Caribou Biosciences (CRBU) 10-Q 6 Aug 24 2024 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2024	Aug. 01, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
Document Transition Report	false
Entity File Number	001-40631
Entity Registrant Name	Caribou Biosciences, Inc.
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	45-3728228
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 Address Postal Zip Code	94710
City Area Code	510
Local Phone Number	982-6030
Security12b Title	Common Stock, par value $0.0001 per share
Trading Symbol	CRBU
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		90,362,771
Entity Central Index Key	0001619856
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q2
Amendment Flag	false
Document Fiscal Year Focus	2024

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
CURRENT ASSETS
Cash and cash equivalents	$ 37,866	$ 51,162
Marketable securities, short-term	223,783	277,665
Accounts receivable	215	148
Contract assets	972	1,425
Other receivables	1,729	2,286
Prepaid expenses and other current assets	6,317	6,155
Total current assets	270,882	338,841
NON-CURRENT ASSETS
Investments in equity securities	9,286	7,753
Marketable securities, long-term	50,124	43,577
Property and equipment, net	19,876	18,270
Operating lease, right of use assets	21,134	22,182
Other assets	1,636	1,586
TOTAL ASSETS	372,938	432,209
CURRENT LIABILITIES
Accounts payable	3,227	3,120
Accrued expenses and other current liabilities	23,626	21,135
Operating lease liabilities, current	1,262	1,200
Deferred revenue ($2,487 and $2,487 from related party, respectively)	2,829	2,847
Total current liabilities	30,944	28,302
LONG-TERM LIABILITIES
Deferred revenue, net of current portion ($2,487 and $3,730 from related party, respectively)	4,604	6,102
MSKCC success payments liability	841	2,939
Operating lease liabilities, non-current	25,528	25,908
Deferred tax liabilities	557	557
Total liabilities	62,474	63,808
COMMITMENTS AND CONTINGENCIES (Note 9)
STOCKHOLDERS’ EQUITY
Common stock, par value $0.0001 per share, 300,000,000 shares authorized at June 30, 2024, and December 31, 2023, respectively; 90,362,771 and 88,448,948 shares issued and outstanding as of June 30, 2024, and December 31, 2023, respectively	9	8
Additional paid-in-capital	688,990	667,648
Accumulated other comprehensive (loss) income	(319)	30
Accumulated deficit	(378,216)	(299,285)
Total stockholders’ equity	310,464	368,401
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 372,938	$ 432,209

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Deferred revenue, current	$ 2,829	$ 2,847
Deferred revenue, noncurrent	$ 4,604	$ 6,102
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares outstanding (in shares)	90,362,771	88,448,948
Common stock, shares issued (in shares)	90,362,771	88,448,948
Related Party
Deferred revenue, current	$ 2,487	$ 2,487
Deferred revenue, noncurrent	$ 2,487	$ 3,730

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Revenue	$ 3,464	$ 3,755	$ 5,893	$ 7,257
Operating expenses:
Research and development	35,480	26,503	69,268	52,212
General and administrative	11,485	10,120	26,128	19,029
Total operating expenses	46,965	36,623	95,396	71,241
Loss from operations	(43,501)	(32,868)	(89,503)	(63,984)
Other income (expense):
Change in fair value of equity securities	(102)	22	(102)	7
Change in fair value of MSKCC success payments liability	1,795	279	2,098	534
Other income, net	4,111	3,048	8,576	5,880
Total other income	5,804	3,349	10,572	6,421
Net loss	(37,697)	(29,519)	(78,931)	(57,563)
Other comprehensive income (loss):
Net unrealized (loss) gain on available-for-sale marketable securities, net of tax	3	(406)	(349)	382
Net comprehensive loss	$ (37,694)	$ (29,925)	$ (79,280)	$ (57,181)
Net loss per share, basic (in dollars per share)	$ (0.42)	$ (0.48)	$ (0.88)	$ (0.94)
Net loss per share, diluted (in dollars per share)	$ (0.42)	$ (0.48)	$ (0.88)	$ (0.94)
Weighted-average common shares outstanding, basic (in shares)	90,340,932	61,417,934	89,821,935	61,302,863
Weighted-average common shares outstanding, diluted (in shares)	90,340,932	61,417,934	89,821,935	61,302,863

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenue	$ 3,464	$ 3,755	$ 5,893	$ 7,257
Related Party
Revenue	$ 2,245	$ 1,150	$ 2,867	$ 1,150

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Private Placement	Common Stock	Common Stock Private Placement	Additional Paid-In Capital	Additional Paid-In Capital Private Placement	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2022			61,029,184
Beginning balance at Dec. 31, 2022	$ 300,871		$ 6		$ 499,598		$ (1,518)	$ (197,215)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under ESPP (in shares)			70,271
Issuance of common stock under ESPP	404				404
Issuance of common stock on exercise of options (in shares)			55,433
Issuance of common stock on exercise of options	115				115
Issuance of common stock in connection with our ATM offering, net of offering expenses (in shares)			168,635
Issuance of common stock in connection with our ATM offering, net of offering expenses	1,007				1,007
Stock-based compensation expense	3,131				3,131
Net loss	(28,044)							(28,044)
Other comprehensive income (loss)	788						788
Ending balance (in shares) at Mar. 31, 2023			61,323,523
Ending balance at Mar. 31, 2023	278,272		$ 6		504,255		(730)	(225,259)
Beginning balance (in shares) at Dec. 31, 2022			61,029,184
Beginning balance at Dec. 31, 2022	300,871		$ 6		499,598		(1,518)	(197,215)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(57,563)
Ending balance (in shares) at Jun. 30, 2023			66,100,039
Ending balance at Jun. 30, 2023	269,458		$ 6		525,366		(1,136)	(254,778)
Beginning balance (in shares) at Mar. 31, 2023			61,323,523
Beginning balance at Mar. 31, 2023	278,272		$ 6		504,255		(730)	(225,259)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on exercise of options (in shares)			86,085
Issuance of common stock on exercise of options	236				236
Issuance of common stock in connection with our ATM offering, net of offering expenses (in shares)				4,690,431
Issuance of common stock in connection with our ATM offering, net of offering expenses		$ 17,290				$ 17,290
Stock-based compensation expense	3,585				3,585
Net loss	(29,519)							(29,519)
Other comprehensive income (loss)	(406)						(406)
Ending balance (in shares) at Jun. 30, 2023			66,100,039
Ending balance at Jun. 30, 2023	269,458		$ 6		525,366		(1,136)	(254,778)
Beginning balance (in shares) at Dec. 31, 2023			88,448,948
Beginning balance at Dec. 31, 2023	368,401		$ 8		667,648		30	(299,285)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under ESPP (in shares)			122,035
Issuance of common stock under ESPP	667				667
Issuance of common stock on exercise of options (in shares)			134,347
Issuance of common stock on exercise of options	489				489
Issuance of common stock in connection with our ATM offering, net of offering expenses (in shares)			1,594,171
Issuance of common stock in connection with our ATM offering, net of offering expenses	$ 11,330		$ 1		11,329
Issuance of common stock on RSU release (in shares)	15,000
Stock-based compensation expense	$ 3,988				3,988
Net loss	(41,234)							(41,234)
Other comprehensive income (loss)	(352)						(352)
Ending balance (in shares) at Mar. 31, 2024			90,314,501
Ending balance at Mar. 31, 2024	343,289		$ 9		684,121		(322)	(340,519)
Beginning balance (in shares) at Dec. 31, 2023			88,448,948
Beginning balance at Dec. 31, 2023	$ 368,401		$ 8		667,648		30	(299,285)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on exercise of options (in shares)	182,217
Net loss	$ (78,931)
Ending balance (in shares) at Jun. 30, 2024			90,362,771
Ending balance at Jun. 30, 2024	310,464		$ 9		688,990		(319)	(378,216)
Beginning balance (in shares) at Mar. 31, 2024			90,314,501
Beginning balance at Mar. 31, 2024	343,289		$ 9		684,121		(322)	(340,519)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under ESPP (in shares)			400
Issuance of common stock under ESPP	2				2
Issuance of common stock on exercise of options (in shares)			47,870
Issuance of common stock on exercise of options	129				129
Stock-based compensation expense	4,738				4,738
Net loss	(37,697)							(37,697)
Other comprehensive income (loss)	3						3
Ending balance (in shares) at Jun. 30, 2024			90,362,771
Ending balance at Jun. 30, 2024	$ 310,464		$ 9		$ 688,990		$ (319)	$ (378,216)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (78,931)	$ (57,563)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,566	1,206
Gain on disposal of fixed assets	0	(34)
Non-cash consideration for licensing and collaboration revenue	(1,634)	(61)
Change in fair value of equity securities	102	(7)
Stock-based compensation expense	8,726	6,716
Change in fair value of MSKCC success payments liability	(2,098)	(534)
Acquired in-process research and development	1,625	0
Accretion of discounts on investments in marketable securities, net	(2,485)	(3,598)
Non-cash lease expense	1,048	1,024
Changes in operating assets and liabilities:
Accounts receivable	(68)	(564)
Contract assets	453	765
Other receivables	557	720
Prepaid expenses and other current assets	(162)	2,356
Other assets	(50)	119
Accounts payable	352	2,042
Accrued expenses and other current liabilities	2,763	(431)
Deferred revenue, current and long-term	(1,515)	5,231
Operating lease liabilities	(318)	(511)
Net cash used in operating activities	(70,069)	(43,124)
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of marketable securities	204,889	171,025
Purchases of marketable securities	(155,419)	(134,674)
Purchases of property and equipment	(3,689)	(4,584)
Payments to acquire in-process research and development	(1,625)	0
Net cash provided by investing activities	44,156	31,767
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock pursuant to private placement with Pfizer	0	17,450
Proceeds from exercise of stock options	619	755
Proceeds from purchases of common stock under ESPP	669	0
Proceeds from issuance of common stock related to our ATM, net of offering expenses	11,329	1,008
Net cash provided by financing activities	12,617	19,213
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	(13,296)	7,856
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH — BEGINNING OF PERIOD	51,208	58,384
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH — END OF PERIOD	37,912	66,240
RECONCILIATION OF CASH, CASH EQUIVALENTS, AND RESTRICTED CASH
Cash and cash equivalents	37,866	66,194
Restricted cash	46	46
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH ON THE BALANCE SHEET	37,912	66,240
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for income taxes	0	170
SUPPLEMENTAL SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Purchases of property and equipment included in accounts payable and accrued expenses	175	2,562
Offering costs included in accrued expenses	$ 0	$ 160

