ALX Oncology (ALXO) 10-Q 11 May 23 2023 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2023	May 04, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
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		40,869,135
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	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 63,194	$ 48,822
Short-term investments	164,750	217,385
Prepaid expenses and other current assets	4,592	4,762
Total current assets	232,536	270,969
Property and equipment, net	3,932	3,889
Long-term investments	28,220	16,699
Other assets	13,450	14,932
Total assets	278,138	306,489
Current liabilities:
Accounts payable	9,826	8,073
Payable and accrued liabilities due to related party	830	1,650
Accrued expenses and other current liabilities	11,235	18,602
Total current liabilities	21,891	28,325
Term loan, non-current	9,450	9,389
Other non-current liabilities	6,409	5,311
Total liabilities	37,750	43,025
Commitments and contingencies (Note 11)
Stockholders’ equity
Common stock, $0.001 par value; 1,000,000,000 shares authorized as of March 31, 2023 and December 31, 2022; 40,863,049 and 40,861,386 shares issued and outstanding as of March 31, 2023 and December 31, 2022, respectively	41	41
Additional paid-in capital	596,086	589,735
Accumulated other comprehensive loss	(88)	(845)
Accumulated deficit	(355,651)	(325,467)
Total stockholders’ equity	240,388	263,464
Total liabilities and stockholders’ equity	$ 278,138	$ 306,489

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
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	40,863,049	40,861,386
Common stock, shares outstanding	40,863,049	40,861,386

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating expenses:
Research and development	$ 24,763	$ 17,073
General and administrative	7,440	7,674
Total operating expenses	32,203	24,747
Loss from operations	(32,203)	(24,747)
Interest income	2,311	225
Interest expense	(387)	(3)
Other income (expense), net	95	(8)
Net loss	$ (30,184)	$ (24,533)
Net loss per share, basic	$ (0.74)	$ (0.60)
Net loss per share, diluted	$ (0.74)	$ (0.60)
Weighted-average shares of common stock used to compute net loss per share, basic	40,862,513	40,616,302
Weighted-average shares of common stock used to compute net loss per share, diluted	40,862,513	40,616,302

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (30,184)	$ (24,533)
Other comprehensive gain (loss), net of tax:
Unrealized gain (loss) on available-for-sale investments	757	(606)
Total comprehensive loss	$ (29,427)	$ (25,139)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2021	$ 363,049	$ 41	$ 564,993		$ (201,985)
Balance, shares at Dec. 31, 2021		40,587,067
Issuance of common stock under equity incentive plans	185		185
Issuance of common stock under equity incentive plans, shares		69,565
Stock-based compensation	5,501		5,501
Unrealized gain (loss) on available-for-sale investments	(606)			$ (606)
Net loss	(24,533)				(24,533)
Balance at Mar. 31, 2022	343,596	$ 41	570,679	(606)	(226,518)
Balance, shares at Mar. 31, 2022		40,656,632
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

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities
Net loss	$ (30,184)	$ (24,533)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	213	58
Non-cash lease costs	305	318
Stock-based compensation	6,351	5,501
Net amortization of premiums and accretion of discounts on investments	(1,114)	107
Accretion of term loan discount and issuance costs	61
Changes in operating assets and liabilities
Prepaid expenses and other current assets	170	(1,577)
Other assets	1,177	(317)
Accounts payable	1,767	1,553
Payable and accrued liabilities due to related party	(820)	(184)
Accrued expenses and other current liabilities	(5,551)	(1,304)
Other non-current liabilities	(191)	(296)
Net cash used in operating activities	(27,816)	(20,674)
Investing activities
Purchase of investments	(72,204)	(183,332)
Maturities of investments	115,189
Purchase of property and equipment	(690)	(589)
Net cash provided by (used in) investing activities	42,295	(183,921)
Financing activities
Proceeds from exercise of stock options under equity incentive plan		185
Principal payments on finance leases	(107)	(105)
Net cash (used in) provided by financing activities	(107)	80
Net increase (decrease) in cash, cash equivalents and restricted cash	14,372	(204,515)
Cash, cash equivalents and restricted cash at beginning of year	48,888	363,667
Cash, cash equivalents and restricted cash at end of period	63,260	159,152
Supplemental disclosure of non-cash investing and financing activities
Purchase of property and equipment in accounts payable and accrued expenses	1,711	147
Right-of-use asset acquired under operating leases		3,419
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents	63,194	159,086
Restricted cash (included in other assets)	66	66
Total cash and cash equivalents and restricted cash	$ 63,260	$ 159,152

