ALX Oncology (ALXO) 10-Q 7 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Oct. 31, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Registrant Name	ALX ONCOLOGY HOLDINGS INC
Entity Central Index Key	0001810182
Entity File Number	001-39386
Entity Tax Identification Number	85-0642577
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	323 Allerton Avenue
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	466-7125
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		52,743,104
Entity Shell Company	false
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	ALXO
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 16,102	$ 22,406
Short-term investments	132,472	160,330
Prepaid expenses and other current assets	7,321	5,923
Total current assets	155,895	188,659
Property and equipment, net	3,112	3,589
Long-term investments	14,036	35,411
Other assets	12,672	14,894
Total assets	185,715	242,553
Current liabilities:
Accounts payable	7,891	8,591
Payable and accrued liabilities due to related party	$ 63	$ 543
Other Liability, Current, Related Party, Type [Extensible Enumeration]	us-gaap:RelatedPartyMember	us-gaap:RelatedPartyMember
Accrued expenses and other current liabilities	$ 24,386	$ 26,867
Total current liabilities	32,340	36,001
Term loan, non-current	9,835	9,639
Other non-current liabilities	6,733	7,201
Total liabilities	48,908	52,841
Commitments and contingencies (Note 11)
Stockholders’ equity
Common stock, $0.001 par value; 1,000,000,000 shares authorized as of September 30, 2024 and December 31, 2023; 52,743,104 and 49,951,989 shares issued and outstanding as of September 30, 2024 and December 31, 2023, respectively	53	50
Additional paid-in capital	728,150	675,678
Accumulated other comprehensive income (loss)	563	256
Accumulated deficit	(591,959)	(486,272)
Total stockholders’ equity	136,807	189,712
Total liabilities and stockholders’ equity	$ 185,715	$ 242,553

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	52,743,104	49,951,989
Common stock, shares outstanding	52,743,104	49,951,989

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating expenses:
Research and development	$ 26,471	$ 45,766	$ 92,841	$ 100,011
General and administrative	6,096	7,509	19,013	22,244
Total operating expenses	32,567	53,275	111,854	122,255
Loss from operations	(32,567)	(53,275)	(111,854)	(122,255)
Interest income	2,303	2,677	7,488	7,654
Interest expense	(446)	(391)	(1,302)	(1,150)
Other income (expense), net	3	(1)	(19)	418
Net loss	$ (30,707)	$ (50,990)	$ (105,687)	$ (115,333)
Net loss per share, basic	$ (0.58)	$ (1.24)	$ (2.05)	$ (2.82)
Net loss per share, diluted	$ (0.58)	$ (1.24)	$ (2.05)	$ (2.82)
Weighted-average shares of common stock used to compute net loss per share, basic	52,693,878	41,147,938	51,544,501	40,963,015
Weighted-average shares of common stock used to compute net loss per share, diluted	52,693,878	41,147,938	51,544,501	40,963,015

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (30,707)	$ (50,990)	$ (105,687)	$ (115,333)
Other comprehensive gain, net of tax:
Unrealized gain on available-for-sale investments	636	86	307	619
Total comprehensive loss	$ (30,071)	$ (50,904)	$ (105,380)	$ (114,714)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	ATM Offering	Common Stock	Common Stock ATM Offering	Additional Paid-in Capital	Additional Paid-in Capital ATM Offering	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance at Dec. 31, 2022	$ 263,464		$ 41		$ 589,735		$ (845)	$ (325,467)
Balance, shares at Dec. 31, 2022			40,861,386
Issuance of common stock under equity incentive plans, shares			1,663
Stock-based compensation	6,351				6,351
Unrealized gain (loss) on available-for-sale investments	757						757
Net loss	(30,184)							(30,184)
Balance at Mar. 31, 2023	240,388		$ 41		596,086		(88)	(355,651)
Balance, shares at Mar. 31, 2023			40,863,049
Balance at Dec. 31, 2022	263,464		$ 41		589,735		(845)	(325,467)
Balance, shares at Dec. 31, 2022			40,861,386
Unrealized gain (loss) on available-for-sale investments	619
Net loss	(115,333)
Balance at Sep. 30, 2023	168,752		$ 41		609,737		(226)	(440,800)
Balance, shares at Sep. 30, 2023			41,151,819
Balance at Mar. 31, 2023	240,388		$ 41		596,086		(88)	(355,651)
Balance, shares at Mar. 31, 2023			40,863,049
Issuance of common stock under equity incentive plans	112				112
Issuance of common stock under equity incentive plans, shares			76,210
Issuance of common stock under employee stock purchase plan	338				338
Issuance of common stock under employee stock purchase plan, shares			52,920
Stock-based compensation	6,237				6,237
Unrealized gain (loss) on available-for-sale investments	(224)						(224)
Net loss	(34,159)							(34,159)
Balance at Jun. 30, 2023	212,692		$ 41		602,773		(312)	(389,810)
Balance, shares at Jun. 30, 2023			40,992,179
Issuance of common stock under equity incentive plans, shares			159,640
Stock-based compensation	6,964				6,964
Unrealized gain (loss) on available-for-sale investments	86						86
Net loss	(50,990)							(50,990)
Balance at Sep. 30, 2023	168,752		$ 41		609,737		(226)	(440,800)
Balance, shares at Sep. 30, 2023			41,151,819
Balance at Dec. 31, 2023	189,712		$ 50		675,678		256	(486,272)
Balance, shares at Dec. 31, 2023			49,951,989
Issuance of common stock under equity incentive plans	237				237
Issuance of common stock under equity incentive plans, shares			113,385
Issuance of common stock through ATM offering, net of commissions and offering costs		$ 3,024				$ 3,024
Issuance of common stock through ATM offering, net of commissions and offering costs, shares				211,819
Stock-based compensation	7,031				7,031
Unrealized gain (loss) on available-for-sale investments	(228)						(228)
Net loss	(35,581)							(35,581)
Balance at Mar. 31, 2024	164,195		$ 50		685,970		28	(521,853)
Balance, shares at Mar. 31, 2024			50,277,193
Balance at Dec. 31, 2023	189,712		$ 50		675,678		256	(486,272)
Balance, shares at Dec. 31, 2023			49,951,989
Issuance of common stock through ATM offering, net of commissions and offering costs, shares				2,005,910
Unrealized gain (loss) on available-for-sale investments	307
Net loss	(105,687)
Balance at Sep. 30, 2024	136,807		$ 53		728,150		563	(591,959)
Balance, shares at Sep. 30, 2024			52,743,104
Balance at Mar. 31, 2024	164,195		$ 50		685,970		28	(521,853)
Balance, shares at Mar. 31, 2024			50,277,193
Issuance of common stock under equity incentive plans	861				861
Issuance of common stock under equity incentive plans, shares			321,753
Issuance of common stock under employee stock purchase plan	306				306
Issuance of common stock under employee stock purchase plan, shares			59,712
Issuance of common stock through ATM offering, net of commissions and offering costs		26,203		$ 2		26,201
Issuance of common stock through ATM offering, net of commissions and offering costs, shares				1,794,091
Stock-based compensation	7,252				7,252
Unrealized gain (loss) on available-for-sale investments	(101)						(101)
Net loss	(39,399)							(39,399)
Balance at Jun. 30, 2024	159,317		$ 52		720,590		(73)	(561,252)
Balance, shares at Jun. 30, 2024			52,452,749
Issuance of common stock under equity incentive plans	534		$ 1		533
Issuance of common stock under equity incentive plans, shares			290,355
Issuance of common stock through ATM offering, net of commissions and offering costs		$ 75				$ 75
Stock-based compensation	6,952				6,952
Unrealized gain (loss) on available-for-sale investments	636						636
Net loss	(30,707)							(30,707)
Balance at Sep. 30, 2024	$ 136,807		$ 53		$ 728,150		$ 563	$ (591,959)
Balance, shares at Sep. 30, 2024			52,743,104

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024
ATM Offering
Commissions	$ 0.8	$ 0.1

