0000950170-23-038050 | 10-Q | XBRL Viewer

Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2023

Anti-dilutive Securities Excluded from Computation of Diluted Net Loss Per Share

The following securities were excluded from the computation of net loss per diluted share of common stock for periods presented as their effect would have been anti-dilutive:


	Six Months Ended June 30,
	2023		2022
	(in thousands)
Options to purchase common stock		30,296		25,616
Unvested restricted common stock		-		1,706
Unvested RSUs		1,776		911
Total		32,072		28,233

Fair Value Measurements

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

6. Fair value measurements

The following tables summarize the Company’s financial assets and liabilities measured at fair value on a recurring basis based on the three-tier fair value hierarchy:


		June 30, 2023
	Valuation Hierarchy	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Estimated Fair Value
		(in thousands)
Financial assets:
Cash equivalents:
Money market funds	Level 1	$	86,623	$	-	$	-		$	86,623
U.S. government and agency securities	Level 2		45,700		12		-			45,712
Total cash equivalents			132,323		12		-			132,335
Short-term marketable securities:
U.S. government and agency securities	Level 2		142,940		15		(868	)		142,087
Corporate debt securities	Level 2		10,065		-		(24	)		10,041
Total short-term marketable securities			153,005		15		(892	)		152,128
Other assets	Level 3		369		-		-			369
Total financial assets		$	285,697	$	27	$	(892	)	$	284,832
Financial liabilities:
Short-term financial liabilities:
Contingent consideration	Level 3	$	58,417	$	-	$	-		$	58,417
Total short-term financial liabilities			58,417		-		-			58,417
Long-term financial liabilities:
Contingent consideration	Level 3		103,317		-		-			103,317
Success payment liabilities	Level 3		36,451		-		-			36,451
Total long-term financial liabilities			139,768		-		-			139,768
Total financial liabilities		$	198,185	$	-	$	-		$	198,185


		December 31, 2022
	Valuation Hierarchy	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Estimated Fair Value
		(in thousands)
Financial assets:
Cash equivalents:
Money market funds	Level 1	$	114,363	$	-	$	-		$	114,363
U.S. government and agency securities	Level 2		40,532		10		-			40,542
Corporate debt securities	Level 2		9,796		1		(2	)		9,795
Total cash equivalents			164,691		11		(2	)		164,700
Short-term marketable securities:
U.S. government and agency securities	Level 2		222,435		2		(3,711	)		218,726
Corporate debt securities	Level 2		28,836		-		(364	)		28,472
Total short-term marketable securities			251,271		2		(4,075	)		247,198
Long-term marketable securities:
U.S. government and agency securities	Level 2		10,314		-		(263	)		10,051
Total long-term marketable securities			10,314		-		(263	)		10,051
Other assets	Level 3		369		-		-			369
Total financial assets		$	426,645	$	13	$	(4,340	)	$	422,318
Financial liabilities:
Short-term financial liabilities:
Contingent consideration	Level 3	$	55,345	$	-	$	-		$	55,345
Total short-term financial liabilities			55,345		-		-			55,345
Long-term financial liabilities:
Contingent consideration	Level 3		95,034		-		-			95,034
Success payment liabilities	Level 3		21,007		-		-			21,007
Total long-term financial liabilities			116,041		-		-			116,041
Total financial liabilities		$	171,386	$	-	$	-		$	171,386

The Company measures the fair value of money market funds based on quoted prices in active markets for identical assets or liabilities. The Level 2 marketable securities include U.S. government and agency securities and corporate debt securities and are valued based on either recent trades of securities in inactive markets or quoted market prices of similar instruments and other significant inputs derived from or corroborated by observable market data.

The following table summarizes available-for-sale debt securities in a continuous unrealized loss position for less than and greater than twelve months for the periods presented:


	Less than 12 months					12 months or greater					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
	(in thousands)
June 30, 2023
U.S. government and agency securities	$	5,431	$	(45	)	$	81,549	$	(823	)	$	86,980	$	(868	)
Corporate debt securities		-		-			10,041		(24	)		10,041		(24	)
Total	$	5,431	$	(45	)	$	91,590	$	(847	)	$	97,021	$	(892	)
December 31, 2022
U.S. government and agency securities	$	49,253	$	(673	)	$	172,845	$	(3,301	)	$	222,098	$	(3,974	)
Corporate debt securities		13,333		(16	)		19,664		(350	)		32,997		(366	)
Total	$	62,586	$	(689	)	$	192,509	$	(3,651	)	$	255,095	$	(4,340	)

The Company determined that there was no material change in the credit risk of the above investments during the three and six months ended June 30, 2023. As such, an allowance for credit losses has not been recognized. As of June 30, 2023, the Company does not intend to sell such securities, and it is not more-likely-than-not that the Company will be required to sell the securities prior to the recovery of the amortized cost basis.

As of June 30, 2023, all marketable securities had an effective maturity date of two years or less. Investments in securities with maturities of less than one year, or those for which management intends to use to fund current operations, are included in current assets and classified as available-for-sale. As of June 30, 2023, the balance in accumulated other comprehensive loss included net unrealized gains (losses) related to the Company’s available-for-sale debt securities.

The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities:


	Contingent Consideration		Cobalt Success Payment Liability			Harvard Success Payment Liability
	(in thousands)
Balance as of December 31, 2022	$	150,379	$	19,016		$	1,991
Changes in fair value – expense (gain)		5,460		(4,760	)		(580	)
Balance as of March 31, 2023		155,839		14,256			1,411
Changes in fair value – expense		5,895		18,505			2,279
Balance as of June 30, 2023	$	161,734	$	32,761		$	3,690

Contingent consideration

The Company utilizes significant estimates and assumptions it believes would be made by a market participant in determining the estimated fair value of the Cobalt Contingent Consideration at each balance sheet date. The fair value of the Cobalt Contingent Consideration was determined by calculating the probability-weighted estimated value of the pre-specified development milestone payments based on the assessment of the likelihood and estimated timing that the milestones would be achieved and the applicable discount rates. The discount rate captures the credit risk associated with the payment of the contingent consideration when earned and due. The Company assesses these estimates on an ongoing basis as additional data impacting the assumptions are obtained.

The fair value of the Cobalt Contingent Consideration was calculated using the following unobservable inputs:


	June 30, 2023		December 31, 2022
Unobservable Input	Range	Weighted-Average	Range	Weighted-Average
Discount rates	13.0% – 15.1%	13.8%	13.4% – 15.1%	14.6%
Probability of milestone achievement	5.0% – 85.0%	36.0%	5.0% – 85.0%	36.0%

The weighted-average unobservable inputs were calculated based on the relative value of the pre-specified development milestones. The estimated fair value of the Cobalt Contingent Consideration may change significantly as development progresses and additional data are obtained, impacting the assumptions regarding probabilities of successful achievement of the milestones used to estimate the fair value of the liability and the timing in which they are expected to be achieved. In evaluating the fair value assumptions, judgment is required to interpret the market data used to develop the estimates. The estimates of fair value may not be indicative of the amounts that could be realized in a current market exchange. Accordingly, the use of different market assumptions, inputs and/or different valuation techniques could result in materially different fair value estimates.

Success payments

The Company utilizes significant estimates and assumptions in determining the estimated fair value of the success payment liabilities and the associated expense or gain at each balance sheet date. The estimated fair value of the Cobalt Success Payment and Harvard Success Payment liabilities was determined using a Monte Carlo simulation methodology, which models the estimated fair value of the liability based on several key assumptions, including the expected volatility, remaining term, risk-free interest rate, estimated number and timing of valuation measurement dates on the basis of which payment may be triggered, and, for the Cobalt Success Payment, the Company’s market capitalization, and, for the Harvard Success Payments, the per share fair value of the Company’s common stock.

The fair values of the Cobalt Success Payments and Harvard Success Payments were calculated using the following unobservable inputs:


	June 30, 2023		December 31, 2022
Unobservable Input	Cobalt	Harvard	Cobalt	Harvard
Expected stock price volatility	72.5%	72.5%	70.0%	70.0%
Expected term (years)	15.6	7.7	16.1	8.2

- 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

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Mar. 31, 2023
At The Market Offering
Issuance of common stock, net of offering costs	$ 985	$ 200

Stock-Based Compensation - Schedule of Unrecognized Stock-Based Compensation Costs Related to Unvested Awards and Weighted-Average Period Over Which Costs are Expected to be Recognized (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense (in thousands)	$ 74,944
Weighted-average period costs expected to be recognized (in years)	2 years 6 months
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense (in thousands)	$ 6,653
Weighted-average period costs expected to be recognized (in years)	2 years 9 months 18 days

- 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

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+ Details

Fair Value Measurements - Changes in Estimated Fair Value of Level 3 Financial Liabilities (Details) - Fair Value, Inputs, Level 3 - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Mar. 31, 2023
Contingent Consideration
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 155,839	$ 150,379
Changes in fair value – expense (gain)	5,895	5,460
Ending Balance	161,734	155,839
Cobalt Success Payment Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	14,256	19,016
Changes in fair value – expense (gain)	18,505	(4,760)
Ending Balance	32,761	14,256
Harvard Success Payment Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	1,411	1,991
Changes in fair value – expense (gain)	2,279	(580)
Ending Balance	$ 3,690	$ 1,411