Organization

Organization	3 Months Ended
	Mar. 31, 2023
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 date of 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. The Company's subsidiaries include: ALX Oncology Limited, incorporated in Ireland, and a wholly-owned subsidiary of ALX Oncology Holdings Inc.; ALX Oncology Inc., incorporated in Delaware, and a wholly-owned subsidiary of ALX Oncology Limited; and Alexo International Holdings Limited, incorporated in Malta, and a wholly-owned subsidiary of ALX Oncology Inc. (collectively, the Subsidiaries). As of March 31, 2023, 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 twelve months after the filing date.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
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, 2022 filed with the SEC on March 9, 2023. The condensed consolidated balance sheet as of March 31, 2023 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, 2023. Reclassifications Certain amounts in the prior period have been reclassified to conform to the current period presentation. 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, 2022. Recent Accounting Pronouncements None.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2023
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. ASC 820 defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value hierarchy of ASC 820 requires an entity to maximize the use of observable inputs when measuring fair value and classifies those inputs into three levels: Level 1—Observable inputs, such as quoted prices in active markets; Level 2—Inputs, other than the quoted prices in active markets, which are observable either directly or indirectly such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the instrument’s anticipated life; and Level 3—Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. 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. The Company classifies money market funds and U.S. treasury securities as Level 1 within the fair value hierarchy as the fair value is based on quoted prices. The Company classifies its investments in U.S. government agency securities, corporate debt securities, commercial paper, and asset-backed securities as Level 2 within the fair value hierarchy as the fair value is estimated by third-party pricing sources using quoted prices for identical or similar instruments in markets that are not active and industry-standard model-based valuation techniques for which all significant inputs are observable in the market or can be corroborated by observable market data for substantially the full term of the assets. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs obtained from various third-party data providers, including but not limited to benchmark yields, reported trades and broker/dealer quotes. Where applicable the market approach utilizes prices and information from market transactions for similar or identical assets. 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 March 31, 2023 and December 31, 2022 (in thousands): March 31, 2023 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents Money market funds Level 1 $ 59,300 $ — $ — $ 59,300 Short-term investments U.S. Treasury securities Level 1 64,536 33 ( 136 ) 64,433 U.S. government agency securities Level 2 29,177 44 ( 1 ) 29,220 Corporate debt securities Level 2 29,020 6 ( 101 ) 28,925 Commercial paper Level 2 37,185 — — 37,185 Asset-backed securities Level 2 5,005 — ( 18 ) 4,987 Long-term investments U.S. Treasury securities Level 1 18,398 92 — 18,490 U.S. government agency securities Level 2 8,201 8 — 8,209 Asset-backed securities Level 2 1,536 — ( 15 ) 1,521 Total $ 252,358 $ 183 $ ( 271 ) $ 252,270 December 31, 2022 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents Money market funds Level 1 $ 36,690 $ — $ — $ 36,690 U.S. government agency securities Level 2 3,484 — — 3,484 Short-term investments U.S. Treasury securities Level 1 73,058 3 ( 438 ) 72,623 U.S. government agency securities Level 2 16,227 36 — 16,263 Corporate debt securities Level 2 56,318 — ( 367 ) 55,951 Commercial paper Level 2 62,087 — — 62,087 Asset-backed securities Level 2 10,512 — ( 51 ) 10,461 Long-term investments U.S. Treasury securities Level 1 5,242 2 — 5,244 U.S. government agency securities Level 2 9,760 — ( 15 ) 9,745 Asset-backed securities Level 2 1,725 — ( 15 ) 1,710 Total $ 275,103 $ 41 $ ( 886 ) $ 274,258 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 March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Cash and cash equivalents $ 59,300 $ 40,174 Short-term investments 164,750 217,385 Long-term investments 28,220 16,699 Total $ 252,270 $ 274,258 Cash and cash equivalents in the above table excludes bank account cash of $ 3.9 million and $ 8.6 million as of March 31, 2023 and December 31, 2022, respectively. The fair value of cash equivalents and available-for-sale investments by contractual maturity was as follows as of March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Maturing in one year or less $ 224,050 $ 257,559 Maturing after one year through five years 28,220 16,699 Total $ 252,270 $ 274,258 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 ended March 31, 2023 and 2022 and there were no financial instruments classified as Level 3 as of March 31, 2023 and 2022. As of March 31, 2023 and December 31, 2022, accrued interest receivable related to the Company’s investments of $ 0.8 million and $ 1.0 million , respectively, was included in prepaid expenses and other current assets as well as other assets on the condensed consolidated balance sheet. As of March 31, 2023, 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 March 31, 2023 , no allowance for credit losses for the Company’s investments was recorded. As of March 31, 2023 and December 31, 2022, securities with a fair value of $ 28.4 million and zero , respectively, were in a continuous net unrealized loss position for more than 12 months. As of March 31, 2023 , the Company has no t recognized any impairment losses on available-for-sale investments.

