Vaxcyte (PCVX) 10-Q 8 May 24 2024 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2024	May 06, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-39323
Entity Registrant Name	VAXCYTE, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-4233385
Entity Address, Address Line One	825 Industrial Road
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	San Carlos
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94070
City Area Code	650
Local Phone Number	837-0111
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	PCVX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		108,795,188
Amendment Flag	false
Entity Central Index Key	0001649094
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 611,512	$ 397,451
Short-term investments	875,006	682,776
Prepaid expenses and other current assets	30,554	15,727
Total current assets	1,517,072	1,095,954
Property and equipment, net	84,835	79,626
Operating lease right-of-use assets	28,905	30,997
Long-term investments	413,247	162,675
Restricted cash	1,103	1,103
Other assets	46,143	37,562
Total noncurrent assets	574,233	311,963
Total assets	2,091,305	1,407,917
Current liabilities:
Accounts payable	21,717	14,587
Accrued compensation	3,088	11,056
Accrued manufacturing expenses	926	52,767
Accrued expenses	54,171	59,815
Operating lease liabilities — current	7,202	7,113
Total current liabilities	87,104	145,338
Operating lease liabilities — long-term	20,218	22,111
Total liabilities	107,322	167,449
Commitments and contingencies
Stockholders' Equity
Preferred stock, $0.001 par value — 10,000,000 shares authorized at March 31, 2024 and December 31, 2023; no shares issued and outstanding at March 31, 2024 and December 31, 2023	0	0
Common stock, $0.001 par value — 500,000,000 shares authorized at March 31, 2024 and December 31, 2023; 108,755,731 and 95,364,831 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	112	98
Additional paid-in capital	3,000,394	2,164,583
Accumulated other comprehensive gain	2,889	179
Accumulated deficit	(1,019,412)	(924,392)
Total stockholders' equity	1,983,983	1,240,468
Total liabilities and stockholders' equity	$ 2,091,305	$ 1,407,917

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	108,755,731	95,364,831
Common stock, shares outstanding (in shares)	108,755,731	95,364,831

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating expenses:
Research and development	$ 94,587	$ 58,080
General and administrative	19,885	13,112
Total operating expenses	114,472	71,192
Loss from operations	(114,472)	(71,192)
Other income (expense), net:
Interest income	21,666	10,393
Grant income	126	654
Realized gains on marketable securities	22	0
Foreign currency transaction losses	(2,362)	(317)
Total other income, net	19,452	10,730
Net loss	$ (95,020)	$ (60,462)
Net loss per share, basic (in dollars per share)	$ (0.85)	$ (0.70)
Net loss per share, diluted (in dollars per share)	$ (0.85)	$ (0.70)
Weighted-average shares outstanding, basic (in shares)	111,690,951	86,206,817
Weighted-average shares outstanding, diluted (in shares)	111,690,951	86,206,817

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net Loss	$ (95,020)	$ (60,462)
Other comprehensive loss:
Unrealized (losses) gains on investments	(1,999)	408
Foreign currency translation adjustments, net	4,709	0
Comprehensive loss	$ (92,310)	$ (60,054)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Gain (Loss)	Follow on public offering	Follow on public offering Common Stock	Follow on public offering Additional Paid-in Capital	At the market offering	At the market offering Common Stock	At the market offering Additional Paid-in Capital
Beginning balance (in shares) at Dec. 31, 2022		79,470,670
Beginning balance at Dec. 31, 2022	$ 953,613	$ 82	$ 1,476,018	$ (522,126)	$ (361)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		100,964
Exercise of stock options	502	$ 1	501
Issuance of common stock (in shares)							1,041,536
Issuance of common stock						$ 41,787	$ 1	$ 41,786
Release of restricted stock units (in shares)		27,681
Release of restricted stock units	(727)		(727)
Vesting of early exercised stock options	2		2
Stock-based compensation expense	9,648		9,648
Unrealized losses on investments	408				408
Foreign currency translation adjustments, net	0
Net Loss	(60,462)			(60,462)
Ending balance (in shares) at Mar. 31, 2023		80,640,851
Ending balance at Mar. 31, 2023	944,771	$ 84	1,527,228	(582,588)	47
Beginning balance (in shares) at Dec. 31, 2023		95,364,831
Beginning balance at Dec. 31, 2023	1,240,468	$ 98	2,164,583	(924,392)	179
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		631,287
Exercise of stock options	5,024	$ 1	5,023
Issuance of common stock (in shares)										12,695,312
Issuance of common stock									$ 816,478	$ 13	$ 816,465
Release of restricted stock units (in shares)		64,301
Release of restricted stock units	(3,306)		(3,306)
Stock-based compensation expense	17,629		17,629
Unrealized losses on investments	(1,999)				(1,999)
Foreign currency translation adjustments, net	4,709				4,709
Net Loss	(95,020)			(95,020)
Ending balance (in shares) at Mar. 31, 2024		108,755,731
Ending balance at Mar. 31, 2024	$ 1,983,983	$ 112	$ 3,000,394	$ (1,019,412)	$ 2,889

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders’ Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
At the market offering
Issuance costs	$ 45,997
Follow on public offering
Issuance costs		$ 1,237

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (95,020)	$ (60,462)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	999	712
Stock-based compensation expense	17,629	9,648
Amortization of operating lease right-of-use assets	2,092	1,630
Net accretion of discounts on investments	(10,991)	(5,990)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(4,958)	(4,702)
Other assets	(8,581)	615
Operating lease liabilities	(1,804)	(1,356)
Accounts payable	5,672	1,789
Accrued compensation	(7,968)	699
Accrued manufacturing expenses	(51,840)	6,689
Accrued expenses	(4,354)	3,038
Net cash used in operating activities	(159,124)	(47,690)
Cash flows from investing activities:
Purchases of property and equipment	(5,678)	(5,609)
Purchases of investments	(687,697)	(483,779)
Manufacturing facility and equipment construction-in-progress	(6,394)	0
Maturities of investments	242,318	40,160
Sale of investments	6,378	1,127
Net cash used in investing activities	(451,073)	(448,101)
Cash flows from financing activities:
Proceeds from exercise of common stock options	5,024	502
Proceeds from issuance of common stock related to at-the-market offering, net of issuance costs	0	41,787
Proceeds from issuance of common stock from follow-on offering, net of issuance costs	816,478	0
Release of restricted stock units	(3,306)	(727)
Net cash provided by financing activities	818,196	41,562
Effect of exchange rate changes on cash and cash equivalents	6,062	23
Net increase (decrease) in cash, cash equivalents and restricted cash	214,061	(454,206)
Cash, cash equivalents and restricted cash, beginning of period	398,554	835,528
Cash, cash equivalents and restricted cash, end of period	612,615	381,322
Supplemental disclosure of non-cash investing activities:
Purchases of property and equipment recorded in accounts payable and accrued expenses	$ 13,719	$ 57

Company Organization and Nature

Company Organization and Nature of Business	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Company Organization and Nature of Business	Company Organization and Nature of Business Vaxcyte, Inc. and its wholly owned consolidated subsidiary, collectively referred to as any of “we,” “us,” “the Company,” or “Vaxcyte,” headquartered in San Carlos, California, was incorporated in the state of Delaware on November 27, 2013 as SutroVax, Inc. and we changed our name to Vaxcyte, Inc. on May 15, 2020. On October 25, 2023, we formed Vaxcyte Switzerland GmbH (“Vaxcyte GmbH”), a wholly owned Swiss subsidiary. We are a clinical-stage vaccine innovation company engineering high-fidelity vaccines to protect humankind from the consequences of bacterial diseases. We are developing broad-spectrum conjugate and novel protein vaccines to prevent or treat bacterial infectious diseases. We are re-engineering the way highly complex vaccines are made through modern synthetic techniques, including advanced chemistry and the XpressCF TM cell-free protein synthesis platform, exclusively licensed from Sutro Biopharma, Inc. (“Sutro Biopharma”). Unlike conventional cell-based approaches, our system for producing difficult-to-make proteins and antigens is intended to accelerate our ability to efficiently create and deliver high-fidelity vaccines with enhanced immunological benefits.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and footnote disclosures normally included in the condensed consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted in accordance with such rules and regulations. The condensed consolidated financial statements include the Company and its wholly owned subsidiary. All intercompany transactions and balances have been eliminated upon consolidation. Unaudited Interim Condensed Consolidated Financial Statements The condensed consolidated balance sheet as of March 31, 2024, the condensed consolidated statements of operations, comprehensive loss and stockholders’ equity for the three months ended March 31, 2024 and 2023 and the condensed consolidated statements of cash flows for the three months ended March 31, 2024 and 2023 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair statement of our financial information. The financial data disclosed in the footnotes to the condensed consolidated financial statements related to the three months ended March 31, 2024 and 2023 are also unaudited. The results of operations for the three months ended March 31, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other future annual or interim period. These interim condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements and related notes thereto for the year ended December 31, 2023 included in our Annual Report on Form 10-K filed with the SEC on February 27, 2024. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements. On an ongoing basis, we evaluate our estimates and assumptions, including those related to stock-based compensation expense, accruals for certain research and development costs, the valuation of deferred tax assets and income taxes. We base our estimates on historical experience and various other assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those estimates. Cash, Cash Equivalents and Restricted Cash We consider all highly liquid investments purchased with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents consist primarily of amounts invested in money market funds and commercial paper and are stated at their fair values. Restricted cash consists of standby letters of credit, which were issued to serve as collateral for the lease agreements related to our current corporate headquarters. Cash, cash equivalents and restricted cash as reported within the condensed consolidated balance sheets that total to the same amounts shown in the condensed consolidated statements of cash flows are as follows: March 31, December 31, (in thousands) Cash and cash equivalents $ 611,512 $ 397,451 Restricted cash 1,103 1,103 Cash, cash equivalents and restricted cash $ 612,615 $ 398,554 Investments Our investments have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. Treasury securities, U.S. government agency securities, corporate debt, commercial paper and asset-backed securities. These securities are recorded on the condensed consolidated balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive gain (loss). The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income (expense), net. Realized gains and losses are also included in other income (expense), net. When the fair value of a debt security declines below its amortized cost basis, any portion of that decline attributable to credit losses, to the extent expected to be nonrecoverable before the sale of the security, is recognized in our condensed consolidated statements of operations. When the fair value of a debt security declines below its amortized cost basis due to changes in interest rates, such amounts are recorded in other comprehensive loss, and are recognized in our condensed consolidated statements of operations only if we sell or intend to sell the security before recovery of its cost basis. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average of shares of common stock outstanding, including pre-funded warrants issued, during the period, without consideration for common stock equivalents. Shares of common stock into which the pre-funded warrants may be exercised are considered outstanding for the purposes of computing net loss per share because the shares may be issued for little consideration, are fully vested and are exercisable after the original issuance date. Diluted net loss per share is the same as basic net loss per share since the effects of potentially dilutive securities are anti-dilutive given the net loss for each period presented. Leases We determine if an arrangement is a lease at inception. In addition, we determine whether a lease meets the classification criteria of a finance or operating lease at the lease commencement date considering whether: (i) the lease transfers ownership of the underlying asset to the lessee at the end of the lease term; (ii) the lease grants the lessee an option to purchase the underlying asset that the lessee is reasonably certain to exercise; (iii) the lease term is for a major part of the remaining economic life of the underlying asset; (iv) the present value of the sum of the lease payments and residual value guaranteed by the lessee equals or exceeds substantially all of the fair value of the underlying asset; and (v) the underlying asset is such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. As of March 31, 2024, our lease population consisted of office operating leases. As of March 31, 2024, we did not have finance leases. Operating leases are included in Operating lease right-of-use (“ROU”) assets, Operating lease liabilities — current and Operating lease liabilities — long term in our condensed consolidated balance sheet. ROU assets represent our right to use the underlying assets for the lease term and lease liabilities represent our obligation to make lease payments arising from the leases. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, if the rate implicit in the lease is not readily determinable, we use our incremental borrowing rate based on the information available at the lease commencement date. We determine the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to ours. The determination of our incremental borrowing rate requires management judgment, including development of a synthetic credit rating and cost of debt, as we currently do not carry any debt. We believe that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgment to the same facts and circumstances could yield a different incremental borrowing rate. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. ROU assets and lease liabilities may include options to extend or terminate leases if it is reasonably certain that we will exercise such options. Lease payments which are fixed and determinable are amortized as rent expense on a straight-line basis over the expected lease term. Variable lease costs, which are dependent on usage, a rate or index, including common area maintenance charges, are expensed as incurred. Lease agreements that include lease and non-lease components are accounted for as a single lease component. Lease agreements with non-cancelable terms of less than 12 months are not recorded on our condensed consolidated balance sheets. Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject us to a concentration of credit risk consist primarily of cash, cash equivalents and investments. We invest in money market funds, U.S. Treasury securities, U.S. government agency securities, corporate debt, commercial paper and asset-backed securities. We maintain bank deposits in federally insured financial institutions and these deposits may exceed federally-insured limits. We are exposed to credit risk in the event of a default by the financial institutions holding our cash and issuers of investments to the extent recorded on the condensed consolidated balance sheets. For example, on March 10, 2023, the California Department of Financial Protection and Innovation took control of Silicon Valley Bank (“SVB”) and appointed the Federal Deposit Insurance Corporation (“FDIC”) as receiver. While SVB was our primary bank at the time, we have not experienced any losses on these deposits or investments as a result of this market event. Management believes that we are not exposed to significant credit risk as our deposits are held at First Citizens Bank & Trust Company, which had agreed to purchase and assume all deposits and loans of Silicon Valley Bridge Bank, and our investments are held under separate financial institution custodial accounts, each of which management continues to believe to be of high credit quality. While we were able to recover all deposited amounts from SVB, and continue to have access to all investments held in the SVB Custodial Accounts, there can be no assurance that our current or future banks will not face similar risks as SVB or that we will be able to recover in full our deposits in the event of similar closures. Our investment policy limits investments to money market funds, certain types of debt securities issued by the U.S. Government and its agencies, corporate debt, commercial paper and asset-backed securities, and places restrictions on the credit ratings, maturities and concentration by type and issuer. We have not experienced any significant losses on our deposits of cash, cash equivalents or investments. We are subject to supplier concentration risk from our suppliers. Although we are working to establish secondary sources of supply, we currently source several of our critical raw materials from single-source suppliers. We also use one contract manufacturing organization (“CMO”), Lonza Ltd. (“Lonza”), to handle most of our manufacturing activities for our VAX-24 and VAX-31 programs. If we were to experience disruptions in raw materials supplied by our suppliers, or in manufacturing activities at Lonza, we may experience significant delays in our product development timelines and may incur substantial costs to secure alternative sources of raw materials or manufacturing. Our future results of operations involve a number of other risks and uncertainties. Factors that could affect our future operating results and cause actual results to vary materially from expectations include, but are not limited to: our early stages of clinical vaccine development; our ability to advance vaccine candidates into, and successfully complete, clinical trials on the timelines we project; our ability to adequately demonstrate sufficient safety and immunogenicity or efficacy of our vaccine candidates; our ability to enroll subjects in our ongoing and future clinical trials; our ability to successfully manufacture and supply our vaccine candidates for clinical trials or for future potential commercialization; our ability to obtain additional capital to finance our operations; our ability to obtain, maintain and protect our intellectual property rights; developments relating to our competitors and our industry, including competing vaccine candidates; general and market conditions; and other risks and uncertainties, including those more fully described in the “Risk Factors” section of this Quarterly Report on Form 10-Q. Recently Issued Accounting Pronouncements — Not Yet Adopted From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies and adopted by us as of the specified effective date. We believe that the impact of recently issued standards that are not yet effective will not have a material impact on our consolidated financial statements and disclosures. In March 2024, the FASB issued Accounting Standards Update (“ASU”) No. 2024-02, Codification Improvements—Amendments to Remove References to the Concepts Statements (“ASU 2024-02”). The amendments in ASU 2024-02 clarify and simplify references to certain concept statements within U.S. GAAP. The new standard is effective for us for the annual period beginning after December 15, 2024. We are currently evaluating the impact of the new guidance and do not expect adoption of ASU 2024-02 will have a material impact on our consolidated financial statements. In March 2024, the FASB issued ASU No. 2024-01 , Compensation—Stock Compensation (Topic 718): Scope Application of Profits Interest and Similar Awards (“ASU 2024-01”). The amendments in ASU 2024-01 improve consistent application of and simplify U.S. GAAP of Topic 718 by clarifying and amending existing guidance. The guidance is effective for us for the annual period beginning after December 15, 2024. We are currently evaluating the impact of the new guidance and do not expect adoption of ASU 2024-01 will have a material impact on our consolidated financial statements. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”). The ASU improves the transparency of income tax disclosures by requiring (i) consistent categories and greater disaggregation of information in the rate reconciliation and (ii) income taxes paid disaggregated by jurisdiction. The guidance is effective for us for the annual period beginning after December 15, 2024. We are currently evaluating the impact of the new guidance and do not expect adoption of ASU 2023-09 will have a material impact on our consolidated financial statements. In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”). The ASU requires entities to report incremental information about significant segment expenses included in a segment’s profit or loss measure as well as the name and title of the chief operating decision maker. The guidance also requires interim disclosures related to reportable segment profit or loss and assets that had previously only been disclosed annually. The guidance is effective for us for the annual period beginning after December 15, 2023. We are currently evaluating the impact of the new guidance and do not expect adoption of ASU 2023-07 will have a material impact on our consolidated financial statements.

