0000950170-23-007033 | 10-K | XBRL Viewer

License and collaboration agreements

12 Months Ended

Dec. 31, 2022

License And Collaboration Agreements [Abstract]

10. License and collaboration agreements

Agreement with Emory University (Emory)

In June 2018, the Company entered into a license agreement with Emory (the Emory License Agreement), pursuant to which Emory granted the Company a worldwide, sublicenseable license under certain of its intellectual property rights to make, have made, develop, use, offer to sell, sell, import and export products containing certain compounds relating to Emory’s hepatitis B virus capsid assembly modulator technology, for all therapeutic and prophylactic uses. Such license is initially exclusive with respect to specified licensed patents owned by Emory and non-exclusive with respect to certain of Emory’s specified know-how. In June 2022, the license to such patents became non-exclusive with respect to all fields except for the treatment and prevention of HBV; however, the Company may select up to six compounds which will maintain exclusivity with respect to all therapeutic and prophylactic uses. With respect to all other compounds that are enabled by the licensed patents, those which are jointly invented by the Company and Emory or inventors in the Schinazi laboratory, or which are disclosed in a specified licensed patent, are licensed to the Company exclusively including as to Emory; whereas all other such compounds are licensed to the Company non-exclusively. Under the terms of the Emory License Agreement, the Company is obligated to use commercially reasonable efforts to bring licensed products to market in accordance with a mutually agreed upon development plan. Unless terminated earlier by either party in accordance with the provisions thereof, the Emory License Agreement shall continue until the expiration of the last–to-expire of the patents licensed to the Company thereunder.

In June 2020, the Company amended the license agreement with Emory. Pursuant to the amended license agreement, Emory granted the Company additional patent rights to certain compounds targeting the treatment or prevention of HBV. As consideration for the additional rights, the Company made a one-time, non-refundable payment to Emory in the amount of $0.2 million, with an additional obligation to pay up to a maximum of $35,000. On the same date, the Company entered into a collaboration agreement with Emory, with the initial research plan pertaining to the synthesis and evaluation of the compounds licensed through the additional patent rights granted in the amended license agreement. The research plan terminates one year from the effective date, with the Company having an option to extend for a second year. In connection with the research plan, the Company will provide Emory funding up to $0.3 million per year.

The Company has agreed to pay Emory up to an aggregate of $125.0 million upon the achievement of specified development, regulatory, and commercial milestones, and all ongoing patent costs. During the year ended December 31, 2022, the Company had $0.2 million expenses related to milestone payments. During the year ended December 31, 2021, the Company made a payment of $0.2 million in relation to milestone payments. The Company also agreed to pay Emory tiered single-digit royalties on worldwide annual net sales of licensed products, on a quarterly basis and calculated on a product-by-product basis. With respect to licensed products containing any of a specified subset of the licensed compounds, such royalties range from a mid-single digit to a high-single digit percentage rate. With respect to licensed products which do not contain such compounds, the royalties span a range of percentage rates within the mid-single digits if a Phase 1 clinical trial is initiated for the product within three years of the effective date of the Emory License Agreement, and range from a low-single digit to a mid-single digit rate if a Phase 1 clinical trial is initiated more than three years after the effective date. During the years ended December 31, 2022 and December 31, 2021, the Company made no payments associated with royalties.

Agreement with Luxna Biotech Co., Ltd. (Luxna)

On December 19, 2018, the Company entered into a license agreement with Luxna, pursuant to which Luxna granted the Company an exclusive, worldwide, sublicenseable license under certain of Luxna’s intellectual property rights to research, develop, make, have made, and commercialize for all therapeutic and prophylactic uses, (i) products containing oligonucleotides targeting the hepatitis B virus genome, (ii) products containing certain oligonucleotides targeting up to three genes which contribute to NASH, which the Company may select at any time during the first eight years of the term, to the extent not licensed to a third party, and (iii) products containing oligonucleotides targeting up to three genes which contribute to hepatocellular carcinoma, which the Company may select at any time during the first three years of the term. As consideration for this agreement, the Company paid an upfront license fee of $0.6 million.

In April 2020, the Company amended the license agreement with Luxna. Pursuant to the amended license agreement, Luxna granted the Company an exclusive, worldwide license under the licensed patents to research, develop, make, have made and commercialize products containing oligonucleotides targeting three families of

viruses: Orthomyxoviridae, Paramyxoviridae, and Coronaviridae (a family which includes SARS-CoV-2). As consideration for the amended license agreement, the Company paid Luxna a one-time non-refundable fee of $0.2 million in April 2020.

The Company is obligated to make payments to Luxna, in aggregate, totaling up to but no more than $55.5 million upon the achievement of specified development, regulatory, and commercial milestones. During the year ended December 31, 2022, the Company did not make any milestone payments, and in the year ended December 31, 2021, the Company recognized $0.5 million in milestone payments. The Company is also required to pay Luxna a low-single digit royalty percentage on net sale of applicable products, if any. During the years ended December 31, 2022 and December 31, 2021, the Company made no payments associated with royalties.

Agreement with Katholieke Universiteit Leuven (KU Leuven)

On June 25, 2020, the Company entered into a Research, Licensing and Commercialization Agreement (KU Leuven Agreement) with KU Leuven, under which the Company is collaborating with KU Leuven’s Rega Institute for Medical Research, as well as its Centre for Drug Design and Discovery, to research and develop potential protease inhibitors for the treatment, diagnosis or prevention of coronaviruses, including of SARS-CoV-2. Unless terminated earlier by either party in accordance with provisions in the agreement, the collaboration period will terminate at the earlier of completion of all collaboration activities or 2.5 years. In connection with the KU Leuven Agreement, KU Leuven and the Company granted each other exclusive cross-licenses to use certain know-how and existing patents of the other party as well as certain joint know-how and joint patents to carry out research and development collaboration activities during the collaboration period. KU Leuven granted to the Company an exclusive (including as to KU Leuven), worldwide license under certain of KU Leuven’s know-how and existing patents, and certain joint patents and joint know-how, to manufacture and commercialize the licensed products for the treatment, diagnosis or detection of viral infections in humans. KU Leuven reserved the right to use all KU Leuven knowhow, existing KU Leuven patents, joint patents and joint know-how for academic and non-commercial research and teaching purposes. As consideration for this license, the Company is obligated to make payments to KU Leuven, in aggregate, totaling up to but no more than $30.0 million upon the achievement of certain commercial sales milestones. For each licensed product developed through KU Leuven and the Company’s collaborative effort, the Company is obligated to make payments to KU Leuven, in aggregate, totaling up to $32.0 million upon the achievement of certain development and regulatory milestones. The Company is also required to pay KU Leuven a low-to-mid-single digit royalty percentage, subject to certain adjustments, on net sales of applicable products, if any. Unless terminated earlier by either party, the agreement shall continue until the expiration of the last to expire royalty term, which is the later of the expiration or termination of the last valid patent claim covering the manufacture, use, sale or importation of the licensed product in a particular country or 10 years after the first commercial sale of a licensed product. During the years ended December 31, 2022 and December 31, 2021, the Company recognized no expenses related to milestone payments.

Agreements with Merck

In December 2020, the Company and Merck Sharp & Dohme Corp. (Merck), a subsidiary of Merck & Co., Inc., entered into an exclusive License and Research Collaboration Agreement (Original Agreement) under which Merck and the Company agreed to apply the Company’s oligonucleotide platform technology to discover, research, optimize and develop oligonucleotides directed against a NASH target and up to one additional liver-targeted cardiometabolic and/or fibrosis target. Under the terms of the Original Agreement, the Company received an upfront payment of $12 million from Merck. With respect to the collaboration target, the Company is eligible to receive up to $458.0 million in development and commercialization milestones as well as tiered royalties on net sales of licensed products. These potential payments consist of (i) potential development milestones (such as for the first dosing of an animal specimen in a Good Laboratory Practice toxicology study, and initiation of Phase 1, 2 and 3 clinical trials), (ii) regulatory milestones (such as for marketing authorizations for a product in certain countries) and (iii) sales-based milestones. The Company is primarily responsible for designing, preparing and evaluating the oligonucleotide molecules and delivering optimized lead molecules, and Merck is responsible for subsequent research, clinical development and commercialization efforts.

In January 2022, the Company and Merck entered into an amendment to the exclusive License and Research Collaboration Agreement (the First Amendment, together with the Original Agreement, the Expanded Arrangement). As a result of the First Amendment, our collaboration with Merck was expanded to include our grant of rights to Merck of an early-stage program with respect to a second undisclosed NASH target, on which the Company had previously been working independently. In addition, under this Expanded Arrangement, Merck has

the ability to add an additional third target of interest in the cardiometabolic/fibrosis space to the collaboration. This right to add an additional third target expired in January 2023. Under the Expanded Arrangement, the Company received an upfront payment of $15 million from Merck for our grant of rights to the program directed at a second undisclosed NASH target. Moreover, the Company may receive an additional payment of $15 million from Merck if Merck elects to designate a third target for collaboration. With respect to the second target in the collaboration, the Company is eligible to receive up to approximately $460.0 million in development and commercialization milestones as well as tiered royalties on net sales. These potential payments consist of (i) potential development milestones (such as for the first dosing of an animal specimen in a Good Laboratory Practice toxicology study, and initiation of Phase 1, 2 and 3 clinical trials), (ii) regulatory milestones (such as for marketing authorizations for a product in certain countries) and (iii) sales-based milestones.

