ALX Oncology (ALXO) 10-Q 9 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 02, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
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	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		40,680,947
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, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 159,086	$ 363,667
Short-term investments	157,510
Prepaid expenses and other current assets	4,929	3,352
Total current assets	321,525	367,019
Property and equipment, net	1,338	897
Long-term investments	25,109
Other assets	15,704	12,267
Total assets	363,676	380,183
Current liabilities:
Accounts payable	5,133	3,764
Payable and accrued liabilities due to related party	1,446	1,630
Accrued expenses and other current liabilities	8,729	9,901
Total current liabilities	15,308	15,295
Other non-current liabilities	4,772	1,839
Total liabilities	20,080	17,134
Commitments and contingencies (Note 10)
Stockholders’ equity
Common stock, $0.001 par value; 1,000,000,000 shares authorized as of March 31, 2022 and December 31, 2021; 40,656,632 and 40,587,067 shares issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	41	41
Additional paid-in capital	570,679	564,993
Accumulated other comprehensive loss	(606)
Accumulated deficit	(226,518)	(201,985)
Total stockholders’ equity	343,596	363,049
Total liabilities and stockholders’ equity	$ 363,676	$ 380,183

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
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	40,656,632	40,587,067
Common stock, shares outstanding	40,656,632	40,587,067

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating expenses:
Research and development	$ 17,073	$ 9,849
General and administrative	7,674	4,359
Total operating expenses	24,747	14,208
Loss from operations	(24,747)	(14,208)
Interest income	225	25
Other income (expense), net	(11)	(2)
Net loss	$ (24,533)	$ (14,185)
Net loss per share , basic and diluted	$ (0.60)	$ (0.35)
Weighted-average shares of common stock used to compute net loss per shares, basic and diluted	40,616,302	40,055,435

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Profit Loss	$ (24,533)	$ (14,185)
Other comprehensive loss, net of tax:
Unrealized loss on available-for-sale investments	(606)
Total comprehensive loss	$ (25,139)	$ (14,185)

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, 2020	$ 429,845	$ 40	$ 548,327		$ (118,522)
Balance, shares at Dec. 31, 2020		39,844,522
Issuance of common stock under equity incentive plans	1,024		1,024
Issuance of common stock under equity incentive plans, shares		364,047
Stock-based compensation	1,800		1,800
Net loss	(14,185)				(14,185)
Balance at Mar. 31, 2021	418,484	$ 40	551,151		(132,707)
Balance, shares at Mar. 31, 2021		40,208,569
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 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

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (24,533)	$ (14,185)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	58	5
Non-cash lease costs	318	58
Stock-based compensation	5,501	1,800
Net amortization of premiums and accretion of discounts on investments	107
Changes in operating assets and liabilities
Prepaid expenses and other current assets	(1,577)	(453)
Other assets	(317)	(583)
Accounts payable	1,553	7,346
Payable and accrued liabilities due to related party	(184)
Accrued expenses and other current liabilities	(1,304)	585
Other non-current liabilities	(296)	292
Net cash used in operating activities	(20,674)	(5,135)
Investing activities
Purchase of investments	(183,332)
Purchase of property and equipment	(589)	(7)
Net cash provided by (used in) investing activities	(183,921)	(7)
Financing activities
Proceeds from exercise of stock options under equity incentive plan	185	778
Principal payments on finance leases	(105)
Net cash provided by financing activities	80	778
Net decrease in cash, cash equivalents and restricted cash	(204,515)	(4,364)
Cash, cash equivalents and restricted cash at beginning of year	363,667	434,219
Cash, cash equivalents and restricted cash at end of year	159,152	429,855
Supplemental disclosure of non-cash investing and financing activities
Purchase of property and equipment in accounts payable and accrued expenses	147
Right-of-use asset acquired under operating leases	3,419
Receivables for cash in-transit on exercise of common stock under equity incentive plans		246
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents	159,086	429,855
Restricted cash (included in other assets)	66
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Total	$ 159,152	$ 429,855