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating activities
Net loss	$ (105,687)	$ (115,333)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	658	629
Non-cash lease costs	1,312	920
Stock-based compensation	21,235	19,552
Net accretion of discounts on investments	(3,920)	(4,606)
Accretion of term loan discount and issuance costs	196	186
Loss on disposal of fixed asset	10
Changes in operating assets and liabilities
Prepaid expenses and other current assets	(1,418)	(4,310)
Other assets	2,170	4,215
Accounts payable	(637)	4,942
Payable and accrued liabilities due to related party	(480)	(1,385)
Accrued expenses and other current liabilities	(1,730)	6,491
Other non-current liabilities	(1,575)	(1,987)
Net cash used in operating activities	(89,866)	(90,686)
Investing activities
Purchase of investments	(102,962)	(171,619)
Maturities of investments	156,422	234,068
Purchase of property and equipment	(387)	(1,126)
Net cash provided by investing activities	53,073	61,323
Financing activities
Proceeds from ATM offering, net of commissions	29,302
Proceeds from exercise of stock options under equity incentive plan	1,632	112
Proceeds from issuance of common stock under employee stock purchase plan	306	338
Principal payments on finance leases	(751)	(325)
Net cash provided by financing activities	30,489	125
Net decrease in cash, cash equivalents and restricted cash	(6,304)	(29,238)
Cash, cash equivalents and restricted cash at beginning of year	22,472	48,888
Cash, cash equivalents and restricted cash at end of period	16,168	19,650
Supplemental disclosure of non-cash investing and financing activities
Purchase of property and equipment in accounts payable and accrued expenses	1,211	1,376
Right-of-use asset acquired under finance leases	1,309	1,187
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents	16,102	19,584
Restricted cash (included in other assets)	66	66
Total cash and cash equivalents and restricted cash	$ 16,168	$ 19,650

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Parenthetical) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($)
Statement of Cash Flows [Abstract]
Commission and offering costs	$ 0.8

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (30,707)	$ (39,399)	$ (35,581)	$ (50,990)	$ (34,159)	$ (30,184)	$ (105,687)	$ (115,333)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Organization

Organization	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
ORGANIZATION	(1) ORGANIZATION Organization ALX Oncology Holdings Inc., or the Company, was formed as a Delaware corporation on April 1, 2020, or Inception. The Company was formed for the purpose of completing the Company’s initial public offering of its common stock and related transactions in order to carry on the business of ALX Oncology Limited. The Company is a clinical-stage immuno-oncology company focused on helping patients fight cancer by developing therapies that block the CD47 checkpoint pathway and bridge the innate and adaptive immune system. ALX Oncology Holdings Inc. is incorporated in Delaware. ALX Oncology Limited, incorporated in Ireland, is a wholly-owned subsidiary of ALX Oncology Holdings Inc. ALX Oncology Inc., incorporated in Delaware, is a wholly-owned subsidiary of ALX Oncology Limited. All the companies, except for ALX Oncology Holdings Inc., are collectively known as the Subsidiaries. As of September 30, 2024, the Company has devoted substantially all of its efforts to the formation and financing of the Company, as well as product development, and has not realized product revenues from its planned principal operations. The Company does not have manufacturing facilities and all manufacturing related activities are contracted out to third-party service providers. Management expects to incur additional losses in the future to conduct product candidate research and development and to conduct pre-commercialization activities and recognizes that the Company will likely raise additional capital to fully implement its business plan. The Company intends to raise such capital through the sale of additional equity, debt financings and/or strategic alliances with third parties. However, there can be no assurance that the Company will be successful in acquiring additional funding at levels sufficient to fund its operations or on terms acceptable to the Company. If the Company is unsuccessful in its efforts to raise additional financing, the Company could be required to significantly reduce operating expenses and delay, reduce the scope of or eliminate some of its development programs or its future commercialization efforts, out-license intellectual property rights to its product candidates and sell unsecured assets, or a combination of the above, any of which may have a material adverse effect on the Company’s business, results of operations, financial condition and/or its ability to fund its scheduled obligations on a timely basis or at all. The Company believes that the existing capital resources will be sufficient to fund the projected operating requirements for at least the next twelve months.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	(2) SIGNIFICANT ACCOUNTING POLICIES Basis of Preparation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States, or U.S. GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or SEC, regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in the Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 7, 2024. The condensed consolidated balance sheet as of September 30, 2024 included herein was derived from the audited financial statements as of that date, but does not include all disclosures including notes required by U.S. GAAP. The accompanying condensed consolidated financial statements reflect all normal recurring adjustments that are necessary to present fairly the results for the interim periods presented. Interim results are not necessarily indicative of the results for the full year ending December 31, 2024. Principles of Consolidation All intercompany balances and transactions have been eliminated in consolidation. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. On an ongoing basis, management evaluates its estimates, including, but not limited to, those related to the estimated useful lives of long-lived assets, clinical trial accruals, fair value of assets and liabilities, fair value of investments and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates. Significant Accounting Policies There have been no new or material changes to the significant accounting policies discussed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. Recent Accounting Pronouncements In August 2020, the FASB issued ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) (ASU 2020-06). ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. The new guidance also modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. ASU 2020-06 is effective for annual periods beginning after December 15, 2023, including interim periods within those annual periods. Early adoption is permitted. ASU 2020-06 allows companies to adopt the guidance through either a modified retrospective method of transition or a fully retrospective method of transition. The Company’s adoption of ASU 2020-06 on January 1, 2024 did not have an impact on its condensed consolidated financial statements and related disclosures. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (ASU 2023-07). The amendments in ASU 2023-07 are intended to improve reportable segment disclosure, primarily through enhanced disclosures about significant segment expenses. ASU 2023-07 is effective for annual periods beginning after December 15, 2023, and interim periods beginning after December 15, 2024. The amendments in this ASU should be applied retrospectively to all prior periods presented in the financial statements. Early adoption is permitted. The Company is evaluating the impact of this guidance on its consolidated financial statements and related disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09). ASU 2023-09 requires enhanced annual disclosures regarding the rate reconciliation and income taxes paid information. ASU 2023-09 is effective for annual periods beginning after December 15, 2024 and may be adopted on a prospective or retrospective basis. Early adoption is permitted. The Company is evaluating the impact of this guidance on its consolidated financial statements and related disclosures.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	(3) FAIR VALUE OF FINANCIAL INSTRUMENTS The fair value of the Company’s financial assets and liabilities are determined in accordance with the fair value hierarchy established in ASC 820, Fair Value Measurements and Disclosures. The following table presents the Company’s investments, which consist of cash equivalents and investments classified as available-for-sale investments, that are measured at fair value on a recurring basis by level within the fair value hierarchy as of September 30, 2024 and December 31, 2023 (in thousands): September 30, 2024 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents Money market funds Level 1 $ 15,013 $ — $ — $ 15,013 Short-term investments U.S. Treasury securities Level 1 65,920 227 — 66,147 U.S. government agency securities Level 2 3,077 13 — 3,090 Corporate debt securities Level 2 61,015 255 — 61,270 Commercial paper Level 2 1,962 3 — 1,965 Asset-backed securities Level 2 — — — — Long-term investments U.S. Treasury securities Level 1 4,922 61 — 4,983 U.S. government agency securities Level 2 3,500 — ( 1 ) 3,499 Corporate debt securities Level 2 5,549 5 — 5,554 Total $ 160,958 $ 564 $ ( 1 ) $ 161,521 December 31, 2023 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents Money market funds Level 1 $ 15,591 $ — $ — $ 15,591 Corporate debt securities Level 2 4,489 1 — 4,490 Short-term investments U.S. Treasury securities Level 1 74,790 80 ( 20 ) 74,850 U.S. government agency securities Level 2 28,215 — ( 38 ) 28,177 Corporate debt securities Level 2 21,881 24 ( 3 ) 21,902 Commercial paper Level 2 34,967 22 ( 9 ) 34,980 Asset-backed securities Level 2 423 — ( 2 ) 421 Long-term investments U.S. Treasury securities Level 1 14,737 75 — 14,812 U.S. government agency securities Level 2 3,009 31 — 3,040 Asset-backed securities Level 2 17,464 95 — 17,559 Total $ 215,566 $ 328 $ ( 72 ) $ 215,822 The fair value of cash equivalents and available-for-sale investments by classification included in the condensed consolidated balance sheets was as follows as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Cash equivalents $ 15,013 $ 20,081 Short-term investments 132,472 160,330 Long-term investments 14,036 35,411 Total $ 161,521 $ 215,822 Cash and cash equivalents in the above table excludes bank account cash of $ 1.1 million and $ 2.3 million as of September 30, 2024 and December 31, 2023, respectively. The fair value of cash equivalents and available-for-sale investments by contractual maturity was as follows as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Maturing in one year or less $ 147,485 $ 180,411 Maturing after one year through five years 14,036 35,411 Total $ 161,521 $ 215,822 The primary objective of the Company’s investment portfolio is to maintain safety of principal, prudent levels of liquidity and acceptable levels of risk. The Company’s investment policy limits investments to certain types of instruments issued by institutions with investment-grade credit ratings, and it places restrictions on maturities and concentration by asset class and issuer. There were no transfers of financial instruments between the fair value measurement levels during the three months and nine months ended September 30, 2024 and 2023 and there were no financial instruments classified as Level 3 as of September 30, 2024 and 2023. As of September 30, 2024 and December 31, 2023, accrued interest receivable related to the Company’s investments of $ 1.2 million and $ 1.0 million , respectively, was included in prepaid expenses and other current assets on the condensed consolidated balance sheet. As of September 30, 2024, the unrealized losses for available-for-sale investments were non-credit related and the Company does not intend to sell the investments that were in an unrealized loss position, nor does it foresee or project that it will be required to sell those investments before recovery of their amortized costs basis, which may be maturity. As of September 30, 2024 and 2023, no allowance for credit losses for the Company’s investments was recorded. As of September 30, 2024 and December 31, 2023, securities with a fair value of zero and $ 5.9 million , respectively, were in a continuous net unrealized loss position for more than 12 months. As of September 30, 2024 and 2023 , the Company has no t recognized any impairment losses on available-for-sale investments.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2024
Balance Sheet Related Disclosures [Abstract]
BALANCE SHEET COMPONENTS	(4) BALANCE SHEET COMPONENTS Prepaid Expenses and Other Current Assets The following table presents the components of prepaid expenses and other current assets as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Prepaid clinical expenses $ 2,917 $ 3,049 Interest and investment receivables 1,183 996 Prepaid expenses 1,150 830 Prepaid insurance 846 609 Other current assets 1,225 439 Total prepaid expenses and other current assets $ 7,321 $ 5,923 Property and Equipment, Net The following table presents the components of property and equipment, net as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Leasehold improvements $ 2,513 $ 2,513 Laboratory equipment 1,828 1,733 Computer hardware and software 496 414 Furniture and fixtures 166 166 Property and equipment, gross 5,003 4,826 Less: accumulated depreciation ( 1,891 ) ( 1,237 ) Property and equipment, net $ 3,112 $ 3,589 Depreciation was $ 0.2 million and $ 0.2 million for the three months ended September 30, 2024 and 2023, respectively. Depreciation was $ 0.7 million and $ 0.6 million for the nine months ended September 30, 2024 and 2023, respectively. Other Assets The following table presents the components of other assets as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Long-term prepaid clinical expenses $ 5,113 $ 7,442 Operating lease right-of-use assets 4,234 4,847 Finance lease right-of-use assets 2,966 2,405 Long-term prepaid contract manufacturing costs 159 — Other 200 200 Total other assets $ 12,672 $ 14,894 Accrued Expenses and Other Current Liabilities The following table presents the components of accrued expenses and other current liabilities as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Accrued clinical and nonclinical study costs $ 10,144 $ 8,873 Accrued contract manufacturing 7,007 9,543 Accrued compensation and related expenses 4,643 6,067 Accrued property and equipment 189 179 Other 2,403 2,205 Total accrued expenses and other current liabilities $ 24,386 $ 26,867