Description of the Business, Or

Description of the Business, Organization, and Liquidity	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Business, Organization, and Liquidity	Description of the Business, Organization, and Liquidity Business and Organization Caribou Biosciences, Inc. (“Company” or “we”) is a clinical-stage C lustered R egularly I nterspaced S hort P alindromic R epeats (“CRISPR”) genome-editing biopharmaceutical company dedicated to developing transformative therapies for patients with devastating diseases. Our genome-editing platform, including our novel chRDNA ( C RISPR h ybrid R NA- DNA , or “chRDNA,” pronounced “chardonnay”) technology, enables more precise genome editing to develop cell therapies that are armored to improve activity against diseases. We are advancing a pipeline of allogeneic, or off-the-shelf, cell therapies from our chimeric antigen receptor (“CAR”) T (“CAR-T”) cell platform as readily available therapeutic treatments for patients. We incorporated in October 2011 as a Delaware corporation and are headquartered in Berkeley, California. We have 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. Our wholly owned subsidiaries hold interests in our equity investments and do not have operating activities. Liquidity We have incurred operating losses and negative cash flows from operations since our inception and we had an accumulated deficit of $378.2 million as of June 30, 2024. During the six months ended June 30, 2024, we incurred a net loss of $78.9 million and used $70.1 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, regulatory approval, and commercialization of our product candidates and on our ability to generate 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, cash equivalents, and marketable securities of $311.8 million as of June 30, 2024, will be sufficient to fund our current operating plan for at least the next 12 months from the date of issuance of our unaudited condensed consolidated financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	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 year ended December 31, 2023, included in our Annual Report on Form 10-K (“Form 10-K”). Basis of Presentation and Principles of Consolidation Our unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and include our accounts and the accounts of our wholly owned subsidiaries. All intercompany accounts and transactions are eliminated in consolidation. Use of Estimates The preparation of unaudited 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 unaudited condensed consolidated financial statements; and the reported amounts of revenue, income, and expenses during the applicable reporting period. On an ongoing basis, we evaluate our estimates and assumptions, including those related to revenue recognition, stock-based compensation expense, accrued expenses related to research and development activities, valuation of the Memorial Sloan Kettering Cancer Center (“MSKCC”) success payments liability, operating lease right-of-use assets and liabilities, and income taxes. Our management bases its estimates on historical experience and 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 operating segment, which is the business of developing a pipeline of allogeneic CAR-T cell therapies. Our president and 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 marketable securities and equity securities. Substantially all our cash and cash equivalents are deposited in accounts at four financial institutions, and our account balances exceed federally insured limits. We mitigate the risks by investing in high-grade instruments, limiting our exposure to one issuer, and we monitor the ongoing creditworthiness of these financial institutions and issuers. Licensees that represent 10% or more of our revenue and accounts receivable and contract assets were as follows: Revenue Revenue Accounts Receivable and Contract Assets Three Months Ended Six Months Ended As of As of June 30, 2024 June 30, 2023 June 30, 2024 June 30, 2023 Licensee A * * 10.4 % * * * Licensee B 18.7 % 17.1 % 20.5 % 19.5 % 59.3 % 47.5 % Licensee C * 36.6 % * 41.1 % * * Licensee D 17.9 % * 21.1 % * * * Licensee E 46.9 % 30.6 % 27.5 % 15.8 % * * Total 83.5 % 84.3 % 79.5 % 76.4 % 59.3 % 47.5 % *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 contract assets should be impaired. No allowance for credit losses or contract asset impairment was recorded as of June 30, 2024, or December 31, 2023. Recent Accounting Pronouncements Not Yet Adopted In October 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-06, Disclosure Improvements: Codification Amendments in Response to the U.S. Securities and Exchange Commission (“SEC”) Disclosure Update and Simplification Initiative. This ASU aligns the requirements in the Accounting Standards Codification (“ASC”) to the removal of certain disclosure requirements set out in Regulation S-X and Regulation S-K, announced by the SEC. The effective date for each amended topic in the ASC is either the date on which the SEC’s removal of the related disclosure requirement from Regulation S-X or Regulation S-K becomes effective or June 30, 2027, if the SEC has not removed the requirements by that date. Early adoption is prohibited. We are currently evaluating the impact of the new guidance and do not expect that the adoption of ASU 2023-06 will have a material impact on our consolidated financial statements. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This ASU requires public entities to disclose information about their reportable segments’ significant expenses and other segment items on an interim and annual basis. Public entities with a single reportable segment are required to apply the disclosure requirements in ASU 2023-07, as well as all existing segment disclosures and reconciliation requirements in ASC 280 on an interim and annual basis. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the impact of the adoption of ASU 2023-07. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This ASU requires public entities, on an annual basis, to provide disclosure of specific categories in the rate reconciliation, as well as disclosure of income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the impact of the adoption of ASU 2023-09. In March 2024, the FASB issued ASU No. 2024-02, Codification Improvements - Amendments to Remove References to the Concepts Statements. The amendments in ASU 2024-02 clarify and simplify references to certain concept statements within U.S. GAAP. ASU 2024-02 is effective for fiscal years beginning after December 15, 2024, with early application permitted. We are currently evaluating the impact of the adoption of ASU 2024-02.

Fair Value Measurements and Fai

Fair Value Measurements and Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements and Fair Value of Financial Instruments	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, Level 2, and Level 3 financial instruments. We generally classify our marketable securities as Level 1 or Level 2. Instruments are classified as Level 2 when observable market prices for identical securities that are traded in less active markets are used. When observable market prices for identical securities are not available, such instruments are priced using benchmark curves, benchmarking of like securities, sector groupings, matrix pricing, and valuation models. These valuation models are proprietary to the pricing providers or brokers and incorporate a number of inputs including, in approximate order of priority: benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications. For certain security types, additional inputs may be used, or some of the standard inputs may not be applicable. Evaluators may prioritize inputs differently on any given day for any security based on market conditions, and not all inputs listed are available for use in the evaluation process for each security valuation on any given day. Changes in the ability to observe valuation inputs may result in a reclassification of levels of certain securities within the fair value hierarchy. We recognize transfers into and out of levels within the fair value hierarchy in the period in which the actual event or change in circumstances that caused the transfer occurs. No such transfers occurred during the six months ended June 30, 2024, and 2023. Level 1 financial instruments are comprised of money market fund investments and U.S. Treasury bills. Level 2 financial instruments are comprised of commercial paper, corporate debt securities, and U.S. government agency bonds. Financial assets and liabilities are considered Level 3 when their fair values are determined using pricing models, discounted cash flow methodologies, or similar techniques, and at least one significant model assumption or input is unobservable. Level 3 financial instruments consist of the MSKCC success payments liability. 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 June 30, 2024 Total Level 1 Level 2 Level 3 Assets: U.S. Treasury bills ($5,786 included in cash and cash equivalents) $ 213,184 $ 213,184 $ — $ — Commercial paper ($18,210 included in cash and cash equivalents) 43,931 — 43,931 — U.S. government agency bonds ($2,995 included in cash and cash equivalents) 33,358 — 33,358 — Money market fund investments (included in cash and cash equivalents) 10,875 10,875 — — Corporate debt securities 10,425 10,425 — Total fair value of assets $ 311,773 $ 224,059 $ 87,714 $ — Liabilities: MSKCC success payments liability $ 841 $ — $ — $ 841 Total fair value of liabilities $ 841 $ — $ — $ 841 Fair Value Measurements as of December 31, 2023 Total Level 1 Level 2 Level 3 Assets: U.S. Treasury bills ($23,527 included in cash and cash equivalents) $ 262,439 $ 262,439 $ — $ — Commercial paper ($9,759 included in cash and cash equivalents) 40,373 — 40,373 — U.S. government agency bonds 40,185 — 40,185 — Money market fund investments (included in cash and cash equivalents) 17,876 17,876 — — Corporate debt securities 11,531 — 11,531 — Total fair value of assets $ 372,404 $ 280,315 $ 92,089 $ — Liabilities: MSKCC success payments liability $ 2,939 $ — $ — $ 2,939 Total fair value of liabilities $ 2,939 $ — $ — $ 2,939 The fair value and amortized cost of cash equivalents and available-for-sale marketable securities by major security type as of June 30, 2024, and December 31, 2023, are presented in the following tables (in thousands): As of June 30, 2024 Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value U.S. Treasury bills ($5,786 included in cash and cash equivalents) $ 213,408 $ 11 $ (235) $ 213,184 Commercial paper ($18,210 included in cash and cash equivalents) 43,961 — (30) 43,931 U.S. government agency bonds ($2,995 included in cash and cash equivalents) 33,414 — (56) 33,358 Money market fund investments (included in cash equivalents) 10,875 — — 10,875 Corporate debt securities 10,435 5 (15) 10,425 Total cash equivalents and marketable securities $ 312,093 $ 16 $ (336) $ 311,773 Classified as: Cash and cash equivalents $ 37,866 Marketable securities, short-term 223,783 Marketable securities, long-term 50,124 Total cash equivalents and marketable securities $ 311,773 As of December 31, 2023 Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value U.S. Treasury bills ($23,527 included in cash and cash equivalents) $ 262,328 $ 331 $ (220) $ 262,439 Commercial paper ($9,759 included in cash and cash equivalents) 40,386 — (13) 40,373 U.S. government agency bonds 40,295 1 (111) 40,185 Money market fund investments (included in cash equivalents) 17,876 — — 17,876 Corporate debt securities 11,489 50 (8) 11,531 Total cash equivalents and marketable securities $ 372,374 $ 382 $ (352) $ 372,404 Classified as: Cash and cash equivalents $ 51,162 Marketable securities, short-term 277,665 Marketable securities, long-term 43,577 Total cash equivalents and marketable securities $ 372,404 The following table presents the fair value of available-for-sale marketable securities by contractual maturities (in thousands): June 30, 2024 Due in less than one year $ 223,783 Due in one to five years 50,124 Total $ 273,907 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, 2023 $ 2,939 Change in fair value (2,098) Balance at June 30, 2024 $ 841 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. We recorded a $1.8 million and $0.3 million change in the fair value of the MSKCC success payments liability as a gain in other income (expense) in our unaudited condensed consolidated statements of operations and comprehensive loss for the three months ended June 30, 2024, and 2023, respectively. We recorded a $2.1 million and $0.5 million change in the fair value of the MSKCC success payments liability as a gain in other income (expense) in our unaudited condensed consolidated statements of operations and comprehensive loss for the six months ended June 30, 2024, and 2023, respectively. The table below summarizes key assumptions used in the valuation of the MSKCC success payments liability: As of Fair value of common stock $ 5.73 Risk-free interest rate 3.88% Expected volatility 79% Probability of achieving multiple of Initial Share Price (1) 5.2% to 18.1% Expected term (years) 3.7 to 5.2 (1) MSKCC is entitled to certain success payments if our common stock fair value increases, during a specified time period, by certain multiples of value based on a comparison of the fair market value of our common stock to $5.1914 per share, adjusted for any future stock splits (“Initial Share Price”). For further information regarding our agreement with MSKCC, see Note 4 to the consolidated financial statements included in our Form 10-K. 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 time period from the initiation of our AMpLify phase 1 clinical trial for our CB-012 product candidate utilizing the know-how, biological materials, and intellectual property licensed under the Exclusive License Agreement, dated November 13, 2020, with MSKCC (“MSKCC Agreement”) until the estimated timing of marketing approval for this product candidate from the U.S. Food and Drug Administration (“FDA”). In addition, we incorporated the estimated number and timing of valuation measurement dates in the calculation of the MSKCC success payments liability. As of June 30, 2024, we did not note any significant changes to the inputs used in the MSKCC success payments liability fair value calculation, other than a change in the fair value of our common stock to $1.64 per share.