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2023
Balance Sheet Related Disclosures [Abstract]
BALANCE SHEET COMPONENTS	(4) BALANCE SHEET COMPONENTS Property and Equipment, Net The following table presents the components of property and equipment, net as of March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Leasehold improvements $ 2,544 $ 2,360 Laboratory equipment 1,475 1,422 Computer hardware and software 363 344 Furniture and fixtures 166 166 Property and equipment, gross 4,548 4,292 Less: accumulated depreciation ( 616 ) ( 403 ) Property and equipment, net $ 3,932 $ 3,889 Depreciation was $ 0.2 million and nominal for the three months ended March 31, 2023 and 2022, respectively. Other Assets The following table presents the components of other assets as of March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Long-term prepaid clinical expenses $ 7,220 $ 7,264 Operating lease right-of-use assets 5,433 5,626 Long-term prepaid contract manufacturing costs 219 1,456 Finance lease right-of-use assets 186 298 Deposits 144 144 Accrued interest receivable 182 78 Restricted cash 66 66 Total other assets $ 13,450 $ 14,932 Accrued Expenses and Other Current Liabilities The following table presents the components of accrued expenses and other current liabilities as of March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Accrued clinical and nonclinical study costs $ 3,531 $ 5,485 Accrued contract manufacturing 3,197 5,249 Accrued compensation and related expenses 2,074 3,708 Accrued professional fees 797 835 Operating lease liabilities, current 777 755 Accrued property and equipment 422 2,110 Finance lease liabilities, current 179 286 Other 258 174 Total accrued expenses and other current liabilities $ 11,235 $ 18,602

Leases

Leases	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
LEASES	(5) LEASES The Company has non-cancelable operating leases for its offices located in the U.S. As of March 31, 2023 , 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. As of March 31, 2023, the right-of-use, or ROU, assets recorded for operating leases and finance leases were $ 5.4 million and $ 0.2 million , respectively. These amounts were included in other assets on the condensed consolidated balance sheets. The following table presents the maturities and balance sheet information of the Company’s operating and finance lease liabilities as of March 31, 2023 (in thousands, except lease term and discount rate): March 31, 2023 Operating Leases Finance Leases 2023 $ 1,240 $ 288 2024 1,267 — 2025 1,305 — 2026 1,187 — 2027 912 — Thereafter 2,069 — Total lease payments 7,980 288 Less: imputed interest ( 2,143 ) ( 109 ) Total lease liabilities $ 5,837 $ 179 Lease liabilities: current (i) $ 781 $ 179 Lease liabilities: non-current (ii) 5,056 — Total lease liabilities $ 5,837 $ 179 Weighted average remaining lease term (in years) 6.1 0.4 Weighted average discount rate 8.5 % 1.7 % (i) Current lease liabilities are presented within accrued expenses and other current liabilities and payable and accrued liabilities due to related party on the condensed consolidated balance sheets and includes a nominal amount due to Tallac Therapeutics, Inc. for an operating lease. Refer to Note 9 “Related Party Transactions” for additional discussion. (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 ended March 31, 2023 and 2022 (in thousands): Three Months Ended March 31, 2023 2022 Operating lease cost $ 318 $ 249 Variable lease cost and other, net (i) 116 52 Short-term lease cost 3 44 Finance lease cost: Amortization of right-of-use assets 112 112 Interest 1 3 Total lease costs $ 550 $ 460 (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 the three months ended March 31, 2023 and 2022 (in thousands): Three Months Ended March 31, 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 310 $ 169 Operating cash flows from finance leases $ 1 $ 3 Financing cash flows from finance leases $ 107 $ 105