Stock-Based Compensation - Summary of RSU Activity (Details) - Restricted Stock Units (RSUs) shares in Thousands	6 Months Ended
	Jun. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested shares as of December 31, 2022 \| shares	885
Granted \| shares	1,269
Vested \| shares	(261)
Forfeited \| shares	(117)
Unvested shares as of June 30, 2023 \| shares	1,776
Weighted-Average Grant Date Fair Value per Share
Unvested shares as of December 31, 2022 \| $ / shares	$ 6.66
Granted \| $ / shares	3.77
Vested \| $ / shares	6.67
Forfeited \| $ / shares	5.12
Unvested shares as of June 30, 2023 \| $ / shares	$ 4.69

Organization - Additional Information (Details) - USD ($) shares in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Aug. 31, 2022
Description Of Organization [Line Items]
Accumulated deficit	$ 1,250,958,000		$ 1,054,836,000
Cash, cash equivalents and marketable securities	325,900,000
Success payment liabilities	34,000,000
Contingent consideration	110,500,000
Net proceeds from issuance of common stock	2,727,000	$ 2,231,000
At The Market Offering
Description Of Organization [Line Items]
Net proceeds from issuance of common stock	$ 27,014,000
Cowen \| At The Market Offering
Description Of Organization [Line Items]
Common stock maximum aggregate offering price				$ 150,000,000
Aggregate common stock sold	4.7
Net proceeds from issuance of common stock	$ 27,600,000
Gross proceeds from issuance of common stock	$ 29,500,000

License and Collaboration Agreements - Summary of Potential Success Payments (Details) - Harvard College $ / shares in Units, $ in Millions	1 Months Ended
	Mar. 31, 2019 USD ($) $ / shares
Multiple of Equity Value at Issuance, 5x
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Per share common stock price required for payment \| $ / shares	$ 20.00
Success payment(s) \| $	$ 5.0
Multiple of Equity Value at Issuance, 10x
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Per share common stock price required for payment \| $ / shares	$ 40.00
Success payment(s) \| $	$ 15.0
Multiple of Equity Value at Issuance, 20x
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Per share common stock price required for payment \| $ / shares	$ 80.00
Success payment(s) \| $	$ 30.0
Multiple of Equity Value at Issuance, 30x
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Per share common stock price required for payment \| $ / shares	$ 120.00
Success payment(s) \| $	$ 50.0
Multiple of Equity Value at Issuance, 40x
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Per share common stock price required for payment \| $ / shares	$ 160.00
Success payment(s) \| $	$ 75.0

Accrued Liabilities

6 Months Ended

Jun. 30, 2023

Payables and Accruals [Abstract]

Accrued liabilities

8. Accrued liabilities

Accrued compensation and accrued expenses and other current liabilities consist of the following:


	June 30, 2023		December 31, 2022
	(in thousands)
Accrued compensation:
Accrued bonuses	$	9,339	$	16,455
Accrued paid time off		6,541		4,794
Accrued payroll		3,112		5,113
Other accrued compensation		677		-
Total accrued compensation	$	19,669	$	26,362
Accrued expenses and other current liabilities:
Accrued research and development services	$	10,365	$	8,733
Accrued professional fees		1,761		1,158
Accrued property and equipment		2,490		1,790
Other accrued current liabilities		3,424		2,866
Total accrued expenses and other current liabilities	$	18,040	$	14,547

Stock-Based Compensation - Schedule of Assumptions Used in Black-Scholes Option-Pricing Model for Estimating Fair Value of Stock Options Granted (Details)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk free interest rate, minimum	3.36%	1.56%
Risk free interest rate, maximum	4.28%	3.36%
Expected volatility	70.00%	70.00%
Expected dividend	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 6 months	5 years 6 months
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	6 years 6 months	6 years 3 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

Employee Benefit Plan

6 Months Ended

Jun. 30, 2023

Retirement Benefits [Abstract]

Employee Benefit Plan

14. Employee benefit plan

In January 2019, the Company adopted a 401(k) retirement and savings plan (the 401(k) Plan) covering all employees. The 401(k) Plan allows employees to make pre- and post-tax contributions up to the maximum allowable amount set by the IRS. The Company matches each participant’s 401(k) contributions, up to $4,000 per year per participant.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480794/715-70-50-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480266/715-60-50-3

+ Details

Acquisitions

6 Months Ended

Jun. 30, 2023

Business Combinations [Abstract]

Acquisitions

3. Acquisitions

Cobalt Biomedicine, Inc.

In February 2019, the Company acquired 100% of the outstanding equity in Cobalt Biomedicine, Inc. (Cobalt), a privately held early-stage biotechnology company developing a platform technology using its fusogen technology to specifically and consistently deliver various biological payloads to cells (the Cobalt acquisition).

As part of the Cobalt acquisition, the Company recorded an intangible asset of $59.2 million, which consists of in-process research and development that is classified as indefinite-lived until the successful completion of the associated research and development technology, at which point it becomes a finite-lived asset and will be amortized over its estimated useful life. If the research and development technology is abandoned, an impairment charge will be recorded. The Company is actively developing the fusogen technology and, accordingly, the intangible asset is not complete. Amortization will begin when regulatory approval of a product candidate developed using the fusogen technology is obtained in a major market, typically either the United States or the European Union.

The Company recognized $140.6 million of goodwill as a result of the Cobalt acquisition, which is primarily attributable to the value the acquisition provides the Company by complementing the Company’s ex vivo portfolio with in vivo fusogen cell engineering technology and furthering the Company’s research in using engineered cells as medicines. The goodwill is not deductible for income tax purposes. There were no impairments of the intangible asset or goodwill since the acquisition.

Pursuant to the terms and conditions in the Cobalt acquisition agreement, the Company has an obligation to pay to certain former Cobalt stockholders contingent consideration (Cobalt Contingent Consideration) of up to an aggregate of $500.0 million upon the achievement of certain specified development milestones and a success payment (Cobalt Success Payment) of up to $500.0 million, each of which is payable in cash or stock. The Cobalt Success Payment is payable if, at pre-determined valuation measurement dates, the Company’s market capitalization equals or exceeds $8.1 billion, and the Company is advancing a program based on the fusogen technology in a clinical trial pursuant to an investigational new drug application, or has filed, or received approval for, a biologics license application or new drug application for a product developed using the fusogen technology. The Cobalt Success Payment can be achieved over a maximum of 20 years from the date of the acquisition, but this period could be shorter upon the occurrence of certain events. A valuation measurement date would also be triggered upon a change of control of the Company if at least one of the Company’s programs based on the fusogen technology is an active research program at the time of such change of control. If the Company’s market capitalization is below $8.1 billion as of the date of a change of control, the amount of the potential Cobalt Success Payment will decrease, and the amount of potential Cobalt Contingent Consideration will increase. As of June 30, 2023, a Cobalt Success Payment had not been triggered.

The following table sets forth various thresholds for the Company’s market capitalizations as of the date of a change of control and the resulting potential Cobalt Success Payment and additional potential Cobalt Contingent Consideration:


Sana market capitalization upon a change of control and resulting impact to Cobalt Success Payment and additional potential Cobalt Contingent Consideration	Cobalt Success Payment		Additional potential Cobalt Contingent Consideration
	(in millions)
Equal to or exceeds $8.1 billion	$	500	$	-
Equal to or exceeds $7.4 billion, but less than $8.1 billion		150		350
Equal to or exceeds $6.8 billion, but less than $7.4 billion		100		400
Less than $6.8 billion		-		500

The Cobalt Success Payment and Cobalt Contingent Consideration liabilities are carried at fair value, with changes in fair value recognized in research and development related success payments and contingent consideration. As of June 30, 2023 and December 31, 2022, the estimated fair value of the Cobalt Success Payment liability was $32.8 million and $19.0 million, respectively, and was recorded in long-term liabilities. In connection with the change in the estimated fair value of the Cobalt Success Payment, the

Company recognized an expense of $18.5 million and a gain of $12.1 million for the three months ended June 30, 2023 and 2022, respectively, and an expense of $13.7 million and a gain of $58.9 million for the six months ended June 30, 2023 and 2022, respectively.

As of June 30, 2023, the estimated fair value of the Cobalt Contingent Consideration was $161.7 million, of which $58.4 million was recorded in short-term liabilities and $103.3 million was recorded in long-term liabilities. As of December 31, 2022, the estimated fair value of the Cobalt Contingent Consideration was $150.4 million, of which $55.4 million was recorded in short-term liabilities and $95.0 million was recorded in long-term liabilities. In connection with the change in the estimated fair value of the Cobalt Contingent Consideration, the Company recognized an expense of $5.9 million and a gain of $3.8 million for the three months ended June 30, 2023 and 2022, respectively, and an expense of $11.4 million and a gain of $4.4 million for the six months ended June 30, 2023 and 2022, respectively.

