0001619856-23-000124 | 10-Q | XBRL Viewer

Fair Value Measurements and Fair Value of Financial Instruments

9 Months Ended

Sep. 30, 2023

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 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 evaluation 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 nine months ended September 30, 2023, and 2022. 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 September 30, 2023
	Total		Level 1		Level 2		Level 3
Assets:
U.S. Treasury bills ($84,502 included in cash and cash equivalents)	$	295,659	$	295,659	$	—	$	—
U.S. government agency bonds	55,476		—		55,476		—
Money market fund investments (included in cash and cash equivalents)	19,556		19,556		—		—
Commercial paper	20,546		—		20,546		—
Corporate debt securities	5,470		—		5,470		—
Total fair value of assets	$	396,707	$	315,215	$	81,492	$	—
Liabilities:
MSKCC success payments liability	$	1,256	$	—	$	—	$	1,256
Total fair value of liabilities	$	1,256	$	—	$	—	$	1,256


	Fair Value Measurements as of December 31, 2022
	Total		Level 1		Level 2		Level 3
Assets:
Commercial paper ($26,669 included in cash and cash equivalents)	$	96,899	$	—	$	96,899	$	—
U.S. Treasury bills	91,966		91,966		—		—
U.S. government agency bonds ($3,976 included in cash and cash equivalents)	63,659		—		63,659		—
Corporate debt securities	36,819		—		36,819		—
Money market fund investments (included in cash and cash equivalents)	27,693		27,693		—		—
Total fair value of assets	$	317,036	$	119,659	$	197,377	$	—
Liabilities:
MSKCC success payments liability	$	1,651	$	—	$	—	$	1,651
Total fair value of liabilities	$	1,651	$	—	$	—	$	1,651

The fair value and amortized cost of cash equivalents and available-for-sale marketable securities by major security type as of September 30, 2023, and December 31, 2022 are presented in the following tables (in thousands):


	As of September 30, 2023
	Amortized Cost Basis		Unrealized Gains		Unrealized Losses		Estimated Fair Value
U.S. Treasury bills ($84,502 included in cash and cash equivalents)	$	296,314	$	15	$	(670)	$	295,659
U.S. government agency bonds	55,789		—		(313)		55,476
Money market investments (included in cash equivalents)	19,556		—		—		19,556
Commercial paper	20,549		—		(3)		20,546
Corporate debt securities	5,481		7		(18)		5,470
Total cash equivalents and marketable securities	$	397,689	$	22	$	(1,004)	$	396,707

Classified as:
Cash and cash equivalents							$	104,058
Marketable securities, short-term							234,430
Marketable securities, long-term							58,219
Total cash equivalents and marketable securities							$	396,707


	As of December 31, 2022
	Amortized Cost Basis		Unrealized Gains		Unrealized Losses		Estimated Fair Value
Commercial paper ($26,669 included in cash equivalents)	$	97,024	$	6	$	(131)	$	96,899
U.S. Treasury bills	92,910		1		(945)		91,966
U.S. government agency bonds ($3,976 included in cash and cash equivalents)	63,926		25		(292)		63,659
Corporate debt securities	37,002		—		(183)		36,819
Money market investments (included in cash equivalents)	27,693		—		—		27,693
Total cash equivalents and marketable securities	$	318,555	$	32	$	(1,551)	$	317,036

Classified as:
Cash and cash equivalents							$	58,338
Marketable securities, short-term							189,325
Marketable securities, long-term							69,373
Total cash equivalents and marketable securities							$	317,036

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 Liability
Balance at December 31, 2022	$	1,651
Change in fair value	(395)
Balance at September 30, 2023	$	1,256

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 $0.1 million and $1.6 million change in the fair value of the MSKCC success payments liability as a loss in other income (expense) in our condensed consolidated statements of operations for the three months ended September 30, 2023, and 2022, respectively. We recorded $0.4 million and $1.0 million change in fair value of the MSKCC success payments liability as a gain in other income (expense) in our condensed consolidated statements of operations for the nine months ended September 30, 2023, and 2022, respectively.

As of December 31, 2022, we utilized a Monte Carlo simulation model that models the future movement of stock prices based on several key variables. This model requires significant estimates and assumptions in determining the estimated fair value of the MSKCC success payments liability at each balance sheet date. The assumptions used to calculate the fair value of the MSKCC success payments liability are subject to a significant amount of judgment including the expected volatility that was estimated using available information about the historical volatility of stocks of publicly traded companies that are similar to us, the estimated term, and the estimated number and timing of valuation measurement dates. The table below summarizes key assumptions used in the valuation of MSKCC success payments liability:


	As of December 31, 2022
Fair value of common stock	$	6.28
Risk-free interest rate	3.88%
Expected volatility	79%
Probability of achieving multiple of Initial Share Price(1)	3.0% to 10.6%
Expected term (years)	4.6 to 6.0

(1)MSKCC is entitled to certain success payments if our common stock fair value increases 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 (the “Initial Share Price”), during a specified time period. 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 estimated 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 (the “MSKCC Agreement”) and 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 September 30, 2023, 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 $4.78 per share.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Stock Based Compensation - Schedule of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Stock Options
Outstanding, Beginning Balance (in shares) \| shares	6,733,074
Granted (in shares) \| shares	3,406,801
Exercised (in shares) \| shares	(209,925)
Cancelled or forfeited (in shares) \| shares	(406,556)
Outstanding, Ending Balance (in shares) \| shares	9,523,394	6,733,074
Exercisable (in shares) \| shares	3,906,573
Vested and expected to vest (in shares) \| shares	9,523,394
Weighted- Average Exercise Price
Outstanding, Beginning Balance (in dollars per share) \| $ / shares	$ 9.01
Granted (in dollars per share) \| $ / shares	5.74
Exercised (in dollars per share) \| $ / shares	3.44
Cancelled or forfeited (in dollars per share) \| $ / shares	6.69
Outstanding, Ending Balance (in dollars per share) \| $ / shares	8.06	$ 9.01
Exercisable (in dollars per share) \| $ / shares	7.88
Vested and expected to vest (in dollars per share) \| $ / shares	$ 8.06
Weighted- Average Remaining Contractual Term (years)
Outstanding (in years)	8 years 3 months 18 days	8 years 2 months 12 days
Exercisable (in years)	7 years 6 months
Vested and expected to vest (in years)	8 years 3 months 18 days
Aggregate Intrinsic Value (in thousands)*
Outstanding \| $	$ 3,139	$ 8,203
Exercisable \| $	2,527
Vested and expected to vest \| $	$ 3,139

Balance Sheet Items - Schedule of Property And Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 25,003	$ 16,327
Less: accumulated depreciation and amortization	(8,405)	(5,649)
Property and equipment, net	16,598	10,678
Lab equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	14,868	12,588
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,938	1,876
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	761	709
Furniture and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	161	161
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 7,275	$ 993

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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Change in fair value	$ 100	$ 1,600	$ (400)	$ (1,000)
Level 3
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at December 31, 2022			1,651
Change in fair value			(395)
Balance at September 30, 2023	$ 1,256		$ 1,256

Revenue

9 Months Ended

Sep. 30, 2023

Revenue from Contract with Customer [Abstract]

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 nine months ended September 30, 2023, and 2022 (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
United States	$	23,285	$	2,966	$	30,416	$	9,761
Rest of world	377		337		503		398
Total	$	23,662	$	3,303	$	30,919	$	10,159

During the three months ended September 30, 2023, we recognized $1.6 million of revenue related to performance obligations satisfied at a point in time, and we recognized $22.1 million of revenue related to performance obligations satisfied over time that included $21.5 million in licensing and collaboration revenue associated with the AbbVie Agreement, of which $20.8 million had been included in deferred revenue as of the beginning of the period.

During the three months ended September 30, 2022, we recognized $1.6 million of revenue related to performance obligations satisfied at a point in time, and we recognized $1.7 million of revenue related to performance obligations satisfied over time.

During the nine months ended September 30, 2023, we recognized $5.8 million of revenue related to performance obligations satisfied at a point in time, and we recognized $25.1 million of revenue related to performance obligations satisfied over time which included $24.5 million in licensing and collaboration revenue associated with the AbbVie Agreement.

During the nine months ended September 30, 2022, we recognized $4.7 million of revenue related to performance obligations satisfied at a point in time, and we recognized $5.5 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 reimbursable research costs related to the AbbVie Agreement, as well as 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. Our deferred revenue primarily results from the upfront payment received relating to our performance obligation to 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 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 nine months ended September 30, 2023 (in thousands):


	Balance as of December 31, 2022		Additions		Deductions		Balance as of September 30, 2023
Accounts receivable	$	202	$	7,631	$	(6,700)	$	1,133

Contract assets:
Unbilled accounts receivable	$	2,247	$	4,664	$	(5,253)	$	1,658

Contract liabilities:
Deferred revenue, current and long-term	$	25,891	$	11,537	$	(27,874)	$	9,554

Unbilled accounts receivable decreased $0.6 million during the nine months ended September 30, 2023, primarily due to the decrease in unbilled research costs under the AbbVie Agreement.

Deferred revenue decreased during the nine months ended September 30, 2023, primarily due to the recognition of deferred revenues related to the completion of our performance obligation to AbbVie as a result of AbbVie’s termination of the AbbVie Agreement, offset by the $7.5 million allocated to the Pfizer information sharing committee, during the nine months ended September 30, 2023. See Notes 4 and 7 to our unaudited condensed consolidated financial statements included elsewhere in this Form 10-Q for additional information.