Leases

Leases	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
LEASES	(5) LEASES The Company has non-cancelable operating leases for its offices located in the U.S. As of September 30, 2024 , these leases expire on various dates between 2026 and 2030 . Certain lease agreements include one or more options to renew, with renewal terms that can extend the lease up to two years after expiration. The Company has the right to exercise or forego the lease renewal options. The lease agreements do not contain any material residual value guarantees or material restrictive covenants. The following table presents the maturities and balance sheet information of the Company’s operating lease liabilities as of September 30, 2024 (in thousands, except lease term and discount rate): September 30, 2024 Operating Leases Finance Leases 2024 $ 319 $ 264 2025 1,305 1,056 2026 1,187 1,056 2027 912 616 2028 939 — Thereafter 1,130 — Total lease payments 5,792 2,992 Less: imputed interest ( 1,161 ) ( 100 ) Total lease liabilities $ 4,631 $ 2,892 Lease liabilities: current (i) $ 923 $ 943 Lease liabilities: non-current (ii) 3,708 1,949 Total lease liabilities $ 4,631 $ 2,892 Weighted average remaining lease term (in years) 4.8 2.8 Weighted average discount rate 8.9 % 8.5 % (i) Current lease liabilities are presented within accrued expenses and other current liabilities on the condensed consolidated balance sheets. (ii) Non-current lease liabilities are presented within other non-current liabilities on the condensed consolidated balance sheets. The following table presents the components of lease costs for the three months and nine months ended September 30, 2024 and 2023 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Operating lease cost $ 311 $ 317 $ 933 $ 952 Variable lease cost and other, net (i) 131 128 429 347 Short-term lease cost 3 2 14 8 Finance lease cost: Amortization of right-of-use assets 254 114 700 338 Interest 63 9 160 11 Total lease costs $ 762 $ 570 $ 2,236 $ 1,656 (i) The variable lease cost and other, net is comprised primarily of common area maintenance charges for the operating lease, which are dependent on usage. These costs are classified as operating lease expense due to the election to not separate lease and non-lease components. These costs were not included within the measurement of the Company’s operating lease ROU assets and operating lease liabilities. The following table presents the supplemental cash flow disclosures for cash paid for leases for the nine months ended September 30, 2024 and 2023 (in thousands): Nine Months Ended September 30, 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 948 $ 931 Operating cash flows from finance leases $ 169 $ 3 Financing cash flows from finance leases $ 751 $ 325 Right-of-use asset acquired under leases Finance leases $ 1,309 $ 1,187

Term Loan

Term Loan	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
TERM LOAN	(6) TERM LOAN Oxford Finance and Silicon Valley Bank Loan In October 2022, the Company entered into a loan and security agreement, as amended, the Loan Agreement, with Oxford Finance LLC, Oxford Finance Credit Fund II LP, and Silicon Valley Bank, or SVB, collectively the Lenders, for a secured term loan facility of up to $ 100.0 million. Pursuant to the Loan Agreement, the Company drew an initial loan of $ 10.0 million. Under the original terms of the Loan Agreement, the Company had the right to draw an additional $ 40.0 million through the end of June 2024. The original terms of the Loan Agreement provided for an additional $ 50.0 million over three tranches, with $ 12.5 million available in each of two tranches based upon the achievement of milestones related to the development of evorpacept and one preclinical product candidate, and $ 25.0 million at the Lenders’ sole discretion. The Company decided not to draw down on any portion of the $ 40.0 million available under the Loan Agreement by the deadline of June 30, 2024. As a result of this decision, the $ 40.0 million was added to the $ 25.0 million available upon the achievement of pre-determined development milestones for a total of $ 65.0 million available, split equally between each of the two tranches. An additional $ 25.0 million is also available at the Lenders’ sole discretion. The proceeds of the loans may be used by the Company for working capital and to fund its general business requirements. Additional information regarding our indebtedness is included in our notes to our consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, which was filed with the SEC on March 7, 2024. During the three months ended September 30, 2024 and 2023, interest expense incurred in connection with the Loan Agreement was $ 0.3 million and $ 0.3 million respectively. During the nine months ended September 30, 2024 and 2023, interest expense incurred in connection with the Loan Agreement was $ 0.9 million and $ 0.8 million respectively. As of September 30, 2024, the Company was in compliance with all financial reporting covenants under the Loan Agreement. As of September 30, 2024, the future maturities under the Loan Agreement are as follows (in thousands): September 30, 2024 2024 $ — 2025 435 2026 5,217 2027 4,948 2028 — Total future maturities 10,600 Less: current portion of term loan — Total term loan, net of current portion 10,600 Less: unamortized debt issuance costs ( 616 ) Less: unaccreted final payment costs ( 149 ) Term loan, non-current, net $ 9,835