Term Loan

Term Loan	3 Months Ended
	Mar. 31, 2023
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, or the Loan Agreement, with Oxford Finance LLC, Oxford Finance Credit Fund II LP, and Silicon Valley Bank (SVB), or 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 and has access to draw an additional $ 40.0 million through the end of 2023. The Loan Agreement provides 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 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, 2022, which was filed with the Securities and Exchange Commission on March 9, 2023. The Company received net proceeds from issuance of the term loan of $ 9.3 million after deducting debt issuance costs of approximately $ 0.7 million. Debt issuance costs were recorded as debt discount on the term loan, offsetting term loan, non-current on the consolidated balance sheet. The debt discount will be amortized over the term of the loan as interest expense using the effective interest method. During the three months ended March 31, 2023, interest expense incurred in connection with the Loan Agreement was $ 0.3 million . We had no outstanding debt as of March 31, 2022 and did no t incur interest expense during the three months ended March 31, 2022. The Company determined that certain loan features were embedded derivatives requiring bifurcation and separate accounting. Those embedded derivatives were bundled together as a single, compound embedded derivative and then bifurcated and accounted for separately from the host contract. As of March 31, 2023, the value of the embedded derivative is not material, but could become material in future periods if an event of default became more probable than is currently estimated. As of March 31, 2023, we were in compliance with all financial reporting covenants under the Loan Agreement. On March 10, 2023, SVB was closed by the California Department of Financial Protection and Innovation, which appointed the Federal Deposit Insurance Corporation (FDIC) to act as receiver. On March 13, 2023, the FDIC created Silicon Valley Bridge Bank, N.A. (SVBB) as successor to SVB. On March 27, 2023, First Citizens BancShares, Inc. (First Citizens Bank) acquired SVBB from the FDIC and plans to operate SVBB as Silicon Valley Bank, a division of First Citizens Bank (SVB-First Citizens). Under the Loan Agreement with Lenders, 50 % of the funding comes from SVB, one of the three Lenders. Given the SVBB acquisition by First Citizens Bank, the Company expects SVB-First Citizens to continue to fulfill SVB’s obligations under the Loan Agreement. As of March 31, 2023, the future maturities under the Loan Agreement are as follows (in thousands): March 31, 2023 2023 $ — 2024 — 2025 435 2026 5,217 2027 4,948 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 ( 941 ) Less: unaccreted final payment costs ( 209 ) Term loan, non-current, net $ 9,450

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 and December 31, 2022, the Company had 40,863,049 and 40,861,386 shares of common stock outstanding, respectively. Common stock reserved for future issuance as of March 31, 2023 consists of the following: March 31, 2023 Stock options issued and outstanding 6,511,136 Stock options authorized for future issuance 4,278,052 Employee Stock Purchase Plan shares authorized for future issuance 1,147,986 Restricted stock issued and outstanding 793,088 Total 12,730,262

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2023
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, 2023, the number of shares available under the 2020 Plan was increased by 1,634,456 shares. As of March 31, 2023, the number of shares of common stock available for issuance under the 2020 Plan was 4,278,052 . 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. As of March 31, 2023, the number of shares of common stock available for issuance under the ESPP was 1,147,986 . 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 March 31, 2023 2022 Research and development $ 3,214 $ 2,075 General and administrative 3,137 3,426 Total $ 6,351 $ 5,501

Related-Party Transactions

Related-Party Transactions	3 Months Ended
	Mar. 31, 2023
Related Party Transactions [Abstract]
RELATED-PARTY TRANSACTIONS	(9) RELATED-PARTY TRANSACTIONS The Company has several related-party agreements with Tallac Therapeutics, Inc., or Tallac. 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, 2022, which was filed with the Securities and Exchange Commission on March 9, 2023. During the three months ended March 31, 2023, there were no material changes to these agreements. Tallac Service Agreement During the three months ended March 31, 2023 and 2022, the Company recorded $ 0.1 million and $ 0.2 million , respectively, as research and development, or R&D, costs in relation to the research and development services agreement with Tallac. Tallac Collaboration Agreement During the three months ended March 31, 2023 and 2022, the Company recorded $ 0.7 million and $ 1.2 million , respectively, as R&D costs in relation to the collaboration agreement with Tallac, or the Tallac Collaboration Agreement. As of March 31, 2023 and December 31, 2022, the Company had accrued expenses of $ 0.7 million and $ 1.6 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. Operating Sub-lease Agreement with Tallac The Company leases office space in Burlingame, California under a single operating sub-lease agreement with Tallac. Refer to Note 5 “Leases” for additional discussion.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2023
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 ended March 31, 2023 and 2022 (in thousands, except share and per share data): Three Months Ended March 31, 2023 2022 Numerator: Net loss $ ( 30,184 ) $ ( 24,533 ) Denominator: Weighted-average shares of common stock outstanding, basic and diluted 40,862,513 40,616,302 Net loss per share, basic and diluted $ ( 0.74 ) $ ( 0.60 ) 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 ended March 31, 2023 and 2022 because including them would have been anti-dilutive: Three Months Ended March 31, 2023 2022 Stock options issued and outstanding 6,511,136 4,944,796 Restricted stock issued and outstanding 793,088 500,387 Employee Stock Purchase Plan estimated shares issuable 14,962 11,674 Total 7,319,186 5,456,857