During the nine months ended September 30, 2023, and 2022, we recognized $23.2 million and $3.4 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 September 30, 2023, was approximately $9.6 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 license and collaboration agreements, and costs to fulfill those contracts do not generate or enhance our resources. As such, no costs to obtain or fulfill a contract have been capitalized in any period.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-9

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-10

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-15

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-13

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org//606/tableOfContent

+ Details

Common Stock - Schedule of Common Stock Reserved for Future Issuance (Details) - USD ($) $ / shares in Units, $ in Millions		2 Months Ended	9 Months Ended
	Aug. 09, 2022	Aug. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)			17,102,467	13,867,717
Authorized amount under shelf registration	$ 400.0
At The Market ATM Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate offering price (up to)			$ 1.0
Common stock shares sold (in shares)			168,635
Public offering price (in dollars per share)			$ 7.32
Aggregate gross proceeds			$ 1.2
At The Market ATM Offering \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate offering price (up to)	$ 100.0
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)			9,523,394	6,733,074
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)			5,894,280	5,833,979
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)			1,516,355	1,044,518
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)			168,438	256,146

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

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, 2022, included in our Annual Report on Form 10-K (“Form 10-K”).

Basis of Presentation and Principles of Consolidation

The condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and include the accounts of Caribou Biosciences, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions are eliminated in consolidation.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires our management to make estimates and assumptions that affect the reported amounts of assets and liabilities; the disclosure of contingent assets and liabilities at the date of our condensed consolidated financial statements; and the reported amounts of revenue, income, and expenses during the applicable reporting period. On an ongoing basis, we evaluate our estimates and assumptions, including those related to revenue recognition, common stock valuation, stock-based compensation expense, accrued expenses related to research and development activities, valuation of the Memorial Sloan Kettering Cancer Center (“MSKCC”) success payments liability, and income taxes. Our management bases its estimates on historical experience and on various other assumptions that they believe to be reasonable under the circumstances, the results of which form the

basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those estimates.

Segments

We operate and manage our business as one reportable operating segment, which is the business of developing a pipeline of allogeneic CAR-T and CAR-NK 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 of our cash and cash equivalents are deposited in accounts at two 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 the 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				Nine Months Ended				As of September 30, 2023		As of December 31, 2022
	September 30, 2023		September 30, 2022		September 30, 2023		September 30, 2022
Licensee A	*		17.2	%	*		16.4	%	23.6	%	23.8	%
Licensee B	90.8	%	51.7	%	79.1	%	54.2	%	62.6	%	36.6	%

Total	90.8	%	68.9	%	79.1	%	70.6	%	86.2	%	60.4	%

*Less than 10%

We monitor economic conditions to identify facts or circumstances that may indicate if any of our accounts receivable are not collectible or if the contract assets should be impaired. No allowance for credit losses or contract asset impairment was recorded as of September 30, 2023, or December 31, 2022.

Recent Accounting Pronouncements

In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-13, Financial Instruments–Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326). This ASU provides guidance on the measurement of credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. ASU 2016-13 replaces the current incurred loss impairment approach with a methodology to reflect expected credit losses and requires consideration of a broader range of reasonable and supportable information to explain credit loss estimates. This ASU is to be applied on a modified retrospective approach and is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022, and interim reporting periods within fiscal years beginning after December 15, 2023. Early adoption is permitted for all entities for fiscal years beginning after December 15, 2018, and interim periods therein. We adopted ASU 2016-13 on January 1, 2023. The impact of ASU 2016-13 on our financial statements and related disclosures was not material.

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, 2022 $ / shares	Sep. 30, 2023
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 interest	6.28	4.78
Risk-free interest rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability interest	0.000388
Expected volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability interest	0.0079
Probability of achieving multiple of Initial Share Price(1) \| Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability interest	0.030
Probability of achieving multiple of Initial Share Price(1) \| Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability interest	0.106
Expected term (years) \| Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumptions term	4 years 7 months 6 days
Expected term (years) \| Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Success payment liability assumptions term	6 years

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (67,565)	$ (72,432)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,785	1,116
Gain on disposal of fixed assets	(34)	0
Non-cash consideration for licensing and collaboration revenue	(61)	(205)
Change in fair value of equity securities	(3)	73
Stock-based compensation expense	10,194	8,615
Change in fair value of MSKCC success payments liability	(395)	(1,041)
Acquired in-process research and development	0	300
(Accretion of discounts) and amortization of premiums on investments, net	(6,042)	106
Non-cash lease expense	1,551	1,622
Changes in operating assets and liabilities:
Accounts receivable	(931)	756
Contract assets	588	(411)
Other receivables	(130)	2,783
Prepaid expenses and other current assets	852	(1,613)
Other assets	(30)	(361)
Accounts payable	1,089	(2,568)
Accrued expenses and other current liabilities	2,848	909
Deferred revenue, current and long-term	(16,337)	(3,277)
Operating lease liabilities	(291)	(279)
Other liabilities	0	(15)
Net cash used in operating activities	(71,912)	(65,922)
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales and maturities of marketable securities	283,193	163,130
Purchases of marketable securities	(310,566)	(252,552)
Purchases of property and equipment	(9,336)	(4,697)
Payments to acquire in-process research and development	0	(300)
Net cash used in investing activities	(36,709)	(94,419)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from follow-on public offering, net of offering expenses	134,536	0
Proceeds from issuance of common stock in a private placement with Pfizer	17,290	0
Proceeds from exercise of stock options and purchases of common stock under employee stock purchase plan	1,508	2,006
Proceeds from issuance of common stock related to at-the-market offering, net of offering expenses	1,007	0
Net cash provided by financing activities	154,341	2,006
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	45,720	(158,335)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH — BEGINNING OF PERIOD	58,384	240,466
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH — END OF PERIOD	104,104	82,131
RECONCILIATION OF CASH, CASH EQUIVALENTS, AND RESTRICTED CASH
Cash and cash equivalents	104,058	82,085
Restricted cash	46	46
TOTAL CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	104,104	82,131
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for income taxes	170	0
SUPPLEMENTAL SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Purchases of property and equipment included in accounts payable and accrued expenses	556	757
Offering costs included in accrued expenses	113	0
Right-of-use-assets obtained in exchange for new operating lease liabilities	$ 0	$ 26,249

Net Loss Per Share - Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator:
Net loss	$ (10,002)	$ (29,519)	$ (28,044)	$ (26,647)	$ (26,697)	$ (19,088)	$ (67,565)	$ (72,432)
Denominator:
Weighted-average common shares outstanding, basic (in shares)	83,783,992			60,886,921			68,878,921	60,731,520
Weighted-average common shares outstanding, diluted (in shares)	83,783,992			60,886,921			68,878,921	60,731,520
Net loss per share, basic (in dollars per share)	$ (0.12)			$ (0.44)			$ (0.98)	$ (1.19)
Net loss per share, diluted (in dollars per share)	$ (0.12)			$ (0.44)			$ (0.98)	$ (1.19)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
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Reference 35: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
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-Name Accounting Standards Codification
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Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
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Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B

Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
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-Section S99
-Paragraph 2
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Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
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-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

Leases - Summary of Future Minimum Commitments Under Lease Contracts (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Remainder of 2023	$ 744
2024	3,876
2025	4,475
2026	5,720
2027	5,922
Thereafter	22,116
Total undiscounted lease payments	42,853
Less: imputed interest	(15,398)
Total discounted lease payments	27,455
Less: current portion of lease liability	(1,139)	$ (966)
Lease liabilities, non-current	26,316	$ 26,780
Expected incentive offset in first year	400
Expected incentive offset in second year	$ 700

Significant Agreements	9 Months Ended
Significant Agreements	Sep. 30, 2023
Significant Agreements [Abstract]
Significant Agreements	Significant Agreements Since December 31, 2022, there have been no material changes to the key terms of our significant agreements other than the termination notice we received from AbbVie Manufacturing Management Unlimited Company (“AbbVie”) for the Collaboration and License Agreement (as amended, the “AbbVie Agreement”) under which we were developing two allogeneic CAR-T cell therapies for AbbVie. For further information regarding our significant agreements, including the AbbVie Agreement, see Note 4 to the consolidated financial statements included in our Form 10-K. See Note 7 to our unaudited condensed consolidated financial statements included elsewhere in this Form 10-Q for additional information on our agreements with Pfizer, Inc. (“Pfizer”), which we entered into on June 29, 2023. Under the AbbVie Agreement, we received an upfront cash payment of $30.0 million from AbbVie during the year ended December 31, 2021. On September 26, 2023, we received notice from AbbVie that AbbVie elected to terminate the AbbVie Agreement. By mutual agreement with AbbVie, termination of the AbbVie Agreement became effective on October 25, 2023. Due to receipt of the termination notice, we stopped performing preclinical research and development services under the AbbVie Agreement and determined that our performance obligation to AbbVie was substantially completed as of September 30, 2023. Consequently, the remaining $20.8 million of deferred revenue from the upfront cash payment was recognized during the three months ended September 30, 2023. During the three months ended September 30, 2023, we recognized $21.5 million in licensing and collaboration revenue associated with the AbbVie Agreement, of which $20.8 million had been included in deferred revenue as of the beginning of the period. During the nine months ended September 30, 2023, we recognized $24.5 million in licensing and collaboration revenue associated with the AbbVie Agreement. For the three and nine months ended September 30, 2022, we recognized $1.7 million and $5.5 million in revenue associated with the AbbVie Agreement, respectively. As of September 30, 2023, we had recorded $1.0 million in accounts receivable and, as of December 31, 2022, we had recorded no amounts in accounts receivable in our condensed consolidated balance sheets relating to the AbbVie Agreement. As of September 30, 2023, and December 31, 2022, we had $0.7 million and $0.9 million, respectively, in contract assets in our condensed consolidated balance sheet and consolidated balance sheet, respectively, relating to the AbbVie Agreement. We enter into agreements with third parties to in-license intellectual property and related materials and know-how. These 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 September 30, 2023, and 2022, we recorded $0.4 million and $0.3 million, respectively, as research and development expense in our condensed consolidated statements of operations related to our license agreements. For the nine months ended September 30, 2023, and 2022, we recorded $1.2 million and $0.8 million, respectively, as research and development expense in our condensed consolidated statements of operations related to our license agreements. For the three months ended September 30, 2023, and 2022, we recorded $0.4 million and $1.4 million, respectively, as general and administrative expense for patent prosecution and maintenance costs in our condensed consolidated statements of operations, which includes reimbursements of patent prosecution and maintenance costs of $0.1 million and $0.9 million, respectively. For the nine months ended September 30, 2023, and 2022, we recorded $2.2 million and $4.7 million, respectively, as general and administrative expense for patent prosecution and maintenance costs in our condensed consolidated statements of operations, which includes reimbursements of patent prosecution and maintenance costs of $1.3 million and $3.1 million, respectively. As of September 30, 2023, certain license and assignment agreements included potential future payments from us for development, regulatory, and sales milestones totaling approximately $161.2 million.