Fair Value Measurements and Fai

Fair Value Measurements and Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements and Fair Value of Financial Instruments	Fair Value Measurements and Fair Value of Financial Instruments Assets and liabilities recorded at fair value on a recurring basis in the condensed consolidated balance sheets, as well as assets and liabilities measured at fair value on a non-recurring basis or disclosed at fair value, are categorized based upon the level of judgment associated with inputs used to measure their fair values. The accounting guidance for fair value provides a framework for measuring fair value and requires certain disclosures about how fair value is determined. Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance also establishes a three-level valuation hierarchy that prioritizes the inputs to valuation techniques used to measure fair value based upon whether such inputs are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions made by the reporting entity. The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows: Level 1— Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2— Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level 3 — Unobservable inputs based on our own data or other assumptions that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. Changes in the ability to observe valuation inputs may result in a reclassification of levels of certain securities within the fair value hierarchy. We recognize transfers into and out of levels within the fair value hierarchy in the period in which the actual event or change in circumstances that caused the transfer occurs. Level 1 securities consist of highly liquid money market funds for which the carrying amounts approximate their fair values due to their short maturities. U.S. Treasury securities are valued using Level 1 inputs based on unadjusted, quoted prices in active markets that are observable at the measurement date for identical assets or liabilities. Level 2 securities, consisting of corporate debt, commercial paper, U.S. government agency securities and asset-backed securities, are measured based on other observable inputs, including broker or dealer quotations or alternative pricing sources. When quoted prices in active markets for identical assets or liabilities are not available, we rely on non-binding quotes from our investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments or historical pricing trends of securities relative to our peers. To validate the fair value determinations provided by our investment managers, we review the pricing movement in the context of overall market trends and trading information from our investment managers. In addition, we assess the inputs and methods used in determining the fair value in order to determine the classification of securities in the fair value hierarchy. We had no Level 3 securities as of March 31, 2024 or December 31, 2023. There were no transfers within the hierarchies during the three months ended March 31, 2024 or the year ended December 31, 2023. The following tables set forth our financial instruments measured at fair value on a recurring basis by level within the fair value hierarchy at March 31, 2024 and December 31, 2023: March 31, 2024 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Assets (in thousands) Cash and cash equivalents: Cash Level 1 $ 20,288 $ — $ — $ 20,288 Money market funds Level 1 107,073 — — 107,073 U.S. Treasury securities Level 1 44,734 — (1) 44,733 Commercial paper Level 2 437,660 — (237) 437,423 Corporate debt Level 2 1,994 1 — 1,995 Total cash and cash equivalents 611,749 1 (238) 611,512 Investments: U.S. Treasury securities Level 1 734,969 — (708) 734,261 Commercial paper Level 2 132,929 — (72) 132,857 Corporate debt Level 2 272,753 26 (508) 272,271 Asset-backed securities Level 2 43,548 — (25) 43,523 U.S. government agency securities Level 2 105,638 — (297) 105,341 Total investments 1,289,837 26 (1,610) 1,288,253 Total assets measured at fair value $ 1,901,586 $ 27 $ (1,848) $ 1,899,765 December 31, 2023 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Assets (in thousands) Cash and cash equivalents: Cash Level 1 $ 50,003 $ — $ — $ 50,003 Money market funds Level 1 47,357 — — 47,357 Commercial paper Level 2 300,256 — (165) 300,091 Total cash and cash equivalents 397,616 — (165) 397,451 Investments: U.S. Treasury securities Level 1 481,704 422 (44) 482,082 Commercial paper Level 2 102,435 7 (35) 102,407 Corporate debt Level 2 133,523 168 (42) 133,649 Asset-backed securities Level 2 23,963 18 — 23,981 U.S. government agency securities Level 2 103,484 — (152) 103,332 Total investments 845,109 615 (273) 845,451 Total assets measured at fair value $ 1,242,725 $ 615 $ (438) $ 1,242,902 The following table presents the contractual maturities of our investments as of March 31, 2024 (in thousands): March 31, 2024 Fair Value Due in less than one year $ 875,006 Due in one to five years 413,247 Total $ 1,288,253

Commercial Manufacturing and Su

Commercial Manufacturing and Supply Agreement	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commercial Manufacturing and Supply Agreement	Commercial Manufacturing and Supply Agreement On October 13, 2023, Vaxcyte GmbH, a Swiss limited liability company and wholly owned subsidiary of ours, entered into a pre-commercial services and commercial manufacturing supply agreement with Lonza (the “Commercial Manufacturing and Supply Agreement”). Pursuant to the Commercial Manufacturing and Supply Agreement, Lonza will (i) construct and build out a dedicated suite (the “Suite”) at Lonza’s facilities in Visp, Switzerland to manufacture certain key components (including drug substance) for our proprietary pneumococcal conjugate vaccine (“PCV”) franchise and any other products or intermediates Vaxcyte GmbH may choose (collectively, the “Products”) and (ii) maintain and operate the Suite (utilizing Lonza’s employees) to manufacture the Products as a service provided to Vaxcyte GmbH, including conducting related quality control and quality assurance operations. Lonza will be a preferred, non-exclusive, supplier of the Products to Vaxcyte GmbH, and Vaxcyte GmbH retains the right to procure the Products from one or more alternate and/or backup manufacturers of the Products (including at our own facilities). Under the Commercial Manufacturing and Supply Agreement, prior to completion of construction and certification of the Suite for commercial operation, Vaxcyte GmbH will contribute to the capital expenditure costs to construct the Suite (and will own certain equipment in the Suite to be purchased or otherwise acquired by Vaxcyte GmbH), and will pay Lonza a fixed-rate monthly service fee for Lonza’s pre-commercial services prior to commencement of commercial operations (which monthly service fee amount is subject to increases in subsequent years). Following commencement of commercial operations of the Suite to manufacture the Products, Vaxcyte GmbH will pay Lonza (i) Suite fees based on allocations of certain of Lonza’s costs to maintain the facility in which the Suite is located and to provide shared services to Vaxcyte GmbH and Lonza’s other customers in such facility, (ii) service fees based upon Lonza’s actual full-time equivalent employee (“FTE”) costs to operate the Suite to manufacture the Products, and (iii) certain other pass-through costs, including for raw materials. In addition, Vaxcyte GmbH may be obligated to pay or reimburse Lonza for certain other fees and expenses under the Commercial Manufacturing and Supply Agreement. Lonza will be eligible for certain financial bonuses, and subject to certain financial penalties, as incentives for the timely completion of certain scale-up activities, receipt of certain regulatory approvals for the Suite and manufacture of the Products in accordance with Vaxcyte GmbH’s commercial requirements. Unless earlier terminated, the Commercial Manufacturing and Supply Agreement will remain in effect until December 31, 2038, subject to automatic renewal for up to three additional renewal periods of five years each, unless Vaxcyte GmbH elects not to renew (with 24 months advanced notice to Lonza). Vaxcyte GmbH is permitted to terminate the Commercial Manufacturing and Supply Agreement for convenience or for Lonza’s uncured material breach, in each case subject to certain notice obligations. Lonza is permitted to terminate the Commercial Manufacturing and Supply Agreement in the event that Vaxcyte GmbH commits certain specified material breaches, including uncured failure to pay material, undisputed amounts of money due to Lonza, subject to certain notice obligations. Either party may terminate the Commercial Manufacturing and Supply Agreement in certain circumstances in the event of the other party’s bankruptcy. In the event that Vaxcyte GmbH terminates the agreement for convenience, or Lonza terminates the agreement in the event that Vaxcyte GmbH commits certain specified material breaches, then certain termination consequences may be triggered, including that (i) Vaxcyte GmbH would forfeit any outstanding entitlement to credit from Lonza of the Repurposing Fee (as defined below), and (ii) Vaxcyte GmbH would be obligated to pay Lonza a termination penalty equal to the greater of (a) Swiss Francs (“CHF”) 70 million, or (b) a prespecified number of months’ FTE fees for the actual FTEs assigned to Vaxcyte GmbH as of the date of termination. Within 30 days of the Effective Date, Vaxcyte GmbH paid Lonza a repurposing fee (the “Repurposing Fee”) of CHF 27 million that will be credited back to Vaxcyte GmbH over a 10-year period starting upon commencement of commercial production. In the event of a termination under certain circumstances, Lonza shall be obligated to provide certain wind-down and transition services to Vaxcyte GmbH for up to 12 and 24 months, respectively. As of March 31, 2024, we have incurred an accumulated (i) $58.2 million of capital expenditures related to the Vaxcyte owned facility buildout and equipment and (ii) $43.6 million of facility buildout expenditures that are owned and controlled by Lonza, including the Repurposing Fee, which have been accounted for as prepaid lease payments and will be recorded as a ROU asset under Accounting Standards Codification (“ASC”) 842 lease accounting when control over the Suite is transferred to us, which we expect to occur when the buildout of the Suite is complete and manufacturing activities commence (see Note 5 “Balance Sheet Details”).