Commitments and Contingencies - Schedule of Additional Information Related to Operating Leases (Details) - ft²	1 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2023
Seattle, WA \| Office/Laboratory
Lessee Lease Description [Line Items]
Square feet		48,000
Commencement Dates, Beginning		2019-03
Commencement Dates, Ending		2020-09
Lease arrangement, contractual expiration period, beginning year		2026-12
Lease arrangement, contractual expiration period, ending year		2028-04
Cambridge, MA \| Office/Laboratory
Lessee Lease Description [Line Items]
Square feet		60,000
Commencement Dates, Beginning		2019-03
Commencement Dates, Ending		2022-01
Lease arrangement, contractual expiration period, beginning year		2025-11
Lease arrangement, contractual expiration period, ending year		2028-02
South San Francisco, CA \| Office/Laboratory
Lessee Lease Description [Line Items]
Square feet		100,000
Commencement Dates, Beginning		2019-12
Commencement Dates, Ending		2022-04
Lease arrangement, contractual expiration period, beginning year		2024-04
Lease arrangement, contractual expiration period, ending year		2030-04
Fremont, CA \| Industrial
Lessee Lease Description [Line Items]
Square feet		163,000
Commencement Dates, Beginning		2021-07
Lease arrangement, contractual expiration period, ending year		2031-11
Rochester, NY \| Office/Laboratory
Lessee Lease Description [Line Items]
Square feet		3,000
Commencement Dates, Beginning		2022-01
Lease arrangement, contractual expiration period, ending year		2025-01
Bothell, WA
Lessee Lease Description [Line Items]
Square feet	79,565
Bothell, WA \| Office/Laboratory/Industrial
Lessee Lease Description [Line Items]
Square feet		80,000
Commencement Dates, Beginning		2023-01
Lease arrangement, contractual expiration period, ending year		2039-01

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 4,500	$ 3,800	$ 8,794	$ 7,414

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of significant accounting policies Basis of presentation The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, and have been prepared in accordance with generally accepted accounting principles in the United States (GAAP). Certain prior period amounts have been reclassified to conform to current period presentation. The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission (SEC) on March 16, 2023 (2022 Annual Report). Significant accounting policies The significant accounting policies used in the preparation of these condensed consolidated financial statements as of June 30, 2023 and for the three and six months ended June 30, 2023 and 2022 are consistent with those discussed in Note 2 in the 2022 Annual Report. Use of estimates The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates. The most significant estimates in the Company’s condensed consolidated financial statements relate to success payment liabilities, contingent consideration, business combinations, accrued expenses, and operating lease right-of-use assets and liabilities. Recent accounting pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard-setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed, the Company does not believe that the adoption of recently issued standards has had or may have a material impact on its condensed consolidated financial statements or disclosures.

Stockholders' Equity - Additional Information (Details) - USD ($) shares in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Aug. 31, 2022
Class Of Stock [Line Items]
Net proceeds from issuance of common stock	$ 2,727,000	$ 2,231,000
At The Market Offering
Class Of Stock [Line Items]
Net proceeds from issuance of common stock	$ 27,014,000
Cowen \| At The Market Offering
Class Of Stock [Line Items]
Common stock maximum aggregate offering price			$ 150,000,000
Aggregate common stock sold	4.7
Gross proceeds from issuance of common stock	$ 29,500,000
Net proceeds from issuance of common stock	$ 27,600,000

- 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/exampleRef
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+ Details

Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Schedule of Additional Information Related to Operating Leases

The following table contains additional information related to the Company’s operating leases:


Location	Use	Approximate Square Footage	Commencement Dates	Expiration Dates
Seattle, WA	Office/Laboratory	48,000	March 2019 to September 2020	December 2026 to April 2028
Cambridge, MA	Office/Laboratory	60,000	March 2019 to January 2022	November 2025 to February 2028
South San Francisco, CA	Office/Laboratory	100,000	December 2019 to April 2022	April 2024 to April 2030
Fremont, CA	Industrial	163,000	July 2021	November 2031
Rochester, NY	Office/Laboratory	3,000	January 2022	January 2025
Bothell, WA	Office/Laboratory/Industrial	80,000	January 2023	January 2039

Summary of Lease Costs

The following table summarizes the Company’s lease costs:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
	(in thousands)
Operating lease cost	$	6,981	$	6,066	$	14,042	$	11,546
Variable lease cost		1,929		1,903		3,911		3,392
Total lease cost	$	8,910	$	7,969	$	17,953	$	14,938

Reconciliation of Undiscounted Operating Lease Cash Flows by Fiscal Year to Present Value of Operating Lease Liabilities

The following table reconciles the Company’s undiscounted operating lease cash flows by fiscal year to the present value of the operating lease liabilities as of June 30, 2023 (in thousands):


2023 (remaining 6 months)	$	11,019
2024		28,021
2025		28,109
2026		25,268
2027		22,779
2028 and thereafter		120,859
Total undiscounted lease payments		236,055
Less: imputed interest		(103,184	)
Less: tenant improvement allowances		(19,736	)
Present value of operating lease liabilities		113,135
Less: current portion of operating lease liabilities	$	(12,890	)
Operating lease liabilities, net of current portion	$	100,245

Net Loss Per Share - Anti-dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares shares in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of dilutive net loss per share	32,072	28,233
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of dilutive net loss per share	30,296	25,616
Unvested Restricted Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of dilutive net loss per share		1,706
Unvested RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of dilutive net loss per share	1,776	911

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
OPERATING ACTIVITIES:
Net loss	$ (196,122)	$ (103,913)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	8,794	7,414
Stock-based compensation expense	18,599	17,666
Change in the estimated fair value of contingent consideration	11,355	(4,358)
Change in the estimated fair value of success payment liabilities	15,444	(69,008)
Non-cash expense for operating lease right-of-use assets	6,755	5,682
Other non-cash items, net	(6,088)	(3,726)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	5,428	(657)
Operating lease right-of-use assets and liabilities	1,444	111
Accounts payable	87	663
Accrued expenses and other liabilities	(3,769)	939
Net cash used in operating activities	(138,073)	(149,187)
INVESTING ACTIVITIES:
Purchases of marketable securities	(71,267)	(45,961)
Proceeds from maturities of marketable securities	180,374	148,160
Purchases of property and equipment	(3,753)	(11,924)
Net cash provided by investing activities	105,354	90,275
FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net	2,727	2,231
Net cash provided by financing activities	29,741	2,231
Net decrease in cash, cash equivalents, and restricted cash	(2,978)	(56,681)
Cash, cash equivalents, and restricted cash at beginning of period	187,273	261,848
Cash, cash equivalents, and restricted cash at end of period	184,295	205,167
SUPPLEMENTAL CASH FLOW INFORMATION:
Operating lease right-of-use assets obtained in exchange for lease obligations	8,984	21,073
Purchases of property and equipment included in accounts payable and accrued liabilities	1,953	3,346
Cash received for amounts related to tenant improvement allowances	1,198	541
Remeasurement of operating lease right-of-use asset for lease modification		$ (12,801)
At The Market Offering
FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net	$ 27,014

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	At The Market Offering	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital At The Market Offering	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance at Dec. 31, 2021	$ 728,502		$ 18	$ 1,515,210		$ (1,366)	$ (785,360)
Beginning balance (in shares) at Dec. 31, 2021			184,929
Vesting of restricted stock			$ 1	(1)
Vesting of restricted stock (in shares)			1,419
Exercise of stock options	652			652
Exercise of stock options (in shares)			284
Stock-based compensation expense	7,755			7,755
Unrealized gain (loss) on marketable securities, net	(3,806)					(3,806)
Net income (loss)	(31,448)						(31,448)
Ending balance at Mar. 31, 2022	701,655		$ 19	1,523,616		(5,172)	(816,808)
Ending balance (in shares) at Mar. 31, 2022			186,632
Beginning balance at Dec. 31, 2021	728,502		$ 18	1,515,210		(1,366)	(785,360)
Beginning balance (in shares) at Dec. 31, 2021			184,929
Net income (loss)	(103,913)
Ending balance at Jun. 30, 2022	639,505		$ 19	1,535,106		(6,347)	(889,273)
Ending balance (in shares) at Jun. 30, 2022			188,430
Beginning balance at Mar. 31, 2022	701,655		$ 19	1,523,616		(5,172)	(816,808)
Beginning balance (in shares) at Mar. 31, 2022			186,632
Vesting of restricted stock (in shares)			1,243
Exercise of stock options	571			571
Exercise of stock options (in shares)			320
Issuance of common stock related to employee stock purchase plan	1,008			1,008
Issuance of common stock related to employee stock purchase plan, Shares			235
Stock-based compensation expense	9,911			9,911
Unrealized gain (loss) on marketable securities, net	(1,175)					(1,175)
Net income (loss)	(72,465)						(72,465)
Ending balance at Jun. 30, 2022	639,505		$ 19	1,535,106		(6,347)	(889,273)
Ending balance (in shares) at Jun. 30, 2022			188,430
Beginning balance at Dec. 31, 2022	$ 499,315		$ 19	1,558,459		(4,327)	(1,054,836)
Beginning balance (in shares) at Dec. 31, 2022	191,022		191,022
Fees incurred related to issuance of common stock from at the market offering		$ (200)			$ (200)
Vesting of restricted stock (in shares)			154
Exercise of stock options	$ 331			331
Exercise of stock options (in shares)			233
Stock-based compensation expense	8,751			8,751
Unrealized gain (loss) on marketable securities, net	2,188					2,188
Net income (loss)	(82,123)						(82,123)
Ending balance at Mar. 31, 2023	428,262		$ 19	1,567,341		(2,139)	(1,136,959)
Ending balance (in shares) at Mar. 31, 2023			191,409
Beginning balance at Dec. 31, 2022	$ 499,315		$ 19	1,558,459		(4,327)	(1,054,836)
Beginning balance (in shares) at Dec. 31, 2022	191,022		191,022
Exercise of stock options (in shares)	590
Net income (loss)	$ (196,122)
Ending balance at Jun. 30, 2023	$ 355,029		$ 20	1,606,832		(865)	(1,250,958)
Ending balance (in shares) at Jun. 30, 2023	196,880		196,880
Beginning balance at Mar. 31, 2023	$ 428,262		$ 19	1,567,341		(2,139)	(1,136,959)
Beginning balance (in shares) at Mar. 31, 2023			191,409
Fees incurred related to issuance of common stock from at the market offering		(985)
Vesting of restricted stock (in shares)			119
Exercise of stock options	691			691
Exercise of stock options (in shares)			357
Issuance of common stock related to employee stock purchase plan	1,705			1,705
Issuance of common stock related to employee stock purchase plan, Shares			409
Stock-based compensation expense	9,848			9,848
Unrealized gain (loss) on marketable securities, net	1,274					1,274
Net income (loss)	(113,999)						(113,999)
Issuance of common stock, net of offering costs (in shares)			4,586
Issuance of common stock, net of offering costs	27,248	$ 27,247	$ 1
Ending balance at Jun. 30, 2023	$ 355,029		$ 20	$ 1,606,832		$ (865)	$ (1,250,958)
Ending balance (in shares) at Jun. 30, 2023	196,880		196,880