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023. 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 March 31, 2023 , the Company had no pending or threatened litigation. Other Contractual Obligations and Other Commitments We have other contractual obligations and other commitments from manufacturing and service contracts, which are presented as follows as of March 31, 2023 (in thousands): March 31, 2023 Total 2023 2024-2025 2026-2027 Thereafter Manufacturing and service contracts 14,423 12,303 2,090 30 — Total $ 14,423 $ 12,303 $ 2,090 $ 30 $ — 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 approximately $ 9.8 million . In addition, the Company has commitments with one other pharmaceutical contract manufacturer, including certain future purchase obligations of approximately $ 4.6 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	3 Months Ended
	Mar. 31, 2023
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	(12 ) SUBSEQUENT EVENTS In preparing the consolidated financial statements as of March 31, 2023 , the Company evaluated subsequent events for recognition and measurement purposes through the filing date of this Quarterly Report on Form 10-Q. The Company concluded that no events or transactions have occurred that require disclosure in the accompanying condensed consolidated financial statements.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
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, 2022 filed with the SEC on March 9, 2023. The condensed consolidated balance sheet as of March 31, 2023 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, 2023.
Reclassifications	Reclassifications Certain amounts in the prior period have been reclassified to conform to the current period presentation.
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.
Adopted Accounting Pronouncements	Accounting Pronouncements None.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 and December 31, 2022 (in thousands): March 31, 2023 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents Money market funds Level 1 $ 59,300 $ — $ — $ 59,300 Short-term investments U.S. Treasury securities Level 1 64,536 33 ( 136 ) 64,433 U.S. government agency securities Level 2 29,177 44 ( 1 ) 29,220 Corporate debt securities Level 2 29,020 6 ( 101 ) 28,925 Commercial paper Level 2 37,185 — — 37,185 Asset-backed securities Level 2 5,005 — ( 18 ) 4,987 Long-term investments U.S. Treasury securities Level 1 18,398 92 — 18,490 U.S. government agency securities Level 2 8,201 8 — 8,209 Asset-backed securities Level 2 1,536 — ( 15 ) 1,521 Total $ 252,358 $ 183 $ ( 271 ) $ 252,270 December 31, 2022 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents Money market funds Level 1 $ 36,690 $ — $ — $ 36,690 U.S. government agency securities Level 2 3,484 — — 3,484 Short-term investments U.S. Treasury securities Level 1 73,058 3 ( 438 ) 72,623 U.S. government agency securities Level 2 16,227 36 — 16,263 Corporate debt securities Level 2 56,318 — ( 367 ) 55,951 Commercial paper Level 2 62,087 — — 62,087 Asset-backed securities Level 2 10,512 — ( 51 ) 10,461 Long-term investments U.S. Treasury securities Level 1 5,242 2 — 5,244 U.S. government agency securities Level 2 9,760 — ( 15 ) 9,745 Asset-backed securities Level 2 1,725 — ( 15 ) 1,710 Total $ 275,103 $ 41 $ ( 886 ) $ 274,258
Schedule of Fair Value of Available for Sale Investments	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 March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Cash and cash equivalents $ 59,300 $ 40,174 Short-term investments 164,750 217,385 Long-term investments 28,220 16,699 Total $ 252,270 $ 274,258
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 March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Maturing in one year or less $ 224,050 $ 257,559 Maturing after one year through five years 28,220 16,699 Total $ 252,270 $ 274,258

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Schedule of Components of Property and Equipment	The following table presents the components of property and equipment, net as of March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Leasehold improvements $ 2,544 $ 2,360 Laboratory equipment 1,475 1,422 Computer hardware and software 363 344 Furniture and fixtures 166 166 Property and equipment, gross 4,548 4,292 Less: accumulated depreciation ( 616 ) ( 403 ) Property and equipment, net $ 3,932 $ 3,889
Schedule of Components of Other Assets, Net	The following table presents the components of other assets as of March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Long-term prepaid clinical expenses $ 7,220 $ 7,264 Operating lease right-of-use assets 5,433 5,626 Long-term prepaid contract manufacturing costs 219 1,456 Finance lease right-of-use assets 186 298 Deposits 144 144 Accrued interest receivable 182 78 Restricted cash 66 66 Total other assets $ 13,450 $ 14,932
Components of Accrued Expenses and Other Current Liabilities	The following table presents the components of accrued expenses and other current liabilities as of March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, 2023 2022 Accrued clinical and nonclinical study costs $ 3,531 $ 5,485 Accrued contract manufacturing 3,197 5,249 Accrued compensation and related expenses 2,074 3,708 Accrued professional fees 797 835 Operating lease liabilities, current 777 755 Accrued property and equipment 422 2,110 Finance lease liabilities, current 179 286 Other 258 174 Total accrued expenses and other current liabilities $ 11,235 $ 18,602