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
STOCKHOLDERS' EQUITY	(7) STOCKHOLDERS’ EQUITY On July 21, 2020, the Company’s amended and restated certificate of incorporation became effective, authorizing 1,000,000,000 shares of common stock, $ 0.001 par value per share, and 100,000,000 shares of undesignated preferred stock, $ 0.001 par value per share. As of September 30, 2024 and December 31, 2023, the Company had 52,743,104 and 49,951,989 shares of common stock outstanding, respectively, and no shares of undesignated preferred stock outstanding, respectively. Common stock reserved for future issuance as of September 30, 2024 consists of the following: September 30, 2024 Stock options issued and outstanding 10,089,807 Stock options authorized for future issuance 1,038,768 Employee Stock Purchase Plan shares authorized for future issuance 1,005,677 RSUs issued and outstanding 1,026,238 PSUs issued and outstanding 357,500 Total 13,517,990 At-the-Market Equity Offering In December 2021, the Company entered into a sales agreement with Cantor Fitzgerald & Co. and Credit Suisse Securities (USA) LLC (Sales Agreement), under which it may offer and sell shares of the Company’ s common stock, having aggregate gross proceeds of up to $ 150.0 million, from time to time through them as the Company ’s sales agents in its at-the-market (ATM) equity offering program. In August 2023, the Company entered into an amendment to the Sales Agreement to include UBS Securities LLC as an additional sales agent and to remove Credit Suisse as a sales agent. As of September 30, 2024, the Company had issued approximately 2,005,910 shares of common stock pursuant to the Sales Agreement for net proceeds of $ 29.3 million . The Company may terminate this ATM program at any time, pursuant to its terms. Pre-Funded Warrants In October 2023, the Company completed an underwritten follow-on public offering (the October 2023 Offering) pursuant to a shelf registration statement, which provides for aggregate offerings of up to $ 450.0 million of the Company’s securities. As part of the October 2023 underwritten public offering, the Company issued pre-funded warrants to certain investors to purchase 1,250,000 shares of common stock in an underwritten public offering at a public offering price of $ 6.379 per pre-funded warrant. Each pre-funded warrant entitles the holder to purchase one share of common stock at an exercise price of $ 0.001 per share. As of September 30, 2024 and December 31, 2023 , respectively, no shares underlying the pre-funded warrants had been exercised. All of the outstanding pre-funded warrants are included in the weighted-average number of shares of common stock used to calculate basic net loss per share attributable to common stockholders (see Note 10 “Net Loss Per Share”).

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	(8) STOCK-BASED COMPENSATION Amended and Restated 2020 Equity Incentive Plan The Company’s Amended and Restated 2020 Equity Incentive Plan, or the 2020 Plan, serves as the successor to the Company’s 2020 Equity Incentive Plan and provides for the granting of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units, performance units and performance shares. On January 1, 2024, the number of shares available under the 2020 Plan was increased by 1,998,080 shares. Performance-Based Restricted Stock Units In February 2024, the Company granted 365,000 performance-based restricted stock units, or PSUs, to certain employees under the 2020 Plan. The PSUs are subject to both performance-based and service-based vesting conditions with a fair value based on the closing price of the underlying common stock on the date of grant. Each PSU is split into two tranches with each tranche having performance goals based on the achievement of pre-determined clinical milestones that result in the shares attributable to such tranche being eligible for vesting, subject to the service-based vesting condition. The service-based vesting condition is satisfied on the one-year anniversary of the performance achievement date for each tranche and is subject to the employee’s continuous service through such vesting date. Upon vesting, each PSU will automatically convert into one share of the Company’s common stock. If the performance condition for a tranche is not met by March 31, 2025, the shares attributable to such tranche will be forfeited. Compensation expense for awards with performance-based vesting requirements are recognized on a tranche-by-tranche basis based on the grant date fair value over the requisite service period using the accelerated attribution method if and when the performance condition is deemed to be probable of being achieved. At each reporting period, the Company will assess the probability of the performance condition being met for each tranche and, as applicable, recognize the cumulative effect of the change in estimate in the period of the change. As of September 30, 2024 , the Company determined that the achievement of the performance conditions for each tranche of PSUs was not probable. As a result, no compensation expense has been recognized for these awards as of and for the three months and nine months ended September 30, 2024. Employee Stock Purchase Plan Under the Company’s 2020 Employee Stock Purchase Plan, or the ESPP, eligible employees are entitled to purchase shares of common stock with accumulated payroll deductions. Stock-based Compensation Expenses Total stock-based compensation expense recognized in the condensed consolidated statements of operations was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Research and development $ 4,648 $ 3,728 $ 14,556 $ 10,011 General and administrative 2,304 3,236 6,679 9,541 Total $ 6,952 $ 6,964 $ 21,235 $ 19,552

Related-Party Transactions

Related-Party Transactions	9 Months Ended
	Sep. 30, 2024
Related Party Transactions [Abstract]
RELATED-PARTY TRANSACTIONS	(9) RELATED-PARTY TRANSACTIONS The Company has several related-party agreements with Tallac Therapeutics, Inc., or Tallac, and with ScalmiBio, Inc., or ScalmiBio. The details of these agreements are described in our notes to our consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, which was filed with the SEC on March 7, 2024. During the three months and nine months ended September 30, 2024, there were no material changes to these agreements. Tallac Service Agreement During the three months ended September 30, 2024 and 2023 , the Company recorded zero and $ 0.1 million , respectively, as research and development, or R&D, costs in relation to the research and development services agreement with Tallac, or the Tallac Services Agreement. During the nine months ended September 30, 2024 and 2023, the Company recorded a nominal amount and $ 0.3 million , respectively, as R&D costs in relation to the Tallac Services Agreement. Per contractual terms, the Tallac Services Agreement terminated on July 1, 2024 . Tallac Collaboration Agreement During the three months ended September 30, 2024 and 2023, the Company recorded $ 0.1 million and $ 0.3 million , respectively, as R&D costs in relation to the collaboration agreement with Tallac, or the Tallac Collaboration Agreement. During the nine months ended September 30, 2024 and 2023, the Company recorded $ 0.7 million and $ 1.2 million , respectively, as R&D costs in relation to the Tallac Collaboration Agreement. As of September 30, 2024 and December 31, 2023 , the Company had accrued expenses of $ 0.1 million and $ 0.5 million , respectively, related to the Tallac Collaboration Agreement, which was presented within the payable and accrued liabilities due to related party on the condensed consolidated balance sheets. ScalmiBio Milestone Payments The Company has agreed to pay up to $ 35.0 million, in aggregate, in certain milestones based on the clinical development of the acquired ScalmiBio technology and has also agreed to pay a low single digit royalty on net sales of any products developed from the ScalmiBio acquired technology for a defined term. The Company has the option to buy-out the royalty payment, prior to the first marketing approval of the developed product. During the three months and nine months ended September 30, 2024 , the Company made no milestone payment and $ 1.0 million milestone pa yment, respectively, as a result of selecting a development candidate, to the stockholders of ScalmiBio, including 31.7 %, or $ 0.3 million, to the Company’s former Chief Executive Officer and current Chief Scientific Officer and President, and 63.5 %, or $ 0.6 million, to another employee of the Company. This milestone payment was recorded as R&D costs within the condensed consolidated statements of operations.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
NET LOSS PER SHARE	(10) NET LOSS PER SHARE The following table sets forth the computation of the basic and diluted net loss per share for the three months and nine months ended September 30, 2024 and 2023 (in thousands, except share and per share data): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Numerator: Net loss $ ( 30,707 ) $ ( 50,990 ) $ ( 105,687 ) $ ( 115,333 ) Denominator: Weighted-average shares of common stock outstanding, basic and diluted 52,693,878 41,147,938 51,544,501 40,963,015 Net loss per share, basic and diluted $ ( 0.58 ) $ ( 1.24 ) $ ( 2.05 ) $ ( 2.82 ) Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods presented as the inclusion of all potential common stock outstanding would have been anti-dilutive. The following outstanding potentially dilutive securities were excluded from the computation of diluted net loss per share for the three months and nine months ended September 30, 2024 and 2023 because including them would have been anti-dilutive: Three Months and Nine Months Ended September 30, 2024 2023 Stock options issued and outstanding 10,089,807 9,114,886 RSUs issued and outstanding 1,026,238 1,084,403 PSUs issued and outstanding 357,500 — Employee Stock Purchase Plan estimated shares issuable 17,520 — Total 11,491,065 10,199,289