Significant Agreements

Significant Agreements	6 Months Ended
	Jun. 30, 2024
Significant Agreements [Abstract]
Significant Agreements	Significant Agreements Since December 31, 2023, there have been no material changes to the key terms of our significant agreements. For further information regarding our significant agreements, see Note 4 to the consolidated financial statements included in our Form 10-K. During the three months ended June 30, 2023, we recognized $1.4 million in revenue associated with the now-terminated Collaboration and License Agreement, dated February 9, 2021 (as amended, “AbbVie Agreement”) with AbbVie Manufacturing Management Unlimited Company (“AbbVie”). During the six months ended June 30, 2023, we recognized $3.0 million in revenue under the AbbVie Agreement. No revenue was recognized under the AbbVie Agreement during each of the three- or six-month periods ended June 30, 2024, as the AbbVie Agreement was terminated effective October 25, 2023. As of June 30, 2024, and December 31, 2023, we had no amounts recorded in accounts receivable, contract assets, or deferred revenue in our consolidated balance sheets related to the AbbVie Agreement. Our significant agreements may include nonrefundable, upfront payments; annual license maintenance fees; sublicensing fees; obligations to reimburse for patent prosecution and maintenance fees; success payments; regulatory clinical and commercial milestones; and royalty payments. Our obligation to make such payments is contingent upon milestones being achieved, licensed products being commercialized, and the agreements remaining in effect. For the three months ended June 30, 2024, and 2023, we recorded $0.3 million and $0.4 million, respectively, as research and development expense in our unaudited consolidated statements of operations and comprehensive loss related to our license agreements. For the six months ended June 30, 2024, and 2023, we recorded $1.6 million and $0.8 million, respectively, as research and development expense in our unaudited condensed consolidated statements of operations and comprehensive loss related to our significant agreements. For the three months ended June 30, 2024, and 2023, we recorded $0.2 million and $1.0 million, respectively, as general and administrative expense for patent prosecution and maintenance costs in our unaudited condensed consolidated statements of operations and comprehensive loss, which includes reimbursements of patent prosecution and maintenance costs of $0.4 million and $0.7 million, respectively. For the six months ended June 30, 2024, and 2023, we recorded $0.4 million and $1.8 million, respectively, as general and administrative expense for patent prosecution and maintenance costs in our unaudited condensed consolidated statements of operations and comprehensive loss, which includes reimbursements of patent prosecution and maintenance costs of $0.5 million and $1.1 million, respectively. As of June 30, 2024, certain license and assignment agreements included potential future payments from us for development, regulatory, and sales milestones totaling approximately $159.9 million.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue	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 table is a summary of revenue by geographic location for the three and six months ended June 30, 2024, and 2023 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 United States $ 3,444 $ 3,746 $ 5,713 $ 7,131 Rest of world 20 9 180 126 Total $ 3,464 $ 3,755 $ 5,893 $ 7,257 During the three months ended June 30, 2024, we recognized $2.8 million of revenue related to performance obligations satisfied at a point in time, and we recognized $0.7 million of revenue related to performance obligations satisfied over time. During the three months ended June 30, 2023, we recognized $2.4 million of revenue related to performance obligations satisfied at a point in time, and we recognized $1.4 million of revenue related to performance obligations satisfied over time. During the six months ended June 30, 2024, we recognized $4.6 million of revenue related to performance obligations satisfied at a point in time, and we recognized $1.3 million of revenue related to performance obligations satisfied over time. During the six months ended June 30, 2023, we recognized $4.3 million of revenue related to performance obligations satisfied at a point in time, and we recognized $3.0 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 our licensees with invoices outstanding as of the end of a reporting period. Contract assets are rights to consideration in exchange for a license that we have granted to a licensee when the right is conditional on something other than the passage of time. Our contract asset balances represent royalties and milestone payments from our other license agreements that are unbilled as of the end of a reporting period. Contract liabilities consist of deferred revenue and relate to amounts invoiced to, or advance consideration received from, licensees that precede our satisfaction of the associated performance obligations. As of June 30, 2024, and December 31, 2023, our deferred revenue balance primarily resulted from the upfront payment received relating to our performance obligation to Pfizer Inc. (“Pfizer”). The remaining deferred revenue relates to upfront payments received under license agreements that also include nonrefundable annual license fees, which are accounted for as material rights for license renewals and are recognized at the point in time when annual license fees are paid by the licensees and the renewal periods begin. The following table presents changes in our contract assets and liabilities during the six months ended June 30, 2024 (in thousands): Balance as of Additions Deductions Balance as of Accounts receivable $ 148 $ 3,193 $ (3,126) $ 215 Contract assets: Unbilled accounts receivable $ 1,425 $ 1,943 $ (2,396) $ 972 Contract liabilities: Deferred revenue, current and long-term $ 8,949 $ 767 $ (2,283) $ 7,433 Unbilled accounts receivable decreased $0.5 million during the six months ended June 30, 2024, primarily due to the decrease in minimum annual royalties under our license agreements. Deferred revenue decreased during the six months ended June 30, 2024, primarily due to the recognition of deferred revenue related to the satisfaction of our performance obligation to Pfizer. See Note 7 to our unaudited condensed consolidated financial statements included elsewhere in this Form 10-Q for additional information. During the six months ended June 30, 2024, and 2023, we recognized $1.6 million and $2.4 million of revenue, respectively, which was included in the opening contract liabilities balances at the beginning of the respective periods. Transaction Prices Allocated to Remaining Performance Obligations Remaining performance obligations represent in aggregate the amount of a transaction price that has been allocated to performance obligations not delivered as of the end of a reporting period. The value of transaction prices allocated to remaining unsatisfied performance obligations as of June 30, 2024, was approximately $7.4 million. We expect to recognize approximately $2.8 million of remaining performance obligations as revenue in the next 12 months and to recognize the remainder thereafter. Capitalized Contract Acquisition Costs and Fulfillment Costs We did not incur any expenses to obtain our existing contracts, 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	6 Months Ended
	Jun. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Items	Balance Sheet Items Other receivables consisted of the following (in thousands): June 30, December 31, Patent cost reimbursements $ 921 $ 1,403 Accrued interest on marketable securities 808 702 Other — 181 Total $ 1,729 $ 2,286 Prepaid expenses and other current assets consisted of the following (in thousands): June 30, December 31, Prepaid contract manufacturing and clinical costs $ 3,763 $ 3,942 Prepaid insurance 170 993 Other 2,384 1,220 Total $ 6,317 $ 6,155 Property and equipment, net, consisted of the following (in thousands): June 30, December 31, Lab equipment $ 18,334 $ 15,581 Leasehold improvements 2,094 2,235 Computer equipment 906 895 Furniture and equipment 712 499 Construction in progress 8,493 8,204 Total property and equipment, gross 30,539 27,414 Less: accumulated depreciation and amortization (10,663) (9,144) Property and equipment, net $ 19,876 $ 18,270 Depreciation and amortization expenses related to property and equipment were $0.9 million and $0.6 million for the three months ended June 30, 2024, and 2023, respectively. Depreciation and amortization expenses related to property and equipment were $1.6 million and $1.2 million, for the six months ended June 30, 2024, and 2023, respectively. Accrued expenses and other current liabilities consisted of the following (in thousands): June 30, December 31, Accrued employee compensation and related expenses $ 6,486 $ 9,517 Accrued research and development expenses 9,698 8,720 Accrued securities litigation settlement 3,900 — Accrued patent expenses 872 613 Accrued expenses related to sublicensing revenues 550 802 Credit card liability 539 377 Other 1,581 1,106 Total $ 23,626 $ 21,135

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2024
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Since December 31, 2023, there have been no new related party transactions, except as set forth below. For further information regarding our related parties, see Note 7 to the consolidated financial statements included in our Form 10-K. Pfizer Investment During the three months ended June 30, 2024, we recognized $0.6 million of revenue from our Information Rights Agreement with Pfizer, dated June 29, 2023, pursuant to which we had originally allocated $7.5 million as a contract with a customer under ASC Topic 606. During the six months ended June 30, 2024, we recognized $1.2 million of revenue from Pfizer. We did not recognize any revenue from Pfizer during each of the three- and six-month periods ended June 30, 2023. As of June 30, 2024, there was approximately $5.0 million of related party deferred revenue ($2.5 million included in current liabilities and $2.5 million included in long-term liabilities) related to our performance obligation to Pfizer. As of December 31, 2023, there was approximately $6.2 million of related party deferred revenue ($2.5 million included in current liabilities and $3.7 million included in long-term liabilities) related to our performance obligation to Pfizer. Edge Animal Health During the three months ended June 30, 2024, we received additional shares of convertible preferred stock pursuant to anti-dilution rights associated with the Exclusive License Agreement for Veterinary Therapeutics (as amended, the “Edge chRDNA License Agreement”) with Edge Animal Health (“Edge”), a private company and related party. Edge issued to us 1,623,275 shares of convertible preferred stock with an estimated fair value of $1.6 million, based on management’s best estimate and judgment. The Edge chRDNA License Agreement is a contract with a customer under ASC 606. Accordingly, we recognized $1.6 million as revenue during each of the three- and six-month periods ended June 30, 2024. We did not recognize any revenue in connection with the Edge chRDNA License Agreement in 2023. On May 16, 2023, we entered into an Exclusive License Agreement for Veterinary Therapeutics (CRISPR-Cas9) (the “Edge Cas9 License Agreement”), under which we granted Edge an exclusive worldwide license to certain CRISPR-Cas9 intellectual property rights in the field of veterinary therapeutics. Previously, on May 15, 2020, we entered into an Option for an Exclusive License under which Edge could exercise its option within three years upon payment of a total of $1.2 million, which option Edge exercised and paid $1.2 million, and we entered into the Edge Cas9 License Agreement. We recognized $1.2 million of revenue in connection with the Edge Cas9 License Agreement for each of the three and six months ended June 30, 2023. We did not recognize any revenue in connection with the Edge Cas9 License Agreement in 2024.