Balance Sheet Details

Balance Sheet Details	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Details	Balance Sheet Details Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets as of March 31, 2024 and December 31, 2023 consisted of the following: March 31, December 31, (in thousands) Interest receivable $ 8,018 $ 3,598 Prepaid expenses 7,774 6,159 VAT on purchases 7,864 — Purchased equipment deposits 4,679 3,856 Grant receivable 127 9 Other current assets 2,092 2,105 Total $ 30,554 $ 15,727 Property and Equipment, Net Property and equipment, net as of March 31, 2024 and December 31, 2023 consisted of the following: March 31, December 31, (in thousands) Furniture and equipment $ 1,610 $ 1,608 Computers and computer software 849 771 Lab equipment 21,766 25,110 Leasehold improvements 2,074 1,460 Manufacturing equipment and auxiliary 10,598 8,134 Manufacturing facility and equipment construction-in-progress (1) 58,209 51,815 Total property and equipment 95,106 88,898 Less: accumulated depreciation and amortization (10,271) (9,272) Property and equipment, net $ 84,835 $ 79,626 ___________ (1) See Note 4, “Commercial Manufacturing and Supply Agreement,” for further details. Depreciation and amortization expense was $1.0 million and $0.7 million for the three months ended March 31, 2024 and 2023, respectively. Other Assets Other assets as of March 31, 2024 and December 31, 2023 consisted of the following: March 31, December 31, (in thousands) Manufacturing facility construction buildout (1) $ 43,575 $ 34,688 Long-term prepaid assets 2,472 2,768 Other long-term assets 96 106 Total $ 46,143 $ 37,562 ___________ (1) See Note 4, “Commercial Manufacturing and Supply Agreement,” for further details. Accrued Expenses Accrued expenses as of March 31, 2024 and December 31, 2023 consisted of the following: March 31, December 31, (in thousands) Clinical studies $ 3,054 $ 2,156 Other research and development 14,185 30,759 Acquired manufacturing rights (1) 25,000 25,000 Other accrued expenses 11,932 1,900 Total $ 54,171 $ 59,815 ___________ (1) See Note 7, “Commitments and Contingencies, Sutro Option Agreement,” for further details.

Leases

Leases	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Leases	Leases Operating Lease Obligations In October 2023, we entered into the Commercial Manufacturing and Supply Agreement with Lonza. We have concluded that this agreement contains an embedded lease and will be accounted for in accordance with ASC 842 Leases upon the commencement date. As of March 31, 2024, the lease had not commenced and, as such, no lease liability or ROU asset was recorded on the consolidated balance sheets and no operating lease expense was recorded on the consolidated statements of operations. See Note 4, “Commercial Manufacturing and Supply Agreement,” for further details. In September 2023, we entered into an assignment and assumption of lease agreement (the “Assignment Agreement”) for a new operating lease in the same building as our current corporate headquarters (the “Assumed Lease Premises”). The assumed lease has an original contractual term of 10 years, expiring on November 30, 2031, unless earlier terminated. Pursuant to the Assignment Agreement, the base rent was abated for three full calendar months following the October 1, 2023 effective date of the Assignment Agreement. Thereafter, we are obligated to pay an aggregate of approximately $1.9 million in rent payments for the remaining nine months of the first year, with a 3% rent adjustment (not inclusive of rent abatement) every year thereafter. Upon commencement of the lease in October 2023, we recorded a ROU asset and lease liability of $16.7 million and $16.8 million, respectively. In January 2021, we entered into a lease agreement for our current corporate headquarters facility located in San Carlos, California and a license agreement for temporary lab and office space in Palo Alto, California. The lease term for our current corporate headquarters facility began on December 3, 2021 and expires on December 31, 2025. We have two 60-month renewal options. We extended the license agreement for our temporary headquarters in the Palo Alto office by 60 days to March 3, 2022 to accommodate our relocation plan. The original term of the license agreement for the temporary space in Palo Alto terminated when the San Carlos office leasehold improvements were completed and we moved into our current corporate headquarters. These two agreements are accounted for as a combined lease because the contracts were negotiated as a package with the same commercial objective. Upon commencement of the San Carlos lease in December 2021, we recorded a ROU asset and lease liability of $28.4 million and $12.9 million, respectively. Information related to our leases are as follows (dollar amounts in thousands): Three Months Ended March 31, March 31, Cash paid for operating lease liabilities $ 2,390 $ 1,671 Weighted-average remaining lease term (in years) 5.61 2.54 Weighted-average discount rate 8.5 % 7.6 % Maturities of lease liabilities as of March 31, 2024 were as follows: Years ending December 31, (in thousands) Remainder of 2024 $ 6,423 2025 9,836 2026 2,899 2027 2,986 2028 3,075 Thereafter 9,502 Total future undiscounted lease payments 34,721 Less: Imputed interest (7,301) Total lease liabilities $ 27,420 Rent expense recognized under the leases was $2.7 million and $1.9 million for the three months ended March 31, 2024 and 2023, respectively.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Contingencies From time to time, we may become involved in legal proceedings arising from the ordinary course of business. We record a liability for such matters when it is probable that future losses will be incurred and that such losses can be reasonably estimated. Significant judgment by us is required to determine both probability and the estimated amount. We do not believe that there is any litigation or asserted or unasserted claim pending that could, individually or in the aggregate, have a material adverse effect on our results of operations or financial condition. Guarantees and Indemnifications In the normal course of business, we enter into agreements that contain a variety of representations and provide for general indemnification. Our exposure under these agreements is unknown because it involves claims that may be made against us in the future. To date, we have not paid any claims or been required to defend any action related to our indemnification obligations. As of March 31, 2024, we did not have any material indemnification claims that were probable or reasonably possible and consequently have not recorded related liabilities. Indemnification To the extent permitted under Delaware law, we have agreed to indemnify our directors and officers for certain events or occurrences while the director or officer is, or was, serving at our request in such capacity. The indemnification period covers all pertinent events and occurrences during the director’s or officer’s service. The maximum potential amount of future payments we could be required to make under these indemnification agreements is not specified in the agreements; however, we have director and officer insurance coverage that reduces our exposure and enables us to recover a portion of any future amounts paid. We have not incurred any material costs as a result of such indemnification and are not currently aware of any indemnification claims. Development and Manufacturing Services Agreements with Lonza In April 2022, we entered into a non-exclusive development and manufacturing services agreement with Lonza effective as of March 22, 2022, which was subsequently amended on May 12, 2022, November 21, 2022 and October 31, 2023 (as amended, the “2022 Lonza DMSA”). Pursuant to the 2022 Lonza DMSA, Lonza is obligated to perform services, including manufacturing process development and clinical manufacture and supply of our proprietary PCV candidates. Subject to the terms and conditions set forth in the 2022 Lonza DMSA, Lonza has granted to us a non-exclusive, worldwide, fully paid-up, irrevocable, transferable license, including the right to grant sublicenses, under the New General Application Intellectual Property, to research, develop, make, have made, use, sell and import the Product. Unless earlier terminated, the 2022 Lonza DMSA shall remain in place for a period of five years. Either party may terminate the 2022 Lonza DMSA for any reason on prior written notice to the other party, provided that Lonza may not exercise such right until a specified future date. In addition, either party may terminate the 2022 Lonza DMSA (i) within a given time period upon any material breach that is left uncured by the other party, or (ii) immediately if the other party becomes insolvent. We may also terminate the 2022 Lonza DMSA upon an extended force majeure event. Upon expiration and/or termination of the 2022 Lonza DMSA and/or any purchase order, we will pay Lonza for all service rendered, all costs incurred, all unreimbursed capital equipment and any cancellation fees (each term as defined in the 2022 Lonza DMSA). In February 2023, we entered into another non-exclusive development and manufacturing services agreement with Lonza effective as of March 1, 2023 (the “2023 Lonza DMSA”). Pursuant to the 2023 Lonza DMSA, Lonza will perform manufacturing process development and the manufacture of components for VAX-24 and VAX-31, including the polysaccharide antigens, our proprietary eCRM protein carrier and conjugated drug substances. Subject to the terms and conditions set forth in the 2023 Lonza DMSA, Lonza has granted to us a non-exclusive, worldwide, fully paid-up, transferable license, including the right to grant sublicenses (subject to the prior written consent of Lonza), under the New General Application Intellectual Property, to use, sell and import the Product manufactured under the 2023 Lonza DMSA (but no other products). Unless earlier terminated, the 2023 Lonza DMSA shall remain in place for a period of five years and shall automatically renew for one additional two-year period unless either party provides written notice of non-renewal at least two years prior to the fifth anniversary of the effective date. We may terminate the 2023 Lonza DMSA for any reason on prior written notice to the other party on a Project Plan-by-Project Plan basis. Either party may terminate the 2023 Lonza DMSA (i) within a given time period upon any material breach that is left uncured by the other party, (ii) immediately if the other party becomes insolvent, is dissolved or liquidated, makes a general assignment for the benefit of its creditors, or files or has filed against it, a petition in bankruptcy or has a receiver appointed for a substantial part of its assets, (iii) upon an extended force majeure event, or (iv) if it becomes apparent to either party at any stage in the provision of the Services that it will be impossible to complete the Services for scientific or technical reasons despite exercise of best commercial efforts by both parties. Pursuant to the reason for termination and the party initiating the termination, we will pay Lonza for some combination of services rendered, costs incurred, unreimbursed capital equipment and/or any cancellation fees. Upon an extended force majeure event, neither party shall have any further liability to the other party (each term as defined in the 2023 Lonza DMSA). Under each of the 2022 Lonza DMSA and 2023 Lonza DMSA (collectively, the “Lonza Agreements”), we pay Lonza agreed-upon fees for their performance of development and manufacturing services and pass-through expenses incurred by Lonza for raw materials, as well as customary procurement and handling fees. Under each Lonza Agreement, we own all rights, title and interest in and to any and all New Customer Intellectual Property (as defined in each Lonza Agreement), and Lonza owns all rights, title and interest in New General Application Intellectual Property (as defined in each Lonza Agreement). Commercial Manufacturing and Supply Agreement with Lonza For details of the Commercial Manufacturing and Supply Agreement with Lonza, see Note 4, “Commercial Manufacturing and Supply Agreement.” Sutro Option Agreement In December 2022, we entered into an option grant agreement with Sutro Biopharma (the “Option Agreement”). Pursuant to the Option Agreement, we acquired from Sutro Biopharma (i) authorization to enter into an agreement with an independent alternate CMO to directly source Sutro Biopharma’s cell-free extract, allowing us to have direct oversight over financial and operational aspects of the relationship with the CMO; and (ii) a right, but not an obligation, to obtain certain exclusive rights to internally manufacture and/or source extract from certain CMOs and the right to independently develop and make improvements to extract (including the right to make improvements to the extract manufacturing process as well as cell lines) for use in connection with the exploitation of certain vaccine compositions (the “Option”). We and Sutro Biopharma agreed to negotiate the terms and conditions of a form definitive agreement to be entered into in the event we exercised the Option, which would include the terms and conditions set forth in an executed term sheet between us (the “Term Sheet”) and such terms that were necessary to give effect to each of the terms and conditions set forth in the Term Sheet (the “Form Definitive Agreement”). The Option period was five years from the date of the Option Agreement, subject to potential acceleration in the event we undergo a change of control. As consideration for the Option and other rights and authorizations granted to us under the Option Agreement, we paid Sutro Biopharma upfront consideration of $22.5 million, consisting of (i) $10.0 million in cash and $7.5 million worth of shares of our common stock (the number of shares calculated based on the arithmetic average of the daily volume weighted average price of our common stock as traded on Nasdaq in the three consecutive trading days immediately prior to the issuance thereof), and (ii) $5.0 million payable within five business days after we and Sutro Biopharma mutually agree in writing upon the Form Definitive Agreement. The 167,780 shares of common stock issued was recorded at fair value of $8.0 million on the date of settlement, December 22, 2022. In the event that we elected to exercise the Option, we agreed to pay Sutro Biopharma an aggregate Option exercise price of $75.0 million in cash in two installments and, upon the occurrence of certain regulatory milestones, certain additional milestone payments totaling up to $60.0 million in cash. On September 28, 2023, we and Sutro Biopharma mutually agreed in writing upon the Form Definitive Agreement to become effective in the event that we exercise the Option and, on October 2, 2023, we paid the $5.0 million accrued commitment. On November 21, 2023 (the “Option Exercise Date”), we exercised the Option by submitting written notice thereof to Sutro Biopharma and concurrently paid Sutro Biopharma $50.0 million in cash as the first of two installment payments for the Option exercise price. Under the Option Agreement, we are obligated to pay Sutro Biopharma an additional $25.0 million in cash within six months of the Option Exercise Date as the second of two installment payments for the Option exercise, which amount has been accrued on our consolidated balance sheets as of March 31, 2024 and December 31, 2023. Upon the occurrence of certain regulatory milestones, we would be obligated to pay Sutro Biopharma certain additional milestone payments totaling up to $60.0 million in cash. In the event that we undergo a change of control, certain rights and payments may be accelerated. As of March 31, 2024 and December 31, 2023, we determined there is no current alternative future use of the acquired manufacturing rights from the Option Agreement. As a result, the amounts paid and accrued for were expensed as incurred. Manufacturing Rights Agreement with Sutro Biopharma Concurrent with the payment of the first installment of the Option exercise price pursuant to the Option Agreement, on November 21, 2023, the manufacturing rights agreement (in the form of the Form Definitive Agreement) between us and Sutro Biopharma (the “Manufacturing Rights Agreement”) became effective. Under the Manufacturing Rights Agreement, we received an exclusive (except as to Sutro Biopharma), perpetual (subject to termination), worldwide license, for no additional royalty (i.e., royalty-free, other than any royalties due under the Sutro Biopharma License Agreement), under Sutro Biopharma’s relevant patents and know-how, to manufacture or have manufactured extract and improvements to extract (in any form) solely for use in the research, development, use, production, sale, offering for sale, export, import, commercialization or other exploitation of Vaccine Compositions (as defined in the Sutro Biopharma License Agreement) as well as certain rights with respect to certain regulatory matters related to extract and its use in connection with such Vaccine Compositions. We have the right to extend our rights and obligations under the Manufacturing Rights Agreement to our affiliates and to sublicense our rights to manufacture extract and improvements to extract to certain third-party CMOs and other contractors (for our benefit and not for such third party’s independent commercial use). For clarity, we are not permitted to manufacture extract for sale to third parties for the independent use of such third parties. Under the Manufacturing Rights Agreement, we have the obligation to protect the confidentiality of the extract manufacturing technology, and Sutro Biopharma has certain audit rights in connection therewith. Under the Manufacturing Rights Agreement, upon our request and at our cost, Sutro Biopharma will support up to two technology transfers to us (or to an affiliate of ours or certain third-party CMOs designated by us) of certain Sutro Biopharma know-how, materials and information to enable us to manufacture or have manufactured extract. Under certain circumstances, Sutro Biopharma may source extract from us or certain third-party CMOs, subject to reimbursement for technology transfer costs. The Manufacturing Rights Agreement contains certain terms with respect to the ownership, prosecution, maintenance and enforcement of certain intellectual property rights licensed or arising under the Manufacturing Rights Agreement, which are generally consistent with the Sutro Biopharma License Agreement. Unless earlier terminated, the Manufacturing Rights Agreement will remain in effect in perpetuity. Sutro Biopharma may only terminate the Manufacturing Rights Agreement in the event of our (i) uncured, intentional, material breach of certain confidentiality provisions resulting in actual, material harm to Sutro Biopharma’s business, (ii) uncured, intentional material breach of certain provisions relating to the use of certain of Sutro Biopharma’s know-how outside of the Vaccine Field, (iii) unintentional, material breach of certain provisions relating to the use of certain of Sutro Biopharma’s know-how outside of the Vaccine Field that we do not use reasonable best efforts to cease and (to the extent reasonably curable) cure in a timely fashion, or (iv) uncured failure to pay the Option exercise price or any undisputed milestone payment under the Option Agreement when due. We may terminate the Manufacturing Rights Agreement at our discretion upon 60 days’ written notice, and both parties may terminate the Manufacturing Rights Agreement upon mutual written consent. Purchase Commitments We enter into agreements in the normal course of business with CMOs and other vendors for manufacturing services and raw materials purchases. We rely on several third-party manufacturers for our manufacturing requirements. As of March 31, 2024, we had the following amounts of non-cancelable purchase commitments related to manufacturing services and raw materials purchased due to our key manufacturing partners. These amounts represent our minimum contractual obligations, including termination fees. If we terminate certain firm orders with key manufacturing partners, we will be required to pay for the manufacturing services scheduled or raw materials purchased under our arrangements. The actual amounts we pay in the future to our vendors under such agreements may differ from the purchase order amounts. Years ending December 31, (in thousands) Remainder of 2024 $ 210,879 2025 57,834 2026 97 2027 393 Total non-cancelable purchase commitments due to our key manufacturing partners $ 269,203