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2023
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 and finance lease liabilities as of March 31, 2023 (in thousands, except lease term and discount rate): March 31, 2023 Operating Leases Finance Leases 2023 $ 1,240 $ 288 2024 1,267 — 2025 1,305 — 2026 1,187 — 2027 912 — Thereafter 2,069 — Total lease payments 7,980 288 Less: imputed interest ( 2,143 ) ( 109 ) Total lease liabilities $ 5,837 $ 179 Lease liabilities: current (i) $ 781 $ 179 Lease liabilities: non-current (ii) 5,056 — Total lease liabilities $ 5,837 $ 179 Weighted average remaining lease term (in years) 6.1 0.4 Weighted average discount rate 8.5 % 1.7 % (i) Current lease liabilities are presented within accrued expenses and other current liabilities and payable and accrued liabilities due to related party on the condensed consolidated balance sheets and includes a nominal amount due to Tallac Therapeutics, Inc. for an operating lease. Refer to Note 9 “Related Party Transactions” for additional discussion. (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 ended March 31, 2023 and 2022 (in thousands): Three Months Ended March 31, 2023 2022 Operating lease cost $ 318 $ 249 Variable lease cost and other, net (i) 116 52 Short-term lease cost 3 44 Finance lease cost: Amortization of right-of-use assets 112 112 Interest 1 3 Total lease costs $ 550 $ 460 (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 the three months ended March 31, 2023 and 2022 (in thousands): Three Months Ended March 31, 2023 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 310 $ 169 Operating cash flows from finance leases $ 1 $ 3 Financing cash flows from finance leases $ 107 $ 105

Term Loan (Tables)

Term Loan (Tables)	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Schedule of Future Maturities Under the Loan Agreement	As of March 31, 2023, the future maturities under the Loan Agreement are as follows (in thousands): March 31, 2023 2023 $ — 2024 — 2025 435 2026 5,217 2027 4,948 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 ( 941 ) Less: unaccreted final payment costs ( 209 ) Term loan, non-current, net $ 9,450

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Common Stock Reserved for Future Issuance	Common stock reserved for future issuance as of March 31, 2023 consists of the following: March 31, 2023 Stock options issued and outstanding 6,511,136 Stock options authorized for future issuance 4,278,052 Employee Stock Purchase Plan shares authorized for future issuance 1,147,986 Restricted stock issued and outstanding 793,088 Total 12,730,262

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 2022 Research and development $ 3,214 $ 2,075 General and administrative 3,137 3,426 Total $ 6,351 $ 5,501

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2023
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 ended March 31, 2023 and 2022 (in thousands, except share and per share data): Three Months Ended March 31, 2023 2022 Numerator: Net loss $ ( 30,184 ) $ ( 24,533 ) Denominator: Weighted-average shares of common stock outstanding, basic and diluted 40,862,513 40,616,302 Net loss per share, basic and diluted $ ( 0.74 ) $ ( 0.60 )
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 ended March 31, 2023 and 2022 because including them would have been anti-dilutive: Three Months Ended March 31, 2023 2022 Stock options issued and outstanding 6,511,136 4,944,796 Restricted stock issued and outstanding 793,088 500,387 Employee Stock Purchase Plan estimated shares issuable 14,962 11,674 Total 7,319,186 5,456,857

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Summary of Other Contractual Obligations and Other Commitments from Manufacturing and Service Contracts	We have other contractual obligations and other commitments from manufacturing and service contracts, which are presented as follows as of March 31, 2023 (in thousands): March 31, 2023 Total 2023 2024-2025 2026-2027 Thereafter Manufacturing and service contracts 14,423 12,303 2,090 30 — Total $ 14,423 $ 12,303 $ 2,090 $ 30 $ —

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Sep. 30, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets and liabilities transfers amount	$ 0	$ 0
Fair value assets transferred into level 3	0
Fair value assets transferred out of level 3		0
Fair value liabilities transferred into level 3	0	0
Fair value liabilities transferred out of level 3	0	$ 0
Accrued interest receivable, investment	$ 800,000		$ 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
Bank account cash			$ 8,600,000	$ 3,900,000
Allowance for credit losses	$ 0
Fair value of securities, continuous unrealized loss position for more than 12 months	28,400,000		$ 0
Impairment losses on available-for-sale investments	$ 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	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Fair Value	$ 252,270	$ 274,258
Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	252,358	275,103
Unrealized Gains	183	41
Unrealized Losses	(271)	(886)
Fair Value	252,270	274,258
Money Market Funds | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	59,300	36,690
Fair Value	59,300	36,690
U.S. Government Agency Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost		3,484
Fair Value		3,484
Short Term Investment U.S. Treasury Securities | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	64,536	73,058
Unrealized Gains	33	3
Unrealized Losses	(136)	(438)
Fair Value	64,433	72,623
Short Term Investment U.S. Government Agency Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	29,177	16,227
Unrealized Gains	44	36
Unrealized Losses	(1)
Fair Value	29,220	16,263
Short Term Investment Corporate Debt Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	29,020	56,318
Unrealized Gains	6
Unrealized Losses	(101)	(367)
Fair Value	28,925	55,951
Short Term Investment Commercial Paper | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	37,185	62,087
Fair Value	37,185	62,087
Short Term Investment Asset-Backed Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	5,005	10,512
Unrealized Losses	(18)	(51)
Fair Value	4,987	10,461
Long Term Investment U.S. Treasury Securities | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	18,398	5,242
Unrealized Gains	92	2
Fair Value	18,490	5,244
Long-term Investment U.S. Government Agency Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	8,201	9,760
Unrealized Gains	8
Unrealized Losses		(15)
Fair Value	8,209	9,745
Long Term Investment Asset-Backed Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	1,536	1,725
Unrealized Losses	(15)	(15)
Fair Value	$ 1,521	$ 1,710