In February 2023, Merck provided to the Company written notice of termination for one of the targets in the collaboration.

The Company determined that the Original Agreement and First Amendment fall within the scope of ASC 808, Collaborative Arrangements (ASC 808), due to Merck and the Company being joint active participants, as well as both parties having significant risks and rewards. The Company analogized to ASC 606, Revenue from Contracts with Customers (ASC 606), for the accounting of payments including upfront payments and other milestones. Management of the Company determined that there was one performance obligation for each of the agreements given the deliverables are not distinct. The Company evaluated the performance obligation within each agreement and determined the performance obligations are satisfied over time as Merck jointly owns any collaboration intellectual property that is developed during the research term. Given the nature of the arrangements, the Company believes that the satisfaction of its performance obligations is best measured by the progress of its efforts. As such, the Company has used an input method based on costs incurred to recognize revenue associated with the upfront payments. This assessment is performed separately for each of the Original Agreement and the First Amendment, and the Company recognizes revenue over time based on the costs incurred. The effect of any updates to the estimated overall costs are recorded as a change in estimate. In addition, variable consideration (e.g., milestone payments) were evaluated based on the Company’s analysis that the possibility of achieving any of the milestone payments is remote, and therefore determined to be constrained and excluded from the transaction price. Similarly, the Company accounts for the future royalties under the sales-based royalty exception in ASC 606-10-55-65 through 55-65B therefore they are not considered in the transaction price and expected to be recognized when future sales occur since that is expected to occur after the performance obligation has been fully satisfied.

During the years ended December 31, 2022, and 2021, the Company recognized $13.9 million and $4.4 million in revenue from collaborative arrangements related to upfront payments. During the years ended December 31, 2022, and 2021, the Company recognized no revenue from collaborative arrangements related to milestone payments. The unrecognized portion of the upfront payments received during the years ended December 31, 2022 and 2021 is recorded on the consolidated balance sheets as “Deferred revenue from collaborations”.

Changes in deferred revenue balances arose as a result of the Company recognizing the following revenue from collaborative arrangements during the periods below (in thousands):


	Year Ended December 31,
	2022			2021

Deferred revenue from collaborations as of January 1	$	7,641		$	12,000
Consideration received in the year	$	15,000		$	—
Revenue from collaborations recognized in the year	$	(13,898	)	$	(4,359	)
Deferred revenue from collaborations as of December 31	$	8,743		$	7,641

Investments (Tables)

12 Months Ended

Dec. 31, 2022

Debt Securities, Available-for-Sale and Held-to-Maturity, after Allowance for Credit Loss [Abstract]

Summary of Available For Sale and Held to Maturity Securities Amortized Cost Gross Unrealized Gains Losses and Fair Value

As of December 31, 2022 and 2021, amortized cost, gross unrealized gains and losses, and estimated fair values of total fixed-maturity securities were as follows:


	December 31, 2022
	Amortized		Gross Unrealized		Gross Unrealized			Estimated
(in thousands)	Cost		Gain		Loss			Fair Value
Available-for-sale securities:
U.S. Treasury bonds	$	44,576	$	-	$	(96	)	$	44,480
Certificates of deposit		-		-		-			-
	$	44,576	$	-	$	(96	)	$	44,480


	December 31, 2021
	Amortized		Gross Unrealized		Gross Unrealized			Estimated
(in thousands)	Cost		Gain		Loss			Fair Value
Available-for-sale securities:
U.S. Treasury bonds	$	15,146	$	-	$	(36	)	$	15,110
Certificates of deposit		3,922		-		(4	)		3,918
	$	19,068	$	-	$	(40	)	$	19,028

Summary of Amortized Cost and Estimated Fair Value of Fixed-maturity Securities

Amortized cost and estimated fair value of fixed-maturity securities at December 31, 2022 by contractual maturity were as follows:


	2022
(in thousands)	Amortized Cost		Estimated Fair Value
Amounts maturing in:
One year or less	$	44,576	$	44,480
More than one year		—		—
Total investments	$	44,576	$	44,480

Fair value measurements

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Fair value measurements

9. Fair value measurements

The following tables present the fair value of the Company’s financial instruments that are measured or disclosed at fair value on a recurring basis:


	Fair Value Measurements as of December 31, 2022
(in thousands)	Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	81,347	$	—	$	—
Certificates of deposit		-		—		—
U.S. Treasury bonds		44,480		—		—
	$	125,827	$	—	$	—


	Fair Value Measurements as of December 31, 2021
(in thousands)	Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	186,816	$	—	$	—
Certificates of deposit		3,918		—		—
U.S. Treasury bonds		15,110		—		—
	$	205,844	$	—	$	—

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Accrued liabilities

12 Months Ended

Dec. 31, 2022

Payables and Accruals [Abstract]

Accrued liabilities

5. Accrued liabilities

Accrued liabilities consisted of the following as of December 31:


(in thousands)	2022		2021
Accrued compensation	$	6,297	$	6,329
Accrued payables		8,203		17,554
Liability for early exercised stock options		66		276
Other		1,473		1,235
Total	$	16,039	$	25,394

Subsequent events - Additional Information (Detail) - Strategic Reprioritization of NASH and COVID-19 Programs - USD ($) $ in Millions		3 Months Ended
	Feb. 08, 2023	Mar. 31, 2023
Scenario Forecast
Subsequent Event [Line Items]
One-time charge		$ 1.0
Subsequent Event
Subsequent Event [Line Items]
Percentage of workforce reduction	10.00%

Capital stock	12 Months Ended
Dec. 31, 2022
Equity [Abstract]
Capital stock	7. Capital stock Common stock On October 20, 2020, the certificate of incorporation was amended to increase the total shares of Common Stock authorized for issuance to 320,000,000 and decrease the total shares of preferred stock authorized for issuance to 10,000,000 with a par value of $0.0001 per share. 300,000,000 shares of the Common Stock were designated as “Voting Common Stock” and 20,000,000 shares of the Common Stock were designated as “Non-Voting Common Stock”. The holders of shares of voting Common Stock are entitled to one vote for each share of Common Stock at all meetings of stockholders. Preferred stock As of December 31, 2022 and 2021, there were 10,000,000 shares of preferred stock authorized and no preferred stock issued.

Capital stock

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Capital stock

7. Capital stock

Common stock

On October 20, 2020, the certificate of incorporation was amended to increase the total shares of Common Stock authorized for issuance to 320,000,000 and decrease the total shares of preferred stock authorized for issuance to 10,000,000 with a par value of $0.0001 per share. 300,000,000 shares of the Common Stock were designated as “Voting Common Stock” and 20,000,000 shares of the Common Stock were designated as “Non-Voting Common Stock”.

The holders of shares of voting Common Stock are entitled to one vote for each share of Common Stock at all meetings of stockholders.

Preferred stock

As of December 31, 2022 and 2021, there were 10,000,000 shares of preferred stock authorized and no preferred stock issued.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI http://asc.fasb.org/topic&trid=2208762

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Income Taxes - Schedule of Expected Income Tax (Benefit) Computed Using Federal Statutory Income Tax Rate to Company's Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax computed at federal statutory rate	21.00%	21.00%
State taxes, net of federal benefit	6.95%	6.91%
R&D credit carryovers	1.25%	0.90%
Change in valuation allowance	(26.32%)	(27.42%)
Stock based compensation	(1.08%)	(1.19%)
Permanent differences	(1.91%)	(0.31%)
Change in fair value of derivatives	0.00%	0.00%
Effective income tax rate	(0.11%)	(0.11%)

Accrued liabilities (Tables)

12 Months Ended

Dec. 31, 2022

Payables and Accruals [Abstract]

Summary of Accrued Liabilities

Accrued liabilities consisted of the following as of December 31:


(in thousands)	2022		2021
Accrued compensation	$	6,297	$	6,329
Accrued payables		8,203		17,554
Liability for early exercised stock options		66		276
Other		1,473		1,235
Total	$	16,039	$	25,394

Capital stock - Additional Information (Detail) - $ / shares	Dec. 23, 2019	Dec. 31, 2022	Dec. 31, 2021	Oct. 20, 2020
Number of shares of common stock authorized		320,000,000	320,000,000	320,000,000
Number of shares of preferred stock authorized		10,000,000	10,000,000	10,000,000
Preferred stock authorized par value		$ 0.0001	$ 0.0001	$ 0.0001
Common stock voting right	one
Preferred Stock, Shares Issued		0	0
Voting Common Stock [Member]
Number of shares of common stock authorized				300,000,000
Non-Voting Common Stock [Member]
Number of shares of common stock authorized				20,000,000

Subsequent events

12 Months Ended

Dec. 31, 2022

Subsequent Events [Abstract]

Subsequent events

15. Subsequent events

Strategic reprioritization of NASH and COVID-19 programs and overall workforce reduction

On February 8, 2023, the Company announced a portfolio reprioritization to prioritize its clinical NASH (ALG-055009) and COVID-19 (ALG-097558) programs as well as maintaining its ongoing NASH oligonucleotide research collaboration with Merck. This was accompanied by a workforce reduction of approximately 10%. The Company expects to record a one‑time charge of approximately $1.0 million related to the reprioritization in the first quarter of 2023.