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Preferred Stock Our certificate of incorporation authorizes us to issue up to 10,000,000 shares of preferred stock with $0.001 par value per share. There were no shares of preferred stock issued or outstanding as of March 31, 2024 and December 31, 2023. Our board of directors (“Board”) are authorized to provide for the issuance of all or any of the shares of preferred stock in one or more series, and to fix, determine or alter the voting powers, designation, preferences and rights of the preferred shares, and the qualifications, limitations or restrictions of any wholly unissued shares, to establish from time to time the number of shares constituting any such series, and to increase or decrease the number of shares, if any. Holders of outstanding shares of preferred stock shall be entitled to receive dividends, when, and as declared by the Board in preference and priority to any declaration or payment of any distribution on common stock. The right to receive dividends on preferred shares of preferred stock shall not be cumulative and no right to dividends shall accrue to holders of preferred stock. No dividends have been paid or declared as of March 31, 2024 and December 31, 2023. Common Stock Our certificate of incorporation authorizes us to issue up to 500,000,000 shares of common stock with $0.001 par value per share, of which 108,755,731 and 95,364,831 shares were issued and outstanding as of March 31, 2024 and December 31, 2023, respectively. The holders of our common stock are also entitled to receive dividends whenever funds are legally available, when and if declared by our Board. As of March 31, 2024 and December 31, 2023, no dividends had been declared. Each share of common stock is entitled to one vote. In July 2021, we entered into an Open Market Sales Agreement SM (the “Original ATM Sales Agreement”) with Jefferies LLC (“Jefferies”), which provided that, upon the terms and subject to the conditions and limitations set forth in the Original ATM Sales Agreement, we may elect to issue and sell, from time to time, shares of our common stock having an aggregate offering price of up to $150.0 million through Jefferies acting as our sales agent or principal. As of February 27, 2023, we had sold 4,995,709 shares of our common stock under the Original ATM Sales Agreement at an average price of $27.57 per share for aggregate gross proceeds of $137.8 million. On February 27, 2023, we and Jefferies entered into an amendment to the Original ATM Sales Agreement (as amended, the “Amended ATM Sales Agreement”) pursuant to which we may offer and sell shares of our common stock having an aggregate offering price of up to $400.0 million, which is in addition to the $150.0 million aggregate offering price under the Original ATM Sales Agreement. The material terms and conditions of the Original ATM Sales Agreement otherwise remain unchanged. We will pay Jefferies a commission of up to 3.0% of the gross sales proceeds of any common stock sold through Jefferies under the Amended ATM Sales Agreement; however, we are not obligated to make any sales of common stock. As of March 31, 2024, we have sold 1,588,807 shares of our common stock under the Amended ATM Sales Agreement at an average price of $44.06 per share for aggregate gross proceeds of $70.0 million ($68.6 million net of commissions and offering expenses). In April 2023, we completed an underwritten public offering of 13,030,000 shares of our common stock, which included the full exercise of the underwriters’ option to purchase an additional 1,830,000 shares, at a price of $41.00 per share and pre-funded warrants to purchase 1,000,000 shares of our common stock at a price of $40.999 per underlying share. In aggregate, we received $545.3 million in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by us, and excluding the exercise of any pre-funded warrants. In February 2024, we completed an underwritten public offering of 12,695,312 shares of our common stock, which included the full exercise of the underwriters’ option to purchase an additional 1,757,812 shares, at a price of $64.00 per share and pre-funded warrants to purchase 781,250 shares of our common stock at a price of $63.999 per underlying share. In aggregate, we received $816.5 million in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by us, and excluding the exercise of any pre-funded warrants. Common stock reserved for future issuance under the 2020 Equity Incentive Plan (the “2020 Plan”) and the 2014 Equity Incentive Plan (the “2014 Plan”) was as follows, and excludes 29,638 shares issued outside of the 2014 Plan and 2020 Plan: March 31, December 31, Options issued and outstanding 10,097,695 9,314,836 Restricted stock units outstanding 1,204,939 753,462 Shares available for future stock option grants 7,733,651 6,065,150 Total 19,036,285 16,133,448

Pre-Funded Warrants

Pre-Funded Warrants	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Pre-Funded Warrants	Pre-Funded Warrants In connection with our underwritten public offering in April 2023, we issued pre-funded warrants to purchase 1,000,000 shares of our common stock at a price of $40.999 per underlying share. Each pre-funded warrant has an exercise price of $0.001 per share. In connection with our underwritten public offering in February 2024, we issued pre-funded warrants to purchase 781,250 shares of our common stock at a price of $63.999 per underlying share. Each pre-funded warrant has an exercise price of $0.001 per share. The public offering prices for the pre-funded warrants were equal to the public offering prices of our common stock, less the $0.001 exercise price of each pre-funded warrant and were recorded as a component of stockholders' equity within additional paid-in-capital. The pre-funded warrants are exercisable, at the option of each holder, in whole or in part by delivering to us a duly executed exercise notice and payment of the exercise price. No fractional shares of common stock will be issued in connection with the exercise of a pre-funded warrant. The holders of the pre-funded warrants may also satisfy their obligation to pay the exercise price through a “cashless exercise,” in which the holder receives the net value of the pre-funded warrant in shares of common stock determined according to the formula set forth in the pre-funded warrant. The pre-funded warrants will not expire until they are fully exercised. However, we may not effect the exercise of any pre-funded warrants, and a holder will not be entitled to exercise any portion of any pre-funded warrants that, upon giving effect to such exercise, would cause: (i) the aggregate number of shares of our common stock beneficially owned by such holder (together with affiliates) to exceed 4.99% or 9.99% of the number of shares of our common stock outstanding immediately after giving effect to the exercise, as applicable; or (ii) the combined voting power of our securities beneficially owned by such holder (together with its affiliates) to exceed 4.99% or 9.99% of the combined voting power of all of our securities outstanding immediately after giving effect to the exercise, as applicable, as such percentage ownership is determined in accordance with the terms of the pre-funded warrants. However, any holder of a pre-funded warrant may increase or decrease such percentage to any other percentage not in excess of 19.99% upon at least 61 days' prior notice for the holder to us. As of March 31, 2024, in aggregate, we have issued pre-funded warrants to purchase 8,031,250 shares of our common stock and no shares underlying the pre-funded warrants had been exercised.