Balance Sheet Items

9 Months Ended

Sep. 30, 2023

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Items

Other receivables consisted of the following (in thousands):


	September 30, 2023		December 31, 2022
Patent cost reimbursements	$	1,202	$	1,638
Accrued interest on marketable securities	543		570
Other	600		7
Total	$	2,345	$	2,215

Prepaid expenses and other current assets consisted of the following (in thousands):


	September 30, 2023		December 31, 2022
Prepaid contract manufacturing and clinical costs	$	3,453	$	4,803
Prepaid insurance	1,402		1,568
Prepaid income taxes	603		431
Other	1,611		1,119
Total	$	7,069	$	7,921

Property and equipment, net, consisted of the following (in thousands):


	September 30, 2023		December 31, 2022
Lab equipment	$	14,868	$	12,588
Leasehold improvements	1,938		1,876
Computer equipment	761		709
Furniture and equipment	161		161
Construction in progress	7,275		993
Total property and equipment, gross	25,003		16,327
Less: accumulated depreciation and amortization	(8,405)		(5,649)
Property and equipment, net	$	16,598	$	10,678

Depreciation and amortization expenses related to property and equipment were $1.6 million and $0.4 million, respectively, for the three months ended September 30, 2023, and 2022. Depreciation and amortization expenses related to property and equipment were $2.8 million and $1.1 million, respectively, for the nine months ended September 30, 2023, and 2022.

Accrued expenses and other current liabilities consisted of the following (in thousands):


	September 30, 2023		December 31, 2022
Accrued employee compensation and related expenses	$	6,688	$	5,752
Accrued research and development expenses	7,866		6,731
Accrued patent expenses	889		1,331
Accrued expenses related to sublicensing revenues	688		596
Credit card liability	453		299
Other	1,646		1,370
Total	$	18,230	$	16,079

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Deferred revenue ($2,487 and $150 from related party, respectively)	$ 2,826	$ 9,937
Deferred revenue, net of current portion ($4,352 and $0 from related party, respectively)	$ 6,728	$ 15,954
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares outstanding (in shares)	0	0
Preferred stock, shares issued (in shares)	0	0
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)	88,430,609	61,029,184
Common stock, shares issued (in shares)	88,430,609	61,029,184
Related Party
Deferred revenue ($2,487 and $150 from related party, respectively)	$ 2,487	$ 150
Deferred revenue, net of current portion ($4,352 and $0 from related party, respectively)	$ 4,352	$ 0

Stock Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Schedule of Stock Option Activity

The following table summarizes stock option activity under our equity incentive plans during the nine months ended September 30, 2023:


	Stock Options	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in thousands)*

Outstanding at December 31, 2022	6,733,074	$	9.01	8.2	$	8,203
Options granted	3,406,801	5.74
Options exercised	(209,925)	3.44
Options cancelled or forfeited	(406,556)	6.69
Outstanding at September 30, 2023	9,523,394	$	8.06	8.3	$	3,139
Exercisable at September 30, 2023	3,906,573	$	7.88	7.5	$	2,527
Vested and expected to vest at September 30, 2023	9,523,394	$	8.06	8.3	$	3,139

*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 and non-employee stock option award on the grant date using the Black-Scholes option-pricing model based on the following assumptions:


	Three Months Ended September 30,		Nine Months Ended September 30,
	2023	2022	2023	2022
Volatility	74.2% to 74.6%	74.2%	74.2% to 75.0%	71.7% to 74.2%
Expected term (in years)	6.0	6.0	5.0 to 6.0	5.5 to 6.0
Risk-free interest rate	4.1% to 4.6%	3.1% to 3.7%	3.5% to 4.6%	1.7% to 3.7%
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 September 30, 2023 was as follows:


	Number of Shares Underlying Outstanding RSUs and PSUs	Weighted-Average Grant Date Fair Value per RSU and PSU
Unvested, January 1, 2023	256,146	$	10.07
Vested	(78,596)	10.04
Forfeited	(9,112)	9.90
Unvested, September 30, 2023	168,438	$	10.10

Schedule of Stock-Based Compensation Expenses Recorded in the Condensed Consolidated Statements of Operations and Comprehensive Loss

We recorded stock-based compensation expense related to employee and non-employee equity-based awards grants in our condensed consolidated statements of operations as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Research and development	$	1,464	$	1,072	$	4,324	$	3,139
General and administrative	2,014		1,601		5,870		5,476
Total	$	3,478	$	2,673	$	10,194	$	8,615

Schedule of Stock-Based Compensation Expense Related to Equity-Based Awards

The above stock-based compensation expense related to the following equity-based awards (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Stock options	$	3,188	$	2,479	$	9,188	$	8,190
ESPP	96		80		427		209
RSUs	194		114		579		216
Total	$	3,478	$	2,673	$	10,194	$	8,615

Summary of Significant Accounting Policies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2023 USD ($) segment	Dec. 31, 2022 USD ($)
Accounting Policies [Abstract]
Number of operating segment	1
Number of reportable segment	1
Allowance for doubtful accounts \| $	$ 0	$ 0

Condensed Consolidated Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue	$ 23,662	$ 3,303	$ 30,919	$ 10,159
Related Party
Revenue	$ 622		$ 1,772

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 924
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479941/924-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-40

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-41

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-4

+ Details

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Research and Development Agreements We enter into various agreements in the ordinary course of business, such as those with suppliers, contract research organizations (“CROs”), contract manufacturing organizations (“CMOs”), clinical trial sites, 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 condensed consolidated financial condition, results of operations, or cash flows. Guarantees and Indemnifications In the normal course of business, we enter into agreements that contain a variety of representations and warranties and provide for certain indemnifications by us. Our exposure under these agreements is unknown because claims may be made against us in the future. To date, we have not paid any claims or been required to defend any action related to our indemnification obligations. As of September 30, 2023, and December 31, 2022, 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 (the “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 (the “Securities Act”) and Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended (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. Additionally, 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 (the “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. We believe these lawsuits are without merit and intend to vigorously defend the claims asserted against us.

Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2023

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 September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Numerator:
Net loss	$	(10,002)	$	(26,647)	$	(67,565)	$	(72,432)
Denominator:
Weighted-average common shares outstanding used to compute net loss per share, basic and diluted	83,783,992		60,886,921		68,878,921		60,731,520
Net loss per share, basic and diluted	$	(0.12)	$	(0.44)	$	(0.98)	$	(1.19)

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 September 30, 2023	As of September 30, 2022
Stock options outstanding	9,523,394	6,649,892
RSUs and PSUs issued and outstanding	168,438	259,769
Shares committed under ESPP	134,276	49,109
	9,826,108	6,958,770

Summary of Significant Accounting Policies - Schedule of Concentration of Credit Risk and other Uncertainties (Details) - Customer Concentration Risk	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Revenue Benchmark \| Major Customers
Concentration Risk [Line Items]
Total	90.80%	68.90%	79.10%	70.60%
Revenue Benchmark \| Licensee A
Concentration Risk [Line Items]
Total		17.20%		16.40%
Revenue Benchmark \| Licensee B
Concentration Risk [Line Items]
Total	90.80%	51.70%	79.10%	54.20%
Accounts Receivable \| Major Customers
Concentration Risk [Line Items]
Total			86.20%		60.40%
Accounts Receivable \| Licensee A
Concentration Risk [Line Items]
Total			23.60%		23.80%
Accounts Receivable \| Licensee B
Concentration Risk [Line Items]
Total			62.60%		36.60%

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2023	Nov. 02, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-40631
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		88,431,136
Entity Central Index Key	0001619856
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Amendment Flag	false
Document Fiscal Year Focus	2023

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

Basis of Presentation and Principles of Consolidation

Use Of Estimates

Use of Estimates

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

Concentration of Credit Risk and Other Uncertainties

Concentrations of Credit Risk 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				Nine Months Ended				As of September 30, 2023		As of December 31, 2022
	September 30, 2023		September 30, 2022		September 30, 2023		September 30, 2022
Licensee A	*		17.2	%	*		16.4	%	23.6	%	23.8	%
Licensee B	90.8	%	51.7	%	79.1	%	54.2	%	62.6	%	36.6	%

Total	90.8	%	68.9	%	79.1	%	70.6	%	86.2	%	60.4	%

*Less than 10%

Recent Accounting Pronouncements and New Accounting Pronouncements Not Yet Adopted

Recent Accounting Pronouncements

- Definition

Disclosure of accounting policy for segment reporting.