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	(11) COMMITMENTS AND CONTINGENCIES Guarantees and Indemnifications In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnifications. The Company’s exposure under these agreements is unknown because it involves claims that may be made against the Company in the future but have not yet been made. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations. However, the Company may record charges in the future as a result of these indemnification obligations. The Company also has indemnification obligations to its officers and directors for specified events or occurrences, subject to some limits, while they are serving at the Company’s request in such capacities. There have been no claims to date and the Company has director and officer insurance that may enable the Company to recover a portion of any amounts paid for future potential claims. The Company believes the fair value of these indemnification agreements is minimal. Accordingly, the Company has no t recorded any liabilities for these agreements as of September 30, 2024. Contingencies From time to time, the Company may be a party to various claims in the normal course of business. Legal fees and other costs associated with such actions will be expensed as incurred. The Company will assess, in conjunction with its legal counsel, the need to record a liability for litigation and contingencies. Reserve estimates will be recorded when and if it is determined that a loss related matter is both probable and reasonably estimable. As of September 30, 2024 , the Company had no pending or threatened litigation. Other Contractual Obligations and Other Commitments The Company has other contractual obligations and other commitments from manufacturing and service contracts, which are presented as follows as of September 30, 2024 (in thousands): September 30, 2024 Total 2024 2025-2026 2027-2028 Thereafter Manufacturing and service contracts $ 3,665 $ 1,874 $ 1,741 $ 50 $ — Total $ 3,665 $ 1,874 $ 1,741 $ 50 $ — In November 2015, the Company entered into a Master Service Agreement, or the MSA, with KBI Biopharma, Inc. relating to formulation development, process development and current good manufacturing practices, or cGMP, manufacturing of evorpacept for use in clinical trials on a project basis. The MSA had an initial term of three years with successive one-year renewal periods, which was extended an additional eight years until November 2026, is cancellable upon notice and is non-exclusive. Statements of work under the MSA commit the Company to certain future purchase obligations of approxim ately $ 1.2 million . In addition, the Company has commitments with other pharmaceutical contract manufacturers, including certain future purchase obligations of approximately $ 2.5 million . These amounts are based on non-cancellable commitments and forecasts that include estimates of future market demand, quantity discounts and manufacturing efficiencies that may impact timing of purchases. The Company enters into contracts in the normal course of business with various third parties for clinical trials, preclinical research studies and testing, manufacturing and other services and products for operating purposes. These contracts generally provide for termination upon notice. Payments due upon cancellation consist only of payments for services provided or expenses incurred, including non-cancellable obligations of the Company’s service providers, up to the date of cancellation.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2024
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	(12 ) SUBSEQUENT EVENTS On September 30, 2024, the Company’s Chief Medical Officer, or the CMO, resigned effective October 11, 2024 to pursue other professional opportunities. The resignation was not the result of any disagreement with the Company related to its operations, policies, or practices. The Company has commenced a search for a new Chief Medical Officer. In connection with the resignation, the CMO and the Company entered into a separation agreement on October 11, 2024. The separation agreement provides a payment equal to $ 503,880 and COBRA coverage under the Company’s group health, dental and vision care plans for up to 18 months following the separation date. In addition, the separation agreement provides for their outstanding stock options and restricted stock units of the Company’s common stock that would otherwise vest in accordance with the terms of the Company’s Amended and Restated 2020 Equity Incentive Plan and the award agreements, absent a termination of employment, during the 12 month period immediately following the separation date to become fully vested and (as applicable) exercisable, and all stock options that are vested or may vest in connection with the separation shall be exercisable until July 11, 2026 . The CMO also remains eligible to receive certain additional severance benefits in accordance with the terms in the separation agreement and pursuant to that certain change in control and severance agreement between the Company and the CMO dated July 9, 2020. In consideration for the compensation noted above, the CMO agreed to a customary general release of claims for the benefit of the Company. To facilitate an orderly transition from their position, the CMO and the Company entered into a consulting agreement in customary form that provides for them to perform transition related consulting services for the Company on an as needed, hourly basis for up to 18 months following the separation date, subject to certain limitations.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Preparation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States, or U.S. GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or SEC, regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in the Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 7, 2024. The condensed consolidated balance sheet as of September 30, 2024 included herein was derived from the audited financial statements as of that date, but does not include all disclosures including notes required by U.S. GAAP. The accompanying condensed consolidated financial statements reflect all normal recurring adjustments that are necessary to present fairly the results for the interim periods presented. Interim results are not necessarily indicative of the results for the full year ending December 31, 2024.
Principles of Consolidation	Principles of Consolidation All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. On an ongoing basis, management evaluates its estimates, including, but not limited to, those related to the estimated useful lives of long-lived assets, clinical trial accruals, fair value of assets and liabilities, fair value of investments and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2020, the FASB issued ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) (ASU 2020-06). ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. The new guidance also modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. ASU 2020-06 is effective for annual periods beginning after December 15, 2023, including interim periods within those annual periods. Early adoption is permitted. ASU 2020-06 allows companies to adopt the guidance through either a modified retrospective method of transition or a fully retrospective method of transition. The Company’s adoption of ASU 2020-06 on January 1, 2024 did not have an impact on its condensed consolidated financial statements and related disclosures. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (ASU 2023-07). The amendments in ASU 2023-07 are intended to improve reportable segment disclosure, primarily through enhanced disclosures about significant segment expenses. ASU 2023-07 is effective for annual periods beginning after December 15, 2023, and interim periods beginning after December 15, 2024. The amendments in this ASU should be applied retrospectively to all prior periods presented in the financial statements. Early adoption is permitted. The Company is evaluating the impact of this guidance on its consolidated financial statements and related disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09). ASU 2023-09 requires enhanced annual disclosures regarding the rate reconciliation and income taxes paid information. ASU 2023-09 is effective for annual periods beginning after December 15, 2024 and may be adopted on a prospective or retrospective basis. Early adoption is permitted. The Company is evaluating the impact of this guidance on its consolidated financial statements and related disclosures.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Financial Assets Measured at Fair Value on Recurring Basis	The following table presents the Company’s investments, which consist of cash equivalents and investments classified as available-for-sale investments, that are measured at fair value on a recurring basis by level within the fair value hierarchy as of September 30, 2024 and December 31, 2023 (in thousands): September 30, 2024 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents Money market funds Level 1 $ 15,013 $ — $ — $ 15,013 Short-term investments U.S. Treasury securities Level 1 65,920 227 — 66,147 U.S. government agency securities Level 2 3,077 13 — 3,090 Corporate debt securities Level 2 61,015 255 — 61,270 Commercial paper Level 2 1,962 3 — 1,965 Asset-backed securities Level 2 — — — — Long-term investments U.S. Treasury securities Level 1 4,922 61 — 4,983 U.S. government agency securities Level 2 3,500 — ( 1 ) 3,499 Corporate debt securities Level 2 5,549 5 — 5,554 Total $ 160,958 $ 564 $ ( 1 ) $ 161,521 December 31, 2023 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents Money market funds Level 1 $ 15,591 $ — $ — $ 15,591 Corporate debt securities Level 2 4,489 1 — 4,490 Short-term investments U.S. Treasury securities Level 1 74,790 80 ( 20 ) 74,850 U.S. government agency securities Level 2 28,215 — ( 38 ) 28,177 Corporate debt securities Level 2 21,881 24 ( 3 ) 21,902 Commercial paper Level 2 34,967 22 ( 9 ) 34,980 Asset-backed securities Level 2 423 — ( 2 ) 421 Long-term investments U.S. Treasury securities Level 1 14,737 75 — 14,812 U.S. government agency securities Level 2 3,009 31 — 3,040 Asset-backed securities Level 2 17,464 95 — 17,559 Total $ 215,566 $ 328 $ ( 72 ) $ 215,822
Schedule of Fair Value of Available for Sale Investments by Classification	The fair value of cash equivalents and available-for-sale investments by classification included in the condensed consolidated balance sheets was as follows as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Cash equivalents $ 15,013 $ 20,081 Short-term investments 132,472 160,330 Long-term investments 14,036 35,411 Total $ 161,521 $ 215,822
Schedule of Fair Value of Available-for-Sale Investments by Contractual Maturity	The fair value of cash equivalents and available-for-sale investments by contractual maturity was as follows as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Maturing in one year or less $ 147,485 $ 180,411 Maturing after one year through five years 14,036 35,411 Total $ 161,521 $ 215,822