Leases

Leases	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Leases	Leases Operating Lease Obligations As of June 30, 2024, we had operating leases for our laboratory and office space in Berkeley, California, consisting of approximately 75,000 square feet, with remaining lease terms up to 8.1 years. Certain of our laboratory and office space lease agreements include options to extend the terms for a period of five years and also contain provisions for future rent increases. In addition to base rent, we pay our share of operating expenses and taxes. The components of lease costs, which are included in our unaudited condensed consolidated statements of operations and comprehensive loss, were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Operating lease cost (1) $ 1,919 $ 1,928 $ 3,872 $ 3,812 Short-term lease cost 62 62 125 125 Total lease cost $ 1,981 $ 1,990 $ 3,997 $ 3,937 (1) Includes $0.6 million and $0.6 million of variable lease cost related to operating expenses and taxes for the three months ended June 30, 2024, and June 30, 2023, respectively. Includes $1.3 million and $1.2 million of variable lease cost related to operating expenses and taxes for the six months ended June 30, 2024, and 2023, respectively. Supplemental information related to our leases was as follows (in thousands): Six Months Ended June 30, 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 1,841 $ 2,058 The following table summarizes the weighted-average remaining lease term and weighted-average discount rate for our corporate laboratory and office leases: June 30, December 31, Weighted-average remaining lease term (years) 6.9 7.4 Weighted-average discount rate 11.3 % 11.3 % The following table summarizes a maturity analysis of our operating lease liabilities showing the aggregate lease payments as of June 30, 2024 (in thousands): Remainder of 2024 (1) $ 1,644 2025 4,475 2026 5,720 2027 5,922 2028 6,122 Thereafter 15,994 Total future undiscounted lease payments 39,877 Less imputed interest (13,087) Total discounted lease payments 26,790 Less current portion of lease liability (1,262) Noncurrent portion of lease liability $ 25,528 (1) Reflects an offset of $0.6 million related to incentives expected to be received in 2024.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Research, Manufacturing, and License Agreements We enter into various agreements in the ordinary course of business, such as those with contract manufacturing organizations (“CMOs”), suppliers, clinical research organizations (“CROs”), clinical trial sites, licensors, assignors, and the like. These agreements provide for termination by either party in certain circumstances, 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 unaudited condensed consolidated financial condition, results of operations, or cash flows. Some of these agreements also include contingent payments that will become payable if and when certain development, regulatory, clinical, and/or commercial milestones are achieved by us. As of June 30, 2024, satisfaction and timing of such contingent payments is uncertain and thus cannot be reasonably estimated. Guarantees and Indemnifications In the ordinary 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. As of June 30, 2024, and December 31, 2023, we did not have any material indemnification claims that were probable or reasonably possible, and consequently, we have not recorded related liabilities. Litigation From time to time, we may become involved in litigation arising in the ordinary course of business. We record a liability for such litigation when it is probable that future losses will be incurred and if such losses can be reasonably estimated. Significant judgment by us is required to determine both probability and the estimated amount. On April 11, 2023, a putative class action lawsuit was filed in the U.S. District Court for the Northern District of California against our company and certain of our officers and current and former members of our board of directors, Bergman v. Caribou Biosciences, Inc., et al. , Case Number 4:23-cv-01742-YGR (“Bergman Case”). The Bergman complaint challenges disclosures regarding our company’s business, operations, and prospects, specifically with respect to the alleged durability of CB-010’s therapeutic effect and the product candidate’s clinical and commercial prospects, in alleged violation of Sections 11 and 15 of the Securities Act of 1933, as amended (“Securities Act”), and Sections 10(b) and 20(a) of the Exchange Act. On September 18, 2023, plaintiffs filed an amended complaint adding the IPO underwriters as defendants and making substantially the same allegations as the original complaint. On November 14, 2023, we filed a motion to dismiss the amended complaint for failure to state a claim. Motion to dismiss briefing was completed on February 21, 2024. On April 22, 2024, we reached an agreement in principle with plaintiffs to settle the Bergman Case for $3.9 million, which is included in general and administrative expense for the three months ended March 31, 2024, in exchange for a full release of the putative class’s claims against us and all of our current and former officers, current and former members of our board of directors, the IPO underwriters, and the other named defendant. The parties filed a settlement agreement with the court on June 26, 2024, which the court must approve before settlement is final. On March 22, 2023, a putative class action lawsuit was filed in Superior Court of the State of California for the County of Alameda against our company and certain of our officers and current and former members of our board of directors, Lowry v. Caribou Biosciences, Inc., et al., Case Number T23-1084 (“Lowry Case”). The Lowry Case challenges disclosures regarding our company’s business, operations, and prospects, specifically with respect to the alleged durability of CB-010’s therapeutic effect and the product candidate’s clinical and commercial prospects, in alleged violation of Sections 11 and 15 of the Securities Act. The allegations and claims in the Lowry Case are substantially similar to the Securities Act claims asserted in the Bergman Case. On April 26, 2023, we filed a motion to stay the Lowry Case during the pendency of the parallel federal court litigation in the Bergman Case, and, on July 11, 2023, our motion to stay was denied. On September 11, 2023, plaintiff filed an amended complaint making substantially the same allegations as the original complaint. On November 9, 2023, we filed a motion to dismiss the amended complaint on the grounds that our certification of incorporation mandates that Securities Act claims against us be brought in federal court. On February 28, 2024, the court granted our motion to dismiss, and, on April 15, 2024, the court entered an order of dismissal.

Common Stock

Common Stock	6 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Common Stock	Common Stock Common stock reserved for future issuance consisted of the following: As of As of Stock options, issued and outstanding 12,040,717 9,410,404 Stock options, authorized for future issuance 6,439,947 5,952,012 Stock available under our employee stock purchase plan 2,278,409 1,516,355 Unvested restricted stock units and performance-based restricted stock units 1,312,339 205,357 Total common stock reserved for future issuance 22,071,412 17,084,128 Shelf Registration Statement On August 9, 2022, we filed a shelf registration statement on Form S-3 (“Shelf Registration Statement”) with the SEC. The Shelf Registration Statement allows us to sell from time to time up to $400.0 million of common stock, preferred stock, debt securities, warrants, rights, or units comprised of any combination of these securities, for our own account in one or more offerings (including the $100.0 million of common stock reserved for our at-the-market equity offering program). The SEC declared the Shelf Registration Statement effective on August 16, 2022. The terms of any offering under the Shelf Registration Statement will be established at the time of such offering, as described in a prospectus supplement to the Shelf Registration Statement to be filed with the SEC prior to the completion of any such offering. In July and August 2023, we issued and sold a total of 22,115,384 shares of our common stock in an underwritten follow-on public offering at a price to the public of $6.50 per share, which included the full exercise of the underwriters’ right to purchase 2,884,615 additional shares of our common stock. The total gross proceeds from the offering were approximately $143.7 million ($134.4 million net of underwriting discounts and commissions and offering expenses). The shares were issued pursuant to the Shelf Registration Statement. At-the-market Equity Offering Program On August 9, 2022, we entered into an at-the-market Open Market Sale Agreement SM (“ATM Sales Agreement”) with Jefferies LLC (“Jefferies”), pursuant to which, through Jefferies as sales agent, we may from time to time, sell shares of our common stock having an aggregate offering price of up to $100.0 million in gross proceeds under the Shelf Registration Statement. As of June 30, 2024, we have sold 1,762,806 shares of our common stock under the ATM Sales Agreement, at an average price per share of $7.32 for aggregate gross proceeds of $12.9 million ($12.3 million net of offering expenses).

Stock Based Compensation

Stock Based Compensation	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock Based Compensation	Stock-Based Compensation Equity Incentive Plans In July 2021, our board of directors adopted, and our stockholders approved, the 2021 Equity Incentive Plan (“2021 Plan”) that became effective on July 22, 2021. As of June 30, 2024, we had 6,439,947 shares available for issuance under the 2021 Plan. The following table summarizes stock option activity under our equity incentive plans during the six months ended June 30, 2024: Stock Options Weighted- Weighted- Aggregate Intrinsic Value (in thousands) (1) Outstanding at December 31, 2023 9,410,404 $ 8.03 8.0 $ 6,432 Options granted 3,137,177 6.44 Options exercised (182,217) 3.39 Options cancelled or forfeited (324,647) 11.38 Outstanding at June 30, 2024 12,040,717 $ 7.59 7.8 $ 19 Exercisable at June 30, 2024 5,262,980 $ 8.01 6.8 $ 19 Vested and expected to vest at June 30, 2024 12,040,717 $ 7.59 7.8 $ 19 (1) 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 at the end of each reporting period referenced above. Grant Date Fair Value During the three months ended June 30, 2024, and 2023, we granted 223,450 and 486,366 stock options to employees with a weighted average grant date fair value of $2.16 and $2.95, respectively. During the six months ended June 30, 2024, and 2023, we granted 3,137,177 and 3,022,706 stock options to employees with a weighted average grant date fair value of $4.42 and $3.94, respectively. We estimated the fair value of each employee stock option award on the grant date using the Black-Scholes option-pricing model based on the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Volatility 75.7% 74.7% to 74.8% 75.7% to 75.9% 74.7% to 75.0% Expected term (in years) 6.0 6.0 5.0 to 6.0 5.0 to 6.0 Risk-free interest rate 4.5% 3.6% to 3.9% 4.0% to 4.5% 3.5% to 4.1% Expected dividend yield 0.0% 0.0% 0.0% 0.0% As of June 30, 2024, there was $31.1 million of unrecognized stock-based compensation expense related to employee stock options that is expected to be recognized over a weighted-average period of 2.7 years. Restricted Stock Units During the six months ended June 30, 2024, we granted 1,143,617 restricted stock units (“RSUs”), and we did not grant any performance-based RSUs (“PSUs”) under the 2021 Plan. A summary of the status of and change in unvested RSUs and PSUs as of June 30, 2024 was as follows: Number of Shares Underlying Outstanding RSUs and PSUs Weighted-Average Grant Date Fair Value per RSU and PSU Unvested, January 1, 2024 205,357 $ 8.49 Granted 1,143,617 6.33 Vested (15,000) 10.64 Forfeited (21,635) 7.55 Unvested, June 30, 2024 1,312,339 $ 6.60 On August 22, 2022, we granted PSUs to our executive officers, which will vest contingent upon the achievement of a clinical milestone for CB-010 during a performance period ending December 31, 2024, and the executive officer’s continued employment during the performance period. As of June 30, 2024, the achievement of this milestone was not considered probable and, therefore, no stock-based compensation was recorded. As of June 30, 2024, the total unrecognized stock-based compensation expense related to unvested RSUs was $6.8 million, which is expected to be recognized over the remaining weighted-average vesting period of 3.2 years. As of June 30, 2024, there was approximately $0.6 million of unrecognized stock-based compensation expense related to unvested PSUs. Employee Stock Purchase Plan (“ESPP”) In July 2021, our board of directors adopted, and our stockholders approved, the ESPP, which became effective on July 22, 2021. We issued 330,002 shares of common stock under the ESPP as of June 30, 2024. We recorded $0.5 million in accrued liabilities related to contributions withheld as of June 30, 2024. Stock-Based Compensation Expense We recorded stock-based compensation expense related to employee equity-based awards grants in our unaudited condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Research and development $ 1,994 $ 1,551 $ 3,610 $ 2,860 General and administrative 2,744 2,034 5,116 3,856 Total $ 4,738 $ 3,585 $ 8,726 $ 6,716 The above stock-based compensation expense related to the following equity-based awards (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Stock options $ 3,891 $ 3,202 $ 7,379 $ 6,000 ESPP 157 189 229 331 RSUs 690 194 1,118 385 Total $ 4,738 $ 3,585 $ 8,726 $ 6,716