Organization

Organization	3 Months Ended
	Mar. 31, 2022
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. The Company owns subsidiaries, consisting of ALX Oncology Limited, incorporated in Ireland; ALX Oncology Inc., incorporated in the United States, Alexo International Holdings Ltd, incorporated in Malta; ScalmiBio, Inc., incorporated in the United States, Alexo Therapeutics International, incorporated in the Cayman Islands, which is a wholly-owned subsidiary of Alexo International Holdings Ltd., and Sirpant Therapeutics, incorporated in the Cayman Islands, which is a wholly-owned subsidiary of Alexo Therapeutics International, or collectively, the Subsidiaries. As of March 31, 2022, 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 has no 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 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	3 Months Ended
	Mar. 31, 2022
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 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 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, 2021 filed with the SEC on February 28, 2022. The condensed consolidated balance sheet as of March 31, 2022 included herein was derived from the audited financial statements as of that date, but does not include all disclosures including notes required by 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, 2022 . 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 those related to the estimated useful lives of long-lived assets, clinical trial accruals, fair value of assets and liabilities, income taxes 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 materially 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, 2021 other than the below policy on Investments. Investments Investments consist of money market funds, U.S. Treasury securities, corporate debt securities and commercial paper. The Company’s investments are classified as available-for-sale and carried at estimated fair values and reported in cash equivalents, short-term investments and long-term investments. Management determines the appropriate classification of the investments at the time they are purchased and evaluates the appropriateness of such classifications at each balance sheet date. Investments with contractual maturities greater than 12 months at date of purchase are considered long-term investments. The Company regularly reviews its investments for declines in estimated fair value below amortized cost. The factors considered in determining whether a credit loss exists include the creditworthiness of the security issuers, the number of investments in an unrealized loss position, the severity and duration of the unrealized losses, and whether it is more likely than not that the Company will be required to sell the investments before the recovery of their amortized cost basis. The cost of investments sold is based on the specific identification method. In circumstances when an unrealized loss is determined to be credit-related, or when the Company intends to sell or is more likely than not required to sell a security before it recovers its amortized cost basis, the difference between the fair value and the amortized cost of the security is recognized within other income (expense), net in the condensed consolidated statements of operations, and an allowance for credit loss is recorded on the condensed consolidated balance sheets. In circumstances when the decline in fair value is non-credit related, the difference is reported in accumulated other comprehensive loss, net of tax as a separate component of consolidated stockholders’ equity. Recent Accounting Pronouncements None.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2022
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 corporate debt securities and commercial paper as Level 2 within the fair value hierarchy as the fair value is estimated by using quoted prices for identical or similar instruments in markets that are not active and 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 as of March 31, 2022 and December 31, 2021 was as follows (in thousands): March 31, 2022 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds Level 1 $ 133,284 $ — $ — $ 133,284 U.S. Treasury securities Level 1 96,360 2 ( 207 ) 96,155 Corporate debt securities Level 2 61,747 3 ( 218 ) 61,532 Commercial paper Level 2 16,133 — — 16,133 Long-term investments U.S. Treasury securities Level 1 15,768 — ( 90 ) 15,678 Corporate debt securities Level 2 9,526 — ( 96 ) 9,430 Total $ 332,818 $ 5 $ ( 611 ) $ 332,212 December 31, 2021 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds Level 1 $ 357,181 $ — $ — $ 357,181 The fair value of cash equivalents and available-for-sale investments by classification included in the condensed consolidated balance sheets was as follows (in thousands): March 31, December 31, 2022 2021 Cash and cash equivalents $ 149,593 $ 357,181 Short-term investments 157,510 — Long-term investments 25,109 — Total $ 332,212 $ 357,181 Cash and cash equivalents in the above table excludes bank account cash of $ 9.5 million and $ 6.5 million as of March 31, 2022 and December 31, 2021, respectively. The fair value of cash equivalents and available-for-sale investments by contractual maturity was as follows (in thousands): March 31, December 31, 2022 2021 Maturing in one year or less $ 307,103 $ 357,181 Maturing after one year through two years 25,109 — Total $ 332,212 $ 357,181 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, 2022 and there were no financial instruments classified as Level 3 as of March 31, 2022. As of March 31, 2022, accrued interest receivable related to the Company's investments was $ 0.6 million and was included in prepaid expenses and other current assets on the condensed consolidated balance sheet. As of March 31, 2022, 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 will it be required to sell those investments before recovery of their amortized costs basis, which may be maturity. As of March 31, 2022 , no allowance for credit losses for the Company's investments was recorded. During the three months ended March 31, 2022 , the Company did no t recognize any impairment losses related to investments.