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	The following table presents the components of prepaid expenses and other current assets as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Prepaid clinical expenses $ 2,917 $ 3,049 Interest and investment receivables 1,183 996 Prepaid expenses 1,150 830 Prepaid insurance 846 609 Other current assets 1,225 439 Total prepaid expenses and other current assets $ 7,321 $ 5,923
Schedule of Components of Property and Equipment	The following table presents the components of property and equipment, net as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Leasehold improvements $ 2,513 $ 2,513 Laboratory equipment 1,828 1,733 Computer hardware and software 496 414 Furniture and fixtures 166 166 Property and equipment, gross 5,003 4,826 Less: accumulated depreciation ( 1,891 ) ( 1,237 ) Property and equipment, net $ 3,112 $ 3,589
Schedule of Components of Other Assets, Net	The following table presents the components of other assets as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Long-term prepaid clinical expenses $ 5,113 $ 7,442 Operating lease right-of-use assets 4,234 4,847 Finance lease right-of-use assets 2,966 2,405 Long-term prepaid contract manufacturing costs 159 — Other 200 200 Total other assets $ 12,672 $ 14,894
Components of Accrued Expenses and Other Current Liabilities	The following table presents the components of accrued expenses and other current liabilities as of September 30, 2024 and December 31, 2023 (in thousands): September 30, December 31, 2024 2023 Accrued clinical and nonclinical study costs $ 10,144 $ 8,873 Accrued contract manufacturing 7,007 9,543 Accrued compensation and related expenses 4,643 6,067 Accrued property and equipment 189 179 Other 2,403 2,205 Total accrued expenses and other current liabilities $ 24,386 $ 26,867

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2024
Leases [Abstract]
Schedule of Maturities of Operating and Finance Lease Liabilities	The following table presents the maturities and balance sheet information of the Company’s operating lease liabilities as of September 30, 2024 (in thousands, except lease term and discount rate): September 30, 2024 Operating Leases Finance Leases 2024 $ 319 $ 264 2025 1,305 1,056 2026 1,187 1,056 2027 912 616 2028 939 — Thereafter 1,130 — Total lease payments 5,792 2,992 Less: imputed interest ( 1,161 ) ( 100 ) Total lease liabilities $ 4,631 $ 2,892 Lease liabilities: current (i) $ 923 $ 943 Lease liabilities: non-current (ii) 3,708 1,949 Total lease liabilities $ 4,631 $ 2,892 Weighted average remaining lease term (in years) 4.8 2.8 Weighted average discount rate 8.9 % 8.5 % (i) Current lease liabilities are presented within accrued expenses and other current liabilities on the condensed consolidated balance sheets. (ii) Non-current lease liabilities are presented within other non-current liabilities on the condensed consolidated balance sheets.
Components of Lease Costs	The following table presents the components of lease costs for the three months and nine months ended September 30, 2024 and 2023 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Operating lease cost $ 311 $ 317 $ 933 $ 952 Variable lease cost and other, net (i) 131 128 429 347 Short-term lease cost 3 2 14 8 Finance lease cost: Amortization of right-of-use assets 254 114 700 338 Interest 63 9 160 11 Total lease costs $ 762 $ 570 $ 2,236 $ 1,656 (i) The variable lease cost and other, net is comprised primarily of common area maintenance charges for the operating lease, which are dependent on usage. These costs are classified as operating lease expense due to the election to not separate lease and non-lease components. These costs were not included within the measurement of the Company’s operating lease ROU assets and operating lease liabilities.
Supplemental Cash Flow Disclosures for Cash Paid for Leases	The following table presents the supplemental cash flow disclosures for cash paid for leases for the nine months ended September 30, 2024 and 2023 (in thousands): Nine Months Ended September 30, 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 948 $ 931 Operating cash flows from finance leases $ 169 $ 3 Financing cash flows from finance leases $ 751 $ 325 Right-of-use asset acquired under leases Finance leases $ 1,309 $ 1,187

Term Loan (Tables)

Term Loan (Tables)	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Schedule of Future Maturities Under the Loan Agreement	As of September 30, 2024, the future maturities under the Loan Agreement are as follows (in thousands): September 30, 2024 2024 $ — 2025 435 2026 5,217 2027 4,948 2028 — Total future maturities 10,600 Less: current portion of term loan — Total term loan, net of current portion 10,600 Less: unamortized debt issuance costs ( 616 ) Less: unaccreted final payment costs ( 149 ) Term loan, non-current, net $ 9,835

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Common Stock Reserved for Future Issuance	Common stock reserved for future issuance as of September 30, 2024 consists of the following: September 30, 2024 Stock options issued and outstanding 10,089,807 Stock options authorized for future issuance 1,038,768 Employee Stock Purchase Plan shares authorized for future issuance 1,005,677 RSUs issued and outstanding 1,026,238 PSUs issued and outstanding 357,500 Total 13,517,990

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Share-Based Compensation Expense	Total stock-based compensation expense recognized in the condensed consolidated statements of operations was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Research and development $ 4,648 $ 3,728 $ 14,556 $ 10,011 General and administrative 2,304 3,236 6,679 9,541 Total $ 6,952 $ 6,964 $ 21,235 $ 19,552

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss per Share	The following table sets forth the computation of the basic and diluted net loss per share for the three months and nine months ended September 30, 2024 and 2023 (in thousands, except share and per share data): Three Months Ended Nine Months Ended September 30, September 30, 2024 2023 2024 2023 Numerator: Net loss $ ( 30,707 ) $ ( 50,990 ) $ ( 105,687 ) $ ( 115,333 ) Denominator: Weighted-average shares of common stock outstanding, basic and diluted 52,693,878 41,147,938 51,544,501 40,963,015 Net loss per share, basic and diluted $ ( 0.58 ) $ ( 1.24 ) $ ( 2.05 ) $ ( 2.82 )
Summary of Outstanding Potentially Dilutive Securities Were Excluded from Computation of Diluted Net Loss Per Share	The following outstanding potentially dilutive securities were excluded from the computation of diluted net loss per share for the three months and nine months ended September 30, 2024 and 2023 because including them would have been anti-dilutive: Three Months and Nine Months Ended September 30, 2024 2023 Stock options issued and outstanding 10,089,807 9,114,886 RSUs issued and outstanding 1,026,238 1,084,403 PSUs issued and outstanding 357,500 — Employee Stock Purchase Plan estimated shares issuable 17,520 — Total 11,491,065 10,199,289

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Summary of Other Contractual Obligations and Other Commitments from Manufacturing and Service Contracts	The Company has other contractual obligations and other commitments from manufacturing and service contracts, which are presented as follows as of September 30, 2024 (in thousands): September 30, 2024 Total 2024 2025-2026 2027-2028 Thereafter Manufacturing and service contracts $ 3,665 $ 1,874 $ 1,741 $ 50 $ — Total $ 3,665 $ 1,874 $ 1,741 $ 50 $ —