+ References + Details

Fair Value Measurements and Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
MSKCC success payments liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Change in fair value	$ (0.1)	$ (1.6)	$ 0.4	$ 1.0

Net Loss Per Share - Computation of the Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	9,826,108	6,958,770
Restricted Stock Units RSU and Performance-Based RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	168,438	259,769
Stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	9,523,394	6,649,892
Shares Committed Under ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	134,276	49,109

Common Stock

9 Months Ended

Sep. 30, 2023

Equity [Abstract]

Common Stock

Common stock reserved for future issuance consisted of the following:


	As of September 30, 2023	As of December 31, 2022
Stock options, issued and outstanding	9,523,394	6,733,074
Stock options, authorized for future issuance	5,894,280	5,833,979
Stock available under our employee stock purchase plan	1,516,355	1,044,518
Unvested restricted stock units and performance-based restricted stock units	168,438	256,146
	17,102,467	13,867,717

Shelf Registration Statement

On August 9, 2022, we filed a shelf registration statement on Form S-3 (“Shelf Registration Statement”) with the U.S. Securities and Exchange Commission (“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 described below). 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 and will be described in a prospectus supplement to the Shelf Registration Statement 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 Open Market Sale AgreementSM (the “ATM Sales Agreement”) with Jefferies LLC (“Jefferies”) with respect to an at-the-market (“ATM”) equity offering program, 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. During the nine months ended September 30, 2023, we sold 168,635 shares of our common stock under the ATM Sales Agreement at an average price per share of $7.32 for aggregate gross proceeds of $1.2 million ($1.0 million net of offering expenses).

Stock Based Compensation - Schedule of Stock Option Expenses Related to Employee and Non-Employee Stock Options Granted (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 3,478	$ 2,673	$ 10,194	$ 8,615
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	1,464	1,072	4,324	3,139
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 2,014	$ 1,601	$ 5,870	$ 5,476

401(k) Savings Plan	9 Months Ended
401(k) Savings Plan	Sep. 30, 2023
Retirement Benefits [Abstract]
401(K) Savings plan	401(k) Savings PlanIn 2017, we established a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code of 1986, as amended (the “Tax Code”). Our 401(k) plan is available to all employees and allows participants to defer a portion of their annual compensation on a pretax basis subject to applicable laws. We also provide a 4% match for employee contributions up to a certain limit. During the three months ended September 30, 2023, and 2022, we contributed $0.3 million and $0.2 million, respectively, to our 401(k) plan. During the nine months ended September 30, 2023, and 2022, we contributed $0.8 million and $0.6 million, respectively, to our 401(k) plan.

Description of the Business, Organization, and Liquidity - Additional Information (Details) $ in Thousands	2 Months Ended	3 Months Ended						9 Months Ended
	Aug. 31, 2023 USD ($) shares	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2023 USD ($) subsidiary	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Subsequent Event [Line Items]
Number of subsidiaries \| subsidiary								4
Accumulated deficit		$ 264,780						$ 264,780		$ 197,215
Net loss		(10,002)	$ (29,519)	$ (28,044)	$ (26,647)	$ (26,697)	$ (19,088)	(67,565)	$ (72,432)
Cash generated in operating activities								(71,912)	$ (65,922)
Cash, cash equivalents and short term marketable securities		$ 396,700						$ 396,700
Public Stock Offering
Subsequent Event [Line Items]
Common stock shares sold (in shares) \| shares	22,115,384
Aggregate offering price	$ 134,400
Over-Allotment Option
Subsequent Event [Line Items]
Common stock shares sold (in shares) \| shares	2,884,615

Fair Value Measurements and Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2023

Fair Value Disclosures [Abstract]

Schedule of Financial Instruments Measured on Recurring Basis

The following table sets forth our financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


	Fair Value Measurements as of September 30, 2023
	Total		Level 1		Level 2		Level 3
Assets:
U.S. Treasury bills ($84,502 included in cash and cash equivalents)	$	295,659	$	295,659	$	—	$	—
U.S. government agency bonds	55,476		—		55,476		—
Money market fund investments (included in cash and cash equivalents)	19,556		19,556		—		—
Commercial paper	20,546		—		20,546		—
Corporate debt securities	5,470		—		5,470		—
Total fair value of assets	$	396,707	$	315,215	$	81,492	$	—
Liabilities:
MSKCC success payments liability	$	1,256	$	—	$	—	$	1,256
Total fair value of liabilities	$	1,256	$	—	$	—	$	1,256


	Fair Value Measurements as of December 31, 2022
	Total		Level 1		Level 2		Level 3
Assets:
Commercial paper ($26,669 included in cash and cash equivalents)	$	96,899	$	—	$	96,899	$	—
U.S. Treasury bills	91,966		91,966		—		—
U.S. government agency bonds ($3,976 included in cash and cash equivalents)	63,659		—		63,659		—
Corporate debt securities	36,819		—		36,819		—
Money market fund investments (included in cash and cash equivalents)	27,693		27,693		—		—
Total fair value of assets	$	317,036	$	119,659	$	197,377	$	—
Liabilities:
MSKCC success payments liability	$	1,651	$	—	$	—	$	1,651
Total fair value of liabilities	$	1,651	$	—	$	—	$	1,651

Schedule of Fair Value and Amortized Cost of Cash Equivalents and Available-for-Sale Marketable Securities


	As of September 30, 2023
	Amortized Cost Basis		Unrealized Gains		Unrealized Losses		Estimated Fair Value
U.S. Treasury bills ($84,502 included in cash and cash equivalents)	$	296,314	$	15	$	(670)	$	295,659
U.S. government agency bonds	55,789		—		(313)		55,476
Money market investments (included in cash equivalents)	19,556		—		—		19,556
Commercial paper	20,549		—		(3)		20,546
Corporate debt securities	5,481		7		(18)		5,470
Total cash equivalents and marketable securities	$	397,689	$	22	$	(1,004)	$	396,707

Classified as:
Cash and cash equivalents							$	104,058
Marketable securities, short-term							234,430
Marketable securities, long-term							58,219
Total cash equivalents and marketable securities							$	396,707


	As of December 31, 2022
	Amortized Cost Basis		Unrealized Gains		Unrealized Losses		Estimated Fair Value
Commercial paper ($26,669 included in cash equivalents)	$	97,024	$	6	$	(131)	$	96,899
U.S. Treasury bills	92,910		1		(945)		91,966
U.S. government agency bonds ($3,976 included in cash and cash equivalents)	63,926		25		(292)		63,659
Corporate debt securities	37,002		—		(183)		36,819
Money market investments (included in cash equivalents)	27,693		—		—		27,693
Total cash equivalents and marketable securities	$	318,555	$	32	$	(1,551)	$	317,036

Classified as:
Cash and cash equivalents							$	58,338
Marketable securities, short-term							189,325
Marketable securities, long-term							69,373
Total cash equivalents and marketable securities							$	317,036

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 Liability
Balance at December 31, 2022	$	1,651
Change in fair value	(395)
Balance at September 30, 2023	$	1,256

Schedule of Assumptions Used in Valuation of MSKCC Success Payments Liability

The table below summarizes key assumptions used in the valuation of MSKCC success payments liability:


	As of December 31, 2022
Fair value of common stock	$	6.28
Risk-free interest rate	3.88%
Expected volatility	79%
Probability of achieving multiple of Initial Share Price(1)	3.0% to 10.6%
Expected term (years)	4.6 to 6.0

Revenue (Tables)

9 Months Ended

Sep. 30, 2023

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 nine months ended September 30, 2023, and 2022 (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
United States	$	23,285	$	2,966	$	30,416	$	9,761
Rest of world	377		337		503		398
Total	$	23,662	$	3,303	$	30,919	$	10,159

Schedule of Changes in Company's Contract Assets and Liabilities

The following table presents changes in our contract assets and liabilities during the nine months ended September 30, 2023 (in thousands):


	Balance as of December 31, 2022		Additions		Deductions		Balance as of September 30, 2023
Accounts receivable	$	202	$	7,631	$	(6,700)	$	1,133

Contract assets:
Unbilled accounts receivable	$	2,247	$	4,664	$	(5,253)	$	1,658

Contract liabilities:
Deferred revenue, current and long-term	$	25,891	$	11,537	$	(27,874)	$	9,554

Leases

9 Months Ended

Sep. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Leases

Operating Lease Obligations

As of September 30, 2023 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 8.8 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 statements of operations, were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Operating lease cost(1)	$	1,937	$	1,822	$	5,749	$	5,443
Short-term lease cost	63		—		188		83
Total lease cost	$	2,000	$	1,822	$	5,937	$	5,526

(1) Included $0.7 million and $0.6 million of variable lease cost related to operating expenses and taxes for the three months ended September 30, 2023, and 2022, respectively. Included $1.9 million and $1.6 million of variable lease cost related to operating expenses and taxes for the nine months ended September 30, 2023, and 2022, respectively.

Supplemental information related to our leases was as follows (in thousands):


	Nine Months Ended September 30,
	2023		2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	2,597	$	2,454

The weighted-average remaining lease term and the weighted-average discount rate for our laboratory and office leases were as follows:


	September 30, 2023		December 31, 2022
Weighted-average remaining lease term (years)	7.6		8.3
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 September 30, 2023 (in thousands):


Remainder of 2023(1)	$	744
2024(2)	3,876
2025	4,475
2026	5,720
2027	5,922
Thereafter	22,116
Total undiscounted lease payments	42,853
Less: imputed interest	(15,398)
Total discounted lease payments	27,455
Less: current portion of lease liability	(1,139)
Noncurrent portion of lease liability	$	26,316

(1)Reflects an offset of $0.4 million related to incentives expected to be received in 2023.