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2022
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, 2022 and December 31, 2021 (in thousands): March 31, December 31, 2022 2021 Laboratory equipment $ 789 $ 324 Computer hardware and software 275 241 Leasehold improvements 229 229 Furniture and fixtures 166 166 Property and equipment, gross 1,459 960 Less: accumulated depreciation and amortization ( 121 ) ( 63 ) Property and equipment, net $ 1,338 $ 897 Depreciation and amortization expense was nominal for the three months ended March 31, 2022 and 2021. Other Assets The following table presents the components of other assets as of March 31, 2022 and December 31, 2021 (in thousands): March 31, December 31, 2022 2021 Long-term prepaid clinical expenses $ 7,011 $ 6,694 Long-term prepaid contract manufacturing costs 2,854 2,854 Operating lease right-of-use assets 4,995 1,829 Finance lease right-of-use assets 634 746 Deposits 144 144 Restricted cash 66 — Total other assets $ 15,704 $ 12,267 Accrued Expenses and Other Current Liabilities The following table presents the components of accrued expenses and other current liabilities as of March 31, 2022 and December 31, 2021 (in thousands): March 31, December 31, 2022 2021 Accrued clinical and nonclinical study costs $ 4,026 $ 4,125 Accrued compensation and related expenses 2,372 3,294 Accrued professional fees 455 790 Accrued contract manufacturing 460 693 Finance lease liabilities, current 429 429 Operating lease liabilities, current 596 313 Other 391 257 Total accrued expenses and other current liabilities $ 8,729 $ 9,901

Leases

Leases	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
LEASES	(5) LEASES In conjunction with the adoption of ASC 842, the Company evaluated its vendor contracts to identify embedded leases, if any, and noted that a pharmaceutical support services agreement entered into in May 2016 included leases under ASC 842 because the Company has the right to direct the use of certain equipment. The embedded leases commenced in September 2020 and expire in August 2023 with no stated option to extend the term. The Company classified the leases as finance leases. In May 2021, the Company entered into a lease agreement for approximately 10,000 square feet of office space located in South San Francisco, California. The lease commenced on June 6, 2021 and expires on August 31, 2026 . The lease does not provide an option to extend after it expires. The total lease payments for the life of the lease is approximately $ 2.0 million. The Company classified the lease as an operating lease. In February 2022, the Company entered into a lease agreement totaling approximately 11,074 square feet of office and laboratory space located in Palo Alto, California. The lease consists of two premises and expires in February 2030 . The lease provides for an option to extend for two years after expiration . The lease for one premise commenced in February 2022 and the second premise commenced in April 2022 . The lease provides for an annual base rent of approximately $ 0.8 million, which increases on an annual basis by 3 %. The total lease payments for the life of the lease is approximately $ 7.0 million. The Company is also responsible for leasehold improvement costs related to the second premise, which are expected to be approximately $ 2.0 million, of which $ 1.5 million is to be paid with interest at a rate of 7 % per annum as additional payments over the life of the lease. The Company classified the lease as an operating lease. The Company has not recognized a right-of-use asset or aggregate lease liability related to the second premise as of March 31, 2022 for the minimum rental payments as the Company did not control the underlying assets at any time in the period ended March 31, 2022. Under the terms of the lease agreement, the Company issued a letter of credit to the landlord in the amount of $ 0.1 million, which is collateralized by a restricted cash deposit of $ 0.1 million (see Note 4 "Other assets"). As of March 31, 2022, the right-of-use asset, or ROU, recorded for operating leases and finance leases was $ 5.0 million and $ 0.6 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, 2022 (in thousands, except lease term and discount rate): March 31, 2022 Operating Leases Finance Leases 2022 (remaining 9 months) $ 752 $ 324 2023 1,013 288 2024 1,033 — 2025 1,064 — 2026 939 — Thereafter 2,145 — Total lease payments 6,946 612 Less: imputed interest ( 1,730 ) ( 8 ) Total lease liabilities $ 5,216 $ 604 Lease liabilities: current (i) $ 620 $ 429 Lease liabilities: non-current (ii) 4,596 175 Total lease liabilities $ 5,216 $ 604 Weighted average remaining lease term (in years) 6.7 1.4 Weighted average discount rate 7.8 % 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. (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 (in thousands): Three Months Ended March 31, 2022 2021 Operating lease cost $ 249 $ 36 Variable lease cost and other, net (i) 52 22 Short-term lease cost 44 3 Finance lease cost: Amortization of right-of-use assets 112 23 Interest 3 1 Total lease costs $ 460 $ 85 (i) The variable lease cost and other, net is comprised primarily of common area maintenance charges for the operating lease, which is 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: Three Months Ended March 31, 2022 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 169 $ 23 Operating cash flows from finance leases $ 3 $ — Financing cash flows from finance leases $ 105 $ —