Equity Incentive Plans

Equity Incentive Plans	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Equity Incentive Plans	. Equity Incentive Plans 2020 and 2014 Equity Incentive Plans In June 2020, our Board adopted, and our stockholders approved, the 2020 Plan, which became effective on June 11, 2020. Under the 2020 Plan, we may grant stock options, appreciation rights, restricted stock and restricted stock units (“RSUs”) to employees, consultants and directors. Stock options granted under the 2020 Plan may be either incentive stock options or nonqualified stock options. Incentive stock options may be granted only to our employees, including officers and directors who are also employees. Nonqualified stock options may be granted to our employees, officers, directors, consultants and advisors. The exercise price of stock options granted under the 2020 Plan must be at least equal to the fair market value of the common stock on the date of grant, except that an incentive stock option granted to an employee who owns more than 10% of the shares of our common stock shall have an exercise price of no less than 110% of the fair value per share on the grant date and expire five years from the date of grant. The maximum term of stock options granted under the 2020 Plan is 10 years, unless subject to the provisions regarding 10% stockholders. Our stock options granted to new employees generally vest over four years at a rate of 25% upon the first anniversary of the vesting commencement date and monthly thereafter. Our other stock options granted to employees generally vest on terms consistent with stock options granted to new employees or monthly over four years from the vesting commencement date. Our RSUs granted to new employees generally vest over four years at a rate of 25% upon one year from the grant date, then 12.5% every six months thereafter. Our other RSUs granted to employees generally vest over three and a half years at a rate of 25% upon six months from the grant date, then 12.5% every six months thereafter. A total of 10,150,000 shares of common stock were approved to be initially reserved for issuance under the 2020 Plan. The number of shares that remained available for issuance under the 2014 Plan as of the effective date of the 2020 Plan and shares subject to outstanding awards under the 2014 Plan as of the effective date of the 2020 Plan that are subsequently canceled, forfeited or repurchased by us will be added to the shares reserved under the 2020 Plan. In addition, the number of shares of common stock available for issuance under the 2020 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to 5% of the outstanding number of shares of our common stock on December 31 of the preceding calendar year or such lesser amount as determined by our Board. Effective January 1, 2024, the number of shares of common stock available under the 2020 Plan increased by 4,768,241 shares pursuant to the evergreen provision. As of March 31, 2024, an aggregate of 7,733,695 shares of common stock were available for issuance under the 2020 Plan. Our 2014 Plan permitted the granting of incentive stock options, non-statutory stock options, restricted stock and other stock-based awards. Subsequent to the adoption of the 2020 Plan, no additional equity awards can be made under the 2014 Plan. As of March 31, 2024, 1,775,740 shares and 9,526,850 shares of common stock were subject to outstanding options and RSUs under the 2014 Plan and 2020 Plan, respectively. The terms of the 2014 Plan permit the exercise of options granted prior to vesting, subject to required approvals. The unvested shares are subject to our lapsing repurchase right upon termination of employment at the original purchase price. Shares purchased by employees pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be issued until those shares vest according to their respective vesting schedules. Cash received for early exercised stock options is recorded as other liabilities on the condensed consolidated balance sheet and is reclassified to common stock and additional paid-in capital as such shares vest. Stock Options and Restricted Stock Units Activity Stock options and RSUs activity under our 2020 Plan and 2014 Plan, which excludes options to purchase 29,638 shares granted outside of the 2020 Plan and 2014 Plan, was as follows: Options Outstanding Stock Options and Restricted Stock Units Activity Options and Restricted Stock Units Available for Grant Number of Options Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Balances — December 31, 2023 6,065,150 9,314,836 $ 25.35 7.75 $ 348,868 Additional shares authorized 4,768,241 Plan shares expired (1,176,888) Options granted (1,418,472) 1,418,472 $ 72.85 Options exercised 6,464 (1) (630,679) $ 8.74 Options forfeited 4,978 (4,978) $ 46.02 Restricted stock units granted (565,682) Restricted stock units withheld 46,279 Restricted stock units forfeited 3,625 Balances — March 31, 2024 7,733,695 10,097,651 $ 33.05 7.98 $ 363,125 Vested and expected to vest — March 31, 2024 10,097,651 $ 33.05 7.98 $ 363,125 Exercisable at March 31, 2024 4,584,552 $ 19.11 6.92 $ 225,684 _______________________________________________ (1) Shares returned due to net exercises. During the three months ended March 31, 2024 and 2023, options to purchase 631,287 and 100,964 shares, respectively, were exercised for cash at a weighted-average price per share of $72.85 and $5.40, respectively. The weighted-average grant date fair value of options granted for the three months ended March 31, 2024 and 2023 was $47.28 and $27.18, respectively. The intrinsic value of the stock options exercised was $38.1 million and $3.8 million for the three months ended March 31, 2024 and 2023, respectively. In March 2022, our Board authorized the issuance of RSUs under our 2020 Plan and adopted a form of Restricted Stock Unit Grant Notice and Restricted Stock Unit Award Agreement (the “RSU Agreement”), which is intended to serve as a standard form agreement for RSU grants issued to employees. RSU activity for the three months ended March 31, 2024 was as follows: Shares Weighted- Average Grant-Date Fair Value Unvested at December 31, 2023 753,462 $ 38.93 Granted 565,682 73.42 Vested and released (110,580) 36.41 Cancelled (3,625) 52.26 Unvested at March 31, 2024 1,204,939 $ 55.31 The weighted-average grant date fair value of RSUs granted during the three months ended March 31, 2024 and 2023 was $73.42 and $41.59, respectively. The aggregate fair value of unvested RSUs is calculated using the closing price of our common stock on the grant date. As of March 31, 2024 and 2023, the unrecognized stock-based compensation cost of unvested RSUs was $62.6 million and $24.4 million, respectively, which is expected to be recognized over a weighted-average period of 2.97 years and 3.10 years, respectively. 2020 Employee Stock Purchase Plan In June 2020, our Board adopted, and our stockholders approved, the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), which became effective on June 11, 2020. The 2020 ESPP permits participants to purchase common stock through payroll deductions of up to 15% of their eligible compensation. Employees enrolled in the 2020 ESPP purchase shares of common stock at a price per share equal to 85% of the lower of the fair market value at the start or end of the six-month purchase periods within a two-year offering period. A total of 650,000 shares of common stock were approved to be initially reserved for issuance under the 2020 ESPP. In addition, the number of shares of common stock available for issuance under the 2020 ESPP will be automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount of 1% of the outstanding number of shares of our common stock on December 31 of the preceding calendar year or such lesser amount as determined by our Board. As of March 31, 2024, there were 2,257,745 shares available under the 2020 ESPP, which reflects increases of 794,706 and nil (as determined by our Board), on January 1, 2023 and 2024, respectively. Stock-based Compensation We estimated the fair value of employee stock options using the Black-Scholes option-pricing model for the three months ended March 31, 2024 and 2023 using the following weighted-average assumptions: Three Months Ended March 31, 2024 2023 Fair Value Assumptions Expected volatility 73.2% - 73.5% 73.6% - 74.0% Expected dividend yield 0% 0% Expected term (in years) 5.4 5.3 - 5.4 Risk-free interest rate 4.0% - 4.3% 3.7% - 4.3% We estimated the fair value of shares under the 2020 ESPP using the Black-Scholes option-pricing model for the three months ended March 31, 2024 and 2023 using the following weighted-average assumptions: Three Months Ended March 31, 2024 2023 Fair Value Assumptions Expected volatility 38.1% - 62.7% 86.4% - 99.7% Expected dividend yield 0% 0% Expected term (in years) 0.5 - 2.0 0.5- 2.0 Risk-free interest rate 4.9% - 5.4% 4.5% - 4.7% We recorded total stock-based compensation expense for the three months ended March 31, 2024 and 2023 related to the 2014 Plan, the 2020 Plan and the 2020 ESPP in the condensed consolidated statements of operations and allocated the amounts as follows: Three Months Ended March 31, 2024 2023 (in thousands) Research and development $ 8,818 $ 4,527 General and administrative 8,811 5,121 Total $ 17,629 $ 9,648

Retirement Plan

Retirement Plan	3 Months Ended
	Mar. 31, 2024
Retirement Benefits [Abstract]
Retirement Plan	11. Retirement Plan

Funding Arrangement

Funding Arrangement	3 Months Ended
	Mar. 31, 2024
Funding Arrangement [Abstract]
Funding Arrangement	Funding Arrangement Our vaccine development program for VAX-A1, a novel conjugate vaccine candidate designed to prevent disease caused by Group A Streptococcus, currently is funded in part by a grant obtained from Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator (“CARB-X”), a global non-profit partnership dedicated to accelerating antibacterial innovation to tackle the rising global threat of drug-resistant bacteria. The CARB-X grant provides for total potential funding of up to $14.6 million (including $11.7 million awarded to date since the grant’s inception in 2019) upon the achievement of VAX-A1 development milestones through June 2024. Our vaccine development program for VAX-GI, a novel preclinical vaccine candidate being developed as a preventative treatment for dysentery and shigellosis, which is caused by Shigella bacteria, is currently funded in part by two grants obtained from the National Institutes of Health (“NIH”) administered by the University of Maryland, Baltimore. Our first grant from the NIH was awarded in April 2021 and provides for potential funding up to five years totaling approximately $0.5 million. In June 2023, we received another grant from the NIH that provides for potential funding up to five years totaling approximately $4.6 million.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share The following table sets forth the computation of basic and diluted net loss per share and excludes shares which are outstanding, but subject to repurchase by us: Three Months Ended 2024 2023 Net loss (in thousands) $ (95,020) $ (60,462) Weighted-average shares outstanding used in computing net loss per share, basic and diluted (1) 111,690,951 86,206,817 Net loss per share, basic and diluted $ (0.85) $ (0.70) __________________________________________ (1) Includes shares of common stock into which pre-funded warrants may be exercised as of March 31, 2024. See Note 9, “Pre-Funded Warrants.” The following potentially dilutive securities outstanding as of the periods presented below were excluded from the computation of diluted net loss per share for the three months ended March 31, 2024 and 2023 because including them would have been anti-dilutive: March 31, 2024 2023 Stock options 11,302,590 9,183,744 Restricted stock units 1,204,939 773,660 Employee stock purchase plan shares 104,775 117,203 Total 12,612,304 10,074,607

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In determining quarterly provisions for income taxes, we use the annual estimated effective tax rate applied to the actual year-to-date profit or loss, adjusted for discrete items arising in that period. Our annual estimated effective tax rate differs from the U.S. federal statutory rate primarily as a result of state taxes and changes in our valuation allowance against our deferred tax assets. For all periods presented, we have incurred net pre-tax losses in the United States. During the three months ended March 31, 2024, there were no material changes to our unrecognized tax benefits, and we do not expect to have any significant changes to unrecognized tax benefits through the end of the fiscal year. For the three months ended March 31, 2024, we reported zero tax provision. We do not have any tax audits or other issues pending.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Loss	$ (95,020)	$ (60,462)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Halley Gilbert [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Halley Gilbert, our Board and Audit Committee member, adopted a 10b5-1 Plan on March 1, 2024. Ms. Gilbert’s 10b5-1 Plan provides for the potential exercise and sale of up to 51,950 shares of our common stock, and expires on May 31, 2025, or upon the earlier completion of all authorized transactions thereunder.
Name	Halley Gilbert
Title	Board and Audit Committee member
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	March 1, 2024
Arrangement Duration	456 days
Aggregate Available	51,950
Jim Wassil [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Jim Wassil, our Chief Operating Officer, adopted a 10b5-1 Plan on March 1, 2024. Mr. Wassil’s 10b5-1 Plan provides for the potential exercise and sale of up to 108,000 shares of our common stock, and expires on September 1, 2025, or upon the earlier completion of all authorized transactions thereunder.
Name	Jim Wassil
Title	Chief Operating Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	March 1, 2024
Arrangement Duration	549 days
Aggregate Available	108,000