Consolidated statements of cash flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (96,046)	$ (128,332)
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion of discount on short term investments	(159)	86
Amortization of right of use assets	1,369	759
Depreciation expense	2,306	3,019
Stock-based compensation	14,693	13,457
Changes in operating assets and liabilities:
Other assets	5,594	(8,072)
Accounts payable	1,722	(313)
Accrued liabilities	(9,140)	9,742
Operating lease liabilities	(1,819)	(1,404)
Other liabilities	(133)	(245)
Deferred revenue from collaborations	2,502	(4,359)
ROU asset	(278)
Net cash and cash equivalents used in operating activities	(79,389)	(115,662)
Cash flows from investing activities:
Purchases of short-term investments	(104,265)	(2,696)
Purchases of long-term investments		(16,390)
Maturities of short-term investments	78,915	23,000
Purchases of property and equipment	(943)	(892)
Net cash and cash equivalents provided by (used in) investing activities	(26,293)	3,022
Cash flows from financing activities:
Payments on finance lease	(61)	(79)
Payments of deferred offering costs		(875)
Proceeds from ESPP purchase	205
Net cash and cash equivalents provided by financing activities	164	78,677
Net decrease in cash, cash equivalents, and restricted cash	(105,518)	(33,963)
Cash, cash equivalents, and restricted cash, beginning of period	186,980	220,943
Cash, cash equivalents, and restricted cash, end of period	81,462	186,980
Reconciliation to amounts on the consolidated balance sheet:
Cash and cash equivalents	81,347	186,816
Restricted cash	115	164
Cash, cash equivalents, and restricted cash, end of period	81,462	186,980
Supplemental disclosures of noncash financing and investing activities:
Mark to market adjustments for available-for-sale investments	(57)	(109)
Equipment acquired through finance lease		284
Receviable due from arrangement	700
Vesting of early exercised options	209	292
Acquisition of right-of-use asset through operating lease obligation		2,647
PP&E Purchase still in Accounts Payable		15
Change in pension obligation	6	749
Follow-on Offering
Cash flows from financing activities:
Proceeds from issuance of common stock		78,584
Employee Stock
Cash flows from financing activities:
Proceeds from issuance of common stock	$ 20	$ 1,047

Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Summary of Estimated Useful Life of Asset

Property and equipment is stated at cost less accumulated depreciation, and is depreciated using the straight-line method over the estimated useful life of the asset, which are as follows:


Lab equipment		3 years
Computer equipment		3 years
Furniture and office equipment		3-8 years
Vehicles		4 years
Leasehold improvements		Shorter of the useful life or remaining lease term

Derivative liabilities and redeemable convertible preferred stock liability - Additional Information (Detail) - shares	Dec. 31, 2022	Dec. 31, 2021
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Preferred Stock, Shares Issued	0	0

Organization - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash, cash equivalent and investments	$ 125,800
Accumulated deficit	$ 399,118	$ 303,072

- Definition

The cumulative amount of the reporting entity's undistributed earnings or deficit.

+ References + Details

Property and equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 2,306	$ 3,019

Investments - Summary of Amortized Cost and Estimated Fair Value of Fixed-maturity Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-Sale and Held-to-Maturity, after Allowance for Credit Loss [Abstract]
Fixed-Maturity Securities, Amortized Cost, One year or less	$ 44,576
Fixed-Maturity Securities, Amortized Cost, Total investments	44,576	$ 19,068
Fixed-Maturity Securities, Estimated Fair Value, One year or less	44,480
Fixed-Maturity Securities, Estimated Fair Value, Total investments	$ 44,480	$ 19,028

Commitments and contingencies

12 Months Ended

Dec. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

Commitments and contingencies

12. Commitments and contingencies

From time to time, the Company may have certain contingent liabilities, including legal matters that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made, and such expenditures can be reasonably estimated. The Company had no contingent liabilities requiring accrual as of December 31, 2022 and 2021. The Company enters into contracts in the normal course of business that includes arrangements with clinical research organizations, vendors for preclinical research and vendors for manufacturing. These agreements generally allow for cancellation with notice. As of December 31, 2022, the Company had no material non-cancellable purchase commitments.

On March 26, 2022, the Company received notice of a complaint (the Complaint) filed by Janssen Biopharma, LLC (Janssen), which generally concerned an alleged breach by certain of our employees of their obligations to Janssen as prior employees of Janssen by purporting to assign to Aligos various inventions allegedly owned by Janssen. The Complaint was filed on March 9, 2022 in the Superior Court of the State of California, County of San Mateo, against the Company, Lawrence M. Blatt, Chairman, Chief Executive Officer and Director of the Company, and Leonid Beigelman, President and Director of the Company. The Complaint alleges breach of contract by Lawrence M. Blatt and Leonid Beigelman and tortious interference with contract by the Company and seeks declaratory judgment of ownership of certain intellectual property by the Company, among other claims. The Complaint states that Janssen is seeking injunctive relief, assignment of certain intellectual property from us to Janssen and monetary damages. The Company believes the allegations in the Complaint are without merit and intends to continue to defend itself vigorously.

On August 22, 2022, the Company filed its response to the Complaint and on August 4, 2022, filed counterclaims against Janssen alleging Janssen has engaged in unfair competition and promissory fraud.

Investments

12 Months Ended

Dec. 31, 2022

Debt Securities, Available-for-Sale and Held-to-Maturity, after Allowance for Credit Loss [Abstract]

Investments

4. Investments

As of December 31, 2022 and 2021, amortized cost, gross unrealized gains and losses, and estimated fair values of total fixed-maturity securities were as follows:


	December 31, 2022
	Amortized		Gross Unrealized		Gross Unrealized			Estimated
(in thousands)	Cost		Gain		Loss			Fair Value
Available-for-sale securities:
U.S. Treasury bonds	$	44,576	$	-	$	(96	)	$	44,480
Certificates of deposit		-		-		-			-
	$	44,576	$	-	$	(96	)	$	44,480


	December 31, 2021
	Amortized		Gross Unrealized		Gross Unrealized			Estimated
(in thousands)	Cost		Gain		Loss			Fair Value
Available-for-sale securities:
U.S. Treasury bonds	$	15,146	$	-	$	(36	)	$	15,110
Certificates of deposit		3,922		-		(4	)		3,918
	$	19,068	$	-	$	(40	)	$	19,028

Changes in fair value are related to changes in market interest rates. The Company expects to collect all contractual principal and interest payments.

Amortized cost and estimated fair value of fixed-maturity securities at December 31, 2022 by contractual maturity were as follows:


	2022
(in thousands)	Amortized Cost		Estimated Fair Value
Amounts maturing in:
One year or less	$	44,576	$	44,480
More than one year		—		—
Total investments	$	44,576	$	44,480

The Company recorded interest income of $1.5 million and $0.2 million, respectively, during the years ended December 31, 2022, and 2021, as a component of interest and other income, net on the Company’s consolidated statement of operations and comprehensive loss.

Income taxes

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Income taxes

11. Income taxes

The components of the current provision for income taxes were as follows for the years ended December 31, 2022 and 2021:


(in thousands)	2022		2021
Current:
State	$	—	$	—
Federal		—		—
Foreign		106		143
Total current provision for income taxes	$	106	$	143

Deferred:
State	$	—	$	—
Federal		—		—
Foreign		—		—
Total deferred provision for income taxes	$	—	$	—

The Company did not have any deferred provision for income taxes for the years ended December 31, 2022 and 2021.