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
STOCKHOLDERS' EQUITY	(6) 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, 2022 and December 31, 2021, the Company had 40,656,632 and 40,587,067 shares of common stock outstanding, respectively. Common stock reserved for future issuance as of March 31, 2022 consists of the following: March 31, 2022 Stock options issued and outstanding 4,944,796 Stock options authorized for future issuance 4,660,347 Employee Stock Purchase Plan shares authorized for future issuance 1,196,693 Restricted stock issued and outstanding 500,387 Total 11,302,223

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
STOCK-BASED COMPENSATION	(7) 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, 2022, the number of shares available under the 2020 Plan was increased by 1,623,483 shares. As of March 31, 2022, the number of shares of common stock available for issuance under the 2020 Plan was 4,660,347 . 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. On January 1, 2022, the number of shares available under the ESPP was increased by 405,871 shares. As of March 31, 2022, the number of shares of common stock available for issuance under the ESPP was 1,196,693 . 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, 2022 2021 Research and development $ 2,075 $ 579 General and administrative 3,426 1,221 Total $ 5,501 $ 1,800 Restricted Stock Units The following table provides a summary of restricted stock unit activity under the 2020 Plan: Number of RSUs Weighted- Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Restricted stock units as of December 31, 2021 15,075 $ 58.56 1.8 $ 324 Granted 504,200 $ 15.20 Vested ( 1,888 ) $ 58.56 Canceled/forfeited ( 17,000 ) $ 15.20 Restricted stock units as of March 31, 2022 500,387 $ 16.34 2.2 $ 8,457

Related-Party Transactions

Related-Party Transactions	3 Months Ended
	Mar. 31, 2022
Related Party Transactions [Abstract]
RELATED-PARTY TRANSACTIONS	(8) RELATED-PARTY TRANSACTIONS Tallac Service Agreement The Company entered into a research and development services agreement, or the Tallac Services Agreement, with Tallac Therapeutics, Inc., or Tallac, effective as of July 1, 2020. The Tallac Services Agreement provides that Tallac will provide certain preclinical research services to the Company for a service fee based on the costs incurred by Tallac plus a mark-up equal to 10.0 % of such costs. The Tallac Services Agreement has an initial term of four years and is renewed automatically for additional one year terms thereafter. The Company records the payments for the research and development services as research and development, or R&D, costs within the condensed consolidated statements of operations. During the three months ended March 31, 2022 and 2021, the Company recorded $ 0.2 million and $ 0.4 million , respectively, as R&D costs in relation to the Tallac Services Agreement. Tallac Collaboration Agreement On March 4, 2021, the Company entered into a collaboration agreement with Tallac, or the Tallac Collaboration Agreement, to jointly develop, manufacture, and commercialize a novel class of cancer immunotherapeutics. The collaboration builds on the Company’s expertise in developing therapies that block the CD47 checkpoint pathway and expands its immuno-oncology pipeline. The companies will leverage their respective scientific and technical expertise to advance an anti-SIRPα antibody conjugated to a Toll-like receptor 9, or TLR9, agonist for targeted activation of both the innate and adaptive immune systems. The key economic components of the collaboration transaction include that both parties will share equally (a) in the cost and expenses of research and development and (b) any profit or loss. The Company accounts for R&D costs in accordance with ASC 730, Research and Development, which states R&D costs must be charged to expense as incurred. Accordingly, the Company records its internal and third-party costs associated with the collaboration as R&D expenses as incurred. When the Company is entitled to reimbursement of the R&D expenses that it incurs under the collaboration, the Company records those reimbursable amounts as a reduction to R&D expenses. The Company also records as R&D expenses, the portion of Tallac’s expenses that the Company is obligated to reimburse, in the period when Tallac incurs such expenses. During the three months ended March 31, 2022 and 2021, the Company recorded $ 1.2 million and nominal , respectively, as R&D costs in relation to the Tallac Collaboration Agreement. The Tallac Collaboration Agreement includes the right to set off clause, as such, the Company records the amount due to or reimbursable from Tallac on a net basis. As of March 31, 2022 and December 31, 2021, the Company had accrued expenses of $ 1.2 million and $ 1.4 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, 2022
Earnings Per Share [Abstract]
NET LOSS PER SHARE	(9) NET LOSS PER SHARE The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share data): Three Months Ended March 31, 2022 2021 Numerator: Net loss $ ( 24,533 ) $ ( 14,185 ) Denominator: Weighted-average shares of common stock outstanding, basic and diluted 40,616,302 40,055,435 Net loss per share, basic and diluted $ ( 0.60 ) $ ( 0.35 ) 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, 2022 and 2021 because including them would have been anti-dilutive: March 31, 2022 2021 Stock options issued and outstanding 4,944,796 4,350,467 Restricted stock issued and outstanding 500,387 — Employee Stock Purchase Plan estimated shares issuable 11,674 1,600 Total 5,456,857 4,352,067