(2)Reflects an offset of $0.7 million related to incentives expected to be received in 2024.

Description of the Business, Organization, and Liquidity	9 Months Ended
	Sep. 30, 2023
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. (the “Company” or “we”) is a clinical-stage Clustered Regularly Interspaced Short Palindromic Repeats (“CRISPR”) genome-editing biopharmaceutical company dedicated to developing transformative therapies for patients with devastating diseases. Our genome-editing platform, including our novel chRDNA (CRISPR hybrid RNA-DNA, or “chRDNA,” pronounced “chardonnay”) technology, enables superior editing precision to develop cell therapies that are armored to improve antitumor activity. We are advancing a pipeline of allogeneic, or off-the-shelf, cell therapies from our chimeric antigen receptor (“CAR”) T (“CAR-T”) cell and CAR-natural killer (“CAR-NK”) cell platforms 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 net losses and negative cash flows from operations since our inception and we had an accumulated deficit of $264.8 million as of September 30, 2023. During the nine months ended September 30, 2023, we incurred a net loss of $67.6 million and used $71.9 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 generation of sufficient revenue to support our cost structure. We may never achieve profitability and, unless and until we do, we will need to continue to raise additional capital. Our management expects that existing cash, cash equivalents, and marketable securities of $396.7 million as of September 30, 2023, will be sufficient to fund our current operating plan for at least the next 12 months from the date of issuance of our condensed consolidated financial statements. In July and August of 2023, we issued and sold a total of 22,115,384 shares of our common stock in an underwritten follow-on public offering for total net proceeds of approximately $134.4 million, which included the full exercise of the underwriters’ right to purchase 2,884,615 additional shares of our common stock.

Related Party Transactions - Pfizer Agreement (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 29, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Related Party Transaction [Line Items]
Common stock, par value (in dollars per share)	$ 0.0001		$ 0.0001		$ 0.0001		$ 0.0001
Term of agreement		36 months
Period of right of first negotiation		30 days
Proceeds from issuance of common stock in a private placement with Pfizer					$ 17,290	$ 0
Contract with customer, increase for new contract					7,500
Revenue			$ 23,662	$ 3,303	30,919	$ 10,159
Liabilities			59,253		59,253		$ 72,894
Deferred revenue			9,554		9,554		25,891
Deferred revenue, current			2,826		2,826		9,937
Deferred revenue, noncurrent			6,728		6,728		15,954
Pfizer
Related Party Transaction [Line Items]
Term of agreement		36 months
Investment owned, percentage		4.99%
Proceeds from issuance of common stock in a private placement with Pfizer		$ 17,500
Contract with customer, increase for new contract		$ 7,500
Related Party
Related Party Transaction [Line Items]
Revenue			622		1,772
Deferred revenue, current			2,487		2,487		150
Deferred revenue, noncurrent			4,352		4,352		$ 0
Related Party \| Pfizer
Related Party Transaction [Line Items]
Revenue			600		600
Deferred revenue			6,900		6,900
Deferred revenue, current			2,500		2,500
Deferred revenue, noncurrent			$ 4,400		$ 4,400
Private Placement
Related Party Transaction [Line Items]
Common stock shares sold (in shares)	4,690,431
Public offering price (in dollars per share)	$ 5.33
Aggregate offering price (up to)	$ 25,000

Revenue - Schedule of Changes in Company's Contract Assets and Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Accounts receivable
Accounts receivable, Beginning Balance	$ 202
Accounts receivable, Additions	7,631
Accounts receivable, Deductions	(6,700)
Accounts receivable, Ending Balance	1,133
Contract assets:
Unbilled accounts receivable, Beginning Balance	2,247
Unbilled accounts receivable, Additions	4,664
Unbilled accounts receivable, Deductions	(5,253)
Unbilled accounts receivable, Ending Balance	1,658
Contract liabilities:
Deferred revenue, current and long-term, Beginning Balance	25,891
Deferred revenue, current and long-term, Additions	11,537
Deferred revenue, current and long-term, Deductions	(27,874)
Deferred revenue, current and long-term, Ending Balance	$ 9,554

Significant Agreements - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized included in the opening contract liabilities balance			$ 23,200,000	$ 3,400,000
Accounts receivable	$ 1,133,000		1,133,000		$ 202,000
Contract assets	1,658,000		1,658,000		2,247,000
Research and development	28,584,000	$ 19,991,000	80,796,000	56,494,000
General and administrative	9,711,000	9,849,000	28,740,000	29,486,000
Collaboration and License Agreement with AbbVie
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received						$ 30,000,000
Revenue recognized included in the opening contract liabilities balance	20,800,000
Revenues	21,500,000	1,700,000	24,500,000	5,500,000
Accounts receivable	1,000,000		1,000,000		0
Contract assets	700,000		700,000		$ 900,000
Intellia Therapeutics, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development	400,000	300,000	1,200,000	800,000
General and administrative	400,000	1,400,000	2,200,000	4,700,000
Future payments for milestones	161,200,000		161,200,000
Intellia Therapeutics, Inc. \| Patents
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reduction in general and administrative expenses	$ 100,000	$ 900,000	$ 1,300,000	$ 3,100,000

Balance Sheet Items - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization expense related to property and equipment	$ 1.6	$ 0.4	$ 2.8	$ 1.1

Balance Sheet Items - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Accrued employee compensation and related expenses	$ 6,688	$ 5,752
Accrued research and development expenses	7,866	6,731
Accrued patent expenses	889	1,331
Accrued expenses related to sublicensing revenues	688	596
Credit card liability	453	299
Other	1,646	1,370
Total	$ 18,230	$ 16,079

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
CURRENT ASSETS
Cash and cash equivalents	$ 104,058	$ 58,338
Marketable securities, short-term	234,430	189,325
Accounts receivable	1,133	202
Contract assets	1,658	2,247
Other receivables	2,345	2,215
Prepaid expenses and other current assets	7,069	7,921
Total current assets	350,693	260,248
NON-CURRENT ASSETS
Investments in equity securities	7,763	7,698
Marketable securities, long-term	58,219	69,373
Property and equipment, net	16,598	10,678
Operating lease, right of use assets	22,680	24,230
Other assets	1,568	1,538
TOTAL ASSETS	457,521	373,765
CURRENT LIABILITIES
Accounts payable	2,377	1,146
Accrued expenses and other current liabilities	18,230	16,079
Lease liabilities, current	1,139	966
Deferred revenue ($2,487 and $150 from related party, respectively)	2,826	9,937
Total current liabilities	24,572	28,128
LONG-TERM LIABILITIES
Deferred revenue, net of current portion ($4,352 and $0 from related party, respectively)	6,728	15,954
MSKCC success payments liability	1,256	1,651
Lease liabilities, non-current	26,316	26,780
Deferred tax liabilities	381	381
Total liabilities	59,253	72,894
COMMITMENTS AND CONTINGENCIES (Note 9)
STOCKHOLDERS’ EQUITY
Preferred stock, par value $0.0001 per share, 10,000,000 shares authorized at September 30, 2023 and December 31, 2022; no shares issued and outstanding as of September 30, 2023 and December 31, 2022	0	0
Common stock, value, issued	8	6
Additional paid-in-capital	664,021	499,598
Accumulated other comprehensive loss	(981)	(1,518)
Accumulated deficit	(264,780)	(197,215)
Total stockholders’ equity	398,268	300,871
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 457,521	$ 373,765

Revenue - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation Of Revenue [Line Items]
Revenue recognized included in the opening contract liabilities balance			$ 23,200	$ 3,400
Decrease in unbilled accounts receivable			(588)	411
Contract with customer, increase for new contract			7,500
Transaction price allocated to the remaining performance obligations	$ 9,600		9,600
Collaboration and License Agreement with AbbVie
Disaggregation Of Revenue [Line Items]
Revenue recognized, performance obligation, amount	21,500		24,500
Revenue recognized included in the opening contract liabilities balance	20,800
Point in Time
Disaggregation Of Revenue [Line Items]
Revenue recognized, performance obligation, amount	1,600	$ 1,600	5,800	4,700
Over Time
Disaggregation Of Revenue [Line Items]
Revenue recognized, performance obligation, amount	$ 22,100	$ 1,700	$ 25,100	$ 5,500

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Net Loss Per Share

9 Months Ended

Sep. 30, 2023

Earnings Per Share [Abstract]

Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Numerator:
Net loss	$	(10,002)	$	(26,647)	$	(67,565)	$	(72,432)
Denominator:
Weighted-average common shares outstanding used to compute net loss per share, basic and diluted	83,783,992		60,886,921		68,878,921		60,731,520
Net loss per share, basic and diluted	$	(0.12)	$	(0.44)	$	(0.98)	$	(1.19)

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 September 30, 2023	As of September 30, 2022
Stock options outstanding	9,523,394	6,649,892
RSUs and PSUs issued and outstanding	168,438	259,769
Shares committed under ESPP	134,276	49,109
	9,826,108	6,958,770

401(k) Savings Plan - Additional Information (Details) - 2017 Plan - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, Employer matching contribution percent of match			4.00%
Employer contribution	$ 0.3	$ 0.2	$ 0.8	$ 0.6