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and footnote disclosures normally included in the condensed consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted in accordance with such rules and regulations. The condensed consolidated financial statements include the Company and its wholly owned subsidiary. All intercompany transactions and balances have been eliminated upon consolidation.
Unaudited Interim Condensed Financial Statements	Unaudited Interim Condensed Consolidated Financial Statements The condensed consolidated balance sheet as of March 31, 2024, the condensed consolidated statements of operations, comprehensive loss and stockholders’ equity for the three months ended March 31, 2024 and 2023 and the condensed consolidated statements of cash flows for the three months ended March 31, 2024 and 2023 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair statement of our financial information. The financial data disclosed in the footnotes to the condensed consolidated financial statements related to the three months ended March 31, 2024 and 2023 are also unaudited. The results of operations for the three months ended March 31, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or for any other future annual or interim period. These interim condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements and related notes thereto for the year ended December 31, 2023 included in our Annual Report on Form 10-K filed with the SEC on February 27, 2024.
Use of Estimates	Use of Estimates
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash
Investments	Investments Our investments have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. Treasury securities, U.S. government agency securities, corporate debt, commercial paper and asset-backed securities. These securities are recorded on the condensed consolidated balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive gain (loss). The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income (expense), net. Realized gains and losses are also included in other income (expense), net. When the fair value of a debt security declines below its amortized cost basis, any portion of that decline attributable to credit losses, to the extent expected to be nonrecoverable before the sale of the security, is recognized in our condensed consolidated statements of operations. When the fair value of a debt security declines below its amortized cost basis due to changes in interest rates, such amounts are recorded in other comprehensive loss, and are recognized in our condensed consolidated statements of operations only if we sell or intend to sell the security before recovery of its cost basis.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average of shares of common stock outstanding, including pre-funded warrants issued, during the period, without consideration for common stock equivalents. Shares of common stock into which the pre-funded warrants may be exercised are considered outstanding for the purposes of computing net loss per share because the shares may be issued for little consideration, are fully vested and are exercisable after the original issuance date. Diluted net loss per share is the same as basic net loss per share since the effects of potentially dilutive securities are anti-dilutive given the net loss for each period presented.
Leases	Leases We determine if an arrangement is a lease at inception. In addition, we determine whether a lease meets the classification criteria of a finance or operating lease at the lease commencement date considering whether: (i) the lease transfers ownership of the underlying asset to the lessee at the end of the lease term; (ii) the lease grants the lessee an option to purchase the underlying asset that the lessee is reasonably certain to exercise; (iii) the lease term is for a major part of the remaining economic life of the underlying asset; (iv) the present value of the sum of the lease payments and residual value guaranteed by the lessee equals or exceeds substantially all of the fair value of the underlying asset; and (v) the underlying asset is such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. As of March 31, 2024, our lease population consisted of office operating leases. As of March 31, 2024, we did not have finance leases. Operating leases are included in Operating lease right-of-use (“ROU”) assets, Operating lease liabilities — current and Operating lease liabilities — long term in our condensed consolidated balance sheet. ROU assets represent our right to use the underlying assets for the lease term and lease liabilities represent our obligation to make lease payments arising from the leases. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, if the rate implicit in the lease is not readily determinable, we use our incremental borrowing rate based on the information available at the lease commencement date. We determine the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to ours. The determination of our incremental borrowing rate requires management judgment, including development of a synthetic credit rating and cost of debt, as we currently do not carry any debt. We believe that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgment to the same facts and circumstances could yield a different incremental borrowing rate. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. ROU assets and lease liabilities may include options to extend or terminate leases if it is reasonably certain that we will exercise such options. Lease payments which are fixed and determinable are amortized as rent expense on a straight-line basis over the expected lease term. Variable lease costs, which are dependent on usage, a rate or index, including common area maintenance charges, are expensed as incurred. Lease agreements that include lease and non-lease components are accounted for as a single lease component. Lease agreements with non-cancelable terms of less than 12 months are not recorded on our condensed consolidated balance sheets.
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject us to a concentration of credit risk consist primarily of cash, cash equivalents and investments. We invest in money market funds, U.S. Treasury securities, U.S. government agency securities, corporate debt, commercial paper and asset-backed securities. We maintain bank deposits in federally insured financial institutions and these deposits may exceed federally-insured limits. We are exposed to credit risk in the event of a default by the financial institutions holding our cash and issuers of investments to the extent recorded on the condensed consolidated balance sheets. For example, on March 10, 2023, the California Department of Financial Protection and Innovation took control of Silicon Valley Bank (“SVB”) and appointed the Federal Deposit Insurance Corporation (“FDIC”) as receiver. While SVB was our primary bank at the time, we have not experienced any losses on these deposits or investments as a result of this market event. Management believes that we are not exposed to significant credit risk as our deposits are held at First Citizens Bank & Trust Company, which had agreed to purchase and assume all deposits and loans of Silicon Valley Bridge Bank, and our investments are held under separate financial institution custodial accounts, each of which management continues to believe to be of high credit quality. While we were able to recover all deposited amounts from SVB, and continue to have access to all investments held in the SVB Custodial Accounts, there can be no assurance that our current or future banks will not face similar risks as SVB or that we will be able to recover in full our deposits in the event of similar closures. Our investment policy limits investments to money market funds, certain types of debt securities issued by the U.S. Government and its agencies, corporate debt, commercial paper and asset-backed securities, and places restrictions on the credit ratings, maturities and concentration by type and issuer. We have not experienced any significant losses on our deposits of cash, cash equivalents or investments. We are subject to supplier concentration risk from our suppliers. Although we are working to establish secondary sources of supply, we currently source several of our critical raw materials from single-source suppliers. We also use one contract manufacturing organization (“CMO”), Lonza Ltd. (“Lonza”), to handle most of our manufacturing activities for our VAX-24 and VAX-31 programs. If we were to experience disruptions in raw materials supplied by our suppliers, or in manufacturing activities at Lonza, we may experience significant delays in our product development timelines and may incur substantial costs to secure alternative sources of raw materials or manufacturing. Our future results of operations involve a number of other risks and uncertainties. Factors that could affect our future operating results and cause actual results to vary materially from expectations include, but are not limited to: our early stages of clinical vaccine development; our ability to advance vaccine candidates into, and successfully complete, clinical trials on the timelines we project; our ability to adequately demonstrate sufficient safety and immunogenicity or efficacy of our vaccine candidates; our ability to enroll subjects in our ongoing and future clinical trials; our ability to successfully manufacture and supply our vaccine candidates for clinical trials or for future potential commercialization; our ability to obtain additional capital to finance our operations; our ability to obtain, maintain and protect our intellectual property rights; developments relating to our competitors and our industry, including competing vaccine candidates; general and market conditions; and other risks and uncertainties, including those more fully described in the “Risk Factors” section of this Quarterly Report on Form 10-Q.
Recently Issued Accounting Pronouncements — Not Yet Adopted	Recently Issued Accounting Pronouncements — Not Yet Adopted From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies and adopted by us as of the specified effective date. We believe that the impact of recently issued standards that are not yet effective will not have a material impact on our consolidated financial statements and disclosures. In March 2024, the FASB issued Accounting Standards Update (“ASU”) No. 2024-02, Codification Improvements—Amendments to Remove References to the Concepts Statements (“ASU 2024-02”). The amendments in ASU 2024-02 clarify and simplify references to certain concept statements within U.S. GAAP. The new standard is effective for us for the annual period beginning after December 15, 2024. We are currently evaluating the impact of the new guidance and do not expect adoption of ASU 2024-02 will have a material impact on our consolidated financial statements. In March 2024, the FASB issued ASU No. 2024-01 , Compensation—Stock Compensation (Topic 718): Scope Application of Profits Interest and Similar Awards (“ASU 2024-01”). The amendments in ASU 2024-01 improve consistent application of and simplify U.S. GAAP of Topic 718 by clarifying and amending existing guidance. The guidance is effective for us for the annual period beginning after December 15, 2024. We are currently evaluating the impact of the new guidance and do not expect adoption of ASU 2024-01 will have a material impact on our consolidated financial statements. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”). The ASU improves the transparency of income tax disclosures by requiring (i) consistent categories and greater disaggregation of information in the rate reconciliation and (ii) income taxes paid disaggregated by jurisdiction. The guidance is effective for us for the annual period beginning after December 15, 2024. We are currently evaluating the impact of the new guidance and do not expect adoption of ASU 2023-09 will have a material impact on our consolidated financial statements. In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”). The ASU requires entities to report incremental information about significant segment expenses included in a segment’s profit or loss measure as well as the name and title of the chief operating decision maker. The guidance also requires interim disclosures related to reportable segment profit or loss and assets that had previously only been disclosed annually. The guidance is effective for us for the annual period beginning after December 15, 2023. We are currently evaluating the impact of the new guidance and do not expect adoption of ASU 2023-07 will have a material impact on our consolidated financial statements.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Schedule of cash, cash equivalents and restricted cash	Cash, cash equivalents and restricted cash as reported within the condensed consolidated balance sheets that total to the same amounts shown in the condensed consolidated statements of cash flows are as follows: March 31, December 31, (in thousands) Cash and cash equivalents $ 611,512 $ 397,451 Restricted cash 1,103 1,103 Cash, cash equivalents and restricted cash $ 612,615 $ 398,554
Schedule of Cash and Cash Equivalents	Cash, cash equivalents and restricted cash as reported within the condensed consolidated balance sheets that total to the same amounts shown in the condensed consolidated statements of cash flows are as follows: March 31, December 31, (in thousands) Cash and cash equivalents $ 611,512 $ 397,451 Restricted cash 1,103 1,103 Cash, cash equivalents and restricted cash $ 612,615 $ 398,554

Fair Value Measurements and F_2

Fair Value Measurements and Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Schedule of Financial Instruments Measured at Fair Value on Recurring Basis	The following tables set forth our financial instruments measured at fair value on a recurring basis by level within the fair value hierarchy at March 31, 2024 and December 31, 2023: March 31, 2024 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Assets (in thousands) Cash and cash equivalents: Cash Level 1 $ 20,288 $ — $ — $ 20,288 Money market funds Level 1 107,073 — — 107,073 U.S. Treasury securities Level 1 44,734 — (1) 44,733 Commercial paper Level 2 437,660 — (237) 437,423 Corporate debt Level 2 1,994 1 — 1,995 Total cash and cash equivalents 611,749 1 (238) 611,512 Investments: U.S. Treasury securities Level 1 734,969 — (708) 734,261 Commercial paper Level 2 132,929 — (72) 132,857 Corporate debt Level 2 272,753 26 (508) 272,271 Asset-backed securities Level 2 43,548 — (25) 43,523 U.S. government agency securities Level 2 105,638 — (297) 105,341 Total investments 1,289,837 26 (1,610) 1,288,253 Total assets measured at fair value $ 1,901,586 $ 27 $ (1,848) $ 1,899,765 December 31, 2023 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Assets (in thousands) Cash and cash equivalents: Cash Level 1 $ 50,003 $ — $ — $ 50,003 Money market funds Level 1 47,357 — — 47,357 Commercial paper Level 2 300,256 — (165) 300,091 Total cash and cash equivalents 397,616 — (165) 397,451 Investments: U.S. Treasury securities Level 1 481,704 422 (44) 482,082 Commercial paper Level 2 102,435 7 (35) 102,407 Corporate debt Level 2 133,523 168 (42) 133,649 Asset-backed securities Level 2 23,963 18 — 23,981 U.S. government agency securities Level 2 103,484 — (152) 103,332 Total investments 845,109 615 (273) 845,451 Total assets measured at fair value $ 1,242,725 $ 615 $ (438) $ 1,242,902
Schedule of Contractual Maturities of Investments	The following table presents the contractual maturities of our investments as of March 31, 2024 (in thousands): March 31, 2024 Fair Value Due in less than one year $ 875,006 Due in one to five years 413,247 Total $ 1,288,253

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets as of March 31, 2024 and December 31, 2023 consisted of the following: March 31, December 31, (in thousands) Interest receivable $ 8,018 $ 3,598 Prepaid expenses 7,774 6,159 VAT on purchases 7,864 — Purchased equipment deposits 4,679 3,856 Grant receivable 127 9 Other current assets 2,092 2,105 Total $ 30,554 $ 15,727
Schedule of Property and Equipment, Net	Property and equipment, net as of March 31, 2024 and December 31, 2023 consisted of the following: March 31, December 31, (in thousands) Furniture and equipment $ 1,610 $ 1,608 Computers and computer software 849 771 Lab equipment 21,766 25,110 Leasehold improvements 2,074 1,460 Manufacturing equipment and auxiliary 10,598 8,134 Manufacturing facility and equipment construction-in-progress (1) 58,209 51,815 Total property and equipment 95,106 88,898 Less: accumulated depreciation and amortization (10,271) (9,272) Property and equipment, net $ 84,835 $ 79,626 ___________ (1) See Note 4, “Commercial Manufacturing and Supply Agreement,” for further details.
Schedule of Other Assets, Noncurrent	Other assets as of March 31, 2024 and December 31, 2023 consisted of the following: March 31, December 31, (in thousands) Manufacturing facility construction buildout (1) $ 43,575 $ 34,688 Long-term prepaid assets 2,472 2,768 Other long-term assets 96 106 Total $ 46,143 $ 37,562 ___________ (1) See Note 4, “Commercial Manufacturing and Supply Agreement,” for further details.
Schedule of Accrued Expenses	Accrued expenses as of March 31, 2024 and December 31, 2023 consisted of the following: March 31, December 31, (in thousands) Clinical studies $ 3,054 $ 2,156 Other research and development 14,185 30,759 Acquired manufacturing rights (1) 25,000 25,000 Other accrued expenses 11,932 1,900 Total $ 54,171 $ 59,815 ___________ (1) See Note 7, “Commitments and Contingencies, Sutro Option Agreement,” for further details.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Schedule of Information Related to Lease	Information related to our leases are as follows (dollar amounts in thousands): Three Months Ended March 31, March 31, Cash paid for operating lease liabilities $ 2,390 $ 1,671 Weighted-average remaining lease term (in years) 5.61 2.54 Weighted-average discount rate 8.5 % 7.6 %
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities as of March 31, 2024 were as follows: Years ending December 31, (in thousands) Remainder of 2024 $ 6,423 2025 9,836 2026 2,899 2027 2,986 2028 3,075 Thereafter 9,502 Total future undiscounted lease payments 34,721 Less: Imputed interest (7,301) Total lease liabilities $ 27,420

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Long-Term Purchase Commitment	Years ending December 31, (in thousands) Remainder of 2024 $ 210,879 2025 57,834 2026 97 2027 393 Total non-cancelable purchase commitments due to our key manufacturing partners $ 269,203

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Schedule of Common Stock Shares Reserved for Future Issuance	Common stock reserved for future issuance under the 2020 Equity Incentive Plan (the “2020 Plan”) and the 2014 Equity Incentive Plan (the “2014 Plan”) was as follows, and excludes 29,638 shares issued outside of the 2014 Plan and 2020 Plan: March 31, December 31, Options issued and outstanding 10,097,695 9,314,836 Restricted stock units outstanding 1,204,939 753,462 Shares available for future stock option grants 7,733,651 6,065,150 Total 19,036,285 16,133,448

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Activity Under Stock Option Plans	Stock options and RSUs activity under our 2020 Plan and 2014 Plan, which excludes options to purchase 29,638 shares granted outside of the 2020 Plan and 2014 Plan, was as follows: Options Outstanding Stock Options and Restricted Stock Units Activity Options and Restricted Stock Units Available for Grant Number of Options Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Balances — December 31, 2023 6,065,150 9,314,836 $ 25.35 7.75 $ 348,868 Additional shares authorized 4,768,241 Plan shares expired (1,176,888) Options granted (1,418,472) 1,418,472 $ 72.85 Options exercised 6,464 (1) (630,679) $ 8.74 Options forfeited 4,978 (4,978) $ 46.02 Restricted stock units granted (565,682) Restricted stock units withheld 46,279 Restricted stock units forfeited 3,625 Balances — March 31, 2024 7,733,695 10,097,651 $ 33.05 7.98 $ 363,125 Vested and expected to vest — March 31, 2024 10,097,651 $ 33.05 7.98 $ 363,125 Exercisable at March 31, 2024 4,584,552 $ 19.11 6.92 $ 225,684 _______________________________________________ (1) Shares returned due to net exercises.
Nonvested Restricted Stock Shares Activity	RSU activity for the three months ended March 31, 2024 was as follows: Shares Weighted- Average Grant-Date Fair Value Unvested at December 31, 2023 753,462 $ 38.93 Granted 565,682 73.42 Vested and released (110,580) 36.41 Cancelled (3,625) 52.26 Unvested at March 31, 2024 1,204,939 $ 55.31
Summary of Estimated Fair Value of Employee Stock Options	We estimated the fair value of employee stock options using the Black-Scholes option-pricing model for the three months ended March 31, 2024 and 2023 using the following weighted-average assumptions: Three Months Ended March 31, 2024 2023 Fair Value Assumptions Expected volatility 73.2% - 73.5% 73.6% - 74.0% Expected dividend yield 0% 0% Expected term (in years) 5.4 5.3 - 5.4 Risk-free interest rate 4.0% - 4.3% 3.7% - 4.3%
Summary of Estimated Fair Value of Shares Under Employee Stock Purchase Plan	We estimated the fair value of shares under the 2020 ESPP using the Black-Scholes option-pricing model for the three months ended March 31, 2024 and 2023 using the following weighted-average assumptions: Three Months Ended March 31, 2024 2023 Fair Value Assumptions Expected volatility 38.1% - 62.7% 86.4% - 99.7% Expected dividend yield 0% 0% Expected term (in years) 0.5 - 2.0 0.5- 2.0 Risk-free interest rate 4.9% - 5.4% 4.5% - 4.7%
Summary of Stock-based Compensation Expense	We recorded total stock-based compensation expense for the three months ended March 31, 2024 and 2023 related to the 2014 Plan, the 2020 Plan and the 2020 ESPP in the condensed consolidated statements of operations and allocated the amounts as follows: Three Months Ended March 31, 2024 2023 (in thousands) Research and development $ 8,818 $ 4,527 General and administrative 8,811 5,121 Total $ 17,629 $ 9,648