401(k) Savings Plan

401(k) Savings Plan	6 Months Ended
	Jun. 30, 2024
Retirement Benefits [Abstract]
401(K) Savings Plan	401(k) Savings Plan In 2017, we established a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code of 1986, as amended (“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 six months ended June 30, 2024, and 2023, we contributed $0.7 million and $0.5 million, respectively, to our 401(k) plan.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes No income tax expense was recorded during each of the three- and six-month periods ended June 30, 2024, and 2023 due to our operating losses.

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Net Loss Per Share	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 Six Months Ended 2024 2023 2024 2023 Numerator: Net loss $ (37,697) $ (29,519) $ (78,931) $ (57,563) Denominator: Weighted-average common shares outstanding used to compute net loss per share, basic and diluted 90,340,932 61,417,934 89,821,935 61,302,863 Net loss per share, basic and diluted $ (0.42) $ (0.48) $ (0.88) $ (0.94) 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 follows: As of As of Stock options outstanding 12,040,717 9,253,848 RSUs issued and outstanding 1,259,982 233,035 Shares committed under ESPP 108,788 149,350 13,409,487 9,636,233

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn July 16, 2024, we announced that we had discontinued preclinical research activities associated with our allogeneic CAR-NK platform and reduced our workforce by 21 positions, or approximately 12%. In connection with the workforce reduction, we will incur approximately $0.5 million to $1.0 million in costs, consisting primarily of cash severance costs, benefits, and transition support services for impacted employees, which we expect to recognize in the third quarter of 2024.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation Our unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and include our accounts and the accounts of our wholly owned subsidiaries. All intercompany accounts and transactions are eliminated in consolidation.
Use Of Estimates	Use of Estimates The preparation of unaudited 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 unaudited condensed consolidated financial statements; and the reported amounts of revenue, income, and expenses during the applicable reporting period. On an ongoing basis, we evaluate our estimates and assumptions, including those related to revenue recognition, stock-based compensation expense, accrued expenses related to research and development activities, valuation of the Memorial Sloan Kettering Cancer Center (“MSKCC”) success payments liability, operating lease right-of-use assets and liabilities, and income taxes. Our management bases its estimates on historical experience and 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 operating segment, which is the business of developing a pipeline of allogeneic CAR-T cell therapies. Our president and 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 marketable securities and equity securities. Substantially all our cash and cash equivalents are deposited in accounts at four financial institutions, and our account balances exceed federally insured limits. We mitigate the risks by investing in high-grade instruments, limiting our exposure to one issuer, and we monitor the ongoing creditworthiness of these financial institutions and issuers. Licensees that represent 10% or more of our revenue and accounts receivable and contract assets were as follows: Revenue Revenue Accounts Receivable and Contract Assets Three Months Ended Six Months Ended As of As of June 30, 2024 June 30, 2023 June 30, 2024 June 30, 2023 Licensee A * * 10.4 % * * * Licensee B 18.7 % 17.1 % 20.5 % 19.5 % 59.3 % 47.5 % Licensee C * 36.6 % * 41.1 % * * Licensee D 17.9 % * 21.1 % * * * Licensee E 46.9 % 30.6 % 27.5 % 15.8 % * * Total 83.5 % 84.3 % 79.5 % 76.4 % 59.3 % 47.5 % *Less than 10%
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In October 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-06, Disclosure Improvements: Codification Amendments in Response to the U.S. Securities and Exchange Commission (“SEC”) Disclosure Update and Simplification Initiative. This ASU aligns the requirements in the Accounting Standards Codification (“ASC”) to the removal of certain disclosure requirements set out in Regulation S-X and Regulation S-K, announced by the SEC. The effective date for each amended topic in the ASC is either the date on which the SEC’s removal of the related disclosure requirement from Regulation S-X or Regulation S-K becomes effective or June 30, 2027, if the SEC has not removed the requirements by that date. Early adoption is prohibited. We are currently evaluating the impact of the new guidance and do not expect that the adoption of ASU 2023-06 will have a material impact on our consolidated financial statements. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This ASU requires public entities to disclose information about their reportable segments’ significant expenses and other segment items on an interim and annual basis. Public entities with a single reportable segment are required to apply the disclosure requirements in ASU 2023-07, as well as all existing segment disclosures and reconciliation requirements in ASC 280 on an interim and annual basis. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the impact of the adoption of ASU 2023-07. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This ASU requires public entities, on an annual basis, to provide disclosure of specific categories in the rate reconciliation, as well as disclosure of income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the impact of the adoption of ASU 2023-09. In March 2024, the FASB issued ASU No. 2024-02, Codification Improvements - Amendments to Remove References to the Concepts Statements. The amendments in ASU 2024-02 clarify and simplify references to certain concept statements within U.S. GAAP. ASU 2024-02 is effective for fiscal years beginning after December 15, 2024, with early application permitted. We are currently evaluating the impact of the adoption of ASU 2024-02.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2024
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 Contract Assets Three Months Ended Six Months Ended As of As of June 30, 2024 June 30, 2023 June 30, 2024 June 30, 2023 Licensee A * * 10.4 % * * * Licensee B 18.7 % 17.1 % 20.5 % 19.5 % 59.3 % 47.5 % Licensee C * 36.6 % * 41.1 % * * Licensee D 17.9 % * 21.1 % * * * Licensee E 46.9 % 30.6 % 27.5 % 15.8 % * * Total 83.5 % 84.3 % 79.5 % 76.4 % 59.3 % 47.5 % *Less than 10%

Fair Value Measurements and F_2

Fair Value Measurements and Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2024
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 June 30, 2024 Total Level 1 Level 2 Level 3 Assets: U.S. Treasury bills ($5,786 included in cash and cash equivalents) $ 213,184 $ 213,184 $ — $ — Commercial paper ($18,210 included in cash and cash equivalents) 43,931 — 43,931 — U.S. government agency bonds ($2,995 included in cash and cash equivalents) 33,358 — 33,358 — Money market fund investments (included in cash and cash equivalents) 10,875 10,875 — — Corporate debt securities 10,425 10,425 — Total fair value of assets $ 311,773 $ 224,059 $ 87,714 $ — Liabilities: MSKCC success payments liability $ 841 $ — $ — $ 841 Total fair value of liabilities $ 841 $ — $ — $ 841 Fair Value Measurements as of December 31, 2023 Total Level 1 Level 2 Level 3 Assets: U.S. Treasury bills ($23,527 included in cash and cash equivalents) $ 262,439 $ 262,439 $ — $ — Commercial paper ($9,759 included in cash and cash equivalents) 40,373 — 40,373 — U.S. government agency bonds 40,185 — 40,185 — Money market fund investments (included in cash and cash equivalents) 17,876 17,876 — — Corporate debt securities 11,531 — 11,531 — Total fair value of assets $ 372,404 $ 280,315 $ 92,089 $ — Liabilities: MSKCC success payments liability $ 2,939 $ — $ — $ 2,939 Total fair value of liabilities $ 2,939 $ — $ — $ 2,939
Schedule of Fair Value and Amortized Cost of Cash Equivalents and Available-for-Sale Marketable Securities	The fair value and amortized cost of cash equivalents and available-for-sale marketable securities by major security type as of June 30, 2024, and December 31, 2023, are presented in the following tables (in thousands): As of June 30, 2024 Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value U.S. Treasury bills ($5,786 included in cash and cash equivalents) $ 213,408 $ 11 $ (235) $ 213,184 Commercial paper ($18,210 included in cash and cash equivalents) 43,961 — (30) 43,931 U.S. government agency bonds ($2,995 included in cash and cash equivalents) 33,414 — (56) 33,358 Money market fund investments (included in cash equivalents) 10,875 — — 10,875 Corporate debt securities 10,435 5 (15) 10,425 Total cash equivalents and marketable securities $ 312,093 $ 16 $ (336) $ 311,773 Classified as: Cash and cash equivalents $ 37,866 Marketable securities, short-term 223,783 Marketable securities, long-term 50,124 Total cash equivalents and marketable securities $ 311,773 As of December 31, 2023 Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value U.S. Treasury bills ($23,527 included in cash and cash equivalents) $ 262,328 $ 331 $ (220) $ 262,439 Commercial paper ($9,759 included in cash and cash equivalents) 40,386 — (13) 40,373 U.S. government agency bonds 40,295 1 (111) 40,185 Money market fund investments (included in cash equivalents) 17,876 — — 17,876 Corporate debt securities 11,489 50 (8) 11,531 Total cash equivalents and marketable securities $ 372,374 $ 382 $ (352) $ 372,404 Classified as: Cash and cash equivalents $ 51,162 Marketable securities, short-term 277,665 Marketable securities, long-term 43,577 Total cash equivalents and marketable securities $ 372,404
Investments Classified by Contractual Maturity Date	The following table presents the fair value of available-for-sale marketable securities by contractual maturities (in thousands): June 30, 2024 Due in less than one year $ 223,783 Due in one to five years 50,124 Total $ 273,907
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, 2023 $ 2,939 Change in fair value (2,098) Balance at June 30, 2024 $ 841
Schedule of Assumptions Used in Valuation of MSKCC Success Payments Liability	The table below summarizes key assumptions used in the valuation of the MSKCC success payments liability: As of Fair value of common stock $ 5.73 Risk-free interest rate 3.88% Expected volatility 79% Probability of achieving multiple of Initial Share Price (1) 5.2% to 18.1% Expected term (years) 3.7 to 5.2 (1) MSKCC is entitled to certain success payments if our common stock fair value increases, during a specified time period, by certain multiples of value based on a comparison of the fair market value of our common stock to $5.1914 per share, adjusted for any future stock splits (“Initial Share Price”). For further information regarding our agreement with MSKCC, see Note 4 to the consolidated financial statements included in our Form 10-K.