Commitments and Contingencies - Reconciliation of Undiscounted Operating Lease Cash Flows by Fiscal Year to Present Value of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
2023 (remaining 6 months)	$ 11,019
2024	28,021
2025	28,109
2026	25,268
2027	22,779
2028 and thereafter	120,859
Total undiscounted lease payments	236,055
Less: imputed interest	(103,184)
Less: tenant improvement allowances	(19,736)
Present value of operating lease liabilities	113,135
Less: current portion of operating lease liabilities	(12,890)	$ (12,393)
Operating lease liabilities, net of current portion	$ 100,245	$ 95,860

Stockholders' Equity

6 Months Ended

Jun. 30, 2023

Equity [Abstract]

Stockholders' Equity

10. Stockholders’ equity

In August 2022, the Company entered into a sales agreement with Cowen and Company, LLC (Cowen), acting as sales agent, pursuant to which it may offer and sell through Cowen up to $150.0 million in shares of the Company’s common stock from time to time in a series of one or more at the market equity offerings. As of June 30, 2023, the Company sold an aggregate of 4.7 million shares of the Company's common stock, resulting in gross proceeds of $29.5 million under the ATM facility. After deducting commissions and expenses, the Company raised $27.6 million in net proceeds under the ATM facility as of June 30, 2023.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

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

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481004/946-505-50-6

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-16

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

Stock-Based Compensation - Schedule of Stock Based Compensation Expense Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 9,848	$ 9,911	$ 18,599	$ 17,666
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	6,693	7,408	12,665	13,120
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 3,155	$ 2,503	$ 5,934	$ 4,546

Stock-Based Compensation - Summary of Additional Information Related to Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Weighted average grant date fair value per share for options granted	$ 2.60	$ 3.83
Aggregate intrinsic value of stock options exercised (in thousands)	$ 2,058	$ 3,917

Fair Value Measurements - Summary of Estimated Fair Value Available For Sale Debt Securities Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value less than 12 months	$ 5,431	$ 62,586
Unrealized losses less than 12 months	(45)	(689)
Fair value 12 months or greater	91,590	192,509
Unrealized losses 12 months or greater	(847)	(3,651)
Total fair value	97,021	255,095
Total unrealized losses	(892)	(4,340)
US Government Agencies Debt Securities
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value less than 12 months	5,431	49,253
Unrealized losses less than 12 months	(45)	(673)
Fair value 12 months or greater	81,549	172,845
Unrealized losses 12 months or greater	(823)	(3,301)
Total fair value	86,980	222,098
Total unrealized losses	(868)	(3,974)
Corporate Debt Securities
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value less than 12 months		13,333
Unrealized losses less than 12 months		(16)
Fair value 12 months or greater	10,041	19,664
Unrealized losses 12 months or greater	(24)	(350)
Total fair value	10,041	32,997
Total unrealized losses	$ (24)	$ (366)

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, and have been prepared in accordance with generally accepted accounting principles in the United States (GAAP). Certain prior period amounts have been reclassified to conform to current period presentation. The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission (SEC) on March 16, 2023 (2022 Annual Report).
Significant accounting policies	Significant accounting policies The significant accounting policies used in the preparation of these condensed consolidated financial statements as of June 30, 2023 and for the three and six months ended June 30, 2023 and 2022 are consistent with those discussed in Note 2 in the 2022 Annual Report.
Use of estimates	Use of estimates The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates. The most significant estimates in the Company’s condensed consolidated financial statements relate to success payment liabilities, contingent consideration, business combinations, accrued expenses, and operating lease right-of-use assets and liabilities.
Recent accounting pronouncements	Recent accounting pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard-setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed, the Company does not believe that the adoption of recently issued standards has had or may have a material impact on its condensed consolidated financial statements or disclosures.

License and collaboration agreements

6 Months Ended

Jun. 30, 2023

License And Collaboration Agreements [Abstract]

License and Collaboration Agreements

4. License and collaboration agreements

Beam Therapeutics Inc.

In October 2021, the Company entered into an option and license agreement with Beam Therapeutics Inc. (Beam), pursuant to which the Company was granted a non-exclusive license to use Beam’s proprietary CRISPR Cas12b nuclease editing technology to research, develop, and commercialize engineered cell therapy products that (i) are directed to certain antigen targets, with respect to the Company’s allogeneic T cell programs, or (ii) comprise certain human cell types, with respect to the Company’s stem cell-derived programs. The Company made an upfront payment of $50.0 million to Beam, which was recorded in research and development expense for the year ended December 31, 2021. Additionally, under the terms of the agreement, the Company may be obligated to pay up to $65.0 million for each licensed product in specified developmental and commercial milestone payments and royalties on licensed products. At the time of the entry into the option and license agreement, a member of the Company’s board of directors was a beneficial owner of greater than 10% of the outstanding shares of Beam. This director is also affiliated with a member of the board of directors of Beam.

President and Fellows of Harvard College

In March 2019, the Company entered into an exclusive license agreement with the President and Fellows of Harvard College (Harvard) to access certain intellectual property for the development of hypoimmune-modified cells.

The Company has paid to Harvard aggregate consideration of $12.0 million, comprising $9.0 million in common stock and $3.0 million in cash. Under the terms of the agreement, the Company may be required to pay to Harvard up to an aggregate of $175.0 million in success payments, payable in cash, based on increases in the fair value of the Company’s common stock (Harvard Success Payments). The potential Harvard Success Payments are based on multiples of increased value ranging from 5x to 40x, based on a comparison of the fair market value of the Company’s common stock relative to the original issuance price of $4.00 per share at ongoing pre-determined valuation measurement dates. The Harvard Success Payments can be achieved over a maximum of 12 years from the effective date of the agreement. If a higher success payment tier is first met at the same time a lower tier is first met, both tiers will be owed. Any previous success payments made to Harvard would be credited against the success payment owed as of any valuation measurement date so that Harvard does not receive multiple success payments in connection with the same threshold. As of June 30, 2023, a Harvard Success Payment had not been triggered.

The following table summarizes the potential success payments and common stock price required for payment:


Multiple of Equity Value at Issuance	5x		10x		20x		30x		40x
Per share common stock price required for payment	$	20.00	$	40.00	$	80.00	$	120.00	$	160.00
Success payment(s) (in millions)	$	5.0	$	15.0	$	30.0	$	50.0	$	75.0

The Harvard Success Payment liabilities are carried at fair value, with the initial value and changes in fair value recognized in research and development related success payments and contingent consideration. As of June 30, 2023 and December 31, 2022, the estimated fair value of the Harvard Success Payment liability was $3.7 million and $2.0 million, respectively, and was recorded in long-term liabilities. In connection with the change in the estimated fair value of the Harvard Success Payment liability, the Company recognized an expense of $2.3 million and a gain of $2.0 million for the three months ended June 30, 2023 and 2022, respectively, and an expense of $1.7 million and a gain of $10.1 million for the six months ended June 30, 2023 and 2022, respectively.

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating expenses:
Research and development	$ 73,044	$ 72,540	$ 140,210	$ 145,229
Research and development related success payments and contingent consideration	26,679	(17,928)	26,799	(73,366)
General and administrative	16,566	18,292	33,332	32,726
Total operating expenses	116,289	72,904	200,341	104,589
Loss from operations	(116,289)	(72,904)	(200,341)	(104,589)
Interest income, net	2,374	637	4,350	976
Other expense, net	(84)	(198)	(131)	(300)
Net loss	$ (113,999)	$ (72,465)	$ (196,122)	$ (103,913)
Net income (loss) per common share - basic	$ (0.59)	$ (0.39)	$ (1.02)	$ (0.56)
Net income (loss) per common share - diluted	$ (0.59)	$ (0.39)	$ (1.02)	$ (0.56)
Weighted-average number of common shares - basic	192,540	187,626	191,888	186,801
Weighted-average number of common shares - diluted	192,540	187,626	191,888	186,801

Fair Value Measurements - Additional Information (Details) - Maximum	6 Months Ended
	Jun. 30, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities maturity period	2 years
Investments in securities with maturities period	1 year

Acquisitions - (Tables)

6 Months Ended

Jun. 30, 2023

Cobalt Biomedicine, Inc

Business Acquisition [Line Items]

Schedule of Various Thresholds for Market Capitalizations Resulting Potential Success Payment and Additional Potential Contingent Consideration


Sana market capitalization upon a change of control and resulting impact to Cobalt Success Payment and additional potential Cobalt Contingent Consideration	Cobalt Success Payment		Additional potential Cobalt Contingent Consideration
	(in millions)
Equal to or exceeds $8.1 billion	$	500	$	-
Equal to or exceeds $7.4 billion, but less than $8.1 billion		150		350
Equal to or exceeds $6.8 billion, but less than $7.4 billion		100		400
Less than $6.8 billion		-		500

Accrued Liabilities - Schedule of Accrued Compensation and Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Accrued compensation:
Accrued bonuses	$ 9,339	$ 16,455
Accrued paid time off	6,541	4,794
Accrued payroll	3,112	5,113
Other accrued compensation	677
Total accrued compensation	19,669	26,362
Accrued expenses and other current liabilities:
Accrued research and development services	10,365	8,733
Accrued professional fees	1,761	1,158
Accrued property and equipment	2,490	1,790
Other accrued current liabilities	3,424	2,866
Total accrued expenses and other current liabilities	$ 18,040	$ 14,547