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Details) - ASU No. 2020-06	Sep. 30, 2024
Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2024

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets and liabilities transfers amount	$ 0	$ 0	$ 0	$ 0
Fair value assets transferred into level 3			0	0
Fair value assets transferred out of level 3			0	0
Fair value liabilities transferred into level 3			0	0
Fair value liabilities transferred out of level 3			0	0
Accrued interest receivable, investment	$ 1,200,000		$ 1,200,000		$ 1,000,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Prepaid Expense and Other Assets, Current		Prepaid Expense and Other Assets, Current		Prepaid Expense and Other Assets, Current
Bank account cash	$ 1,100,000		$ 1,100,000		$ 2,300,000
Allowance for credit losses	0	$ 0	0	0
Fair value of securities, continuous unrealized loss position for more than 12 months	$ 0		0		$ 5,900,000
Impairment losses on available-for-sale investments			$ 0	$ 0

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Schedule of Available for Sale Investments Measured at Fair Value of Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Fair Value	$ 161,521	$ 215,822
Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	160,958	215,566
Unrealized Gains	564	328
Unrealized Losses	(1)	(72)
Fair Value	161,521	215,822
Money Market Funds | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	15,013	15,591
Fair Value	15,013	15,591
Corporate Debt Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost		4,489
Unrealized Gains		1
Fair Value		4,490
Short Term Investment U.S. Treasury Securities | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	65,920	74,790
Unrealized Gains	227	80
Unrealized Losses		(20)
Fair Value	66,147	74,850
Short Term Investment U.S. Government Agency Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	3,077	28,215
Unrealized Gains	13
Unrealized Losses		(38)
Fair Value	3,090	28,177
Short Term Investment Corporate Debt Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	61,015	21,881
Unrealized Gains	255	24
Unrealized Losses		(3)
Fair Value	61,270	21,902
Short Term Investment Commercial Paper | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	1,962	34,967
Unrealized Gains	3	22
Unrealized Losses		(9)
Fair Value	1,965	34,980
Short Term Investment Asset-Backed Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost		423
Unrealized Losses		(2)
Fair Value		421
Long Term Investment U.S. Treasury Securities | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	4,922	14,737
Unrealized Gains	61	75
Fair Value	4,983	14,812
Long Term Investment Corporate Debt Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	5,549
Unrealized Gains	5
Fair Value	5,554
Long-term Investment U.S. Government Agency Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	3,500	3,009
Unrealized Gains		31
Unrealized Losses	(1)
Fair Value	$ 3,499	3,040
Long Term Investment Asset-Backed Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost		17,464
Unrealized Gains		95
Fair Value		$ 17,559

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Schedule of Fair Value of Available for Sale Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total available-for-sale investments	$ 161,521	$ 215,822
Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents available for sale	15,013	20,081
Short-term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments available for sale	132,472	160,330
Long-term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long term investments available for sale	$ 14,036	$ 35,411

Fair Value of Financial Instr_6

Fair Value of Financial Instruments - Schedule of Fair Value of Available-for-sale Investments by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract]
Maturing in one year or less	$ 147,485	$ 180,411
Maturing after one year through five years	14,036	35,411
Total available-for-sale investments	$ 161,521	$ 215,822

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Components of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid clinical expenses	$ 2,917	$ 3,049
Interest and investment receivables	1,183	996
Prepaid expenses	1,150	830
Prepaid insurance	846	609
Other current assets	1,225	439
Total prepaid expenses and other current assets	$ 7,321	$ 5,923

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Components of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 5,003	$ 4,826
Less: accumulated depreciation	(1,891)	(1,237)
Property and equipment, net	3,112	3,589
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	2,513	2,513
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,828	1,733
Computer Hardware and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	496	414
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 166	$ 166

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Balance Sheet Related Disclosures [Abstract]
Depreciation	$ 0.2	$ 0.2	$ 0.7	$ 0.6

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Components of Other Assets, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Operating lease right-of-use assets	$ 4,234	$ 4,847
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total other assets	Total other assets
Finance lease right-of-use assets	$ 2,966	$ 2,405
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total other assets	Total other assets
Other	$ 200	$ 200
Total other assets	12,672	14,894
Long-term Prepaid Clinical Expenses
Property Plant And Equipment [Line Items]
Long-term prepaid expenses	5,113	7,442
Long-term Prepaid Contract Manufacturing Costs
Property Plant And Equipment [Line Items]
Long-term prepaid expenses	$ 159	$ 0

Balance Sheet Components - Comp

Balance Sheet Components - Components of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Accrued clinical and nonclinical study costs	$ 10,144	$ 8,873
Accrued contract manufacturing	7,007	9,543
Accrued compensation and related expenses	4,643	6,067
Accrued property and equipment	189	179
Other	2,403	2,205
Total accrued expenses and other current liabilities	$ 24,386	$ 26,867

Leases - Additional Information

Leases - Additional Information (Details)	9 Months Ended
	Sep. 30, 2024
Lessee Lease Description [Line Items]
Operating lease, description	The Company has non-cancelable operating leases for its offices located in the U.S. As of September 30, 2024, these leases expire on various dates between 2026 and 2030.
Option to extend term	Certain lease agreements include one or more options to renew, with renewal terms that can extend the lease up to two years after expiration.
Minimum
Lessee Lease Description [Line Items]
Lessee operating lease expiration year	2026
Maximum
Lessee Lease Description [Line Items]
Lessee operating lease expiration year	2030
Lessee operating lease renewal term	2 years

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Operating and Finance Lease Liabilities (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2024	$ 319
2025	1,305
2026	1,187
2027	912
2028	939
Thereafter	1,130
Total lease payments	5,792
Less: imputed interest	(1,161)
Operating lease liabilities	4,631
Lease liabilities: current	$ 923
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities and Other Liabilities
Lease liabilities: non-current	$ 3,708
Operating lease, liability, noncurrent, statement of financial position [extensible list]	Other non-current liabilities
Total lease liabilities	$ 4,631
Weighted average remaining lease term (in years)	4 years 9 months 18 days
Weighted average discount rate	8.90%
Finance Lease, Liability, Payment, Due [Abstract]
2024	$ 264
2025	1,056
2026	1,056
2027	616
Finance lease liablities	2,992
Less: imputed interest	(100)
Finance lease liabilities	2,892
Finance lease liabilities, current	$ 943
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities and Other Liabilities
Finance lease liability, noncurrent	$ 1,949
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Noncurrent
Total lease liabilities	$ 2,892
Weighted average remaining lease term (in years)	2 years 9 months 18 days
Weighted average discount rate	8.50%

Leases - Components of Lease Co

Leases - Components of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Operating lease cost	$ 311	$ 317	$ 933	$ 952
Variable lease cost and other, net	131	128	429	347
Short-term lease cost	3	2	14	8
Finance lease cost, Amortization of right-of-use assets	254	114	700	338
Finance lease cost, Interest	63	9	160	11
Total lease costs	$ 762	$ 570	$ 2,236	$ 1,656

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Disclosures for Cash Paid for Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 948	$ 931
Operating cash flows from finance leases	169	3
Financing cash flows from finance leases	751	325
Finance leases	$ 1,309	$ 1,187

Term Loan - Additional Informat

Term Loan - Additional Information (Details) - Oxford-SVB Loan Agreement - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2022	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024
Debt Instrument [Line Items]
Draw an additional loan	$ 50
Available borrowing capacity upon pre-determined achievement of milestones						$ 25
Borrowing capacity upon pre-determinedachievement of milestones						65
Interest expense		$ 0.3	$ 0.3	$ 0.9	$ 0.8
Tranche A
Debt Instrument [Line Items]
Issuance of term loan	10
Draw an additional loan	40
Not to draw an additional loan						40
Tranche B
Debt Instrument [Line Items]
Available borrowing capacity upon achievement of milestones	12.5
Tranche C
Debt Instrument [Line Items]
Available borrowing capacity upon achievement of milestones	12.5
Tranche D
Debt Instrument [Line Items]
Available borrowing capacity at lender's discretion	25
Additional borrowing capacity at lender's discretion						$ 25
Maximum | Secured Term Loan Facility
Debt Instrument [Line Items]
Term loan, principal amount	$ 100