A reconciliation of the expected income tax (benefit) computed using the federal statutory income tax rate to the Company’s effective income tax rate is as follows for the years ended December 31, 2022 and 2021:


	2022			2021
Income tax computed at federal statutory rate		21.00	%		21.00	%
State taxes, net of federal benefit		6.95	%		6.91	%
R&D credit carryovers		1.25	%		0.90	%
Change in valuation allowance		-26.32	%		-27.42	%
Stock based compensation		-1.08	%		-1.19	%
Permanent differences		-1.91	%		-0.31	%
Change in fair value of derivatives		0.00	%		0.00	%
Effective income tax rate		-0.11	%		-0.11	%

The components of the deferred tax assets and liabilities were as follows at December 31:


(in thousands)	2022			2021
Deferred tax assets:
Net operating loss carryforward	$	82,775		$	72,425
Operating lease liabilities		4,057			4,622
Tax credits		8,025			6,177
Other accruals and reserves		1,398			1,461
Stock-based compensation		2,055			1,216
Deferred revenue		27			2,140
Capitalized SEC 174 costs		14,138			—
Other		253			22
		112,728			88,063
Valuation allowance		(109,560	)		(84,288	)
Net deferred tax assets	$	3,168		$	3,775
Deferred tax liabilities:
Right of use assets	$	(2,803	)	$	(3,205	)
Stock-based compensation		—			—
Property and equipment		(365	)		(570	)
Total deferred tax liabilities	$	(3,168	)	$	(3,775	)
Total deferred income taxes	$	—		$	—

Management believes that, based on a number of factors, including the Company’s historical operating performance and accumulated deficit, it is more likely than not that the deferred tax assets will not be utilized, such that a full valuation allowance has been recorded against the Company’s deferred tax assets. In assessing the reliability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized on a jurisdiction by jurisdiction basis. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. The valuation allowance increased by $25.3 million and $35.2 million during the years ended December 31, 2022 and 2021, respectively.

As of December 31, 2022, the Company had $272.4 million of federal and $352.7 million of state net operating loss (NOL) carryforwards available to offset future taxable income. The Company’s federal NOL carryforwards can be carried forward indefinitely while state NOL carryforwards, if not utilized, will begin expiring in 2038. As of December 31, 2022, the Company had $3.2 million of Australia NOL carryforwards, which carryforward indefinitely. As of December 31, 2022, the Company had research and development credit carryforwards of $7.9 million and $3.9 million available to reduce future taxable income, if any, for federal and state income tax purposes, respectively. If not utilized, the federal credit carryforwards will begin expiring in 2038. The California credit carryforwards have no expiration date. Under Sections 382 and 383 of the Code, and corresponding provisions of state law, if a corporation undergoes an “ownership change” (generally defined as a greater than 50 percentage point change (by value) in its equity ownership over a rolling three-year period), the Company’s ability to use its pre-change NOL carryforwards and other pre-change tax attributes to offset its post-change income may be limited. We performed a Code Section 382 analysis in 2021 and determined there was an ownership change that resulted in Section 382 limitations. The ownership change limited our ability to utilize NOLs against future taxable income but will not result in the expiration of any NOLs. We may in the future experience ownership changes as a result of changes in our stock ownership (some of which are not in our control). In addition, under current tax law, federal NOL carryforwards generated in periods after December 31, 2017, may be carried forward indefinitely but, in taxable years beginning after December 31, 2020, may only be used to offset 80% of our taxable income. For these reasons, our ability to utilize our NOL carryforwards and other tax attributes to reduce future tax liabilities may be limited.

The Company adopted the provisions of FASB Accounting Standards Codification (ASC) 740-10, Accounting for Uncertainty in Income Taxes, upon the date of incorporation. ASC 740-10 prescribes a comprehensive model for the recognition, measurement, presentation and disclosure in financial statements of any uncertain tax positions that have been taken or expected to be taken on a tax return. It is the Company’s policy to include penalties and interest expense related to income taxes as a component of other expense and interest expense, respectively, as necessary. During the years ended December 31, 2022 and 2021, the Company had not recognized any tax-related penalties or interest. No liability related to uncertain tax positions is recorded on the financial statements related to uncertain tax positions.


(in thousands)	2022			2021
Balance, beginning of the period	$	2,441		$	1,536
Increase related to prior year positions		687			63
Increase / (decrease) related to current year positions		(28	)		842
Balance, ending of the period	$	3,100		$	2,441

The Company does not expect that its uncertain tax positions will materially change in the next twelve months. The reversal of the uncertain tax benefits would not impact the Company's effective tax rate as the Company continues to maintain a full valuation allowance against its deferred tax assets.

The Company files income tax returns in the United States, including California, and other states, Australia, Belgium, and China. The Company is not currently under examination by income tax authorities in federal, state or other jurisdictions. All income tax returns will remain open for examination by the federal, state and foreign authorities for three or four years, from the date of utilization of any NOLs or credits.

In January 2018, the FASB released guidance on the accounting for tax on the global intangible low-taxed income (GILTI) provisions of the Tax Cuts and Jobs Act of 2017. The GILTI provisions impose a tax on foreign

income in excess of a deemed return on tangible assets of foreign corporations. The guidance allows companies to make an accounting policy election to either (i) account for GILTI as a component of tax expense in the period in which they are subject to the rules (the period cost method), or (ii) account for GILTI in the Company’s measurement of deferred taxes (the deferred method). After completing the analysis of the GILTI provisions, the Company elected to account for GILTI using the period cost method.

On March 27, 2020, the Coronavirus Aid, Relief and Economic Security Act (the CARES Act) was signed into law. The CARES Act includes provisions relating to refundable payroll tax credits, deferment of the employer portion of certain payroll taxes, NOL carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The Company analyzed the provisions of the CARES Act and determined there was no significant impact to its income taxes for the year ended December 31, 2022.

On June 29, 2020, the California Governor signed into law Assembly Bill 85 (A.B. 85). A.B. 85, which includes several tax measures, provides for a three-year suspension of the use of NOLs for medium and large businesses and a three-year cap on the use of business incentive tax credits to offset no more than $5 million of tax per year. Generally, A.B. 85 suspends the use of NOLs for taxable years 2020, 2021, and 2022 for taxpayers with taxable income of $1 million or more. Since the Company did not generate California source taxable income of more than $1 million in taxable years 2020, 2021 or 2022, no impact resulted.

On December 27, 2020, the Consolidated Appropriations Act, 2021 (the CAA) was signed into law. The CAA includes provisions meant to clarify and modify certain items put forth in the CARES Act, while providing aid to businesses affected by the pandemic. The CAA allows deductions for expenses paid for by the Paycheck Protection Program and Economic Injury Disaster Loan (EIDL) Program, clarifies forgiveness of EIDL advances, and includes other business provisions. The Company analyzed the provisions of the CAA and determined there was no significant impact to its 2022 tax provision.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-URI http://asc.fasb.org/topic&trid=2144680

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Commitments and contingencies - Additional Information (Detail) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Contingent liabilities	$ 0	$ 0

Summary of significant accounting policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)
Financing Sources [Line Items]
Re-measurement loss	$ 42,000	$ 6,000
Number of reportable segments \| Segment	1
Product revenue	$ 0
Property and equipment, net	$ 4,816,000	6,180,000
Cash equivalent qualification, description	The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents.
Restricted cash	$ 115,000	$ 164,000
Investments, maturity period	1 year 6 months	1 year 6 months
Other than temporary impairment losses, investments	$ 0	$ 0
Impairment of long lived assets	0	0
Royalties due	0
Expenses on milestone payments	0
Dividends, common stock, cash	$ 0
Expected dividend yield	0.00%
Percentage of expected average remaining working lives of employees	10.00%
Research and Development
Financing Sources [Line Items]
Expenses on milestone payments		500,000
US
Financing Sources [Line Items]
Property and equipment, net	$ 4,100,000	5,000,000.0
Belgium
Financing Sources [Line Items]
Property and equipment, net	$ 700,000	$ 1,200,000

Property and equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total, at cost	$ 14,384	$ 13,442
Accumulated depreciation	(9,568)	(7,262)
Total, net	4,816	6,180
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	6,087	5,940
Lab equipment [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	6,179	5,709
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	1,052	994
Furniture and office equipment [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	739	472
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	305	305
Asset under construction [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	$ 22	$ 22

License and Collaboration Agreements (Tables)

12 Months Ended

Dec. 31, 2022

License And Collaboration Agreements [Abstract]

Schedule of Deferred Revenue from Collaborative Arrangements

Changes in deferred revenue balances arose as a result of the Company recognizing the following revenue from collaborative arrangements during the periods below (in thousands):


	Year Ended December 31,
	2022			2021

Deferred revenue from collaborations as of January 1	$	7,641		$	12,000
Consideration received in the year	$	15,000		$	—
Revenue from collaborations recognized in the year	$	(13,898	)	$	(4,359	)
Deferred revenue from collaborations as of December 31	$	8,743		$	7,641

License and Collaboration Agreements - Summary of Deferred Revenue from Collaborative Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
License And Collaboration Agreements [Abstract]
Deferred revenue from collaborations as of January 1	$ 7,641	$ 12,000
Consideration received in the year	15,000
Revenue from collaborations recognized in the year	(13,898)	(4,359)
Deferred revenue from collaborations as of December 31	$ 8,743	$ 7,641

Leases

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Leases

6. Leases

The Company has operating and finance leases for corporate offices, research and development facilities, and certain vehicles and lab equipment. These leases have remaining lease terms of four to six years, some of which include options to extend the leases for five to eight years. The Company has determined that it is not reasonably certain to exercise the options under any leases. The lease of research and development facilities includes costs for

utilities and common area maintenance which have been included in the calculation of lease payments. Differences between lease payments as measured at lease inception and variations in monthly payments will be recognized as operating expenses in the period in which the obligation is incurred. The Company entered into a 5-year lease in the fourth quarter of 2021. The lease is for approximately 12,000 square feet of office space in South San Francisco, with a renewal option for an additional 5-years, which we are not certain to renew at this time. The rental payments under the lease agreement are approximately $2.7 million over the lease term.