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following table is a summary of revenue by geographic location for the three and six months ended June 30, 2024, and 2023 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 United States $ 3,444 $ 3,746 $ 5,713 $ 7,131 Rest of world 20 9 180 126 Total $ 3,464 $ 3,755 $ 5,893 $ 7,257
Schedule of Changes in Company's Contract Assets and Liabilities	The following table presents changes in our contract assets and liabilities during the six months ended June 30, 2024 (in thousands): Balance as of Additions Deductions Balance as of Accounts receivable $ 148 $ 3,193 $ (3,126) $ 215 Contract assets: Unbilled accounts receivable $ 1,425 $ 1,943 $ (2,396) $ 972 Contract liabilities: Deferred revenue, current and long-term $ 8,949 $ 767 $ (2,283) $ 7,433

Balance Sheet Items (Tables)

Balance Sheet Items (Tables)	6 Months Ended
	Jun. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Schedule of Other Receivables	Other receivables consisted of the following (in thousands): June 30, December 31, Patent cost reimbursements $ 921 $ 1,403 Accrued interest on marketable securities 808 702 Other — 181 Total $ 1,729 $ 2,286
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): June 30, December 31, Prepaid contract manufacturing and clinical costs $ 3,763 $ 3,942 Prepaid insurance 170 993 Other 2,384 1,220 Total $ 6,317 $ 6,155
Schedule of Property and Equipment	Property and equipment, net, consisted of the following (in thousands): June 30, December 31, Lab equipment $ 18,334 $ 15,581 Leasehold improvements 2,094 2,235 Computer equipment 906 895 Furniture and equipment 712 499 Construction in progress 8,493 8,204 Total property and equipment, gross 30,539 27,414 Less: accumulated depreciation and amortization (10,663) (9,144) Property and equipment, net $ 19,876 $ 18,270
Summary of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): June 30, December 31, Accrued employee compensation and related expenses $ 6,486 $ 9,517 Accrued research and development expenses 9,698 8,720 Accrued securities litigation settlement 3,900 — Accrued patent expenses 872 613 Accrued expenses related to sublicensing revenues 550 802 Credit card liability 539 377 Other 1,581 1,106 Total $ 23,626 $ 21,135

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule Of Components Lease Cost	The components of lease costs, which are included in our unaudited condensed consolidated statements of operations and comprehensive loss, were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Operating lease cost (1) $ 1,919 $ 1,928 $ 3,872 $ 3,812 Short-term lease cost 62 62 125 125 Total lease cost $ 1,981 $ 1,990 $ 3,997 $ 3,937 (1) Includes $0.6 million and $0.6 million of variable lease cost related to operating expenses and taxes for the three months ended June 30, 2024, and June 30, 2023, respectively. Includes $1.3 million and $1.2 million of variable lease cost related to operating expenses and taxes for the six months ended June 30, 2024, and 2023, respectively.
Schedule Of Supplemental Information Related To Leases	Supplemental information related to our leases was as follows (in thousands): Six Months Ended June 30, 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 1,841 $ 2,058 The following table summarizes the weighted-average remaining lease term and weighted-average discount rate for our corporate laboratory and office leases: June 30, December 31, Weighted-average remaining lease term (years) 6.9 7.4 Weighted-average discount rate 11.3 % 11.3 %
Summary of Future Minimum Lease Payment Under Leases	The following table summarizes a maturity analysis of our operating lease liabilities showing the aggregate lease payments as of June 30, 2024 (in thousands): Remainder of 2024 (1) $ 1,644 2025 4,475 2026 5,720 2027 5,922 2028 6,122 Thereafter 15,994 Total future undiscounted lease payments 39,877 Less imputed interest (13,087) Total discounted lease payments 26,790 Less current portion of lease liability (1,262) Noncurrent portion of lease liability $ 25,528 (1) Reflects an offset of $0.6 million related to incentives expected to be received in 2024.

Common Stock (Tables)

Common Stock (Tables)	6 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Schedule of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance consisted of the following: As of As of Stock options, issued and outstanding 12,040,717 9,410,404 Stock options, authorized for future issuance 6,439,947 5,952,012 Stock available under our employee stock purchase plan 2,278,409 1,516,355 Unvested restricted stock units and performance-based restricted stock units 1,312,339 205,357 Total common stock reserved for future issuance 22,071,412 17,084,128

Stock Based Compensation (Table

Stock Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Stock Option Activity	The following table summarizes stock option activity under our equity incentive plans during the six months ended June 30, 2024: Stock Options Weighted- Weighted- Aggregate Intrinsic Value (in thousands) (1) Outstanding at December 31, 2023 9,410,404 $ 8.03 8.0 $ 6,432 Options granted 3,137,177 6.44 Options exercised (182,217) 3.39 Options cancelled or forfeited (324,647) 11.38 Outstanding at June 30, 2024 12,040,717 $ 7.59 7.8 $ 19 Exercisable at June 30, 2024 5,262,980 $ 8.01 6.8 $ 19 Vested and expected to vest at June 30, 2024 12,040,717 $ 7.59 7.8 $ 19 (1) 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 at the end of each reporting period referenced above.
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 stock option award on the grant date using the Black-Scholes option-pricing model based on the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Volatility 75.7% 74.7% to 74.8% 75.7% to 75.9% 74.7% to 75.0% Expected term (in years) 6.0 6.0 5.0 to 6.0 5.0 to 6.0 Risk-free interest rate 4.5% 3.6% to 3.9% 4.0% to 4.5% 3.5% to 4.1% Expected dividend yield 0.0% 0.0% 0.0% 0.0%
Schedule of Restricted Stock Units Activity (RSUs)	A summary of the status of and change in unvested RSUs and PSUs as of June 30, 2024 was as follows: Number of Shares Underlying Outstanding RSUs and PSUs Weighted-Average Grant Date Fair Value per RSU and PSU Unvested, January 1, 2024 205,357 $ 8.49 Granted 1,143,617 6.33 Vested (15,000) 10.64 Forfeited (21,635) 7.55 Unvested, June 30, 2024 1,312,339 $ 6.60
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 equity-based awards grants in our unaudited condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Research and development $ 1,994 $ 1,551 $ 3,610 $ 2,860 General and administrative 2,744 2,034 5,116 3,856 Total $ 4,738 $ 3,585 $ 8,726 $ 6,716
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 June 30, Six Months Ended June 30, 2024 2023 2024 2023 Stock options $ 3,891 $ 3,202 $ 7,379 $ 6,000 ESPP 157 189 229 331 RSUs 690 194 1,118 385 Total $ 4,738 $ 3,585 $ 8,726 $ 6,716

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2024
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 Six Months Ended 2024 2023 2024 2023 Numerator: Net loss $ (37,697) $ (29,519) $ (78,931) $ (57,563) Denominator: Weighted-average common shares outstanding used to compute net loss per share, basic and diluted 90,340,932 61,417,934 89,821,935 61,302,863 Net loss per share, basic and diluted $ (0.42) $ (0.48) $ (0.88) $ (0.94)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: As of As of Stock options outstanding 12,040,717 9,253,848 RSUs issued and outstanding 1,259,982 233,035 Shares committed under ESPP 108,788 149,350 13,409,487 9,636,233

Description of the Business, _2

Description of the Business, Organization, and Liquidity - Additional Information (Details) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2024 USD ($) subsidiary	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of subsidiaries | subsidiary					4
Accumulated deficit	$ 378,216				$ 378,216		$ 299,285
Net loss	37,697	$ 41,234	$ 29,519	$ 28,044	78,931	$ 57,563
Cash used in operating activities					70,069	$ 43,124
Cash, cash equivalents and short term marketable securities	$ 311,800				$ 311,800

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	6 Months Ended
	Jun. 30, 2024 USD ($) segment	Dec. 31, 2023 USD ($)
Accounting Policies [Abstract]
Number of operating segment	1
Number of reportable segment	1
Allowance for doubtful accounts | $	$ 0	$ 0

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		6 Months Ended		12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Revenue | Major Customers
Concentration Risk [Line Items]
Total	83.50%	84.30%	79.50%	76.40%
Revenue | Licensee A
Concentration Risk [Line Items]
Total			10.40%
Revenue | Licensee B
Concentration Risk [Line Items]
Total	18.70%	17.10%	20.50%	19.50%
Revenue | Licensee C
Concentration Risk [Line Items]
Total		36.60%		41.10%
Revenue | Licensee D
Concentration Risk [Line Items]
Total	17.90%		21.10%
Revenue | Licensee E
Concentration Risk [Line Items]
Total	46.90%	30.60%	27.50%	15.80%
Accounts Receivable and Contract Assets | Major Customers
Concentration Risk [Line Items]
Total			59.30%		47.50%
Accounts Receivable and Contract Assets | Licensee B
Concentration Risk [Line Items]
Total			59.30%		47.50%