Term Loan - Schedule of Future

Term Loan - Schedule of Future Maturities Under the Loan Agreement (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Long-Term Debt, Fiscal Year Maturity [Abstract]
2025	$ 435
2026	5,217
2027	4,948
Total future maturities	10,600
Less: current portion of term loan	0
Total term loan, net of current portion	10,600
Less: unamortized debt issuance costs	(616)
Less: unaccreted final payment costs	(149)
Term loan, non-current, net	$ 9,835	$ 9,639

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended			9 Months Ended
	Oct. 31, 2023	Dec. 31, 2021	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2024	Dec. 31, 2023	Jul. 21, 2020
Class Of Stock [Line Items]
Common stock, shares authorized			1,000,000,000			1,000,000,000	1,000,000,000	1,000,000,000
Common stock, par value			$ 0.001			$ 0.001	$ 0.001	$ 0.001
Preferred stock, par value								$ 0.001
Common stock, shares outstanding			52,743,104			52,743,104	49,951,989
Net proceeds received						$ 29,302
Underwritten Follow-on Public Offering | Maximum
Class Of Stock [Line Items]
Aggregate offerings of securities	$ 450,000
Underwritten Follow-on Public Offering | Pre-funded Warrants
Class Of Stock [Line Items]
Warrants to purchase of common stock	1,250,000
Shares original issue price	$ 6.379
Common stock exercise price	$ 0.001
At-the-Market Equity Offering | Common Stock | Maximum
Class Of Stock [Line Items]
Gross proceeds from issuance of common stock		$ 150,000
ATM Offering
Class Of Stock [Line Items]
Aggregate offerings of securities			$ 75	$ 26,203	$ 3,024
ATM Offering | Common Stock
Class Of Stock [Line Items]
Additional shares issued				1,794,091	211,819	2,005,910
Net proceeds received						$ 29,300
Aggregate offerings of securities				$ 2
Undesignated Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares authorized								100,000,000
Convertible preferred stock, shares outstanding			0			0	0

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock Reserved for Future Issuance (Details)	Sep. 30, 2024 shares
Class Of Stock [Line Items]
Common stock reserved for future issuance	13,517,990
Stock Options Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance	10,089,807
Stock Options Authorized for Future Issuance
Class Of Stock [Line Items]
Common stock reserved for future issuance	1,038,768
Employee Stock Purchase Plan Shares Authorized for Future Issuance
Class Of Stock [Line Items]
Common stock reserved for future issuance	1,005,677
RSUs Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance	1,026,238
PSUs Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance	357,500

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 01, 2024	Feb. 29, 2024	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expenses			$ 6,952,000	$ 6,964,000	$ 21,235,000	$ 19,552,000
Performance-Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expenses			$ 0		$ 0
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares reserved for future issuance	1,998,080
2020 Plan | Performance-Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of units. granted		365,000
Vesting terms					Each PSU is split into two tranches with each tranche having performance goals based on the achievement of pre-determined clinical milestones that result in the shares attributable to such tranche being eligible for vesting, subject to the service-based vesting condition. The service-based vesting condition is satisfied on the one-year anniversary of the performance achievement date for each tranche and is subject to the employee’s continuous service through such vesting date. Upon vesting, each PSU will automatically convert into one share of the Company’s common stock. If the performance condition for a tranche is not met by March 31, 2025, the shares attributable to such tranche will be forfeited.
Number of shares issuable upon vesting of each option			1		1

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 6,952	$ 6,964	$ 21,235	$ 19,552
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	4,648	3,728	14,556	10,011
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,304	$ 3,236	$ 6,679	$ 9,541

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Related Party Transaction [Line Items]
Research and development costs	$ 26,471	$ 45,766	$ 92,841	$ 100,011
Accrued expenses due	$ 63		$ 63		$ 543
Other Liability, Current, Related Party, Type [Extensible Enumeration]	us-gaap:RelatedPartyMember		us-gaap:RelatedPartyMember		us-gaap:RelatedPartyMember
ScalmiBio, Inc
Related Party Transaction [Line Items]
Maximum milestone payments payable	$ 35,000		$ 35,000
Retention milestone payment	$ 0		1,000
ScalmiBio, Inc | Former Chief Executive Officer and current Chief Scientific Officer and President
Related Party Transaction [Line Items]
Research and development costs			$ 300
Business acquisition, percentage of voting interests acquired	31.70%		31.70%
ScalmiBio, Inc | Employee
Related Party Transaction [Line Items]
Research and development costs			$ 600
Business acquisition, percentage of voting interests acquired	63.50%		63.50%
Research and Development Services Agreement | Tallac Therapeutics
Related Party Transaction [Line Items]
Research and development costs	$ 0	100	$ 300	300
Agreement termination date			Jul. 01, 2024
Collaboration Agreement | Tallac Therapeutics
Related Party Transaction [Line Items]
Research and development costs	100	$ 300	$ 700	$ 1,200
Accrued expenses due	$ 100		$ 100		$ 500
Other Liability, Current, Related Party, Type [Extensible Enumeration]	us-gaap:RelatedPartyMember		us-gaap:RelatedPartyMember		us-gaap:RelatedPartyMember

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Basic and Diluted Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net loss	$ (30,707)	$ (39,399)	$ (35,581)	$ (50,990)	$ (34,159)	$ (30,184)	$ (105,687)	$ (115,333)
Denominator:
Weighted-average shares of common stock outstanding, basic	52,693,878			41,147,938			51,544,501	40,963,015
Weighted-average shares of common stock outstanding, diluted	52,693,878			41,147,938			51,544,501	40,963,015
Net loss per share, basic	$ (0.58)			$ (1.24)			$ (2.05)	$ (2.82)
Net loss per share, diluted	$ (0.58)			$ (1.24)			$ (2.05)	$ (2.82)

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Outstanding Potentially Dilutive Securities Were Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	11,491,065	10,199,289	11,491,065	10,199,289
Stock Options Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	10,089,807	9,114,886	10,089,807	9,114,886
RSUs Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	1,026,238	1,084,403	1,026,238	1,084,403
PSUs Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	357,500		357,500
Employee Stock Purchase Plan Estimated Shares Issuable
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	17,520		17,520

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended
	Nov. 30, 2015 USD ($)	Sep. 30, 2024 USD ($) Litigation
Commitments And Contingencies [Line Items]
Guarantee obligations		$ 3,665,000
Future purchase obligations		$ 3,665,000
Number of pending or threatened litigation | Litigation		0
Master Service Agreement
Commitments And Contingencies [Line Items]
Initial term of agreement	3 years
Renewal periods of agreement	1 year
Future purchase obligations	$ 1,200,000
Other Pharmaceutical Manufacturing Contract
Commitments And Contingencies [Line Items]
Future purchase obligations	$ 2,500,000
Indemnification Agreement
Commitments And Contingencies [Line Items]
Guarantee obligations		$ 0

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Other Contractual Obligations and Other Commitments from Manufacturing and Service Contracts (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Manufacturing and service contracts, Total	$ 3,665
Manufacturing and service contracts, 2024 (remaining three months)	1,874
Manufacturing and service contracts, 2025 - 2026	1,741
Manufacturing and service contracts, 2027 - 2028	50
Contractual Obligation, Total	3,665
Contractual Obligation, 2024 (remaining three months)	1,874
Contractual Obligation, 2025 - 2026	1,741
Contractual Obligation, 2027 - 2028	$ 50

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Subsequent Events - Chief Medical Officer	Oct. 11, 2024 USD ($)
Subsequent Event [Line Items]
Cash payment	$ 503,880
Award exercisable period upon resignation	12 months
Exercisable date	Jul. 11, 2026
Maximum
Subsequent Event [Line Items]
COBRA coverage Period	18 months
Consulting service period upon resignation	18 months