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Schedule of Fair Value of Available for Sale Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total available-for-sale investments	$ 252,270	$ 274,258
Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents available for sale	59,300	40,174
Short-term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments available for sale	164,750	217,385
Long-term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long term investments available for sale	$ 28,220	$ 16,699

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	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract]
Maturing in one year or less	$ 224,050	$ 257,559
Maturing after one year through five years	28,220	16,699
Total available-for-sale investments	$ 252,270	$ 274,258

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Components of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 4,548	$ 4,292
Less: accumulated depreciation	(616)	(403)
Property and equipment, net	3,932	3,889
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	2,544	2,360
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,475	1,422
Computer Hardware and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	363	344
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
	Mar. 31, 2023	Mar. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Depreciation	$ 0.2	$ 0.2

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Components of Other Assets, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Operating lease right-of-use assets	$ 5,433	$ 5,626
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total other assets	Total other assets
Finance lease right-of-use assets	$ 186	$ 298
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total other assets	Total other assets
Deposits	$ 144	$ 144
Accrued interest receivable	182	78
Restricted cash	66	66
Total other assets	13,450	14,932
Long-term Prepaid Clinical Expenses
Property Plant And Equipment [Line Items]
Long-term prepaid expenses	7,220	7,264
Long-term Prepaid Contract Manufacturing Costs
Property Plant And Equipment [Line Items]
Long-term prepaid expenses	$ 219	$ 1,456

Balance Sheet Components - Comp

Balance Sheet Components - Components of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Accrued clinical and nonclinical study costs	$ 3,531	$ 5,485
Accrued contract manufacturing	3,197	5,249
Accrued compensation and related expenses	2,074	3,708
Accrued professional fees	797	835
Operating lease liabilities, current	$ 777	$ 755
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Total accrued expenses and other current liabilities	Total accrued expenses and other current liabilities
Accrued property and equipment	$ 422	$ 2,110
Finance lease liabilities, current	$ 179	$ 286
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Total accrued expenses and other current liabilities	Total accrued expenses and other current liabilities
Other	$ 258	$ 174
Total accrued expenses and other current liabilities	$ 11,235	$ 18,602

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Lessee Lease Description [Line Items]
Operating lease ROU assets	$ 5,433	$ 5,626
Operating lease, description	The Company has non-cancelable operating leases for its offices located in the U.S. As of March 31, 2023, 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.
Finance lease ROU assets	$ 186	$ 298
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) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2023	$ 1,240
2024	1,267
2025	1,305
2026	1,187
2027	912
Thereafter	2,069
Total lease payments	7,980
Less: imputed interest	(2,143)
Operating lease liabilities	5,837
Lease liabilities: current	781
Lease liabilities: non-current	$ 5,056
Operating lease, liability, noncurrent, statement of financial position [extensible list]	Other non-current liabilities
Total lease liabilities	$ 5,837
Weighted average remaining lease term (in years)	6 years 1 month 6 days
Weighted average discount rate	8.50%
Finance Lease, Liability, Payment, Due [Abstract]
2023	$ 288
Total lease payments	288
Less: imputed interest	(109)
Finance lease liabilities	179
Finance lease liabilities, current	179	$ 286
Total lease liabilities	$ 179
Weighted average remaining lease term (in years)	4 months 24 days
Weighted average discount rate	1.70%

Leases - Components of Lease Co

Leases - Components of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Leases [Abstract]
Operating lease cost	$ 318	$ 249
Variable lease cost and other, net	116	52
Short-term lease cost	3	44
Finance lease cost, Amortization of right-of-use assets	112	112
Finance lease cost, Interest	1	3
Total lease costs	$ 550	$ 460

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Disclosures for Cash Paid for Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 310	$ 169
Operating cash flows from finance leases	1	3
Financing cash flows from finance leases	$ 107	$ 105