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	(10) 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, 2022. 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, 2022 , the Company had no pending or threatened litigation. Other Contractual Obligations and Other Commitments 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, is cancellable upon notice and is non-exclusive. Statements of work under the MSA commit the Company to certain future purchase obligations of approximately $ 51.8 million as of March 31, 2022. In addition, the Company has commitments with two other drug product manufacturers that commit the Company to certain future purchase obligations of approximately $ 2.5 million as of March 31, 2022 . The Company expects to make payments for these commitments through 2026 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, 2022
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	(11 ) SUBSEQUENT EVENTS The Company evaluated subsequent events and transactions that occurred after the balance sheet date up to the date financial statements were issued. The Company did not identify any subsequent events that would have required adjustment or disclosure in the financial statements.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
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 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 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, 2021 filed with the SEC on February 28, 2022. The condensed consolidated balance sheet as of March 31, 2022 included herein was derived from the audited financial statements as of that date, but does not include all disclosures including notes required by 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, 2022 .
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 those related to the estimated useful lives of long-lived assets, clinical trial accruals, fair value of assets and liabilities, income taxes 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 materially differ from those estimates.
Investments	Investments Investments consist of money market funds, U.S. Treasury securities, corporate debt securities and commercial paper. The Company’s investments are classified as available-for-sale and carried at estimated fair values and reported in cash equivalents, short-term investments and long-term investments. Management determines the appropriate classification of the investments at the time they are purchased and evaluates the appropriateness of such classifications at each balance sheet date. Investments with contractual maturities greater than 12 months at date of purchase are considered long-term investments. The Company regularly reviews its investments for declines in estimated fair value below amortized cost. The factors considered in determining whether a credit loss exists include the creditworthiness of the security issuers, the number of investments in an unrealized loss position, the severity and duration of the unrealized losses, and whether it is more likely than not that the Company will be required to sell the investments before the recovery of their amortized cost basis. The cost of investments sold is based on the specific identification method. In circumstances when an unrealized loss is determined to be credit-related, or when the Company intends to sell or is more likely than not required to sell a security before it recovers its amortized cost basis, the difference between the fair value and the amortized cost of the security is recognized within other income (expense), net in the condensed consolidated statements of operations, and an allowance for credit loss is recorded on the condensed consolidated balance sheets. In circumstances when the decline in fair value is non-credit related, the difference is reported in accumulated other comprehensive loss, net of tax as a separate component of consolidated stockholders’ equity.
Adopted Accounting Pronouncements	Accounting Pronouncements None.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Available for Sale Investments 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 as of March 31, 2022 and December 31, 2021 was as follows (in thousands): March 31, 2022 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds Level 1 $ 133,284 $ — $ — $ 133,284 U.S. Treasury securities Level 1 96,360 2 ( 207 ) 96,155 Corporate debt securities Level 2 61,747 3 ( 218 ) 61,532 Commercial paper Level 2 16,133 — — 16,133 Long-term investments U.S. Treasury securities Level 1 15,768 — ( 90 ) 15,678 Corporate debt securities Level 2 9,526 — ( 96 ) 9,430 Total $ 332,818 $ 5 $ ( 611 ) $ 332,212 December 31, 2021 Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds Level 1 $ 357,181 $ — $ — $ 357,181
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 (in thousands): March 31, December 31, 2022 2021 Cash and cash equivalents $ 149,593 $ 357,181 Short-term investments 157,510 — Long-term investments 25,109 — Total $ 332,212 $ 357,181
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 (in thousands): March 31, December 31, 2022 2021 Maturing in one year or less $ 307,103 $ 357,181 Maturing after one year through two years 25,109 — Total $ 332,212 $ 357,181