Leases with an initial term of 12 months or less are not recorded on the balance sheet, and the Company recognizes lease expense for these leases on a straight-line basis over the lease terms. Leases with terms greater than 12 months are included in operating lease ROU assets and operating lease liabilities in the Company’s consolidated balance sheets as of December 31, 2022 and 2021. Lease expense for lease payments is recognized on a straight-line basis over the lease term.

Maturities of lease liabilities as of December 31, 2022, were as follows:


(in thousands)	Operating Lease			Finance Lease
Year ending December 31:
2023	$	3,425		$	189
2024		3,305			64
2025		3,418			63
2026		3,534			42
2027		1,170			—
Thereafter		-			—
		14,852			358
Less: imputed interest		(2,616	)		(20	)
Present value of lease liabilities		12,236			338
Less: current portion		(3,035	)		(108	)
Lease liabilities net of current portion	$	9,201		$	230

The components of lease expense were as follows for the years ended December 31, 2022 and 2021:


(in thousands)	2022		2021
Operating lease cost	$	2,504	$	1,990
Finance lease cost:
Amortization of right-of-use assets		108		107
Interest on lease liabilities		13		15
Total finance lease cost	$	121	$	122
Short-term lease cost	$	—	$	89

The Company made payments of $3.4 million and $2.8 million during the years ended December 31, 2022, and 2021, respectively, which are included as cash flow from operations on the consolidated statements of cash flows.

As of December 31, 2022 and 2021, $0.7 million and $0.6 million of finance lease ROU assets, respectively, were presented as part of property and equipment on the consolidated balance sheet with accumulated amortization of $0.3 million and $0.2 million, respectively.

Additional information related to the Company’s leases was as follows as of December 31:


	2022			2021
Operating Lease:
Weighted-average remaining lease term (years)		4.21			5.18
Weighted-average discount rate		9.04	%		9.08	%
Finance Lease:
Weighted-average remaining lease term (years)		3.26			3.83
Weighted-average discount rate		5.15	%		4.86	%

Organization

12 Months Ended

Dec. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization

1. Organization

Description of business

Aligos Therapeutics, Inc. (Aligos-US) was incorporated in the state of Delaware on February 5, 2018 (inception). On September 10, 2018, the Company formed Aligos Belgium BVBA (the Subsidiary or Aligos-Belgium). On March 30, 2020, the Company formed as a wholly owned subsidiary, Aligos Australia Pty LTD (Aligos-Australia), a proprietary limited company. On May 18, 2021, the Company formed as a wholly owned subsidiary, Aligos Therapeutics (Shanghai) Co. Ltd. (Aligos-Shanghai) and together with Aligos-US, Aligos-Belgium, and Aligos-Australia being the Company or Aligos.

Aligos is a clinical-stage biopharmaceutical company developing novel therapeutics to address unmet medical needs in liver diseases and viral infections, including therapeutics for nonalcoholic steatohepatitis (NASH), coronaviruses, and chronic hepatitis B.

The Company is devoting substantially all of its efforts to the research and development of its drug candidates. The Company has not generated any product revenue to date. The Company is also subject to a number of risks similar to other companies in the biotechnology industry, including the uncertainty of success of its preclinical studies and clinical trials, regulatory approval of drug candidates, uncertainty of market acceptance of products, competition from substitute products and larger companies, the need to obtain additional financing, compliance with government regulations, protection of proprietary technology, dependence on third-parties, product liability, and dependence on key individuals.

Liquidity

The Company has incurred losses and negative cash flows from operations since its inception. As of December 31, 2022 and 2021, the Company had an accumulated deficit of approximately $399.1 million and $303.1 million, respectively. Management expects to continue to incur additional substantial losses in the foreseeable future as a result of expanded research and development activities.

As of December 31, 2022, the Company has cash, cash equivalent and investments of approximately $125.8 million, which is available to fund future operations. The Company expects to continue to spend substantial amounts to continue the nonclinical and clinical development of its current and future programs. If the Company is able to gain marketing approval for drug candidates that are being developed, it will require significant additional amounts of cash in order to launch and commercialize such drug candidates. In addition, other unanticipated costs may arise. Because the design and outcome of the Company’s planned and anticipated clinical trials is highly uncertain, the Company cannot reasonably estimate the actual amounts necessary to successfully complete the development and commercialization of any drug candidate the Company may develop.

The Company expects to finance its cash needs through a combination of public or private equity offerings, debt financings, collaborations, strategic alliances, licensing arrangements and other marketing or distribution arrangements. Based on the Company’s research and development plans, it is expected that the Company’s existing cash, cash equivalents and investments, will enable the Company to fund its operations for at least 12 months following the date the consolidated financial statements are issued. However, the Company’s operating plan may change as a result of many factors currently unknown, and the Company may need to seek additional funds sooner than planned. Moreover, it is particularly difficult to estimate with certainty the Company’s future expenses given the dynamic nature of its business, the COVID-19 pandemic and the macro-economic environment generally.

The Company’s ability to raise additional funds will depend on financial, economic and other factors, many of which are beyond its control. In particular, the COVID-19 pandemic continues to rapidly evolve and has already resulted in a significant disruption of global financial markets. If the disruption persists or deepens, the Company could be unable to access additional capital, which could negatively affect its ability to consummate certain corporate development transactions or other important, beneficial or opportunistic investments. If additional funds

are not available to the Company when needed, on terms that are acceptable to the Company, or at all, the Company may be required to: delay, limit, reduce or terminate nonclinical studies, clinical trials or other research and development activities or eliminate one or more of its development programs altogether; or delay, limit, reduce or terminate its efforts to establish manufacturing and sales and marketing capabilities or other activities that may be necessary to commercialize any future approved products, or reduce the Company’s flexibility in developing or maintaining its sales and marketing strategy.

Investments - Summary of Available For Sale and Held to Maturity Securities Amortized Cost Gross Unrealized Gains Losses and Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Available For Sale And Held To Maturity Securities Amortised Cost Gross Unrealised Gains Losses And Fair Value [Line Items]
Available-for-sale securities, Amortized Cost	$ 44,576	$ 19,068
Available-for-sale securities, Gross Unrealized Loss	(96)	(40)
Available-for-sale securities, Estimated Fair Value	44,480	19,028
U.S. Treasury bonds [Member]
Schedule Of Available For Sale And Held To Maturity Securities Amortised Cost Gross Unrealised Gains Losses And Fair Value [Line Items]
Available-for-sale securities, Amortized Cost	44,576	15,146
Available-for-sale securities, Gross Unrealized Loss	(96)	(36)
Available-for-sale securities, Estimated Fair Value	$ 44,480	15,110
Certificates of deposit [Member]
Schedule Of Available For Sale And Held To Maturity Securities Amortised Cost Gross Unrealised Gains Losses And Fair Value [Line Items]
Available-for-sale securities, Amortized Cost		3,922
Available-for-sale securities, Gross Unrealized Loss		(4)
Available-for-sale securities, Estimated Fair Value		$ 3,918

Consolidated balance sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred Stock, Par Value	$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par Value	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	320,000,000	320,000,000
Common Stock, Shares, Issued	42,922,980	42,690,229
Common Stock, Shares, Outstanding	42,922,980	42,690,229

Summary of significant accounting policies (Policies)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Risks and uncertainties

The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing. As a result, the Company is unable to predict the timing or amount of increased expenses or when or if the Company will be able to achieve or maintain profitability. Drug candidates currently under development will require significant additional research and development efforts, including extensive nonclinical and clinical testing and regulatory approval.

Moreover, it is particularly difficult to estimate with certainty the Company’s future expenses given the dynamic nature of its business, the COVID-19 pandemic and the macro-economic environment generally.

Basis of presentation

The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented. Any reference in these notes to applicable accounting guidance is meant to refer to the authoritative U.S. GAAP included in the Accounting Standards Codification (ASC), and Accounting Standards Update (ASU) issued by the Financial Accounting Standards Board (the FASB).