Term Loan - Additional Informat

Term Loan - Additional Information (Details)		1 Months Ended	3 Months Ended
	Mar. 27, 2023	Oct. 31, 2022 USD ($)	Mar. 31, 2023 USD ($) Lenders	Mar. 31, 2022 USD ($)
Oxford-SVB Loan Agreement
Debt Instrument [Line Items]
Issuance of term loan		$ 9,300,000
Draw an additional loan		50,000,000
deduction of debt issuance costs		700,000
Interest expense			$ 300,000
Number of lenders | Lenders			3
SVB
Debt Instrument [Line Items]
Loan Agreement with Lenders	50%
Term Loan | Oxford-SVB Loan Agreement
Debt Instrument [Line Items]
Interest expense				$ 0
Outstanding debt				$ 0
Tranche A | Oxford-SVB Loan Agreement
Debt Instrument [Line Items]
Issuance of term loan		10,000,000
Draw an additional loan		40,000,000
Tranche B | Oxford-SVB Loan Agreement
Debt Instrument [Line Items]
Available borrowing capacity upon achievement of milestones		12,500,000
Tranche C | Oxford-SVB Loan Agreement
Debt Instrument [Line Items]
Available borrowing capacity upon achievement of milestones		12,500,000
Tranche D | Oxford-SVB Loan Agreement
Debt Instrument [Line Items]
Available borrowing capacity at lender's discretion		25,000,000
Maximum | Secured Term Loan Facility | Oxford-SVB Loan Agreement
Debt Instrument [Line Items]
Term loan, principal amount		$ 100,000,000

Term Loan - Schedule of Future

Term Loan - Schedule of Future Maturities Under the Loan Agreement (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
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	(941)
Less: unaccreted final payment costs	(209)
Term loan, non-current, net	$ 9,450	$ 9,389

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - $ / shares	Mar. 31, 2023	Dec. 31, 2022	Jul. 21, 2020
Class Of Stock [Line Items]
Common stock, shares authorized	1,000,000,000	1,000,000,000	1,000,000,000
Common stock, par value	$ 0.001	$ 0.001	$ 0.001
Preferred stock, par value			$ 0.001
Common stock, shares outstanding	40,863,049	40,861,386
Undesignated Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares authorized			100,000,000

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock Reserved for Future Issuance (Details)	Mar. 31, 2023 shares
Class Of Stock [Line Items]
Common stock reserved for future issuance	12,730,262
Stock Options Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance	6,511,136
Stock Options Authorized for Future Issuance
Class Of Stock [Line Items]
Common stock reserved for future issuance	4,278,052
Employee Stock Purchase Plan Shares Authorized for Future Issuance
Class Of Stock [Line Items]
Common stock reserved for future issuance	1,147,986
Restricted Stock Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance	793,088

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - shares	Jan. 01, 2023	Mar. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance		12,730,262
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance		1,147,986
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance		4,278,052
Number of additional shares reserved for future issuance	1,634,456

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 6,351	$ 5,501
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	3,214	2,075
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,137	$ 3,426

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Related Party Transaction [Line Items]
Research and development costs	$ 24,763	$ 17,073
Research and Development Services Agreement | Tallac Therapeutics
Related Party Transaction [Line Items]
Research and development costs	100	200
Collaboration Agreement | Tallac Therapeutics
Related Party Transaction [Line Items]
Research and development costs	700	$ 1,200
Accrued expenses due	$ 700		$ 1,600

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
	Mar. 31, 2023	Mar. 31, 2022
Numerator:
Net loss	$ (30,184)	$ (24,533)
Denominator:
Weighted-average shares of common stock outstanding, basic	40,862,513	40,616,302
Weighted-average shares of common stock outstanding, diluted	40,862,513	40,616,302
Net loss per share, basic	$ (0.74)	$ (0.60)
Net loss per share, diluted	$ (0.74)	$ (0.60)

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
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	7,319,186	5,456,857
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	6,511,136	4,944,796
Restricted Stock Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	793,088	500,387
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	14,962	11,674

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended
	Nov. 30, 2015 USD ($)	Mar. 31, 2023 USD ($) Litigation
Commitments And Contingencies [Line Items]
Guarantee obligations		$ 14,423,000
Future purchase obligations		$ 14,423,000
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	$ 9,800,000
Other Pharmaceutical Manufacturing Contract
Commitments And Contingencies [Line Items]
Future purchase obligations		$ 4,600,000
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	Mar. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Manufacturing and service contracts, Total	$ 14,423
Manufacturing and service contracts, 2023	12,303
Manufacturing and service contracts, 2024 - 2025	2,090
Manufacturing and service contracts, 2026 - 2027	30
Contractual Obligation, Total	14,423
Contractual Obligation, 2023	12,303
Contractual Obligation, 2024 - 2025	2,090
Contractual Obligation, 2026 - 2027	$ 30