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2022
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, 2022 and December 31, 2021 (in thousands): March 31, December 31, 2022 2021 Laboratory equipment $ 789 $ 324 Computer hardware and software 275 241 Leasehold improvements 229 229 Furniture and fixtures 166 166 Property and equipment, gross 1,459 960 Less: accumulated depreciation and amortization ( 121 ) ( 63 ) Property and equipment, net $ 1,338 $ 897
Schedule of Components of Other Assets, Net	The following table presents the components of other assets as of March 31, 2022 and December 31, 2021 (in thousands): March 31, December 31, 2022 2021 Long-term prepaid clinical expenses $ 7,011 $ 6,694 Long-term prepaid contract manufacturing costs 2,854 2,854 Operating lease right-of-use assets 4,995 1,829 Finance lease right-of-use assets 634 746 Deposits 144 144 Restricted cash 66 — Total other assets $ 15,704 $ 12,267
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, 2022 and December 31, 2021 (in thousands): March 31, December 31, 2022 2021 Accrued clinical and nonclinical study costs $ 4,026 $ 4,125 Accrued compensation and related expenses 2,372 3,294 Accrued professional fees 455 790 Accrued contract manufacturing 460 693 Finance lease liabilities, current 429 429 Operating lease liabilities, current 596 313 Other 391 257 Total accrued expenses and other current liabilities $ 8,729 $ 9,901

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2022
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, 2022 (in thousands, except lease term and discount rate): March 31, 2022 Operating Leases Finance Leases 2022 (remaining 9 months) $ 752 $ 324 2023 1,013 288 2024 1,033 — 2025 1,064 — 2026 939 — Thereafter 2,145 — Total lease payments 6,946 612 Less: imputed interest ( 1,730 ) ( 8 ) Total lease liabilities $ 5,216 $ 604 Lease liabilities: current (i) $ 620 $ 429 Lease liabilities: non-current (ii) 4,596 175 Total lease liabilities $ 5,216 $ 604 Weighted average remaining lease term (in years) 6.7 1.4 Weighted average discount rate 7.8 % 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. (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 (in thousands): Three Months Ended March 31, 2022 2021 Operating lease cost $ 249 $ 36 Variable lease cost and other, net (i) 52 22 Short-term lease cost 44 3 Finance lease cost: Amortization of right-of-use assets 112 23 Interest 3 1 Total lease costs $ 460 $ 85 (i) The variable lease cost and other, net is comprised primarily of common area maintenance charges for the operating lease, which is 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: Three Months Ended March 31, 2022 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 169 $ 23 Operating cash flows from finance leases $ 3 $ — Financing cash flows from finance leases $ 105 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Common Stock Reserved for Future Issuance	Common stock reserved for future issuance as of March 31, 2022 consists of the following: March 31, 2022 Stock options issued and outstanding 4,944,796 Stock options authorized for future issuance 4,660,347 Employee Stock Purchase Plan shares authorized for future issuance 1,196,693 Restricted stock issued and outstanding 500,387 Total 11,302,223

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Restricted Stock Unit Activity	The following table provides a summary of restricted stock unit activity under the 2020 Plan: Number of RSUs Weighted- Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Restricted stock units as of December 31, 2021 15,075 $ 58.56 1.8 $ 324 Granted 504,200 $ 15.20 Vested ( 1,888 ) $ 58.56 Canceled/forfeited ( 17,000 ) $ 15.20 Restricted stock units as of March 31, 2022 500,387 $ 16.34 2.2 $ 8,457
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, 2022 2021 Research and development $ 2,075 $ 579 General and administrative 3,426 1,221 Total $ 5,501 $ 1,800

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2022
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 (in thousands, except share and per share data): Three Months Ended March 31, 2022 2021 Numerator: Net loss $ ( 24,533 ) $ ( 14,185 ) Denominator: Weighted-average shares of common stock outstanding, basic and diluted 40,616,302 40,055,435 Net loss per share, basic and diluted $ ( 0.60 ) $ ( 0.35 )
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, 2022 and 2021 because including them would have been anti-dilutive: March 31, 2022 2021 Stock options issued and outstanding 4,944,796 4,350,467 Restricted stock issued and outstanding 500,387 — Employee Stock Purchase Plan estimated shares issuable 11,674 1,600 Total 5,456,857 4,352,067

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets transferred from level 1 to level 2	$ 0
Fair value assets transferred from level 2 to level 1	0
Fair value liabilities transferred from level 1 to level 2	0
Fair value liabilities transferred from level 2 to level 1	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
Fair value liabilities transferred out of level 3	0
Bank account cash	9,500,000	$ 6,500,000
Allowance for credit losses	0
Impairment losses related to investments	0
Prepaid Expenses and Other Current Assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Accrued interest receivable, investment	$ 600,000