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of basic and diluted net loss per share and excludes shares which are outstanding, but subject to repurchase by us: Three Months Ended 2024 2023 Net loss (in thousands) $ (95,020) $ (60,462) Weighted-average shares outstanding used in computing net loss per share, basic and diluted (1) 111,690,951 86,206,817 Net loss per share, basic and diluted $ (0.85) $ (0.70) __________________________________________ (1) Includes shares of common stock into which pre-funded warrants may be exercised as of March 31, 2024. See Note 9, “Pre-Funded Warrants.”
Schedule of Potentially Dilutive Securities Excluded From Computation of Diluted Net Loss Per Share	The following potentially dilutive securities outstanding as of the periods presented below were excluded from the computation of diluted net loss per share for the three months ended March 31, 2024 and 2023 because including them would have been anti-dilutive: March 31, 2024 2023 Stock options 11,302,590 9,183,744 Restricted stock units 1,204,939 773,660 Employee stock purchase plan shares 104,775 117,203 Total 12,612,304 10,074,607

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents And Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounting Policies [Abstract]
Cash and cash equivalents	$ 611,512	$ 397,451
Restricted cash	1,103	1,103
Cash, cash equivalents and restricted cash	$ 612,615	$ 398,554	$ 381,322	$ 835,528

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2024 Lease
Accounting Policies [Abstract]
Number of finance lease	0

Fair Value Measurements and F_3

Fair Value Measurements and Fair Value of Financial Instruments - Additional Information (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) Security	Dec. 31, 2023 USD ($) Security
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair value assets transferred into level 3 | $	$ 0	$ 0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Number of securities | Security	0	0

Fair Value Measurements and F_4

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Abstract]
Fair Value	$ 1,288,253
Fair value, recurring
Cash and Cash Equivalents [Abstract]
Amortized Cost	611,749	$ 397,616
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(238)	(165)
Fair Value	611,512	397,451
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	1,289,837	845,109
Gross Unrealized Gains	26	615
Gross Unrealized Losses	(1,610)	(273)
Fair Value	1,288,253	845,451
Total assets measured at fair value, amortized cost	1,901,586	1,242,725
Total assets measured at fair value, gross unrealized gains	27	615
Total assets measured at fair value, gross unrealized losses	(1,848)	(438)
Total assets measured at fair value, fair value	1,899,765	1,242,902
Fair value, recurring | Cash | Level 1
Cash and Cash Equivalents [Abstract]
Amortized Cost	20,288	50,003
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	20,288	50,003
Fair value, recurring | Money market funds | Level 1
Cash and Cash Equivalents [Abstract]
Amortized Cost	107,073	47,357
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	107,073	47,357
Fair value, recurring | U.S. Treasury securities | Level 1
Cash and Cash Equivalents [Abstract]
Amortized Cost	44,734
Gross Unrealized Gains	0
Gross Unrealized Losses	(1)
Fair Value	44,733
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	734,969	481,704
Gross Unrealized Gains	0	422
Gross Unrealized Losses	(708)	(44)
Fair Value	734,261	482,082
Fair value, recurring | Commercial paper | Level 2
Cash and Cash Equivalents [Abstract]
Amortized Cost	437,660	300,256
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(237)	(165)
Fair Value	437,423	300,091
Fair value, recurring | Commercial paper | Level 2
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	132,929	102,435
Gross Unrealized Gains	0	7
Gross Unrealized Losses	(72)	(35)
Fair Value	132,857	102,407
Fair value, recurring | Corporate debt | Level 2
Cash and Cash Equivalents [Abstract]
Amortized Cost	1,994
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Fair Value	1,995
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	272,753	133,523
Gross Unrealized Gains	26	168
Gross Unrealized Losses	(508)	(42)
Fair Value	272,271	133,649
Fair value, recurring | Asset-backed securities | Level 2
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	43,548	23,963
Gross Unrealized Gains	0	18
Gross Unrealized Losses	(25)	0
Fair Value	43,523	23,981
Fair value, recurring | U.S. government agency securities | Level 2
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	105,638	103,484
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(297)	(152)
Fair Value	$ 105,341	$ 103,332

Fair Value Measurements and F_5

Fair Value Measurements and Fair Value of Financial Instruments - Schedule of Contractual Maturities of Investments (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Fair Value Disclosures [Abstract]
Due in less than one year	$ 875,006
Due in one to five years	413,247
Total	$ 1,288,253

Commercial Manufacturing and _2

Commercial Manufacturing and Supply Agreement - Additional Information (Details) - 3 months ended Mar. 31, 2024	CHF (SFr) renewalOption	USD ($)
Supply Commitment [Line Items]
Additional renewal period | renewalOption	3
Automatic renewal period, advanced notice period	24 months
Repurposing fee, credit duration	10 years
Minimum
Supply Commitment [Line Items]
Termination of agreement, wind-down and transition services period	12 months
Maximum
Supply Commitment [Line Items]
Termination of agreement, wind-down and transition services period	24 months
Lonza Commercial Manufacturing and Supply Agreement
Supply Commitment [Line Items]
Automatic renewal period	5 years
Agreement termination penalty		$ 70,000,000
Repurposing fee | SFr	SFr 27,000,000
Capital expenditure related to the facility build out and equipment		58,200,000
Facility build out expenditures		$ 43,600,000

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest receivable	$ 8,018	$ 3,598
Prepaid expenses	7,774	6,159
VAT on purchases	7,864	0
Purchased equipment deposits	4,679	3,856
Grant receivable	127	9
Other current assets	2,092	2,105
Total	$ 30,554	$ 15,727

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Total property and equipment	$ 95,106	$ 88,898
Less: accumulated depreciation and amortization	(10,271)	(9,272)
Property and equipment, net	84,835	79,626
Furniture and equipment
Property Plant And Equipment [Line Items]
Total property and equipment	1,610	1,608
Computers and computer software
Property Plant And Equipment [Line Items]
Total property and equipment	849	771
Lab equipment
Property Plant And Equipment [Line Items]
Total property and equipment	21,766	25,110
Leasehold improvements
Property Plant And Equipment [Line Items]
Total property and equipment	2,074	1,460
Manufacturing equipment and auxiliary
Property Plant And Equipment [Line Items]
Total property and equipment	10,598	8,134
Manufacturing facility and equipment construction in progress
Property Plant And Equipment [Line Items]
Total property and equipment	$ 58,209	$ 51,815

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation and amortization expense	$ 1	$ 0.7

Balance Sheet Details - Sched_3

Balance Sheet Details - Schedule of Other Assets, Noncurrent (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Manufacturing facility construction buildout	$ 43,575	$ 34,688
Long-term prepaid assets	2,472	2,768
Other long-term assets	96	106
Total	$ 46,143	$ 37,562

Balance Sheet Details - Sched_4

Balance Sheet Details - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Clinical studies	$ 3,054	$ 2,156
Other research and development	14,185	30,759
Acquired manufacturing rights	25,000	25,000
Other accrued expenses	11,932	1,900
Total	$ 54,171	$ 59,815

Leases - Additional Information

Leases - Additional Information (Details)	1 Months Ended		3 Months Ended
	Sep. 30, 2023 USD ($)	Jan. 31, 2021 renewalOption	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Oct. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Lessee Lease Description [Line Items]
Operating lease right-of-use assets			$ 28,905,000		$ 30,997,000
Total lease liabilities			27,420,000
Operating lease rent expense recognized			2,700,000	$ 1,900,000
New Corporate Headquarters Facility
Lessee Lease Description [Line Items]
Number of renewal options | renewalOption		2
Operating lease, renewal term		60 months
Operating lease, extended term		60 days
San Carlos
Lessee Lease Description [Line Items]
Operating lease right-of-use assets							$ 28,400,000
Total lease liabilities							$ 12,900,000
Lonza Commercial Manufacturing and Supply Agreement
Lessee Lease Description [Line Items]
Operating lease right-of-use assets					0
Total lease liabilities					$ 0
Operating lease rent expense recognized			$ 0
Assignment Agreement
Lessee Lease Description [Line Items]
Operating lease right-of-use assets						$ 16,700,000
Total lease liabilities						$ 16,800,000
Operating lease, agreement term			10 years
Assumed lease rental payment	$ 1,900,000
Operating lease, rent adjustment percentage			0.03

Leases - Schedule of Informatio

Leases - Schedule of Information Related to ROU Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Leases [Abstract]
Cash paid for operating lease liabilities	$ 2,390	$ 1,671
Weighted-average remaining lease term (in years)	5 years 7 months 9 days	2 years 6 months 14 days
Weighted-average discount rate	8.50%	7.60%

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Leases [Abstract]
Remainder of 2024	$ 6,423
2025	9,836
2026	2,899
2027	2,986
2028	3,075
Thereafter	9,502
Total future undiscounted lease payments	34,721
Less: Imputed interest	(7,301)
Total lease liabilities	$ 27,420

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2022	Mar. 31, 2024	Dec. 31, 2023	Nov. 21, 2023	Oct. 02, 2023
Other Commitments [Line Items]
Contractual agreements, minimum term		5 years
Option agreement, term		5 years
Sutro Biopharma Inc
Other Commitments [Line Items]
Upfront consideration	$ 22.5
Upfront consideration in cash	10
Upfront consideration in cash after agreement date	$ 5
Number of common stock issued (in shares)	167,780
Fair value on date of settlement	$ 8
Option exercise price in cash	75		$ 25
Additional milestone payments in cash	60		$ 60
Accrued payment				$ 50	$ 5
Sutro Biopharma Inc | Common Stock
Other Commitments [Line Items]
Upfront consideration	$ 7.5

Commitments and Contingencies_2

Commitments and Contingencies - Purchase Commitments (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remainder of 2024	$ 210,879
2025	57,834
2026	97
2027	393
Total non-cancelable purchase commitments due to our key manufacturing partners	$ 269,203

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)			1 Months Ended		3 Months Ended		12 Months Ended
	Feb. 02, 2024 USD ($) $ / shares shares	Apr. 21, 2023 USD ($) $ / shares shares	Apr. 30, 2023 $ / shares shares	Feb. 27, 2023 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) vote $ / shares shares	Mar. 31, 2023 USD ($)	Dec. 31, 2023 $ / shares shares	Jul. 31, 2021 USD ($)
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)					10,000,000		10,000,000
Preferred stock, par value (in dollars per share) | $ / shares					$ 0.001		$ 0.001
Preferred stock, shares outstanding (in shares)					0		0
Preferred stock, shares issued (in shares)					0		0
Preferred stock, dividends per share, declared (in dollars per share) | $ / shares					$ 0		$ 0
Preferred stock, dividends, per share, cash paid (in dollars per share) | $ / shares					$ 0		$ 0
Common stock, shares authorized (in shares)					500,000,000		500,000,000
Common stock, par value (in dollars per share) | $ / shares					$ 0.001		$ 0.001
Common stock, shares outstanding (in shares)					108,755,731		95,364,831
Common stock, shares issued (in shares)					108,755,731		95,364,831
Common stock, dividends, per share, declared | $ / shares					$ 0		$ 0
Proceeds from issuance of common stock related to at-the-market offering, net of issuance costs | $					$ 0	$ 41,787,000
Equity incentive plan, shares issued					29,638
Common Stock, Number Of Votes | vote					1
Over Allotment Option
Class of Stock [Line Items]
Average price (in dollars per share) | $ / shares	$ 64
Underwriters' option to purchase additional shares	1,757,812
Pre-funded warrants to purchase (in shares)	781,250		1,000,000
Prefunded warrants price per share (in dollars per share) | $ / shares	$ 63.999		$ 40.999
Net proceeds from follow on offering | $	$ 816,500,000
Sale of stock, number of shares issued in transaction (in shares)	12,695,312
Over Allotment Option
Class of Stock [Line Items]
Shares issued		13,030,000
Underwriters' option to purchase additional shares		1,830,000
Common stock price per share | $ / shares		$ 41
Pre-funded warrants to purchase (in shares)		1,000,000
Prefunded warrants price per share (in dollars per share) | $ / shares		$ 40.999
Net proceeds from follow on offering | $		$ 545,300,000
ATM Sales Agreement
Class of Stock [Line Items]
Aggregate offering price | $				$ 150,000,000
Jefferies LLC | ATM Sales Agreement
Class of Stock [Line Items]
Aggregate offering price | $				$ 137,800,000
Common stock shares sold				4,995,709	1,588,807
Average price (in dollars per share) | $ / shares				$ 27.57
Maximum commission percentage of gross proceeds from common stock sold								3%
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Intrinsic Value, Amount Per Share | $ / shares					$ 44.06
Aggregate gross proceeds from issuance of common stock | $					$ 70,000,000
Proceeds from issuance of common stock related to at-the-market offering, net of issuance costs | $					$ 68,600,000
Jefferies LLC | Maximum | ATM Sales Agreement
Class of Stock [Line Items]
Aggregate offering price | $				$ 400,000,000				$ 150,000,000