Restricted Cash - Additional Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($) LettersOfCredit	Jul. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Restricted Cash And Cash Equivalents Items [Line Items]
Standby letters of credit	$ 10,500		$ 10,500
Number of standby letters of credit \| LettersOfCredit	2
Restricted cash and cash equivalents, noncurrent, nature of restriction, description	standby letters of credit
Restricted cash, current	$ 6,100		$ 6,100
Fremont, California
Restricted Cash And Cash Equivalents Items [Line Items]
Standby letters of credit	$ 6,700
Subsequent \| Fremont, California
Restricted Cash And Cash Equivalents Items [Line Items]
Future letter of credit amount		$ 600

Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	$ 132,323	$ 164,691
Gross Unrealized Holding Gains	12	11
Gross Unrealized Holding Losses		(2)
Estimated Fair Value	132,335	164,700
Cash Equivalents \| Money Market Funds \| Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	86,623	114,363
Estimated Fair Value	86,623	114,363
Cash Equivalents \| US Government Agencies Debt Securities \| Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	45,700	40,532
Gross Unrealized Holding Gains	12	10
Estimated Fair Value	45,712	40,542
Cash Equivalents \| Corporate Debt Securities \| Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost		9,796
Gross Unrealized Holding Gains		1
Gross Unrealized Holding Losses		(2)
Estimated Fair Value		9,795
Short-term Marketable Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	153,005	251,271
Gross Unrealized Holding Gains	15	2
Gross Unrealized Holding Losses	(892)	(4,075)
Estimated Fair Value	152,128	247,198
Short-term Marketable Securities \| US Government Agencies Debt Securities \| Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	142,940	222,435
Gross Unrealized Holding Gains	15	2
Gross Unrealized Holding Losses	(868)	(3,711)
Estimated Fair Value	142,087	218,726
Short-term Marketable Securities \| Corporate Debt Securities \| Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	10,065	28,836
Gross Unrealized Holding Losses	(24)	(364)
Estimated Fair Value	10,041	28,472
Long-term Marketable Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost		10,314
Gross Unrealized Holding Losses		(263)
Estimated Fair Value		10,051
Long-term Marketable Securities \| US Government Agencies Debt Securities \| Fair Value, Inputs, Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost		10,314
Gross Unrealized Holding Losses		(263)
Estimated Fair Value		10,051
Financial Assets
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	285,697	426,645
Gross Unrealized Holding Gains	27	13
Gross Unrealized Holding Losses	(892)	(4,340)
Estimated Fair Value	284,832	422,318
Other Assets \| Fair Value, Inputs, Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	369	369
Estimated Fair Value	369	369
Short-term Financial Liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	58,417	55,345
Estimated Fair Value	58,417	55,345
Short-term Financial Liabilities \| Contingent consideration \| Fair Value, Inputs, Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	58,417	55,345
Estimated Fair Value	58,417	55,345
Long-term Financial Liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	139,768	116,041
Estimated Fair Value	139,768	116,041
Long-term Financial Liabilities \| Contingent consideration \| Fair Value, Inputs, Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	103,317	95,034
Estimated Fair Value	103,317	95,034
Long-term Financial Liabilities \| Success Payment Liabilities \| Fair Value, Inputs, Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	36,451	21,007
Estimated Fair Value	36,451	21,007
Financial Liabilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	198,185	171,386
Estimated Fair Value	$ 198,185	$ 171,386

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Schedule of Stock Based Compensation Expense Recognized

Stock-based compensation expense is recognized in the condensed consolidated statements of operations as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
	(in thousands)
Research and development	$	6,693	$	7,408	$	12,665	$	13,120
General and administrative		3,155		2,503		5,934		4,546
Total stock-based compensation expense	$	9,848	$	9,911	$	18,599	$	17,666

Schedule of Unrecognized Stock-Based Compensation Costs Related to Unvested Awards and Weighted-Average Period Over Which Costs are Expected to be Recognized

Unrecognized stock-based compensation costs related to unvested awards and the weighted-average period over which the costs are expected to be recognized as of June 30, 2023 are as follows:


	Stock Options		RSUs
Unrecognized stock-based compensation expense (in thousands)	$	74,944	$	6,653
Weighted-average period costs expected to be recognized (in years)		2.5		2.8

Summary of Stock Option Activity

A summary of the Company’s stock option activity is as follows:


	Stock Options (in thousands)			Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2022		23,686		$	7.79		8.3	$	10,628
Granted		7,959			3.93
Exercised		(590	)		1.76
Forfeited/Cancelled		(759	)		7.82
Outstanding as of June 30, 2023		30,296		$	6.89		8.3	$	36,614
Exercisable as of June 30, 2023		11,245		$	7.33		7.1	$	15,381

Schedule of Assumptions Used in Black-Scholes Option-Pricing Model for Estimating Fair Value of Stock Options Granted

The fair value of stock options granted to employees, directors, and consultants was estimated on the date of grant using the Black-Scholes option pricing model using the following assumptions:


	Six Months Ended June 30,
Assumptions	2023	2022
Risk free interest rate	3.36% – 4.28%	1.56% – 3.36%
Expected volatility	70.0%	70.0%
Expected term (years)	5.50 – 6.50	5.50 – 6.25
Expected dividend	0%	0%

Summary of Additional Information Related to Stock Option Activity

The following table summarizes additional information related to stock option activity:


	Six Months Ended June 30,
	2023		2022
Weighted average grant date fair value per share for options granted	$	2.60	$	3.83
Aggregate intrinsic value of stock options exercised (in thousands)	$	2,058	$	3,917

Summary of RSU Activity

A summary of the Company’s RSU activity is as follows:


	RSUs (in thousands)			RSUs Weighted-Average Grant Date Fair Value per Share
Unvested shares as of December 31, 2022		885		$	6.66
Granted		1,269			3.77
Vested		(261	)		6.67
Forfeited		(117	)		5.12
Unvested shares as of June 30, 2023		1,776		$	4.69

Property and Equipment, Net (Tables)

6 Months Ended

Jun. 30, 2023

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment, Net

Property and equipment, net consists of the following:


	June 30, 2023			December 31, 2022
	(in thousands)
Laboratory equipment	$	63,851		$	61,842
Leasehold improvements		34,427			34,427
Construction in progress		4,199			1,711
Computer equipment, software, and other		2,947			2,914
Total property and equipment, at cost		105,424			100,894
Less: Accumulated depreciation		(42,770	)		(33,977	)
Property and equipment, net	$	62,654		$	66,917

Acquisitions - Schedule of Various Thresholds for Market Capitalizations Resulting Potential Success Payment and Additional Potential Contingent Consideration (Details) - Cobalt Biomedicine, Inc $ in Millions	1 Months Ended
	Feb. 28, 2019 USD ($)
Market Capitalization Equal to or Exceeds $8.1 billion
Business Acquisition [Line Items]
Cobalt Success Payment	$ 500
Market Capitalization Equal to or exceeds $7.4 billion, but less than $8.1 billion
Business Acquisition [Line Items]
Cobalt Success Payment	150
Additional potential Cobalt Contingent Consideration	350
Market Capitalization Equal to or exceeds $6.8 billion, but less than $7.4 billion
Business Acquisition [Line Items]
Cobalt Success Payment	100
Additional potential Cobalt Contingent Consideration	400
Market Capitalization Less than $6.8 billion
Business Acquisition [Line Items]
Additional potential Cobalt Contingent Consideration	$ 500

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 173,787	$ 176,765
Marketable securities	152,128	247,198
Restricted cash	6,100	6,100
Prepaid expenses and other current assets	6,606	14,374
Total current assets	338,621	444,437
Long-term marketable securities		10,051
Property and equipment, net	62,654	66,917
Operating lease right-of-use assets	94,715	92,486
Long-term restricted cash	4,408	4,408
Intangible asset	59,195	59,195
Goodwill	140,627	140,627
Other non-current assets	6,927	4,599
TOTAL ASSETS	707,147	822,720
Current liabilities:
Accounts payable	3,089	2,857
Accrued compensation	19,669	26,362
Accrued expenses and other current liabilities	18,040	14,547
Operating lease liabilities	12,890	12,393
Contingent consideration	58,417	55,345
Total current liabilities	112,105	111,504
Operating lease liabilities, net of current portion	100,245	95,860
Contingent consideration, net of current portion	103,317	95,034
Success payment liabilities, net of current portion	36,451	21,007
Total liabilities	352,118	323,405
Commitments and contingencies (Note 9)
Stockholders' equity:
Preferred stock, $0.0001 par value; 50,000 shares authorized; zero shares issued and outstanding as of June 30, 2023 and December 31, 2022
Common stock, $0.0001 par value; 750,000 shares authorized; 196,880 and 191,022 shares issued and outstanding as of June 30, 2023 and December 31, 2022, respectively	20	19
Additional paid-in capital	1,606,832	1,558,459
Accumulated other comprehensive loss	(865)	(4,327)
Accumulated deficit	(1,250,958)	(1,054,836)
Total stockholders' equity	355,029	499,315
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 707,147	$ 822,720

Restricted Cash

6 Months Ended

Jun. 30, 2023

Restricted Cash and Cash Equivalents [Abstract]

Restricted Cash

5. Restricted cash

As of June 30, 2023 and December 31, 2022, the Company maintained two standby letters of credit totaling $10.5 million in the aggregate, which are collateralized with a bank account at a financial institution in accordance with the applicable lease agreements. The Company’s letter of credit related to its lease for industrial space located in Fremont, California was reduced from $6.7 million to $0.6 million in July 2023, and as such, $6.1 million in restricted cash is included in current assets on the balance sheet as of June 30, 2023.