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, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 332,212	$ 357,181
Fair Value on Recurring Basis
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	332,818
Unrealized Gains	5
Unrealized Losses	(611)
Fair Value	332,212
US Treasury Securities | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	96,360
Unrealized Gains	2
Unrealized Losses	(207)
Fair Value	96,155
Corporate Debt Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	61,747
Unrealized Gains	3
Unrealized Losses	(218)
Fair Value	61,532
Long Term Investment US Treasury Securities | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	15,768
Unrealized Losses	(90)
Fair Value	15,678
Long Term Investment Corporate Debt Securities | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	9,526
Unrealized Losses	(96)
Fair Value	9,430
Money Market Funds | Level 1 | Fair Value on Recurring Basis
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	133,284	357,181
Fair Value	133,284	$ 357,181
Commercial Paper | Level 2 | Fair Value on Recurring Basis
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	16,133
Fair Value	$ 16,133

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, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total available-for-sale investments	$ 332,212	$ 357,181
Cash and Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents available for sale	149,593	$ 357,181
Short-term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments available for sale	157,510
Long-term Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long term investments available for sale	$ 25,109

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, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Maturing in one year or less	$ 307,103	$ 357,181
Maturing after one year through two years	25,109
Total available-for-sale investments	$ 332,212	$ 357,181

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Components of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,459	$ 960
Less: accumulated depreciation and amortization	(121)	(63)
Property and equipment, net	1,338	897
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	789	324
Computer Hardware and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	275	241
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	229	229
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 166	$ 166

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Components of Other Assets, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Other assets	$ 15,704	$ 12,267
Long-term Prepaid Clinical Expenses
Property Plant And Equipment [Line Items]
Other assets	7,011	6,694
Long-term Prepaid Contract Manufacturing Costs
Property Plant And Equipment [Line Items]
Other assets	2,854	2,854
Operating Lease Right-of-use Assets
Property Plant And Equipment [Line Items]
Other assets	4,995	1,829
Finance Lease Right-of-use Assets
Property Plant And Equipment [Line Items]
Other assets	634	746
Deposits
Property Plant And Equipment [Line Items]
Other assets	144	$ 144
Restricted Cash
Property Plant And Equipment [Line Items]
Other assets	$ 66

Balance Sheet Components - Comp

Balance Sheet Components - Components of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accrued clinical and nonclinical study costs	$ 4,026	$ 4,125
Accrued compensation and related expenses	2,372	3,294
Accrued professional fees	455	790
Accrued contract manufacturing	460	693
Finance lease liabilities, current	429	429
Operating lease liabilities, current	596	313
Other	391	257
Total accrued expenses and other current liabilities	$ 8,729	$ 9,901

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	1 Months Ended		3 Months Ended
	Feb. 28, 2022USD ($)ft²	May 31, 2021USD ($)ft²	Mar. 31, 2022USD ($)
Lessee Lease Description [Line Items]
Operating lease ROU assets			$ 5,000
Total lease payment			6,946
Operating lease liabilities			5,216
Finance lease ROU assets			$ 600
Office Space at 323 Allerton Avenue, South San Francisco, California
Lessee Lease Description [Line Items]
Lessee, operating lease commencing end date		Jun. 6, 2021
Lessee operating lease expiration year		Aug. 31, 2026
Operating lease ROU assets		$ 2,000
Area of operating lease | ft²		10,000
Operating lease, description			Company entered into a lease agreement for approximately 10,000 square feet of office space located in South San Francisco, California. The lease commenced on June 6, 2021 and expires on August 31, 2026. The lease does not provide an option to extend after it expires. The total lease payments for the life of the lease is approximately $2.0 million. The Company classified the lease as an operating lease.
Office and Laboratory Space Located In Palo Alto, California
Lessee Lease Description [Line Items]
Lease operating lease expiration period	2030-02
Lease operating lease commencement period	2022-02
Lease operating lease not yet commenced, commencement period	2022-04
Annual base rent	$ 800
Percentage of increase of annual rent	3.00%
Total lease payment	$ 7,000
Lessee operating lease leasehold improvements	2,000
Lessee Operating Lease Leasehold Improvements Additional Payments	$ 1,500
Annual interest rate of additional payments over life of lease	7.00%
Letter of credit	$ 100
Restricted cash deposits	$ 100
Area of operating lease | ft²	11,074
Lessee operating lease renewal term	2 years
Option to extend term			The lease provides for an option to extend for two years after expiration
Existence of option to extend	true