Principles of consolidation

The accompanying consolidated financial statements include Aligos-US and its wholly owned subsidiaries Aligos-Belgium, Aligos-Australia and Aligos-Shanghai. All intercompany balances and transactions have been eliminated.

Use of estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP generally requires management to make certain estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. The Company regularly evaluates estimates and assumptions related to assets and liabilities, at the dates of the consolidated financial statements and the reported amounts of expenses during the reporting period. Areas where management uses subjective judgments include, but are not limited to, right-of-use assets, lease obligations, impairment of long-lived assets, stock-based compensation, accrued research and development costs, revenue from collaborations, deferred revenue, redeemable convertible preferred stock liability and pension liabilities in the accompanying consolidated financial statements. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from these estimates under different assumptions or conditions.

Foreign currency

The Company’s foreign subsidiaries use the U.S. dollar as their functional currency, and they initially measure the foreign currency denominated assets and liabilities at the transaction date. Monetary assets and liabilities are then re-measured at exchange rates in effect at the end of each period, and non-monetary assets and liabilities are converted at historical rates. A re-measurement loss was recognized during the year ended December 31, 2022 of $42,000, and a re-measurement loss was recognized during the year ended December 31, 2021 of $6,000, and are

reflected within interest and other income (expense), net on the consolidated statements of operations and comprehensive loss.

Segment information

The Company has determined that the Chief Executive Officer is its Chief Operating Decision Maker. The Company’s Chief Executive Officer reviews financial information presented on a consolidated basis for the purposes of assessing the performance and making decisions on how to allocate resources. Accordingly, the Company has determined that it operates in a single reportable segment. No product revenue has been generated since inception.

The Company has $4.1 million and $0.7 million of fixed assets in Aligos-US and Aligos-Belgium, respectively, as of December 31, 2022 and $5.0 million and $1.2 million of fixed assets in Aligos-US and Aligos‑Belgium, respectively as of December 31, 2021.

Cash equivalents

The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents.

Restricted cash

As of December 31, 2022 and 2021, the restricted cash balance was $0.1 million and $0.2 million, respectively, and was used primarily to secure letters of credit in relation to the Company’s operating leases and deposits on rental assets (Note 6), as well as employee withholdings for the employee stock purchase plan.

Investments

The Company generally invests its excess cash in money market funds and investment grade short-to-intermediate-term fixed income securities. Such investments are included in cash, cash equivalents, short-term and long-term investments on the consolidated Balance Sheets.

The Company determines the appropriate classification of short-term and long-term securities at the time of purchase and re-evaluates such designation as of each balance sheet date. Securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity, otherwise securities are classified as available-for sale. Held-to-maturity securities are carried at amortized cost. Available-for-sale debt securities are measured and reported at fair value using quoted prices in active markets for similar securities. Unrealized gains and losses on available-for-sale securities are reported as a separate component of stockholders’ equity. Premiums or discounts from par value are amortized to investment income over the life of the underlying investment. The cost of securities sold is determined on a specific identification basis, and realized gains and losses are included in interest and other income (expense), net within the consolidated statements of operations and comprehensive loss.

For both held-to-maturity and available-for-sale investments, the Company periodically reviews each individual security position that has an unrealized loss, or impairment, to determine if that impairment is other-than-temporary. If the Company believes an impairment of a security position is other than temporary, based on available quantitative and qualitative information as of the report date, the loss will be recognized as other income (expense), net, in the Company’s consolidated statements of operations and a new cost basis in the investment is established. No impairment charges were recorded during the years ended December 31, 2022 and 2021.

As of December 31, 2022 and 2021, investments consisted of Certificates of Deposit and U.S. Treasury securities, with original maturities of up to 1.50 years.

Concentrations of credit risk and significant suppliers

The Company has no significant off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, restricted cash and investments. Periodically, the Company maintains deposits in accredited financial institutions in excess of federally insured limits. The Company deposits its cash in financial institutions that it believes have high credit quality and has not experienced any losses on such accounts and does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company generally invests its excess capital in money market funds, U.S. treasury bonds, U.S. treasury bills and certificates of deposit that are subject to minimal credit and market risks.

The Company is dependent on various third parties to manufacture compounds for the Company to conduct research and studies for its programs. These programs would be adversely delayed by a significant interruption in the supply of active pharmaceutical ingredients.

Leases

The Company determines if an arrangement is a lease at the inception of the lease. Operating leases are included in operating lease right-of-use (ROU) assets and operating lease liabilities in the consolidated balance sheet. Finance leases are included in property and equipment and finance lease liabilities in the consolidated balance sheet.

ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. When the Company’s leases do not provide an implicit rate, an incremental borrowing rate is used based on the information available at the commencement dates in determining the present value of lease payments. The Company uses the implicit rate when readily determinable. The operating lease ROU assets also include any lease payments made and excludes lease incentives when paid by the Company or on the Company’s behalf. The Company’s lease terms may include the period covered by options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for operating leases is recognized on a straight-line basis over the lease term.

The Company has lease agreements with lease and non-lease components. The Company elected to not separate lease and non-lease components for all of its building leases. For vehicle leases, lease and non-lease components are accounted for separately. The Company also made an accounting policy election to recognize lease expense for leases with a term of 12 months or less on a straight-line basis over the lease term and not recognize ROU assets or lease liabilities for such leases.

Property and equipment

Property and equipment is stated at cost less accumulated depreciation, and is depreciated using the straight-line method over the estimated useful life of the asset, which are as follows:


Lab equipment		3 years
Computer equipment		3 years
Furniture and office equipment		3-8 years
Vehicles		4 years
Leasehold improvements		Shorter of the useful life or remaining lease term

Expenditures for repairs and maintenance of assets are charged to expense as incurred. Upon retirement or sale, the cost and related accumulated depreciation of assets disposed of are removed from the accounts and any resulting gain or loss is included in loss from operations.

Impairment of long-lived assets

The Company regularly reviews the carrying amount of its property, equipment and intangible assets to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. If indications of impairment exist, projected future undiscounted cash flows associated with the asset are compared to the carrying amount to determine whether the asset’s value is recoverable. If the carrying value of the asset exceeds such projected undiscounted cash flows, the asset will be written down to its estimated fair value. No impairment charges were recorded during the years ended December 31, 2022 or 2021.

Research and development expenses

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits, facilities costs, depreciation, and third-party license fees. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized.

In-process research and development (IPR&D) expense represents the costs to acquire technologies to be used in research and development that have not reached technological feasibility or have no alternative future uses and thus are expensed as incurred. IPR&D expense also includes upfront license fees and milestones paid to collaborators for technologies with no alternative use.

Collaborative arrangements

The Company enters into collaboration arrangements with pharmaceutical and other partners, under which the Company may grant licenses to its collaboration partners to research and develop potential drug candidates. Consideration under these contracts may include an upfront payment, development, regulatory, sales and other milestone payments. Contractual payments received for research and development activities performed are recognized on a gross basis in revenue from collaboration arrangements.

The Company may also perform research and development activities under the collaboration agreements where the Company may be granted licenses from its collaboration partners. Contractual payments to the other party in collaboration agreements and costs incurred by the Company are recognized on a gross basis in research and development expenses. Royalties and license payments are recorded as due.

When the Company enters into collaboration arrangements, the Company assesses whether the arrangement falls within the scope of ASC 808, Collaborative Arrangements (ASC 808) based on whether the arrangement involves joint operating activities and whether both parties would be active participants and would be exposed to significant risks and rewards of the arrangement. To the extent that the arrangement falls within the scope of ASC 808, the Company assesses whether the payments between the parties fall within the scope of other accounting literature such as ASC 606, Revenue from Contracts with Customers (ASC 606).

During the year ended December 31, 2022, the Company did not make any milestone payments. No royalties were due; therefore, the Company did not pay or expense any royalties. During the year ended December 31, 2021, a development milestone was met and so the Company made a payment of $0.5 million. The milestone payments were included in research and development in the consolidated statement of operations. The upfront payment received during the year ended December 31, 2021 was recorded on the consolidated balance sheet as deferred revenue from collaborations.

Fair value measurements

Certain assets and liabilities of the Company are carried at fair value under U.S. GAAP. Fair value is defined 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. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

Level 1—Quoted prices in active markets for identical assets or liabilities.

Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques.

Stock-based compensation

The Company’s stock-based awards consist of restricted stock awards and stock options. For stock-based awards issued to employees and nonemployees, the Company measures the estimated fair value of the stock-based awards on the date of grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective awards. The Company records expense for awards with service-based vesting using the straight-line method. The Company accounts for forfeitures as they occur.

The Company classifies stock-based compensation expense in its consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s cash compensation costs are classified.

The fair value of each restricted stock award is determined based on the number of shares granted and the value of the Company’s common stock on the date of grant. The fair value of each stock option award is estimated on the date of grant using the Black-Scholes option pricing model. The Black-Scholes option-pricing model requires the use of a number of assumptions including the fair value of the common stock, expected volatility, risk-free interest rate, expected dividends, and expected term of the option.