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021		60,263,158
Beginning balance at Dec. 31, 2021	$ 387,825	$ 6	$ 485,748	$ (135)	$ (97,794)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock plans (in shares)		36,596
Issuance of common stock under employee stock plans	361		361
Issuance of common stock on exercise of stock options (in shares)		389,855
Issuance of common stock on exercise of options	629		629
Stock-based compensation expense	3,024		3,024
Net loss	(19,088)				(19,088)
Other comprehensive income (loss)	(954)			(954)	0
Ending balance (in shares) at Mar. 31, 2022		60,689,609
Ending balance at Mar. 31, 2022	371,797	$ 6	489,762	(1,089)	(116,882)
Beginning balance (in shares) at Dec. 31, 2021		60,263,158
Beginning balance at Dec. 31, 2021	387,825	$ 6	485,748	(135)	(97,794)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(72,432)
Ending balance (in shares) at Sep. 30, 2022		60,986,936
Ending balance at Sep. 30, 2022	324,114	$ 6	496,369	(2,035)	(170,226)
Beginning balance (in shares) at Mar. 31, 2022		60,689,609
Beginning balance at Mar. 31, 2022	371,797	$ 6	489,762	(1,089)	(116,882)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on exercise of stock options (in shares)		148,761
Issuance of common stock on exercise of options	363		363
Stock-based compensation expense	2,918		2,918
Net loss	(26,697)				(26,697)
Other comprehensive income (loss)	(492)			(492)
Ending balance (in shares) at Jun. 30, 2022		60,838,370
Ending balance at Jun. 30, 2022	347,889	$ 6	493,043	(1,581)	(143,579)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock on exercise of stock options (in shares)		148,566
Issuance of common stock on exercise of options	654		654
Stock-based compensation expense	2,672		2,672
Net loss	(26,647)
Other comprehensive income (loss)	(454)			(454)
Ending balance (in shares) at Sep. 30, 2022		60,986,936
Ending balance at Sep. 30, 2022	324,114	$ 6	496,369	(2,035)	(170,226)
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 employee stock plans (in shares)		70,271
Issuance of common stock under employee stock plans	404		404
Issuance of common stock on exercise of stock options (in shares)		55,433
Issuance of common stock on exercise of options	115		115
Issuance of common stock (in shares)		168,635
Issuance of common stock	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]
Issuance of common stock on exercise of stock options (in shares)	209,925
Net loss	$ (67,565)
Ending balance (in shares) at Sep. 30, 2023		88,430,609
Ending balance at Sep. 30, 2023	398,268	$ 8	664,021	(981)	(264,780)
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 stock options (in shares)		86,085
Issuance of common stock on exercise of options	236		236
Issuance of common stock (in shares)		4,690,431
Issuance of common stock	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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock plans (in shares)		68,183
Issuance of common stock under employee stock plans	382		382
Issuance of common stock on exercise of stock options (in shares)		83,407
Issuance of common stock on exercise of options	372		372
Issuance of common stock on RSU release (in shares)		63,596
Issuance of common stock (in shares)		22,115,384
Issuance of common stock	134,425	$ 2	134,423
Stock-based compensation expense	3,478		3,478
Net loss	(10,002)				(10,002)
Other comprehensive income (loss)	155			155
Ending balance (in shares) at Sep. 30, 2023		88,430,609
Ending balance at Sep. 30, 2023	$ 398,268	$ 8	$ 664,021	$ (981)	$ (264,780)

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesNo income tax expense was recorded during each of the three- and nine-month periods ended September 30, 2023, and 2022 due to our operating losses.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
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-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Stock Based Compensation - Schedule of Stock-based Compensation Expense Related to Equity-Based Awards (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 3,478	$ 2,673	$ 10,194	$ 8,615
Stock options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	3,188	2,479	9,188	8,190
ESPP
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	96	80	427	209
RSUs
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 194	$ 114	$ 579	$ 216

Related Party Transactions - Additional Information (Details) - USD ($)		3 Months Ended		9 Months Ended
	May 15, 2020	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	May 16, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Carrying value of investment		$ 7,763,000		$ 7,763,000			$ 7,698,000
Revenue		23,662,000	$ 3,303,000	30,919,000	$ 10,159,000
Edge Animal Health
Related Party Transaction [Line Items]
Exercise option, term						3 years
Revenue			$ 0	1,200,000	$ 0
Related Party
Related Party Transaction [Line Items]
Revenue		622,000		1,772,000
Convertible Preferred Stock \| Private Company License Agreement
Related Party Transaction [Line Items]
Convertible preferred stock issued (in shares)	7,500,000
Fair value of convertible preferred stock	$ 7,500,000
Carrying value of investment		$ 7,500,000		$ 7,500,000			$ 7,500,000

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsWe did not have any subsequent events as of the filing date of this Quarterly Report on Form 10-Q.

Common Stock (Tables)

9 Months Ended

Sep. 30, 2023

Equity [Abstract]

Schedule of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consisted of the following:


	As of September 30, 2023	As of December 31, 2022
Stock options, issued and outstanding	9,523,394	6,733,074
Stock options, authorized for future issuance	5,894,280	5,833,979
Stock available under our employee stock purchase plan	1,516,355	1,044,518
Unvested restricted stock units and performance-based restricted stock units	168,438	256,146
	17,102,467	13,867,717

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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility		74.20%
Expected term (in years)	6 years	6 years
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	74.20%		74.20%	71.70%
Expected term (in years)			5 years	5 years 6 months
Risk-free interest rate	4.10%	3.10%	3.50%	1.70%
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	74.60%		75.00%	74.20%
Expected term (in years)			6 years	6 years
Risk-free interest rate	4.60%	3.70%	4.60%	3.70%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stock Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		26 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	17,102,467		17,102,467		17,102,467	13,867,717
Stock options granted during period (in shares)			3,406,801
Unrecognized stock based-compensation expenses	$ 29,700		$ 29,700		$ 29,700
Weighted-average period (in years)			2 years 8 months 12 days
Accrued liabilities	200		$ 200		200
Stock-based compensation expense	3,478	$ 2,673	$ 10,194	$ 8,615
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period (in years)			1 year 6 months
Unrecognized stock-based compensation expense	900		$ 900		900
Stock-based compensation expense	194	$ 114	579	$ 216
Performance Restricted Stock Units (PRSU)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 600		$ 600		$ 600
Employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted during period (in shares)	384,095	372,600	3,406,801	1,206,750
Non-Employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 0	$ 100	$ 0	$ 100
Employee and Non-Employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share)	$ 3.64	$ 6.43	$ 3.91	$ 5.84
2021 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	5,894,280		5,894,280		5,894,280
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock in connection with at-the-market offering, net of offering expenses (in shares)					207,567

Stock Based Compensation

9 Months Ended

Sep. 30, 2023

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 (the “2021 Plan”) that became effective on July 22, 2021. As of September 30, 2023, we had 5,894,280 shares available for issuance under the 2021 Plan.

The following table summarizes stock option activity under our equity incentive plans during the nine months ended September 30, 2023:


	Stock Options	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in thousands)*

Outstanding at December 31, 2022	6,733,074	$	9.01	8.2	$	8,203
Options granted	3,406,801	5.74
Options exercised	(209,925)	3.44
Options cancelled or forfeited	(406,556)	6.69
Outstanding at September 30, 2023	9,523,394	$	8.06	8.3	$	3,139
Exercisable at September 30, 2023	3,906,573	$	7.88	7.5	$	2,527
Vested and expected to vest at September 30, 2023	9,523,394	$	8.06	8.3	$	3,139

Grant Date Fair Value

During the three months ended September 30, 2023, and 2022, we granted 384,095 and 372,600 stock options to employees with a weighted average grant date fair value of $3.64 and $6.43, respectively. During the nine months ended September 30, 2023, and 2022, we granted 3,406,801 and 1,206,750 stock options to employees with a weighted average grant date fair value of $3.91 and $5.84, respectively.

We estimated the fair value of each employee and non-employee stock option award on the grant date using the Black-Scholes option-pricing model based on the following assumptions:


	Three Months Ended September 30,		Nine Months Ended September 30,
	2023	2022	2023	2022
Volatility	74.2% to 74.6%	74.2%	74.2% to 75.0%	71.7% to 74.2%
Expected term (in years)	6.0	6.0	5.0 to 6.0	5.5 to 6.0
Risk-free interest rate	4.1% to 4.6%	3.1% to 3.7%	3.5% to 4.6%	1.7% to 3.7%
Expected dividend yield	0.0%	0.0%	0.0%	0.0%

As of September 30, 2023, there was $29.7 million of unrecognized stock-based compensation expense related to employee and non-employee stock options that is expected to be recognized over a weighted-average period of 2.7 years.

Restricted Stock Units

During the nine months ended September 30, 2023, we did not grant any restricted stock units (“RSUs”) or performance-based RSUs (“PSUs”) under the 2021 Plan. A summary of the status of and change in unvested RSUs and PSUs as of September 30, 2023 was as follows:


	Number of Shares Underlying Outstanding RSUs and PSUs	Weighted-Average Grant Date Fair Value per RSU and PSU
Unvested, January 1, 2023	256,146	$	10.07
Vested	(78,596)	10.04
Forfeited	(9,112)	9.90
Unvested, September 30, 2023	168,438	$	10.10

The PSUs were granted to our executive officers and will vest contingent upon the achievement of a clinical milestone for CB-010 during a performance period ending December 31, 2024, and an executive officer’s continued employment during the performance period. As of September 30, 2023, the achievement of this milestone was not considered probable and, therefore, no stock-based compensation was recorded.

