Option Plans - Schedule_3

Stock Option Plans - Schedule of Stock Option Expenses Related to Employee and Non-Employee Stock Options Granted (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	$ 935	$ 248	$ 1,871	$ 771
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	484	173	970	526
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	$ 451	$ 75	$ 901	$ 245

Stock Option Plans - Schedule_4

Stock Option Plans - Schedule of Stock-based Compensation Expense Related to Equity-Based Awards (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	$ 935	$ 248	$ 1,871	$ 771
Stock Options Outstanding
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	894	248	1,830	771
ESPP
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	$ 41		$ 41

401(k) Savings Plan - Additiona

401(k) Savings Plan - Additional Information (Details) - 2017 Plan - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, Employer matching contribution percent of match	4.00%
Employer contribution	$ 0.3	$ 0.2

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Benefit from income taxes		$ 213,000		$ 1,465,000
CARES Act
Benefit from income taxes	$ 0	$ 200,000	$ 0	$ 1,500,000

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator
Net loss and comprehensive loss	$ (20,974)	$ (14,311)	$ (13,159)	$ (7,933)	$ (1,872)	$ (9,800)	$ (48,444)	$ (19,605)
Denominator:
Weighted-average common shares outstanding, basic and diluted	45,889,646			8,537,965			22,052,944	8,470,019
Net loss per share, basic and diluted	$ (0.46)			$ (0.93)			$ (2.20)	$ (2.31)

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of the Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities	4,984,756	19,289,379
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities		14,119,631
Stock Options Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities	4,965,952	4,759,953
Shares Committed Under ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities	18,804
Common Shares Subject to Nonrecourse Notes
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive Securities		409,795