Commitments and Contingencies - Summary of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Lease, Cost [Abstract]
Operating lease cost	$ 6,981	$ 6,066	$ 14,042	$ 11,546
Variable lease cost	1,929	1,903	3,911	3,392
Total lease cost	$ 8,910	$ 7,969	$ 17,953	$ 14,938

Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Stock Options
Stock Options Outstanding, Beginning Balance \| shares	23,686
Stock Options, Granted \| shares	7,959
Stock Options, Exercised \| shares	(590)
Stock Options, Forfeited/Cancelled \| shares	(759)
Stock Options Outstanding, Ending Balance \| shares	30,296	23,686
Stock Options Exercisable \| shares	11,245
Weighted-Average Exercise Price per Share
Weighted-Average Exercise Price per Share Outstanding, Beginning Balance \| $ / shares	$ 7.79
Weighted-Average Exercise Price per Share, Granted \| $ / shares	3.93
Weighted-Average Exercise Price per Share, Exercised \| $ / shares	1.76
Weighted-Average Exercise Price per Share, Forfeited/Cancelled \| $ / shares	7.82
Weighted-Average Exercise Price per Share Outstanding, Ending Balance \| $ / shares	6.89	$ 7.79
Weighted-Average Exercise Price Per Share Exercisable \| $ / shares	$ 7.33
Weighted-Average Remaining Contractual Life (years)
Weighted-Average Remaining Contractual Life (years), Outstanding	8 years 3 months 18 days	8 years 3 months 18 days
Weighted-Average Remaining Contractual Life (years), Exercisable	7 years 1 month 6 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding \| $	$ 36,614	$ 10,628
Aggregate Intrinsic Value, Exercisable \| $	$ 15,381

Income Taxes

6 Months Ended

Jun. 30, 2023

Income Tax Disclosure [Abstract]

Income Taxes

12. Income taxes

The Company’s income tax provision for interim periods is determined using an estimate of the Company’s annual effective tax rate, adjusted for discrete items arising in the quarter. The Company’s effective tax rate differs from the U.S. statutory tax rate primarily due to a valuation allowance on the deferred tax assets. Deferred tax assets and deferred tax liabilities are recognized based on temporary differences between the financial reporting and tax basis of assets and liabilities using statutory rates. A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized. Due to the uncertainty surrounding the realization of the favorable tax attributes in future tax returns, the Company has recorded a full valuation allowance against the Company’s otherwise recognizable net deferred tax assets.

The Company applies judgment in its determination of the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. As of June 30, 2023 and December 31, 2022, the Company’s uncertain tax positions were immaterial.

- 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
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Employee Benefit Plan - Additional Information (Details)	6 Months Ended
	Jun. 30, 2023 USD ($)
Maximum
Defined Contribution Plan Disclosure [Line Items]
Matching contribution by employer under retirement and savings plan	$ 4,000

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 105,424	$ 100,894
Less: Accumulated depreciation	(42,770)	(33,977)
Property and equipment, net	62,654	66,917
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, at cost	63,851	61,842
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, at cost	34,427	34,427
Construction In Progress
Property Plant And Equipment [Line Items]
Property and equipment, at cost	4,199	1,711
Computer Equipment, Software and Other
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 2,947	$ 2,914

Accrued Liabilities (Tables)

6 Months Ended

Jun. 30, 2023

Payables and Accruals [Abstract]

Schedule of Accrued Compensation and Accrued Expenses and Other Current Liabilities

Accrued compensation and accrued expenses and other current liabilities consist of the following:


	June 30, 2023		December 31, 2022
	(in thousands)
Accrued compensation:
Accrued bonuses	$	9,339	$	16,455
Accrued paid time off		6,541		4,794
Accrued payroll		3,112		5,113
Other accrued compensation		677		-
Total accrued compensation	$	19,669	$	26,362
Accrued expenses and other current liabilities:
Accrued research and development services	$	10,365	$	8,733
Accrued professional fees		1,761		1,158
Accrued property and equipment		2,490		1,790
Other accrued current liabilities		3,424		2,866
Total accrued expenses and other current liabilities	$	18,040	$	14,547

Fair Value Measurements - Summary of Estimated Fair Value of Contingent Consideration Unobservable Inputs (Details) - Cobalt Contingent Consideration	Jun. 30, 2023	Dec. 31, 2022
Probability of Milestone Achievement \| Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	0.05	0.05
Probability of Milestone Achievement \| Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	0.85	0.85
Probability of Milestone Achievement \| Weighted-Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	0.36	0.36
Discount Rates \| Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	0.13	0.134
Discount Rates \| Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	0.151	0.151
Discount Rates \| Weighted-Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	0.138	0.146

Property and Equipment, Net

6 Months Ended

Jun. 30, 2023

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

7. Property and equipment, net

Property and equipment, net consists of the following:


	June 30, 2023			December 31, 2022
	(in thousands)
Laboratory equipment	$	63,851		$	61,842
Leasehold improvements		34,427			34,427
Construction in progress		4,199			1,711
Computer equipment, software, and other		2,947			2,914
Total property and equipment, at cost		105,424			100,894
Less: Accumulated depreciation		(42,770	)		(33,977	)
Property and equipment, net	$	62,654		$	66,917

Depreciation expense was $4.5 million and $3.8 million for the three months ended June 30, 2023 and 2022, respectively, and $8.8 million and $7.4 million for the six months ended June 30, 2023 and 2022, respectively.

Fair Value Measurements - Summary of Estimated Fair Value of Success Payment Liabilities Unobservable Inputs (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Expected Stock Price Volatility \| Cobalt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value measurement input	0.725	0.70
Expected Stock Price Volatility \| Harvard
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value measurement input	0.725	0.700
Expected Term (Years) \| Cobalt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value measurement input expected term (years)	15 years 7 months 6 days	16 years 1 month 6 days
Expected Term (Years) \| Harvard
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value measurement input expected term (years)	7 years 8 months 12 days	8 years 2 months 12 days

License and Collaboration Agreements - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2019	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2022	Oct. 31, 2021
Beam Therapeutics Inc. (Beam) \| Research and Development Expense
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment to collaborators						$ 50,000,000
Beam Therapeutics Inc. (Beam) \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Developmental and commercial milestone payments and royalties on licensed products payable								$ 65,000,000.0
Beam Therapeutics Inc. (Beam) \| Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Beneficial ownership percentage held by a member of board of directors								10.00%
Harvard College
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Share issue price	$ 4.00
Aggregated consideration paid	$ 12,000,000.0
Common stock shares issued	9,000,000.0
Payment to collaborators	$ 3,000,000.0
Maximum period expected to achieve for success payments	12 years
Harvard College \| Long-term Liabilities
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Estimated fair value of success payment liability		$ 3,700,000		$ 3,700,000			$ 2,000,000
Harvard College \| Research and Development Expense
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Expense in connection with change in estimated fair value of success payment liability		$ (2,300,000)	$ 2,000,000	$ (1,700,000)	$ 10,100,000
Harvard College \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Cobalt success payment	$ 175,000,000.0

Organization

6 Months Ended

Jun. 30, 2023

Accounting Policies [Abstract]

Organization

1. Organization

Sana Biotechnology, Inc. (the Company or Sana) is a biotechnology company focusing on utilizing engineered cells as medicines. The Company’s operations to date have included identifying and developing potential product candidates, executing preclinical studies, establishing manufacturing capabilities, preparing for clinical trials of our product candidates, acquiring technology, organizing and staffing the Company, business planning, establishing and maintaining the Company’s intellectual property portfolio, raising capital, and providing general and administrative support for these operations.

Liquidity and capital resources

The Company is subject to a number of risks and uncertainties similar to other biotechnology companies in the development stage, including, but not limited to, those related to the need to obtain adequate additional funding, possible failure of preclinical testing or clinical trials, the need to obtain marketing approval for its product candidates, building out internal and external manufacturing capabilities, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of the Company’s products, the need to protect the Company’s intellectual property and proprietary technologies, and the need to attract and retain key scientific and management personnel. If the Company does not successfully commercialize or partner any of its product candidates, it will be unable to generate product revenue or achieve profitability. Until such time as the Company can generate significant revenue from product sales, if ever, it expects to finance its operations with the proceeds from additional equity or debt financings or capital obtained in connection with strategic collaborations or licensing or other arrangements. In the event that additional financing is required, the Company may not be able to raise it on terms acceptable to it or at all.

In August 2022, the Company entered into a sales agreement with Cowen and Company, LLC (Cowen), acting as sales agent, pursuant to which it may offer and sell through Cowen up to $150.0 million in shares of the Company’s common stock from time to time in a series of one or more at the market equity offerings (collectively, the ATM facility). As of June 30, 2023, the Company sold an aggregate of 4.7 million shares of the Company's common stock, resulting in gross proceeds of $29.5 million under the ATM facility. After deducting commissions and expenses, the Company raised $27.6 million in net proceeds under the ATM facility as of June 30, 2023.

The Company has incurred operating losses each year since inception and expects such losses to continue for the foreseeable future. As of June 30, 2023, the Company had cash, cash equivalents, and marketable securities of $325.9 million, and an accumulated deficit of $1.3 billion, which includes cumulative non-cash charges related to the revaluation of the success payment liabilities and contingent consideration of $34.0 million and $110.5 million, respectively.