Fair Value Measurements and F_3

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Financial Instruments Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Assets:
Cash and cash equivalents	$ 37,866	$ 51,162	$ 66,194
U.S. Treasury bills
Assets:
Cash and cash equivalents	5,786	23,527
Commercial paper
Assets:
Cash and cash equivalents	18,210	9,759
Fair Value, Recurring
Assets:
Assets fair value	311,773	372,404
Liabilities:
Liabilities fair value	841	2,939
Fair Value, Recurring | U.S. Treasury bills
Assets:
Assets fair value	213,184	262,439
Fair Value, Recurring | Commercial paper
Assets:
Assets fair value	43,931	40,373
Fair Value, Recurring | US Government Agency Bonds
Assets:
Assets fair value	33,358	40,185
Fair Value, Recurring | Money market funds
Assets:
Assets fair value	10,875	17,876
Fair Value, Recurring | Corporate debt securities
Assets:
Assets fair value	10,425	11,531
Fair Value, Recurring | MSKCC success payments liability
Liabilities:
Liabilities fair value	841	2,939
Fair Value, Recurring | Level 1
Assets:
Assets fair value	224,059	280,315
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring | Level 1 | U.S. Treasury bills
Assets:
Assets fair value	213,184	262,439
Fair Value, Recurring | Level 1 | Commercial paper
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 1 | US Government Agency Bonds
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 1 | Money market funds
Assets:
Assets fair value	10,875	17,876
Fair Value, Recurring | Level 1 | Corporate debt securities
Assets:
Assets fair value		0
Fair Value, Recurring | Level 1 | MSKCC success payments liability
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring | Level 2
Assets:
Assets fair value	87,714	92,089
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring | Level 2 | U.S. Treasury bills
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 2 | Commercial paper
Assets:
Assets fair value	43,931	40,373
Fair Value, Recurring | Level 2 | US Government Agency Bonds
Assets:
Assets fair value	33,358	40,185
Fair Value, Recurring | Level 2 | Money market funds
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 2 | Corporate debt securities
Assets:
Assets fair value	10,425	11,531
Fair Value, Recurring | Level 2 | MSKCC success payments liability
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring | Level 3
Assets:
Assets fair value	0	0
Liabilities:
Liabilities fair value	841	2,939
Fair Value, Recurring | Level 3 | U.S. Treasury bills
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | Commercial paper
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | US Government Agency Bonds
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | Money market funds
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | Corporate debt securities
Assets:
Assets fair value	0	0
Fair Value, Recurring | Level 3 | MSKCC success payments liability
Liabilities:
Liabilities fair value	$ 841	$ 2,939

Fair Value Measurements and F_4

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Fair Value and Amortized Cost of Cash Equivalents and Available-for-Sale Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Debt Securities, Available-for-Sale [Line Items]
Cash, cash equivalents, and available-for-sale, amortized cost	$ 312,093	$ 372,374
Cash and cash equivalents, Amortized Cost Basis	37,866	51,162	$ 66,194
Unrealized Gains	16	382
Unrealized Losses	(336)	(352)
Available-for-sale marketable securities and cash and cash equivalents, Estimated Fair Value	311,773	372,404
Marketable securities, short-term	223,783	277,665
Marketable securities, long-term	50,124	43,577
U.S. Treasury bills
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost Basis	5,786	23,527
Commercial paper
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost Basis	18,210	9,759
US Government Agency Bonds
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost Basis	2,995
Money market funds
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost Basis	10,875	17,876
Cash and cash equivalents, Estimated Fair Value	10,875	17,876
U.S. Treasury bills
Debt Securities, Available-for-Sale [Line Items]
Cash, cash equivalents, and available-for-sale, amortized cost	213,408	262,328
Unrealized Gains	11	331
Unrealized Losses	(235)	(220)
Available-for-sale marketable securities and cash and cash equivalents, Estimated Fair Value	213,184	262,439
U.S. government agency bonds
Debt Securities, Available-for-Sale [Line Items]
Available-for-sale marketable securities, Amortized Cost Basis	33,414	40,295
Unrealized Gains	0	1
Unrealized Losses	(56)	(111)
Available-for-sale marketable securities, Estimated Fair Value	33,358	40,185
Commercial paper
Debt Securities, Available-for-Sale [Line Items]
Cash, cash equivalents, and available-for-sale, amortized cost		40,386
Available-for-sale marketable securities, Amortized Cost Basis	43,961
Unrealized Gains	0	0
Unrealized Losses	(30)	(13)
Available-for-sale marketable securities and cash and cash equivalents, Estimated Fair Value		40,373
Available-for-sale marketable securities, Estimated Fair Value	43,931
Corporate debt securities
Debt Securities, Available-for-Sale [Line Items]
Available-for-sale marketable securities, Amortized Cost Basis	10,435	11,489
Unrealized Gains	5	50
Unrealized Losses	(15)	(8)
Available-for-sale marketable securities, Estimated Fair Value	$ 10,425	$ 11,531

Fair Value Measurements and F_5

Fair Value Measurements and Fair Value of Financial Instruments - Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Due in less than one year	$ 223,783	$ 277,665
Due in one to five years	50,124	$ 43,577
Total	$ 273,907

Fair Value Measurements and F_6

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Change in Fair Value of Financial Liability (Details) - MSKCC success payments liability - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Change in fair value	$ (1,800)	$ (300)	$ (2,100)	$ (500)
Level 3
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at December 31, 2023			2,939
Change in fair value			(2,098)
Balance at June 30, 2024	$ 841		$ 841

Fair Value Measurements and F_7

Fair Value Measurements and Fair Value of Financial Instruments - Additional Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2023
Fair value of common stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, measurement input	1.64		1.64		5.73
MSKCC success payments liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Change in fair value	$ 1.8	$ 0.3	$ 2.1	$ 0.5

Fair Value Measurements and F_8

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Assumptions Used in Valuation of MSKCC Success Payments Liability (Details)	12 Months Ended
	Dec. 31, 2023 $ / shares	Jun. 30, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Common stock value per share (in dollars per share)	$ 5.1914
Fair value of common stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, measurement input	5.73	1.64
Risk-free interest rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, measurement input	0.0388
Expected volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, measurement input	0.79
Probability of achieving multiple of Initial Share Price | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, measurement input	0.052
Probability of achieving multiple of Initial Share Price | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability, measurement input	0.181
Expected term (years) | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumptions term	3 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	5 years 2 months 12 days

Significant Agreements - Additi

Significant Agreements - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development	$ 35,480,000	$ 26,503,000	$ 69,268,000	$ 52,212,000
General and administrative	11,485,000	10,120,000	26,128,000	19,029,000
Future payments for milestones	159,900,000		159,900,000
Intellia Therapeutics, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development	300,000	400,000	1,600,000	800,000
General and administrative	200,000	1,000,000	400,000	1,800,000
Intellia Therapeutics, Inc. | Patents
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reduction in general and administrative expenses	400,000	700,000	500,000	1,100,000
Collaboration and License Agreement with AbbVie
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenues	$ 0	$ 1,400,000	$ 0	$ 3,000,000

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation Of Revenue [Line Items]
Revenue	$ 3,464	$ 3,755	$ 5,893	$ 7,257
United States
Disaggregation Of Revenue [Line Items]
Revenue	3,444	3,746	5,713	7,131
Rest of world
Disaggregation Of Revenue [Line Items]
Revenue	$ 20	$ 9	$ 180	$ 126

Revenue - Additional Informatio

Revenue - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation Of Revenue [Line Items]
Decrease in unbilled accounts receivable			$ (453)	$ (765)
Revenue recognized included in the opening contract liabilities balance			1,600	2,400
Transaction price allocated to the remaining performance obligations	$ 7,400		7,400
Point in Time
Disaggregation Of Revenue [Line Items]
Revenue recognized, performance obligation, amount	2,800	$ 2,400	4,600	4,300
Over Time
Disaggregation Of Revenue [Line Items]
Revenue recognized, performance obligation, amount	$ 700	$ 1,400	$ 1,300	$ 3,000

Revenue - Schedule of Changes i

Revenue - Schedule of Changes in Company's Contract Assets and Liabilities (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2024 USD ($)
Accounts receivable
Accounts receivable, Beginning Balance	$ 148
Accounts receivable, Additions	3,193
Accounts receivable, Deductions	(3,126)
Accounts receivable, Ending Balance	215
Contract assets:
Unbilled accounts receivable, Beginning Balance	1,425
Unbilled accounts receivable, Additions	1,943
Unbilled accounts receivable, Deductions	(2,396)
Unbilled accounts receivable, Ending Balance	972
Contract liabilities:
Deferred revenue, current and long-term, Beginning Balance	8,949
Deferred revenue, current and long-term, Additions	767
Deferred revenue, current and long-term, Deductions	(2,283)
Deferred revenue, current and long-term, Ending Balance	$ 7,433

Revenue - Additional Informat_2

Revenue - Additional Information (Details1) $ in Millions	Jun. 30, 2024 USD ($)
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	$ 7.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-07-01
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	$ 2.8
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	Jun. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Patent cost reimbursements	$ 921	$ 1,403
Accrued interest on marketable securities	808	702
Other	0	181
Total	$ 1,729	$ 2,286

Balance Sheet Items - Schedul_2

Balance Sheet Items - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Prepaid contract manufacturing and clinical costs	$ 3,763	$ 3,942
Prepaid insurance	170	993
Other	2,384	1,220
Total	$ 6,317	$ 6,155

Balance Sheet Items - Schedul_3

Balance Sheet Items - Schedule of Property And Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 30,539	$ 27,414
Less: accumulated depreciation and amortization	(10,663)	(9,144)
Property and equipment, net	19,876	18,270
Lab equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	18,334	15,581
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	2,094	2,235
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	906	895
Furniture and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	712	499
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 8,493	$ 8,204

Balance Sheet Items - Additiona

Balance Sheet Items - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization expense related to property and equipment	$ 0.9	$ 0.6	$ 1.6	$ 1.2

Balance Sheet Items - Summary o

Balance Sheet Items - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Accrued employee compensation and related expenses	$ 6,486	$ 9,517
Accrued research and development expenses	9,698	8,720
Accrued securities litigation settlement	3,900	0
Accrued patent expenses	872	613
Accrued expenses related to sublicensing revenues	550	802
Credit card liability	539	377
Other	1,581	1,106
Total	$ 23,626	$ 21,135