As of September 30, 2023, the total unrecognized stock-based compensation expense related to unvested RSUs was $0.9 million, which is expected to be recognized over the remaining weighted-average vesting period of 1.5 years. As of September 30, 2023, 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 have issued 207,567 shares of common stock under the ESPP as of September 30, 2023. We recorded $0.2 million in accrued liabilities related to contributions withheld as of September 30, 2023.

Stock-Based Compensation Expense

We recorded stock-based compensation expense related to employee and non-employee equity-based awards grants in our condensed consolidated statements of operations as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Research and development	$	1,464	$	1,072	$	4,324	$	3,139
General and administrative	2,014		1,601		5,870		5,476
Total	$	3,478	$	2,673	$	10,194	$	8,615

The above stock-based compensation expense related to the following equity-based awards (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Stock options	$	3,188	$	2,479	$	9,188	$	8,190
ESPP	96		80		427		209
RSUs	194		114		579		216
Total	$	3,478	$	2,673	$	10,194	$	8,615

There was no stock-based compensation expense related to non-employees for the three months ended September 30, 2023, and was less than $0.1 million for the three months ended September 30, 2022. There was no stock-based compensation expense related to non-employees for the nine months ended September 30, 2023, and $0.1 million for the nine months ended September 30, 2022.

Balance Sheet Items (Tables)

9 Months Ended

Sep. 30, 2023

Balance Sheet Related Disclosures [Abstract]

Schedule of Other Receivables

Other receivables consisted of the following (in thousands):


	September 30, 2023		December 31, 2022
Patent cost reimbursements	$	1,202	$	1,638
Accrued interest on marketable securities	543		570
Other	600		7
Total	$	2,345	$	2,215

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	September 30, 2023		December 31, 2022
Prepaid contract manufacturing and clinical costs	$	3,453	$	4,803
Prepaid insurance	1,402		1,568
Prepaid income taxes	603		431
Other	1,611		1,119
Total	$	7,069	$	7,921

Schedule of Property and Equipment

Property and equipment, net, consisted of the following (in thousands):


	September 30, 2023		December 31, 2022
Lab equipment	$	14,868	$	12,588
Leasehold improvements	1,938		1,876
Computer equipment	761		709
Furniture and equipment	161		161
Construction in progress	7,275		993
Total property and equipment, gross	25,003		16,327
Less: accumulated depreciation and amortization	(8,405)		(5,649)
Property and equipment, net	$	16,598	$	10,678

Summary of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	September 30, 2023		December 31, 2022
Accrued employee compensation and related expenses	$	6,688	$	5,752
Accrued research and development expenses	7,866		6,731
Accrued patent expenses	889		1,331
Accrued expenses related to sublicensing revenues	688		596
Credit card liability	453		299
Other	1,646		1,370
Total	$	18,230	$	16,079

Balance Sheet Items - Schedule of Other Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Patent cost reimbursements	$ 1,202	$ 1,638
Accrued interest on marketable securities	543	570
Other	600	7
Total	$ 2,345	$ 2,215

Leases (Tables)

9 Months Ended

Sep. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Schedule Of Components Lease Cost

The components of lease costs, which are included in our statements of operations, were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Operating lease cost(1)	$	1,937	$	1,822	$	5,749	$	5,443
Short-term lease cost	63		—		188		83
Total lease cost	$	2,000	$	1,822	$	5,937	$	5,526

Schedule Of Supplemental Information Related To Leases

Supplemental information related to our leases was as follows (in thousands):


	Nine Months Ended September 30,
	2023		2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	2,597	$	2,454

The weighted-average remaining lease term and the weighted-average discount rate for our laboratory and office leases were as follows:


	September 30, 2023		December 31, 2022
Weighted-average remaining lease term (years)	7.6		8.3
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 September 30, 2023 (in thousands):


Remainder of 2023(1)	$	744
2024(2)	3,876
2025	4,475
2026	5,720
2027	5,922
Thereafter	22,116
Total undiscounted lease payments	42,853
Less: imputed interest	(15,398)
Total discounted lease payments	27,455
Less: current portion of lease liability	(1,139)
Noncurrent portion of lease liability	$	26,316

(1)Reflects an offset of $0.4 million related to incentives expected to be received in 2023.

(2)Reflects an offset of $0.7 million related to incentives expected to be received in 2024.

Leases - Schedule Of Components Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 1,937	$ 1,822	$ 5,749	$ 5,443
Short-term lease cost	63	0	188	83
Total lease cost	2,000	1,822	5,937	5,526
Variable lease cost	$ 700	$ 600	$ 1,900	$ 1,600

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	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost Basis	$ 397,689	$ 318,555
Cash and cash equivalents, Amortized Cost Basis	104,058	58,338	$ 82,085
Unrealized Gains	22	32
Unrealized Losses	(1,004)	(1,551)
Available-for-sale marketable securities and cash and cash equivalents, Estimated Fair Value	396,707	317,036
Marketable securities, short-term	234,430	189,325
Marketable securities, long-term	58,219	69,373
Commercial paper
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost Basis		26,669
Money market funds
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost Basis	19,556	27,693
Cash and cash equivalents, Estimated Fair Value	19,556	27,693
U.S. Treasury bills
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost Basis	296,314
Available-for-sale marketable securities, Amortized Cost Basis		92,910
Cash and cash equivalents, Amortized Cost Basis	84,502
Unrealized Gains	15	1
Unrealized Losses	(670)	(945)
Available-for-sale marketable securities and cash and cash equivalents, Estimated Fair Value	295,659
Available-for-sale marketable securities, Estimated Fair Value		91,966
U.S. government agency bonds
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost Basis		63,926
Available-for-sale marketable securities, Amortized Cost Basis	55,789
Unrealized Gains	0	25
Unrealized Losses	(313)	(292)
Available-for-sale marketable securities and cash and cash equivalents, Estimated Fair Value		63,659
Available-for-sale marketable securities, Estimated Fair Value	55,476
Commercial paper
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost Basis		97,024
Available-for-sale marketable securities, Amortized Cost Basis	20,549
Unrealized Gains	0	6
Unrealized Losses	(3)	(131)
Available-for-sale marketable securities and cash and cash equivalents, Estimated Fair Value		96,899
Available-for-sale marketable securities, Estimated Fair Value	20,546
Corporate debt securities
Debt Securities, Available-for-Sale [Line Items]
Available-for-sale marketable securities, Amortized Cost Basis	5,481	37,002
Unrealized Gains	7	0
Unrealized Losses	(18)	(183)
Available-for-sale marketable securities, Estimated Fair Value	$ 5,470	$ 36,819

Stock Based Compensation - Schedule of Restricted Stock Units Activity (RSUs) (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Number of Shares Underlying Outstanding RSUs and PSUs
Vested (in shares) \| shares	(78,596)
Weighted-Average Grant Date Fair Value per RSU and PSU
Vested, Weighted-Average Grant Date Fair Value per RSU and PRSU (in dollars per share) \| $ / shares	$ 10.04
Restricted Stock Units RSU and Performance-Based RSUs
Number of Shares Underlying Outstanding RSUs and PSUs
Unvested, January 1, 2023 (in shares) \| shares	256,146
Forfeited (in shares) \| shares	(9,112)
Unvested, June 30, 2023 (in shares) \| shares	168,438
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	$ 10.07
Forfeited, Weighted-Average Grant Date Fair Value per RSU and PRSU (in dollars per share) \| $ / shares	9.90
Unvested, Weighted-Average Grant Date Fair Value per RSU, Ending Balance (in dollars per share) \| $ / shares	$ 10.10

Leases - Schedule Of Supplemental Information Related To Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Operating cash flows from operating leases	$ 2,597	$ 2,454
Operating lease, weighted average remaining lease term	7 years 7 months 6 days		8 years 3 months 18 days
Weighted-average discount rate	11.30%		11.30%

Revenue - Additional Information (Details1) $ in Millions	Sep. 30, 2023 USD ($)
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	$ 9.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	$ 2.8
Remaining performance obligation, expected timing of satisfaction, period	12 months

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2023

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				Nine Months Ended				As of September 30, 2023		As of December 31, 2022
	September 30, 2023		September 30, 2022		September 30, 2023		September 30, 2022
Licensee A	*		17.2	%	*		16.4	%	23.6	%	23.8	%
Licensee B	90.8	%	51.7	%	79.1	%	54.2	%	62.6	%	36.6	%

Total	90.8	%	68.9	%	79.1	%	70.6	%	86.2	%	60.4	%

*Less than 10%

Balance Sheet Items - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Prepaid contract manufacturing and clinical costs	$ 3,453	$ 4,803
Prepaid insurance	1,402	1,568
Prepaid income taxes	603	431
Other	1,611	1,119
Total	$ 7,069	$ 7,921

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Revenue	$ 23,662	$ 3,303	$ 30,919	$ 10,159
Operating expenses:
Research and development	28,584	19,991	80,796	56,494
General and administrative	9,711	9,849	28,740	29,486
Total operating expenses	38,295	29,840	109,536	85,980
Loss from operations	(14,633)	(26,537)	(78,617)	(75,821)
Other income (expense):
Change in fair value of equity securities	(4)	31	3	(73)
Change in fair value of MSKCC success payments liability	(139)	(1,607)	395	1,041
Other income, net	4,774	1,466	10,654	2,421
Total other income (expense)	4,631	(110)	11,052	3,389
Net loss	(10,002)	(26,647)	(67,565)	(72,432)
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale marketable securities, net of tax	155	(454)	537	(1,900)
Net comprehensive loss	$ (9,847)	$ (27,101)	$ (67,028)	$ (74,332)
Net loss per share, basic (in dollars per share)	$ (0.12)	$ (0.44)	$ (0.98)	$ (1.19)
Net loss per share, diluted (in dollars per share)	$ (0.12)	$ (0.44)	$ (0.98)	$ (1.19)
Weighted-average common shares outstanding, basic (in shares)	83,783,992	60,886,921	68,878,921	60,731,520
Weighted-average common shares outstanding, diluted (in shares)	83,783,992	60,886,921	68,878,921	60,731,520

Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation Of Revenue [Line Items]
Revenue	$ 23,662	$ 3,303	$ 30,919	$ 10,159
United States
Disaggregation Of Revenue [Line Items]
Revenue	23,285	2,966	30,416	9,761
Rest of world
Disaggregation Of Revenue [Line Items]
Revenue	$ 377	$ 337	$ 503	$ 398

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

- Definition

+ References

+ Details

Related Party Transactions	9 Months Ended
Related Party Transactions	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Edge Animal Health On May 15, 2020, we entered into an Exclusive License Agreement for Veterinary Therapeutics (as amended, the “Edge chRDNA License Agreement”) with Edge Animal Health (“Edge”), a private company, related party, under which we granted Edge an exclusive worldwide license to Cas9 and Cas12a chRDNA intellectual property rights and know-how in the defined field of veterinary therapeutics. As consideration for this exclusive license, Edge issued to us 7,500,000 shares of convertible preferred stock with an estimated fair value of $7.5 million, which was the price paid for similar shares by another investor, and which was an arm’s length transaction. This represents a material voting interest in Edge and entitles us to hold one of the four board of director seats and to jointly vote with another stockholder on a second board of director seat. As of September 30, 2023, we had appointed one of the four Edge directors. We concluded that Edge is a variable interest entity and that we are not its primary beneficiary based on our representation on its board of directors. As Edge’s convertible preferred stock is not in substance common stock, we recorded this investment using the measurement alternative in accordance with ASC 321, Investments–Equity Securities. Under the measurement alternative, our investment in Edge’s convertible preferred stock was initially recorded at its estimated fair value, and the carrying value may be adjusted through earnings upon an impairment or when there is an observable price change involving the same or a similar investment with Edge. As of each of September 30, 2023, and December 31, 2022, the carrying value of the Edge investment was $7.5 million. There have been no changes to the carrying value of the investment during the three months ended September 30, 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 had 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 Edge paid, and we entered into the Edge Cas9 License Agreement. We did not recognize any revenue in connection with the Edge Cas9 License Agreement during the three months ended September 30, 2023. We recognized $1.2 million of revenue in connection with the Edge Cas9 License Agreement during the nine months ended September 30, 2023. We did not recognize any revenue in connection with the Edge Cas9 License Agreement in 2022. Pfizer Investment On June 29, 2023, we entered into a Securities Purchase Agreement (the “Securities Purchase Agreement”) with Pfizer, pursuant to which we, in a private placement transaction (the “Pfizer Investment”), agreed to issue and sell to Pfizer 4,690,431 shares of our common stock, par value $0.0001 per share, at a purchase price of $5.33 per share, for aggregate gross proceeds of approximately $25.0 million. The issuance and sale of the shares to Pfizer closed on June 30, 2023. We granted certain registration rights to Pfizer under the Securities Purchase Agreement covering the resale of the shares. Unless otherwise agreed by Pfizer, we have agreed to use the proceeds from the Pfizer Investment solely in connection with (i) the development program for our allogeneic anti-BCMA CAR-T cell therapy known as CB-011 that is being evaluated in the CaMMouflage clinical trial and/or (ii) any other single-targeted anti-BCMA CAR-T cell therapy using an anti-BCMA single-chain variable fragment owned or controlled by us (collectively, cell therapies described in clauses (i) and (ii) are referred to as a “BCMA Product Candidate”), for 36 months beginning on June 29, 2023. On June 29, 2023, in connection with the Pfizer Investment, we and Pfizer also entered into an Information Rights Agreement (the “Information Rights Agreement”), having a thirty-six (36)-month term. Under the Information Rights Agreement, we granted Pfizer a thirty (30)-calendar day right of first negotiation (“ROFN”) if we commence or engage with any third party with respect to a potential grant of rights to develop and/or commercialize a BCMA Product Candidate, including, without limitation, a license agreement, a co-promotion/co-commercialization agreement, a profit share agreement, a joint venture agreement, or an asset sale agreement (a “Grant of Program Rights”). If we and Pfizer do not reach an agreement with respect to a Grant of Program Rights within the 30-day period, then we may pursue negotiations and enter into an agreement with any third party. If we and such third party do not reach agreement on the Grant of Program Rights within a specified time period, Pfizer’s right of first negotiation would be reinstated. Under the Information Rights Agreement, we also agreed to grant Pfizer the right to designate one representative to serve on our scientific advisory board. Through an information sharing committee, we will provide calendar quarter updates to Pfizer regarding the development program for a BCMA Product Candidate. Additionally, we agreed to provide Pfizer access to any preclinical or interim or final clinical data (including raw data) and results generated as part of the development program for a BCMA Product Candidate at the same time that we provide such data to a third party (other than to our service providers or the FDA or other regulatory authorities), subject to certain confidentiality exceptions. On June 29, 2023, we and Pfizer also entered into a Voting Agreement, pursuant to which, for a period of 12 months, Pfizer agreed to cause our voting securities that Pfizer beneficially owns (within the meaning of Rules 13d-3 or 13d-5 under the Exchange Act) in excess of 4.99% of our then issued and outstanding voting securities to be voted (i) with respect to any matter directly relating to remuneration of directors, directors’ insurance, or indemnification or release from liability of directors, in a manner proportionally consistent with the votes properly cast for and against by holders of voting securities not beneficially owned by Pfizer, and (ii) with respect to any other matter in which Pfizer shall have the right to vote such voting securities, in accordance with the recommendation of our board of directors or any applicable committee thereof. We recorded the issuance of our common stock at its estimated fair value of $17.5 million, which reflects a discount for the lack of marketability of the shares. The remaining $7.5 million of the aggregate purchase price was allocated to the Information Rights Agreement, which represented a contract with a customer. We concluded that the information sharing committee represents the only performance obligation under the Information Rights Agreement. The ROFN does not provide Pfizer with a material right and is therefore not a performance obligation. We recognize revenue over time as the measure of progress which we believe best depicts the obligations to Pfizer. The information sharing committee will meet quarterly over the 36-month term of the Information Rights Agreement, which results in recognition of the transaction price over the 36-month term. During each of the three- and nine-month periods ended September 30, 2023, we recognized $0.6 million of revenue from Pfizer. As of September 30, 2023, there was approximately $6.9 million of related party deferred revenue ($2.5 million included in current liabilities and $4.4 million included in long-term liabilities) related to our performance obligation to Pfizer.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Financial Instruments Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Liabilities:
Cash and cash equivalents	$ 104,058	$ 58,338	$ 82,085
U.S. government agency bonds
Liabilities:
Cash and cash equivalents		3,976
Commercial paper
Liabilities:
Cash and cash equivalents		26,669
Fair Value, Recurring
Assets:
Assets fair value	396,707	317,036
Liabilities:
Liabilities fair value	1,256	1,651
Fair Value, Recurring \| U.S. Treasury bills
Assets:
Assets fair value	295,659	91,966
Fair Value, Recurring \| U.S. government agency bonds
Assets:
Assets fair value	55,476	63,659
Fair Value, Recurring \| Money market funds
Assets:
Assets fair value	19,556	27,693
Fair Value, Recurring \| Commercial paper
Assets:
Assets fair value	20,546	96,899
Fair Value, Recurring \| Corporate debt securities
Assets:
Assets fair value	5,470	36,819
Fair Value, Recurring \| MSKCC success payments liability
Liabilities:
Liabilities fair value	1,256	1,651
Fair Value, Recurring \| Level 1
Assets:
Assets fair value	315,215	119,659
Liabilities:
Liabilities fair value	0	0
Fair Value, Recurring \| Level 1 \| U.S. Treasury bills
Assets:
Assets fair value	295,659	91,966
Fair Value, Recurring \| Level 1 \| U.S. government agency bonds
Assets:
Assets fair value	0	0
Fair Value, Recurring \| Level 1 \| Money market funds
Assets:
Assets fair value	19,556	27,693
Fair Value, Recurring \| Level 1 \| Commercial paper
Assets:
Assets fair value	0	0
Fair Value, Recurring \| Level 1 \| Corporate debt securities
Assets:
Assets fair value	0	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	81,492	197,377
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 \| U.S. government agency bonds
Assets:
Assets fair value	55,476	63,659
Fair Value, Recurring \| Level 2 \| Money market funds
Assets:
Assets fair value	0	0
Fair Value, Recurring \| Level 2 \| Commercial paper
Assets:
Assets fair value	20,546	96,899
Fair Value, Recurring \| Level 2 \| Corporate debt securities
Assets:
Assets fair value	5,470	36,819
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	1,256	1,651
Fair Value, Recurring \| Level 3 \| U.S. Treasury bills
Assets:
Assets fair value	0	0
Fair Value, Recurring \| Level 3 \| U.S. 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 \| Commercial paper
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	$ 1,256	$ 1,651

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0	$ 0	$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Leases - Additional Information (Details)	Sep. 30, 2023 ft²
Commitments and Contingencies Disclosure [Abstract]
Area of real estate property (in square feet)	75,000
Remaining lease term (in years)	8 years 9 months 18 days
Lease renewal term (in years)	5 years