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Operating and Finance Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2022 (remaining 9 months)	$ 752
2023	1,013
2024	1,033
2025	1,064
2026	939
Thereafter	2,145
Total lease payments	6,946
Less: imputed interest	(1,730)
Operating lease liabilities	5,216
Lease liabilities: current	620
Lease liabilities: non-current	4,596
Total lease liabilities	$ 5,216
Weighted average remaining lease term (in years)	6 years 8 months 12 days
Weighted average discount rate	7.80%
Finance Lease, Liability, Payment, Due [Abstract]
2022 (remaining 9 months)	$ 324
2023	288
Total lease payments	612
Less: imputed interest	(8)
Finance lease liabilities	604
Finance lease liabilities, current	429	$ 429
Finance leases: non-current	175
Total lease liabilities	$ 604
Weighted average remaining lease term (in years)	1 year 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, 2022	Mar. 31, 2021
Leases [Abstract]
Operating lease cost	$ 249	$ 36
Variable lease cost and other, net	52	22
Short-term lease cost	44	3
Finance lease cost, Amortization of right-of-use assets	112	23
Finance lease cost, Interest	3	1
Total lease costs	$ 460	$ 85

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Disclosures for Cash Paid for Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 169	$ 23
Operating cash flows from finance leases	3
Financing cash flows from finance leases	$ 105

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - $ / shares	Mar. 31, 2022	Dec. 31, 2021	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	40,656,632	40,587,067
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, 2022shares
Class Of Stock [Line Items]
Common stock reserved for future issuance	11,302,223
Stock Options Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance	4,944,796
Stock Options Authorized for Future Issuance
Class Of Stock [Line Items]
Common stock reserved for future issuance	4,660,347
Employee Stock Purchase Plan Shares Authorized for Future Issuance
Class Of Stock [Line Items]
Common stock reserved for future issuance	1,196,693
Restricted Stock Issued and Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance	500,387

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - shares	Jan. 01, 2022	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance		11,302,223
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance		1,196,693
Number of additional shares reserved for future issuance	405,871
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance		4,660,347
Number of additional shares reserved for future issuance	1,623,483

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 5,501	$ 1,800
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	2,075	579
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,426	$ 1,221

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of RSUs, Balance	15,075
Number of RSUs, Granted	504,200
Number of RSUs, Vested	(1,888)
Number of RSUs, Canceled/forfeited	(17,000)
Number of RSUs, Balance	500,387	15,075
Weighted-Average Grant Date Fair Value, Balance	$ 58.56
Weighted-Average Grant Date Fair Value, Granted	15.20
Weighted-Average Grant Date Fair Value, Vested	58.56
Weighted-Average Grant Date Fair Value, Canceled/forfeited	15.20
Weighted-Average Grant Date Fair Value, Balance	$ 16.34	$ 58.56
Weighted Average Remaining Contractual Life (Years), Balance	2 years 2 months 12 days	1 year 9 months 18 days
Aggregate Intrinsic Value, Balance	$ 8,457	$ 324

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	Jul. 01, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
R&D costs		$ 17,073	$ 9,849
Research and Development Services Agreement | Tallac Therapeutics
Related Party Transaction [Line Items]
Initial term of agreement with related party	4 years
Markup cost in percentage	10.00%
Agreement automatically renewal additional term unless terminated	1 year
R&D costs		200	400
Collaboration Agreement | Tallac Therapeutics
Related Party Transaction [Line Items]
R&D costs		1,200
Accrued expenses		$ 1,200		$ 1,400

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, 2022	Mar. 31, 2021
Numerator:
Net loss	$ (24,533)	$ (14,185)
Denominator:
Weighted-average shares of common stock outstanding, basic and diluted	40,616,302	40,055,435
Net loss per share, basic and diluted	$ (0.60)	$ (0.35)

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, 2022	Mar. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,456,857	4,352,067
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	4,944,796	4,350,467
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	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	11,674	1,600

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended	3 Months Ended
	Nov. 30, 2015	Mar. 31, 2022USD ($)Litigation
Commitments And Contingencies [Line Items]
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		$ 51,800,000
Master Service Agreement | Two Drug Product Manufacturer
Commitments And Contingencies [Line Items]
Future purchase obligations		$ 2,500,000
Payments for future purchase obligations commitment, year		2026
Indemnification Agreement
Commitments And Contingencies [Line Items]
Guarantee obligations		$ 0