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	May 16, 2024	Dec. 31, 2023	Jun. 29, 2023
Related Party Transaction [Line Items]
Revenue	$ 3,464,000	$ 3,755,000	$ 5,893,000	$ 7,257,000
Deferred revenue	7,433,000		7,433,000			$ 8,949,000
Deferred revenue ($2,487 and $2,487 from related party, respectively)	2,829,000		2,829,000			2,847,000
Deferred revenue, net of current portion ($2,487 and $3,730 from related party, respectively)	4,604,000		4,604,000			6,102,000
Pfizer
Related Party Transaction [Line Items]
Revenue	600,000
Pfizer | Related Party
Related Party Transaction [Line Items]
Revenue			1,200,000	$ 0
Deferred revenue	5,000,000		5,000,000			6,200,000	$ 7,500,000
Deferred revenue ($2,487 and $2,487 from related party, respectively)	2,500,000		2,500,000			2,500,000
Deferred revenue, net of current portion ($2,487 and $3,730 from related party, respectively)	2,500,000		2,500,000			$ 3,700,000
Edge Animal Health
Related Party Transaction [Line Items]
Revenue	$ 1,600,000		1,600,000
Edge Animal Health | Convertible Preferred Stock
Related Party Transaction [Line Items]
Convertible preferred stock issued (in shares)	1,623,275
Fair value of convertible preferred stock	$ 1,600,000		1,600,000
Edge Cas9 License Agreement
Related Party Transaction [Line Items]
Revenue	$ 1,200,000		$ 1,200,000
Exercise option, term					3 years

Leases - Additional Information

Leases - Additional Information (Details)	Jun. 30, 2024 ft²
Commitments and Contingencies Disclosure [Abstract]
Area of real estate property (in square feet)	75,000
Remaining lease term (in years)	8 years 1 month 6 days
Lease renewal term (in years)	5 years

Leases - Schedule Of Components

Leases - Schedule Of Components Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 1,919	$ 1,928	$ 3,872	$ 3,812
Short-term lease cost	62	62	125	125
Total lease cost	1,981	1,990	3,997	3,937
Variable lease cost	$ 600	$ 600	$ 1,300	$ 1,200

Leases - Schedule Of Supplement

Leases - Schedule Of Supplemental Information Related To Leases (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Operating cash flows from operating leases	$ 1,841	$ 2,058
Operating lease, weighted average remaining lease term	6 years 10 months 24 days		7 years 4 months 24 days
Weighted-average discount rate	11.30%		11.30%

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Commitments Under Lease Contracts (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Remainder of 2024	$ 1,644
2025	4,475
2026	5,720
2027	5,922
2028	6,122
Thereafter	15,994
Total future undiscounted lease payments	39,877
Less imputed interest	(13,087)
Total discounted lease payments	26,790
Less current portion of lease liability	(1,262)	$ (1,200)
Operating lease liabilities, non-current	25,528	$ 25,908
Expected incentive offset in first year	$ 600

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Litigation settlement, amount awarded to other party	$ 3.9

Common Stock - Schedule of Comm

Common Stock - Schedule of Common Stock Reserved for Future Issuance (Details) - USD ($) $ / shares in Units, $ in Millions		2 Months Ended	6 Months Ended
	Aug. 09, 2022	Aug. 31, 2023	Jun. 30, 2024	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)			22,071,412	17,084,128
Authorized amount under shelf registration	$ 400
At The Market ATM Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate offering price (up to)			$ 12.3
Common stock shares sold (in shares)			1,762,806
Public offering price (in dollars per share)			$ 7.32
Aggregate gross proceeds			$ 12.9
At The Market ATM Offering | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate offering price (up to)	$ 100
Public Stock Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate offering price (up to)		$ 134.4
Common stock shares sold (in shares)		22,115,384
Public offering price (in dollars per share)		$ 6.50
Aggregate gross proceeds		$ 143.7
Over-Allotment Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares sold (in shares)		2,884,615
Stock options, issued and outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)			12,040,717	9,410,404
Stock options, authorized for future issuance
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)			6,439,947	5,952,012
Stock available under our employee stock purchase plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)			2,278,409	1,516,355
Unvested restricted stock units and performance-based restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)			1,312,339	205,357

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended		35 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	22,071,412		22,071,412		22,071,412	17,084,128
Stock options granted during period (in shares)			3,137,177
Unrecognized stock based-compensation expenses	$ 31,100,000		$ 31,100,000		$ 31,100,000
Weighted-average period (in years)			2 years 8 months 12 days
Stock-based compensation expense	4,738,000	$ 3,585,000	$ 8,726,000	$ 6,716,000
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock based-compensation expenses	600,000		$ 600,000		600,000
Weighted-average period (in years)			3 years 2 months 12 days
Unrecognized stock-based compensation expense, excluding options	6,800,000		$ 6,800,000		$ 6,800,000
Stock-based compensation expense	$ 690,000	$ 194,000	$ 0	$ 385,000
Shares committed under ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	2,278,409		2,278,409		2,278,409	1,516,355
Accrued liabilities	$ 500,000		$ 500,000		$ 500,000
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense			$ 1,118,000
Employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted during period (in shares)	223,450	486,366	3,137,177	3,022,706
Weighted average grant date fair value (in dollars per share)	$ 2.16	$ 2.95	$ 4.42	$ 3.94
2021 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	6,439,947		6,439,947		6,439,947
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock in connection with our ATM offering, net of offering expenses (in shares)					330,002

Stock Based Compensation - Sche

Stock Based Compensation - Schedule of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
Stock Options
Outstanding, Beginning Balance (in shares) | shares	9,410,404
Granted (in shares) | shares	3,137,177
Exercised (in shares) | shares	(182,217)
Cancelled or forfeited (in shares) | shares	(324,647)
Outstanding, Ending Balance (in shares) | shares	12,040,717	9,410,404
Exercisable (in shares) | shares	5,262,980
Vested and expected to vest (in shares) | shares	12,040,717
Weighted- Average Exercise Price
Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 8.03
Granted (in dollars per share) | $ / shares	6.44
Exercised (in dollars per share) | $ / shares	3.39
Cancelled or forfeited (in dollars per share) | $ / shares	11.38
Outstanding, Ending Balance (in dollars per share) | $ / shares	7.59	$ 8.03
Exercisable (in dollars per share) | $ / shares	8.01
Vested and expected to vest (in dollars per share) | $ / shares	$ 7.59
Weighted- Average Remaining Contractual Term (years)
Outstanding (in years)	7 years 9 months 18 days	8 years
Exercisable (in years)	6 years 9 months 18 days
Vested and expected to vest (in years)	7 years 9 months 18 days
Aggregate Intrinsic Value (in thousands)(1)
Outstanding | $	$ 19	$ 6,432
Exercisable | $	19
Vested and expected to vest | $	$ 19

Stock Based Compensation - Sc_2

Stock Based Compensation - Schedule of Estimated Fair Value of Stock Options on the Grant Date Using Black-Scholes Option-Pricing Model (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	75.70%
Volatility		74.70%	75.70%	74.70%
Volatility		74.80%	75.90%	75%
Expected term (in years)	6 years	6 years
Risk-free interest rate	4.50%
Risk-free interest rate		3.60%	4%	3.50%
Risk-free interest rate		3.90%	4.50%	4.10%
Expected dividend yield	0%	0%	0%	0%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)			5 years	5 years
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)			6 years	6 years

Stock Based Compensation - Sc_3

Stock Based Compensation - Schedule of Restricted Stock Units Activity (RSUs) (Details)	6 Months Ended
	Jun. 30, 2024 $ / shares shares
Number of Shares Underlying Outstanding RSUs and PSUs
Granted (in shares) | shares	1,143,617
Weighted-Average Grant Date Fair Value per RSU and PSU
Granted, Weighted-Average Grant Date Fair Value per RSU (in dollars per share) | $ / shares	$ 6.33
Restricted Stock Units RSU and Performance-Based RSUs
Number of Shares Underlying Outstanding RSUs and PSUs
Unvested, beginning of period (in shares) | shares	205,357
Vested (in shares) | shares	(15,000)
Forfeited (in shares) | shares	(21,635)
Unvested, end of period (in shares) | shares	1,312,339
Weighted-Average Grant Date Fair Value per RSU and PSU
Unvested, Weighted-Average Grant Date Fair Value per RSU, Beginning Balance (in dollars per share) | $ / shares	$ 8.49
Vested, Weighted-Average Grant Date Fair Value per RSU and PRSU (in dollars per share) | $ / shares	10.64
Forfeited, Weighted-Average Grant Date Fair Value per RSU and PRSU (in dollars per share) | $ / shares	7.55
Unvested, Weighted-Average Grant Date Fair Value per RSU, Ending Balance (in dollars per share) | $ / shares	$ 6.60

Stock Based Compensation - Sc_4

Stock Based Compensation - Schedule of Stock Option Expenses Related to Employee and Non-Employee Stock Options Granted (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 4,738	$ 3,585	$ 8,726	$ 6,716
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	1,994	1,551	3,610	2,860
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 2,744	$ 2,034	$ 5,116	$ 3,856

Stock Based Compensation - Sc_5

Stock Based Compensation - Schedule of Stock-based Compensation Expense Related to Equity-Based Awards (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 4,738,000	$ 3,585,000	$ 8,726,000	$ 6,716,000
Stock options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	3,891,000	3,202,000	7,379,000	6,000,000
ESPP
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	157,000	189,000	229,000	331,000
RSUs
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 690,000	$ 194,000	$ 0	$ 385,000

401(k) Savings Plan - Additiona

401(k) Savings Plan - Additional Information (Details) - 2017 Plan - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, Employer matching contribution percent of match	4%
Employer contribution	$ 0.7	$ 0.5

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0	$ 0	$ 0

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				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Numerator:
Net loss	$ (37,697)	$ (41,234)	$ (29,519)	$ (28,044)	$ (78,931)	$ (57,563)
Denominator:
Weighted-average common shares outstanding, basic (in shares)	90,340,932		61,417,934		89,821,935	61,302,863
Weighted-average common shares outstanding, diluted (in shares)	90,340,932		61,417,934		89,821,935	61,302,863
Net loss per share, basic (in dollars per share)	$ (0.42)		$ (0.48)		$ (0.88)	$ (0.94)
Net loss per share, diluted (in dollars per share)	$ (0.42)		$ (0.48)		$ (0.88)	$ (0.94)

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	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	13,409,487	9,636,233
Stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	12,040,717	9,253,848
Restricted Stock Units RSU and Performance-Based RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	1,259,982	233,035
Shares committed under ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	108,788	149,350

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Subsequent Event $ in Millions	Jul. 16, 2024 USD ($) position
Subsequent Event [Line Items]
Restructuring and related cost, number of positions eliminated | position	21
Restructuring and related cost, number of positions eliminated, period percent	12%
Employee Severance | Minimum
Subsequent Event [Line Items]
Restructuring and related cost, expected cost	$ 0.5
Employee Severance | Maximum
Subsequent Event [Line Items]
Restructuring and related cost, expected cost	$ 1