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Common Stock Shares Reserved for Future Issuance (Details) - 2020 Plan and 2014 Plan - shares	Mar. 31, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Common stock reserved for future issuances (in shares)	19,036,285,000	16,133,448,000
Options issued and outstanding
Class of Stock [Line Items]
Common stock reserved for future issuances (in shares)	10,097,695,000	9,314,836,000
Restricted stock units outstanding
Class of Stock [Line Items]
Common stock reserved for future issuances (in shares)	1,204,939,000	753,462,000
Shares available for future stock option grants
Class of Stock [Line Items]
Common stock reserved for future issuances (in shares)	7,733,651,000	6,065,150,000

Pre-Funded Warrants - Additiona

Pre-Funded Warrants - Additional Information (Details) - $ / shares		1 Months Ended	3 Months Ended
	Feb. 02, 2024	Apr. 30, 2023	Mar. 31, 2024
Class of Warrant or Right [Line Items]
Warrants exercised (in dollars per share)	$ 0.001	$ 0.001
Increase or decrease of pre-funded warrant percentage not exceed			19.99%
Pre -funded Warrant exercised (in shares)			0
Pre Funded Warrants
Class of Warrant or Right [Line Items]
Class of warrant or right, number of securities called by warrants or rights (in shares)			8,031,250
Minimum
Class of Warrant or Right [Line Items]
Pre-funded warrants of common stock shares outstanding Immediately after effect to the exercise			4.99%
Combined voting power of securities outstanding immediately after effect to the exercise			4.99%
Maximum
Class of Warrant or Right [Line Items]
Pre-funded warrants of common stock shares outstanding Immediately after effect to the exercise			9.99%
Combined voting power of securities outstanding immediately after effect to the exercise			9.99%
Over Allotment Option
Class of Warrant or Right [Line Items]
Pre-funded warrants to purchase (in shares)	781,250	1,000,000
Prefunded warrants price per share (in dollars per share)	$ 63.999	$ 40.999
Pre-funded warrant recorded as a component of stockholders' equity within additional paid-in-capital (in dollars per share)	$ 0.001

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended
	Jan. 01, 2024	Jan. 01, 2023	Jun. 11, 2020	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period for stock options granted			4 years
Vesting percentage for stock options granted			25%
Options granted (in shares)				29,638
Exercise of stock options (in shares)				631,287	100,964
Weighted-average exercise price per share, options exercised (in dollars per share)				$ 72.85	$ 5.40
Weighted-average grant date fair value of options granted (in dollars per share)				$ 47.28	$ 27.18
Intrinsic value of the stock options exercised				$ 38.1	$ 3.8
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, number (in shares)				1,204,939		753,462
Restricted stock units outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period for stock options granted			4 years
Vesting percentage for stock options granted			25%
Vesting percentage for stock options granted, Six months thereafter			12.50%
Other Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period for stock options granted			3 years 6 months
Vesting percentage for stock options granted, Six months thereafter			12.50%
Weighted-average grant date fair value of options granted (in dollars per share)				$ 73.42	$ 41.59
Share-based payment arrangement, nonvested award, excluding option, cost not yet recognized, amount				$ 62.6	$ 24.4
Unrecognized share-based compensation expense, expected to be recognized				2 years 11 months 19 days	3 years 1 month 6 days
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price expire in years form the date of grant			5 years
Stock options granted term			10 years
Percentage of provisions subject to stockholders			10%
Shares reserved for issuance (in shares)			10,150,000
Term of plan			10 years
Percentage of outstanding number of shares			5%
Available for issuance of shares increased (in shares)				4,768,241
Number of shares available for grant (in shares)				7,733,695,000
Number of shares outstanding (in shares)				1,775,740
2014 Equity Incentive Plan | Restricted stock units outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares outstanding (in shares)				9,526,850
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance (in shares)			650,000
Term of plan			10 years
Percentage of outstanding number of shares			1%
Available for issuance of shares increased (in shares)	0	794,706
Percentage of payroll deductions of eligible compensation			15%
Employees purchase shares of common stock of lower of fair market value			85%
Purchase period			6 months
Offering period			2 years
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, number (in shares)				2,257,745
Minimum | 2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Incentive stock option granted to employees owning percentage of shares of common stock			10%
Maximum | 2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of fair value per share on the grant date			110%

Equity Incentive Plans - Summar

Equity Incentive Plans - Summary of Activity Under Stock Option Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Options and Restricted Stock Units Available for Grant
Options and Restricted Stock Units Available for Grant, plan shares expired (in shares)	(1,176,888,000)
Options and Restricted Stock Units Available for Grant, forfeited (in shares)	4,978,000
Number of Options
Options granted (in shares)	29,638
Weighted- Average Exercise Price Per Share
Weighted-average exercise price per share, options exercised (in dollars per share)	$ 72.85	$ 5.40
2020 Plan and 2014 Plan
Options and Restricted Stock Units Available for Grant
Options and Restricted Stock Units Available for Grant, Beginning Balance (in shares)	6,065,150,000
Options and Restricted Stock Units Available for Grant, Additional shares authorized (in shares)	4,768,241,000
Options and Restricted Stock Units Available for Grant, granted (in shares)	(1,418,472,000)
Options and Restricted Stock Units Available for Grant, exercised (in shares)	6,464,000
Options and Restricted Stock Units Available for Grant, Ending Balance (in shares)	7,733,695,000		6,065,150,000
Number of Options
Beginning balance (in shares)	9,314,836,000
Options granted (in shares)	1,418,472,000
Number of Options, exercised	(630,679,000)
Number of Options, forfeited	(4,978,000)
Ending balance (in shares)	10,097,651,000		9,314,836,000
Number of Options, Vested and expected to vest	10,097,651,000
Number of Options, Exercisable	4,584,552,000
Weighted- Average Exercise Price Per Share
Weighted-Average Exercise Price Per Share, Beginning Balance (in dollars per share)	$ 25.35
Weighted-Average Exercise Price Per Share, Options granted (in dollars per share)	72.85
Weighted-average exercise price per share, options exercised (in dollars per share)	8.74
Weighted-Average Exercise Price Per Share, Options forfeited (in dollars per share)	46.02
Weighted-Average Exercise Price Per Share, Ending Balance (in dollars per share)	33.05		$ 25.35
Weighted-Average Exercise Price Per Share, Vested and expected to vest (in dollars per share)	33.05
Weighted-Average Exercise Price Per Share, Exercisable (in dollars per share)	$ 19.11
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-Average Remaining Contractual Term (Years)	7 years 11 months 23 days		7 years 9 months
Weighted-Average Remaining Contractual Term (Years), Vested and expected to vest	7 years 11 months 23 days
Weighted-Average Remaining Contractual Term (Years), Exercisable	6 years 11 months 1 day
Aggregate Intrinsic Value	$ 363,125		$ 348,868
Aggregate Intrinsic Value, Vested and expected to vest	363,125
Aggregate Intrinsic Value, Exercisable	$ 225,684
2020 Plan and 2014 Plan | Restricted Stock Units
Options and Restricted Stock Units Available for Grant
Options and Restricted Stock Units Available for Grant, granted (in shares)	(565,682,000)
Options and Restricted Stock Units Available for Grant, forfeited (in shares)	3,625,000
Options and Restricted Stock Units Available for Grant, units withheld (in shares)	46,279,000

Equity Incentive Plans - Nonves

Equity Incentive Plans - Nonvested Restricted Stock Shares Activity (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Shares
Beginning balance (in shares) | shares	753,462
Granted (in shares) | shares	565,682
Vested and released (in shares) | shares	(110,580)
Cancelled (in shares) | shares	(3,625)
Ending balance (in shares) | shares	1,204,939
Weighted- Average Grant-Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 38.93
Granted (in dollars per share) | $ / shares	73.42
Vested and released (in dollars per share) | $ / shares	36.41
Cancelled (in dollars per share) | $ / shares	52.26
Ending balance (in dollars per share) | $ / shares	$ 55.31

Equity Incentive Plans - Summ_2

Equity Incentive Plans - Summary of Estimated Fair Value of Employee Stock Options (Details)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Fair Value Assumptions
Expected volatility, Minimum	73.20%	73.60%
Expected volatility, Maximum	73.50%	74%
Expected dividend yield	0%	0%
Expected term (in years)	5 years 4 months 24 days
Risk-free interest rate, Minimum	4%	3.70%
Risk-free interest rate, Maximum	4.30%	4.30%
2020 Employee Stock Purchase Plan
Fair Value Assumptions
Expected volatility, Minimum	38.10%	86.40%
Expected volatility, Maximum	62.70%	99.70%
Expected dividend yield	0%	0%
Risk-free interest rate, Minimum	4.90%	4.50%
Risk-free interest rate, Maximum	5.40%	4.70%
Minimum
Fair Value Assumptions
Expected term (in years)		5 years 3 months 18 days
Minimum | 2020 Employee Stock Purchase Plan
Fair Value Assumptions
Expected term (in years)	6 months	6 months
Maximum
Fair Value Assumptions
Expected term (in years)		5 years 4 months 24 days
Maximum | 2020 Employee Stock Purchase Plan
Fair Value Assumptions
Expected term (in years)	2 years	2 years

Equity Incentive Plans - Summ_3

Equity Incentive Plans - Summary of Estimated Fair Value of Shares Under Employee Stock Purchase Plan (Details)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Fair Value Assumptions
Expected volatility, Minimum	73.20%	73.60%
Expected volatility, Maximum	73.50%	74%
Expected dividend yield	0%	0%
Expected term (in years)	5 years 4 months 24 days
Risk-free interest rate, Minimum	4%	3.70%
Risk-free interest rate, Maximum	4.30%	4.30%
Minimum
Fair Value Assumptions
Expected term (in years)		5 years 3 months 18 days
Maximum
Fair Value Assumptions
Expected term (in years)		5 years 4 months 24 days
2020 Employee Stock Purchase Plan
Fair Value Assumptions
Expected volatility, Minimum	38.10%	86.40%
Expected volatility, Maximum	62.70%	99.70%
Expected dividend yield	0%	0%
Risk-free interest rate, Minimum	4.90%	4.50%
Risk-free interest rate, Maximum	5.40%	4.70%
2020 Employee Stock Purchase Plan | Minimum
Fair Value Assumptions
Expected term (in years)	6 months	6 months
2020 Employee Stock Purchase Plan | Maximum
Fair Value Assumptions
Expected term (in years)	2 years	2 years

Equity Incentive Plans - Summ_4

Equity Incentive Plans - Summary of Stock-based Compensation Expense (Details) - 2014 Plan, 2020 Plan and 2020 ESPP - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 17,629	$ 9,648
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	8,818	4,527
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 8,811	$ 5,121

Retirement Plan - Additional In

Retirement Plan - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Retirement Benefits [Abstract]
Company contributions	$ 0.7	$ 0.4

Funding Arrangement - Additiona

Funding Arrangement - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2021	Mar. 31, 2024	Mar. 31, 2023	Jun. 30, 2023
Funding Arrangement [Line Items]
Grant income		$ 126	$ 654
CARB-X Agreement
Funding Arrangement [Line Items]
Grant receivable on unreimbursed, eligible costs incurred		100	0
CARB-X Agreement | Maximum
Funding Arrangement [Line Items]
Initial funding committed by award		14,600
CARB-X Agreement | Minimum
Funding Arrangement [Line Items]
Potential funding committed by award		11,700
National Institutes Of Health
Funding Arrangement [Line Items]
Potential funding amount of award to develop vaccine to prevent shingella infections	$ 500			$ 4,600
National Institutes Of Health | Maximum
Funding Arrangement [Line Items]
Potential funding period of award to develop vaccine to prevent shingella infections	5 years			5 years
Cost Reimbursement Sub-Award Agreement
Funding Arrangement [Line Items]
Grant income		$ 0	$ 700

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net loss (in thousands)	$ (95,020)	$ (60,462)
Weighted-average shares outstanding, basic (in shares)	111,690,951	86,206,817
Weighted-average shares outstanding, diluted (in shares)	111,690,951	86,206,817
Net loss per share, basic (in dollars per share)	$ (0.85)	$ (0.70)
Net loss per share, diluted (in dollars per share)	$ (0.85)	$ (0.70)

Net Loss Per Share - Schedule_2

Net Loss Per Share - Schedule of Potentially Dilutive Securities Excluded From Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	12,612,304	10,074,607
Options issued and outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	11,302,590	9,183,744
Restricted stock units outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	1,204,939	773,660
Employee stock purchase plan shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	104,775	117,203

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details)	3 Months Ended
	Mar. 31, 2024 USD ($)
Income Tax Disclosure [Abstract]
Tax provision	$ 0