The Company determined the expected stock volatility using a weighted-average of the historical volatility of a group of guideline companies that issued options with substantially similar terms, and expects to continue to do so until such time as the Company has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the simplified method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company has not paid, and does not anticipate paying, cash dividends on its common stock; therefore, the expected dividend yield is assumed to be zero.

The fair value of the Company’s 2020 Employee Stock Purchase Plan (the ESPP) is determined on the date the offering period begins using a Black-Scholes option-pricing model and similar assumptions for stock options as described above.

See Note 8 for the assumptions used by the Company in determining the grant date fair value of stock-based awards granted, as well as a summary of the stock-based award activity under the Company’s stock-based compensation plan for years ended December 31, 2022 and 2021.

Income taxes

Deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established.

The Company accounts for uncertain tax positions recognized in the consolidated financial statements by prescribing a more-likely-than-not threshold for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related interest and penalties.

Net loss per share

Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities.

Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, redeemable convertible preferred stock, stock options, common stock subject to repurchase related to early exercise of stock options, unvested restricted stock subject to repurchase, warrants and convertible notes are considered to be potentially dilutive securities.

Accordingly, in periods in which the Company reports a net loss, diluted net loss per share is the same as basic net loss per share, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.

Benefit plans

The Company has established a defined contribution savings plan for its employees in Aligos-US under Section 401(k) of the Internal Revenue Code, and a defined benefits plan for its employees in Aligos-Belgium.

The Company uses the standard method for the recognition of the actuarial results as described in ASC 715. This means application of a 10% corridor and amortization over the expected average remaining working lives of

the employees. The plan contains benefits to the plan participant on the normal plan retirement date and benefits to the partner after death of the plan participant. This plan is recognized under ASC 715.

Recently issued accounting standards

In June 2016, the FASB issued ASU No. 2016-13. Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13), which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. Currently, U.S. GAAP delays recognition of the full amount of credit losses until the loss is probable of occurring. Under this ASU, the income statement will reflect an entity’s current estimate of all expected credit losses. The measurement of expected credit losses will be based upon historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. In November 2018, the FASB issued ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments—Credit Losses (ASU 2018-19), which clarifies that receivables from operating leases are accounted for using the lease guidance and not as financial instruments. In April 2019, the FASB issued ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments—Credit Losses (ASU 2019-04), which clarifies the new expected credit loss methodology for loans, receivables and other financial assets, including recoveries and accrued interest on receivables. In November 2019, the FASB issued ASU No. 2019-11, Codification Improvements to Topic 326, Financial Instruments—Credit Losses (ASU 2019-11), which clarifies guidance around how to report expected recoveries. The standard is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted. The Company is evaluating the potential impact of this standard on its consolidated financial statements.

In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (ASU 2019-12). The guidance removes specific exceptions to the general principles in ASC 740, improves application of income tax-related guidance and reduces complexity related to the accounting for income taxes. The standard is effective for fiscal years beginning after December 15, 2021, and interim periods with fiscal years beginning after December 15, 2022. Early adoption is permitted. The Company has evaluated the impact of this standard and there is not a material impact on its consolidated financial statements.

From time to time, new accounting pronouncements are issued by FASB that the Company adopts as of the specified effective date. The Company qualifies as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012 and has the option to not “opt out” of the extended transition related to complying with new or revised accounting standards. This means that when a standard is issued or revised and it has different application dates for public and nonpublic companies, the Company has the option to adopt the new or revised standard at the time nonpublic companies adopt the new or revised standard and can do so until such time that the Company either (i) irrevocably elects to “opt out” of such extended transition period or (ii) no longer qualifies as an emerging growth company.

Leases - Additional Information (Detail) $ in Millions	12 Months Ended
Leases - Additional Information (Detail) $ in Millions	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) ft²
Lessee Lease Description [Line Items]
Operating lease, payments	$ 3.4	$ 2.8
Finance lease right of use assets	0.7	0.6
Finance lease right of use assets accumulated amortization	$ 0.3	$ 0.2
Operating lease, term of contract		5 years
Operating lease area of office space \| ft²		12,000
Operating lease renewal option		5 years
Operating lease rental payments		$ 2.7
Minimum [Member]
Lessee Lease Description [Line Items]
Operating and finance lease remaining lease term	4 years
Operating lease option to extend	5 years
Maximum [Member]
Lessee Lease Description [Line Items]
Operating and finance lease remaining lease term	6 years
Operating lease option to extend	8 years

Property and equipment

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Property and equipment

3. Property and equipment

The components of property and equipment were as follows as of December 31, 2022 and 2021:


(in thousands)	2022			2021
Leasehold improvements	$	6,087		$	5,940
Lab equipment		6,179			5,709
Computer equipment		1,052			994
Furniture and office equipment		739			472
Vehicles		305			305
Asset under construction		22			22
Total, at cost		14,384			13,442
Accumulated depreciation		(9,568	)		(7,262	)
Total, net	$	4,816		$	6,180

During the years ended December 31, 2022 and December 31, 2021, depreciation expense was $2.3 million and $3.0 million, respectively. Finance leases for vehicles and lab equipment are also included in property and equipment on the consolidated balance sheets (Note 6).

Stock-based Compensation - Summary of Stock Based Compensation Expense Was Allocated (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	$ 14,693	$ 13,457
Research and Development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	8,006	7,554
General and Administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	$ 6,687	$ 5,903

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2022	Mar. 06, 2023	Jun. 30, 2022
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Entity Registrant Name	Aligos Therapeutics, Inc.
Entity Central Index Key	0001799448
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 35.2
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common Stock, par value, $0.0001 per share
Trading Symbol	ALGS
Security Exchange Name	NASDAQ
Entity File Number	001-39617
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-4724808
Entity Address, Address Line One	One Corporate Drive
Entity Address, Address Line Two	2nd Floor
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	800
Local Phone Number	466-6059
Document Annual Report	true
Document Transition Report	false
Auditor Firm ID	42
Auditor Name	Ernst & Young LLP
Auditor Location	San Mateo, California
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the Registrant’s Definitive Proxy Statement relating to the 2023 Annual Meeting of Stockholders, which will be filed with the Securities and Exchange Commission within 120 days after the end of the Registrant’s fiscal year ended December 31, 2022, are incorporated by reference into Part III of this Report.
Voting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		39,847,751
Non-voting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,092,338

Income Taxes - Additional Information (Detail) - USD ($)		12 Months Ended
	Jun. 29, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 27, 2020
Income Tax Contingency [Line Items]
Deferred provision for income taxes		$ 0	$ 0
Increase in valuation allowance		$ 25,300,000	35,200,000
Deferred tax assets net operating loss carryforwards ownership change in percentage		50.00%
Offset percentage of taxable income		80.00%
Unrecognized tax benefits, income tax penalties and interest expense		$ 0	0
Unrecognized tax benefits		3,100,000	$ 2,441,000	$ 1,536,000
Impact of CARES Act to Income Taxes		0
Suspension period	3 years
Cap period	3 years
Incentive tax credits offset amount of tax	$ 5,000,000
Taxable income	$ 1,000,000
CAA impact to tax provision					$ 0
Uncertain tax positions related to liability		0
Australia
Income Tax Contingency [Line Items]
Net operating loss carryforwards		3,200,000
Federal [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards		$ 272,400,000
Deferred tax assets net operating loss carryforwards expiration year		2038
Deferred tax assets, research and development tax credit carryforwards		$ 7,900,000
Tax credit research and development carryforward expiration year		2038
State [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards		$ 352,700,000
Deferred tax assets, research and development tax credit carryforwards		$ 3,900,000

Consolidated statements of changes in stockholders' equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2020	$ 220,039	$ 4	$ 394,963	$ (174,740)	$ (188)
Beginning balance, Shares at Dec. 31, 2020		38,120,606
Issuance of common stock upon exercise of stock options	394		394
Issuance of common stock upon exercise of stock options, shares		124,013
Stock Issued During Period, Value, Employee Stock Purchase Plan	653		653
Stock Issued During Period, Shares, Employee Stock Purchase Plans		45,610
Issuance of common stock, shares		4,400,000
Issuance of common stock	78,584		78,584
Costs related to the follow-on offering	(875)		(875)
Stock-based compensation expense related to employee stock awards	12,541		12,541
Stock-based compensation expense related to employee stock purchases	795		795
Vesting of early exercised common stock	292		292
Other comprehensive income (loss)	640				640
Net loss	(128,332)			(128,332)
Ending balance at Dec. 31, 2021	184,731	$ 4	487,347	(303,072)	452
Ending balance, Shares at Dec. 31, 2021		42,690,229
Issuance of common stock upon exercise of stock options	20	$ 0	20
Issuance of common stock upon exercise of stock options, shares		12,896
Stock Issued During Period, Value, Employee Stock Purchase Plan	205	$ 0	205
Stock Issued During Period, Shares, Employee Stock Purchase Plans		219,855
Stock-based compensation expense related to employee stock awards	13,540		13,540
Stock-based compensation expense related to employee stock purchases	1,292		1,292
Vesting of early exercised common stock	209		209
Other comprehensive income (loss)	(51)				(51)
Net loss	(96,046)			(96,046)
Ending balance at Dec. 31, 2022	$ 103,900	$ 4	$ 502,613	$ (399,118)	$ 401
Ending balance, Shares at Dec. 31, 2022		42,922,980