Net Loss Per Share

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Net Loss Per Share

13. Net loss per share

Basic and diluted net loss per common share are calculated by dividing net loss by the weighted-average number of common shares outstanding during the relevant period, without consideration for common stock equivalents. The Company was in a loss position for all periods presented, and basic net loss per share and diluted net loss per share are therefore the same for all periods, as the inclusion of all potential common securities outstanding would have been anti-dilutive.

The following securities were excluded from the computation of net loss per diluted share of common stock for periods presented as their effect would have been anti-dilutive:


	Six Months Ended June 30,
	2023		2022
	(in thousands)
Options to purchase common stock		30,296		25,616
Unvested restricted common stock		-		1,706
Unvested RSUs		1,776		911
Total		32,072		28,233

Acquisitions - Schedule of Various Thresholds for Market Capitalizations Resulting Potential Success Payment and Additional Potential Contingent Consideration (Parenthetical) (Details) - Sana $ in Billions	Feb. 28, 2019 USD ($)
Market Capitalization Equal to or Exceeds $8.1 billion
Business Acquisition [Line Items]
Threshold market capitalization	$ 8.1
Market Capitalization Equal to or exceeds $7.4 billion, but less than $8.1 billion
Business Acquisition [Line Items]
Threshold market capitalization	7.4
Market Capitalization Equal to or exceeds $6.8 billion, but less than $7.4 billion
Business Acquisition [Line Items]
Threshold market capitalization	6.8
Market Capitalization Less than $6.8 billion
Business Acquisition [Line Items]
Threshold market capitalization	$ 6.8

Stock-Based Compensation

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stock-based compensation

11. Stock-based compensation

Equity incentive plans

In February 2021, the Company adopted the 2021 Incentive Award Plan (2021 Plan) and the 2021 Employee Stock Purchase Plan (2021 ESPP), both of which became effective on the completion of the Company’s initial public offering. The 2021 Plan

provides for a variety of stock-based compensation awards, including stock options, restricted stock awards (RSAs), and restricted stock units (RSUs). The 2021 ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their earnings, subject to plan limitations. Unless otherwise determined by the Company’s board of directors, employees may purchase shares at 85% of the lower of the fair market value of the Company’s common stock on the first date of an offering period or on the purchase date. As of June 30, 2023, 15.6 million shares and 4.8 million shares were available for future issuance under the 2021 Plan and the 2021 ESPP, respectively.

Stock-based compensation expense

Stock-based compensation expense is recognized in the condensed consolidated statements of operations as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
	(in thousands)
Research and development	$	6,693	$	7,408	$	12,665	$	13,120
General and administrative		3,155		2,503		5,934		4,546
Total stock-based compensation expense	$	9,848	$	9,911	$	18,599	$	17,666

Unrecognized stock-based compensation costs related to unvested awards and the weighted-average period over which the costs are expected to be recognized as of June 30, 2023 are as follows:


	Stock Options		RSUs
Unrecognized stock-based compensation expense (in thousands)	$	74,944	$	6,653
Weighted-average period costs expected to be recognized (in years)		2.5		2.8

Stock options

A summary of the Company’s stock option activity is as follows:


	Stock Options (in thousands)			Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2022		23,686		$	7.79		8.3	$	10,628
Granted		7,959			3.93
Exercised		(590	)		1.76
Forfeited/Cancelled		(759	)		7.82
Outstanding as of June 30, 2023		30,296		$	6.89		8.3	$	36,614
Exercisable as of June 30, 2023		11,245		$	7.33		7.1	$	15,381

The fair value of stock options granted to employees, directors, and consultants was estimated on the date of grant using the Black-Scholes option pricing model using the following assumptions:


	Six Months Ended June 30,
Assumptions	2023	2022
Risk free interest rate	3.36% – 4.28%	1.56% – 3.36%
Expected volatility	70.0%	70.0%
Expected term (years)	5.50 – 6.50	5.50 – 6.25
Expected dividend	0%	0%

The following table summarizes additional information related to stock option activity:


	Six Months Ended June 30,
	2023		2022
Weighted average grant date fair value per share for options granted	$	2.60	$	3.83
Aggregate intrinsic value of stock options exercised (in thousands)	$	2,058	$	3,917

Restricted stock

A summary of the Company’s RSU activity is as follows:


	RSUs (in thousands)			RSUs Weighted-Average Grant Date Fair Value per Share
Unvested shares as of December 31, 2022		885		$	6.66
Granted		1,269			3.77
Vested		(261	)		6.67
Forfeited		(117	)		5.12
Unvested shares as of June 30, 2023		1,776		$	4.69

The fair value of RSUs that vested during the six months ended June 30, 2023 and 2022 was $1.1 million and $0.2 million, respectively.

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2023

Fair Value Assets and Liabilities Measured on Recurring Basis

The following tables summarize the Company’s financial assets and liabilities measured at fair value on a recurring basis based on the three-tier fair value hierarchy:


		June 30, 2023
	Valuation Hierarchy	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Estimated Fair Value
		(in thousands)
Financial assets:
Cash equivalents:
Money market funds	Level 1	$	86,623	$	-	$	-		$	86,623
U.S. government and agency securities	Level 2		45,700		12		-			45,712
Total cash equivalents			132,323		12		-			132,335
Short-term marketable securities:
U.S. government and agency securities	Level 2		142,940		15		(868	)		142,087
Corporate debt securities	Level 2		10,065		-		(24	)		10,041
Total short-term marketable securities			153,005		15		(892	)		152,128
Other assets	Level 3		369		-		-			369
Total financial assets		$	285,697	$	27	$	(892	)	$	284,832
Financial liabilities:
Short-term financial liabilities:
Contingent consideration	Level 3	$	58,417	$	-	$	-		$	58,417
Total short-term financial liabilities			58,417		-		-			58,417
Long-term financial liabilities:
Contingent consideration	Level 3		103,317		-		-			103,317
Success payment liabilities	Level 3		36,451		-		-			36,451
Total long-term financial liabilities			139,768		-		-			139,768
Total financial liabilities		$	198,185	$	-	$	-		$	198,185


		December 31, 2022
	Valuation Hierarchy	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Estimated Fair Value
		(in thousands)
Financial assets:
Cash equivalents:
Money market funds	Level 1	$	114,363	$	-	$	-		$	114,363
U.S. government and agency securities	Level 2		40,532		10		-			40,542
Corporate debt securities	Level 2		9,796		1		(2	)		9,795
Total cash equivalents			164,691		11		(2	)		164,700
Short-term marketable securities:
U.S. government and agency securities	Level 2		222,435		2		(3,711	)		218,726
Corporate debt securities	Level 2		28,836		-		(364	)		28,472
Total short-term marketable securities			251,271		2		(4,075	)		247,198
Long-term marketable securities:
U.S. government and agency securities	Level 2		10,314		-		(263	)		10,051
Total long-term marketable securities			10,314		-		(263	)		10,051
Other assets	Level 3		369		-		-			369
Total financial assets		$	426,645	$	13	$	(4,340	)	$	422,318
Financial liabilities:
Short-term financial liabilities:
Contingent consideration	Level 3	$	55,345	$	-	$	-		$	55,345
Total short-term financial liabilities			55,345		-		-			55,345
Long-term financial liabilities:
Contingent consideration	Level 3		95,034		-		-			95,034
Success payment liabilities	Level 3		21,007		-		-			21,007
Total long-term financial liabilities			116,041		-		-			116,041
Total financial liabilities		$	171,386	$	-	$	-		$	171,386

Summary of Estimated Fair Value Available For Sale Debt Securities Continuous Unrealized Loss Position

The following table summarizes available-for-sale debt securities in a continuous unrealized loss position for less than and greater than twelve months for the periods presented:


	Less than 12 months					12 months or greater					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
	(in thousands)
June 30, 2023
U.S. government and agency securities	$	5,431	$	(45	)	$	81,549	$	(823	)	$	86,980	$	(868	)
Corporate debt securities		-		-			10,041		(24	)		10,041		(24	)
Total	$	5,431	$	(45	)	$	91,590	$	(847	)	$	97,021	$	(892	)
December 31, 2022
U.S. government and agency securities	$	49,253	$	(673	)	$	172,845	$	(3,301	)	$	222,098	$	(3,974	)
Corporate debt securities		13,333		(16	)		19,664		(350	)		32,997		(366	)
Total	$	62,586	$	(689	)	$	192,509	$	(3,651	)	$	255,095	$	(4,340	)

Changes in Estimated Fair Value of Level 3 Financial Liabilities

The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities:


	Contingent Consideration		Cobalt Success Payment Liability			Harvard Success Payment Liability
	(in thousands)
Balance as of December 31, 2022	$	150,379	$	19,016		$	1,991
Changes in fair value – expense (gain)		5,460		(4,760	)		(580	)
Balance as of March 31, 2023		155,839		14,256			1,411
Changes in fair value – expense		5,895		18,505			2,279
Balance as of June 30, 2023	$	161,734	$	32,761		$	3,690

Success Payment Liabilities

Summary of Estimated Fair Value of Liabilities using Unobservable Inputs

The fair values of the Cobalt Success Payments and Harvard Success Payments were calculated using the following unobservable inputs:


	June 30, 2023		December 31, 2022
Unobservable Input	Cobalt	Harvard	Cobalt	Harvard
Expected stock price volatility	72.5%	72.5%	70.0%	70.0%
Expected term (years)	15.6	7.7	16.1	8.2

Cobalt Contingent Consideration

Summary of Estimated Fair Value of Liabilities using Unobservable Inputs

The fair value of the Cobalt Contingent Consideration was calculated using the following unobservable inputs:


	June 30, 2023		December 31, 2022
Unobservable Input	Range	Weighted-Average	Range	Weighted-Average
Discount rates	13.0% – 15.1%	13.8%	13.4% – 15.1%	14.6%
Probability of milestone achievement	5.0% – 85.0%	36.0%	5.0% – 85.0%	36.0%

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (113,999)	$ (72,465)	$ (196,122)	$ (103,913)
Other comprehensive loss, net of tax:
Unrealized gain (loss) on marketable securities, net	1,274	(1,175)	3,462	(4,981)
Total comprehensive loss	$ (112,725)	$ (73,640)	$ (192,660)	$ (108,894)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

License and collaboration agreements (Tables)

6 Months Ended

Jun. 30, 2023

License And Collaboration Agreements [Abstract]

Summary of Potential Success Payments

The following table summarizes the potential success payments and common stock price required for payment:


Multiple of Equity Value at Issuance	5x		10x		20x		30x		40x
Per share common stock price required for payment	$	20.00	$	40.00	$	80.00	$	120.00	$	160.00
Success payment(s) (in millions)	$	5.0	$	15.0	$	30.0	$	50.0	$	75.0

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2023	Jul. 27, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Entity Registrant Name	Sana Biotechnology, Inc.
Entity Central Index Key	0001770121
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		196,942,065
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity File Number	001-39941
Entity Tax Identification Number	83-1381173
Entity Address Address Line1	188 East Blaine Street
Entity Address, Address Line Two	Suite 400
Entity Address City Or Town	Seattle
Entity Address State Or Province	WA
Entity Address Postal Zip Code	98102
City Area Code	206
Local Phone Number	701-7914
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation State Country Code	DE
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	SANA
Security Exchange Name	NASDAQ

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	196,880,000	191,022,000
Common stock, shares outstanding	196,880,000	191,022,000

Acquisitions - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2019	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Business Acquisition [Line Items]
Goodwill		$ 140,627,000		$ 140,627,000		$ 140,627,000
Estimated fair value of contingent consideration, short term liabilities		58,417,000		58,417,000		55,345,000
Estimated fair value of contingent consideration, long-term liabilities		103,317,000		103,317,000		95,034,000
Change in the estimated fair value of contingent consideration				11,355,000	$ (4,358,000)
Cobalt Biomedicine, Inc \| Acquisition Agreement
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired	100.00%
Goodwill	$ 140,600,000
Business acquisition, impairment of intangible assets or goodwill	0
Maximum contingent consideration upon achievement of certain pre-specified development milestones	$ 500,000,000.0
Maximum term for success payment	20 years
Cobalt Biomedicine, Inc \| Acquisition Agreement \| Research and Development Expense
Business Acquisition [Line Items]
Estimated fair value of contingent consideration		161,700,000		161,700,000		150,400,000
Estimated fair value of contingent consideration, short term liabilities		58,400,000		58,400,000		55,400,000
Estimated fair value of contingent consideration, long-term liabilities		103,300,000		103,300,000		95,000,000.0
Change in estimated fair value of success payment		18,500,000	$ (12,100,000)	13,700,000	(58,900,000)
Change in the estimated fair value of contingent consideration		5,900,000	$ (3,800,000)	11,400,000	$ (4,400,000)
Cobalt Biomedicine, Inc \| Acquisition Agreement \| Long-term Liabilities \| Research and Development Expense
Business Acquisition [Line Items]
Estimated fair value of success payment liability		$ 32,800,000		$ 32,800,000		$ 19,000,000.0
Cobalt Biomedicine, Inc \| Acquisition Agreement \| Minimum
Business Acquisition [Line Items]
Threshold market capitalization	$ 8,100,000,000
Cobalt Biomedicine, Inc \| Acquisition Agreement \| Market Capitalization Equal to or Exceeds $8.1 billion
Business Acquisition [Line Items]
Cobalt success payment	500,000,000.0
Cobalt Biomedicine, Inc \| Acquisition Agreement \| IPR&D
Business Acquisition [Line Items]
Business combination, intangible assets	$ 59,200,000

Commitments and Contingencies - Additional Information (Details) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2022 USD ($) ft²	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)
Lessee Lease Description [Line Items]
Obligation to pay base rent			$ 236,055
Weighted-average remaining lease term			7 years 6 months
Weighted-average incremental borrowing rate			10.94%
Bothell, Washington
Lessee Lease Description [Line Items]
Square feet \| ft²	79,565
Option to extend the lease term			with the option to extend the lease for up to three additional five-year terms.
Reimbursement of tenant improvements	$ 19,900	$ 19,900
Optional additional tenant improvement allowance	$ 8,000	$ 8,000
Optional additional tenant improvement allowance, interest rate	6.50%	6.50%
Obligation to pay base rent	$ 68,800	$ 68,800
Letter of credit	$ 1,600	1,600
Fremont, California
Lessee Lease Description [Line Items]
Option to extend the lease term			option to renew the lease for two additional five-year terms
Increase decrease in operating lease right-of-use assets			$ 12,800
Increase decrease in operating lease right-of-use liabilities			$ 12,800
Construction in progress costs write-off		$ 4,500

Stock-Based Compensation - Additional Information (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended	6 Months Ended
	Feb. 28, 2021	Jun. 30, 2023	Jun. 30, 2022
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of vested		$ 1.1	$ 0.2
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage related to employees able to purchase shares at lower of fair market value	85.00%
Number of shares available for future issuance		4.8
2021 Employee Stock Purchase Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage allowed for eligible employees to purchase shares of common stock	15.00%
2021 Incentive Award Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future issuance		15.6

- 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

Commitments and Contingencies

6 Months Ended

Jun. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

9. Commitments and contingencies

Lease commitments

The Company’s lease portfolio primarily comprises operating leases for office, laboratory, non-good manufacturing practices pilot plant manufacturing, and industrial space. These leases contain various rent abatement periods, after which they require monthly lease payments that may be subject to annual increases throughout the lease term. Certain leases include options to extend the term. The renewal option is considered in the remaining lease term for the lease only when the Company is reasonably certain it will renew the lease. Certain leases provide the Company with the right to make tenant improvements, including the addition of laboratory space or build-out of manufacturing capabilities, and include a lease incentive allowance.

In June 2022, the Company entered into a lease agreement for 79,565 square feet of office, laboratory, and industrial space located in Bothell, Washington (the Bothell facility). The initial term of the lease expires in February 2039, with the option to extend the lease for up to three additional five-year terms. The lease agreement also provides for up to $19.9 million for reimbursement of tenant improvements, as well as an additional $8.0 million for tenant improvements, available at the Company’s election, which the Company would be obligated to repay to the landlord monthly over the initial term of the lease with interest at a rate of 6.5% per annum. The Company is obligated to pay base rent of approximately $68.8 million over the initial term of the lease. In accordance with the lease agreement, the Company has obtained a letter of credit in the amount of $1.6 million. The Company recognized the right-of-use asset and lease liability in the three months ended March 31, 2023, when the lease commenced.

In July 2021, the Company entered into a lease for industrial space located in Fremont, California (the Fremont facility), with the intent to establish and develop its manufacturing operations at the Fremont facility. However, the Company determined in June 2022 to establish and develop its manufacturing operations at the Bothell facility rather than the Fremont facility. The original right-of-use asset and lease liability for the Fremont facility was calculated assuming the Company would exercise its option to renew the

lease for two additional five-year terms. The Company remeasured the lease for the Fremont facility in 2022 due to the shorter expected lease term, which resulted in a $12.8 million reduction in the related right-of-use asset and lease liability. Additionally, the Company wrote off $4.5 million of construction in progress costs incurred in connection with the Fremont facility in general and administrative expense in the three months ended June 30, 2022.

The following table contains additional information related to the Company’s operating leases:


Location	Use	Approximate Square Footage	Commencement Dates	Expiration Dates
Seattle, WA	Office/Laboratory	48,000	March 2019 to September 2020	December 2026 to April 2028
Cambridge, MA	Office/Laboratory	60,000	March 2019 to January 2022	November 2025 to February 2028
South San Francisco, CA	Office/Laboratory	100,000	December 2019 to April 2022	April 2024 to April 2030
Fremont, CA	Industrial	163,000	July 2021	November 2031
Rochester, NY	Office/Laboratory	3,000	January 2022	January 2025
Bothell, WA	Office/Laboratory/Industrial	80,000	January 2023	January 2039

Throughout the term of the lease agreements, the Company is responsible for paying, in addition to base rent, certain operating costs, such as common area maintenance, taxes, utilities, and insurance. These additional charges are considered variable lease costs and are recognized in the period in which the costs are incurred.

The following table summarizes the Company’s lease costs:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
	(in thousands)
Operating lease cost	$	6,981	$	6,066	$	14,042	$	11,546
Variable lease cost		1,929		1,903		3,911		3,392
Total lease cost	$	8,910	$	7,969	$	17,953	$	14,938

As of June 30, 2023, the weighted-average remaining lease term was 7.5 years, and the weighted-average incremental borrowing rate was 10.94%.

The following table reconciles the Company’s undiscounted operating lease cash flows by fiscal year to the present value of the operating lease liabilities as of June 30, 2023 (in thousands):


2023 (remaining 6 months)	$	11,019
2024		28,021
2025		28,109
2026		25,268
2027		22,779
2028 and thereafter		120,859
Total undiscounted lease payments		236,055
Less: imputed interest		(103,184	)
Less: tenant improvement allowances		(19,736	)
Present value of operating lease liabilities		113,135
Less: current portion of operating lease liabilities	$	(12,890	)
Operating lease liabilities, net of current portion	$	100,245