Leases - Summary of Additional Information Related to the leases (Detail)	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Additional Information Related To The Leases [Abstract]
Weighted-average remaining lease term (years)	4 years 2 months 15 days	5 years 2 months 4 days
Weighted-average discount rate	9.04%	9.08%
Weighted-average remaining lease term (years)	3 years 3 months 3 days	3 years 9 months 29 days
Weighted-average discount rate	5.15%	4.86%

Property and equipment (Tables)

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Summary of Property and Equipment

The components of property and equipment were as follows as of December 31, 2022 and 2021:


(in thousands)	2022			2021
Leasehold improvements	$	6,087		$	5,940
Lab equipment		6,179			5,709
Computer equipment		1,052			994
Furniture and office equipment		739			472
Vehicles		305			305
Asset under construction		22			22
Total, at cost		14,384			13,442
Accumulated depreciation		(9,568	)		(7,262	)
Total, net	$	4,816		$	6,180

Income Taxes - Schedule of Components of Current Provision for Income Taxes (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Current:
Foreign	$ 106,000	$ 143,000
Total current provision for income taxes	106,000	143,000
Deferred:
Total deferred provision for income taxes	$ 0	$ 0

Income Taxes - Summary of Changes to Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 2,441	$ 1,536
Increase related to prior year positions	687	63
Increase / (decrease) related to current year positions	(28)	842
Ending balance	$ 3,100	$ 2,441

Net loss per share - Schedule of Earnings Per Share Basic and Diluted (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share, Basic and Diluted [Abstract]
Net loss	$ (96,046)	$ (128,332)
Weighted average common stock outstanding, basic and diluted	42,695,227	39,855,403
Net loss per share – basic and diluted	$ (2.25)	$ (3.22)

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580

Reference 25: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8924-108599

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124509347&loc=SL7669625-108580

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

+ Details

Income Taxes - Components of Deferred Tax Assets And Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforward	$ 82,775	$ 72,425
Operating lease liabilities	4,057	4,622
Tax credits	8,025	6,177
Other accruals and reserves	1,398	1,461
Stock-based compensation	2,055	1,216
Deferred revenue	27	2,140
Capitalized SEC 174 costs	14,138
Other	253	22
Total deferred tax assets	112,728	88,063
Valuation allowance	(109,560)	(84,288)
Net deferred tax assets	3,168	3,775
Deferred tax liabilities:
Right of use assets	(2,803)	(3,205)
Property and equipment	(365)	(570)
Total deferred tax liabilities	$ (3,168)	$ (3,775)

Leases - Summary of Components of Lease Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Lease, Cost [Abstract]
Operating lease cost	$ 2,504	$ 1,990
Finance lease cost:
Amortization of right-of-use assets	108	107
Interest on lease liabilities	13	15
Total finance lease cost	$ 121	122
Short-term lease cost		$ 89

Summary of significant accounting policies - Summary of Estimated Useful Life of Asset (Detail)	12 Months Ended
	Dec. 31, 2022
Lab Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Vehicles [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	4 years
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	Shorter of the useful life orremaining lease term
Minimum [Member] \| Furniture and Office Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Maximum [Member] \| Furniture and Office Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	8 years

Stock-based compensation

12 Months Ended

Dec. 31, 2022

Share-based Payment Arrangement [Abstract]

Stock-based compensation

8. Stock-based compensation

2018 Equity incentive plan

The Company’s 2018 Equity Incentive Plan (the 2018 Plan) allows the Company to issue restricted stock awards and restricted stock units, and to grant incentive stock options or non-qualified stock options. Incentive stock options may be granted only to the Company’s employees including officers and members of the Board who are also employees. Restricted stock awards, restricted stock units and non-qualified stock options may be granted to employees, members of the Board, outside advisors, and consultants of the Company (the Participants). The Company is authorized to issue awards for 4,913,665 shares of Common Stock under the 2018 Plan. The Company has granted awards of common stock in the form of 4,279,693 shares as of December 31, 2022 with none remaining available for future grant. Following the Company’s IPO in October 2020, all remaining shares from the 2018 Plan will be available for issuance under the 2020 Plan (as defined below).

2020 Incentive award plan

The Company adopted the 2020 Incentive Award Plan (the 2020 Plan) effective October 15, 2020. The 2020 Plan provides for a variety of stock-based compensation awards, including stock options, stock appreciation rights, or SARs, restricted stock awards, restricted stock unit awards, performance bonus awards, performance stock unit awards, dividend equivalents, or other stock or cash based awards. The Company has granted 8,967,670 shares subject to awards as of December 31, 2022 with 562,010 remaining available for future grant.

Following the effectiveness of the 2020 Plan, the Company will not make any further grants under the 2018 Plan. However, the 2018 Plan will continue to govern the terms and conditions of the outstanding awards granted under this plan. Shares of common stock subject to awards granted under the 2018 Plan that are forfeited or lapse unexercised and which following the effective date of the 2020 Plan are not issued under the 2018 Plan will be available for issuance under the 2020 Plan.

2020 Employee stock purchase plan

The Company adopted the 2020 Employee Stock Purchase Plan (the 2020 ESPP) effective on October 15, 2020. The 2020 ESPP enables eligible employees of the Company to purchase shares of common stock at a discount

to fair market value. The Company has initially reserved for issuance 368,901 shares of common stock pursuant to the 2020 ESPP. As of December 31, 2022, 265,465 grants of awards under this plan have been made.

During the year ended December 31, 2022 and 2021, the Company's 2020 ESPP compensation expense was $1.3 million and $0.8 million, respectively. The assumptions that the Company used to determine the grant-date fair value of shares granted to participants were as follows, disclosed on a grant date basis:


	2022		2021

Expected term (in years)	0.5 - 2.0 years		0.5 - 2.0 years
Risk-free interest rate	1.54% - 4.62%		0.03% - 0.54%
Dividend yield		—		—
Volatility	57.21% - 73.67		50.41% - 97.14%
Weighted-average estimated fair value of purchase rights	$0.28 - $2.46		$4.13 - $13.49

Stock options

The exercise price for incentive stock options is at least 100% of the fair market value on the date of grant for stockholders owning less than 10% of the voting power of all classes of stock, or at least 110% of the fair market value for stockholders owning more than 10% of the voting power of all classes of stock. Options generally expire in 10 years and vest over periods determined by the Board, generally 48 months. Certain stock options referred to as “early exercise stock options” permit the holders to exercise the option in whole or in part prior to the full vesting of the option in exchange for unvested shares of Restricted Stock with respect to any unvested portion of the option so exercised.

During the years ended December 31, 2022 and December 31, 2021, the Company’s stock option compensation expense was approximately $13.4 million and $12.2 million, respectively, and there was no recognized tax benefit in either year. As of December 31, 2022, the unamortized expense balance was $28.3 million, to be amortized over a weighted-average period of 2.26 years.

The assumptions that the Company used to determine the grant-date fair value of stock options granted to Participants were as follows, presented on a weighted-average basis:


	2022			2021
Expected term (in years)		5.95			5.72
Risk-free interest rate		2.20	%		0.99	%
Dividend yield		—			—
Volatility		80.41	%		81.21	%

Stock option activity during the year ended December 31, 2022 and 2021 was as follows:


	Number of Options			Weighted- Average Exercise Price per Share		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in $000)

Outstanding as of December 31, 2020		5,488,148		$	11.19		9.57	$	90,335

Granted		482,380		$	20.31
Exercised		(123,621	)	$	3.16				2,338
Forfeited or expired		(154,393	)	$	13.66
Outstanding as of December 31, 2021		5,692,514		$	12.07		8.63	$	16,763

Granted		5,090,824		$	2.58
Exercised		(12,896	)	$	1.57				19
Forfeited or expired		(930,315	)	$	8.72
Outstanding as of December 31, 2022		9,840,127		$	7.49		8.28	$	—
Options vested and expected to vest as of December 31, 2022		9,836,359		$	7.49		8.28	$	—
Options vested and exercisable as of December 31, 2022		3,730,149		$	9.33		7.65	$	—

The weighted-average grant date fair value of stock options granted was $1.80 per share during the year ended December 31, 2022. The weighted-average grant date fair value of stock options granted was $13.76 per share during the year ended December 31, 2021.

During the years ended December 31, 2022 and 2021 the Company did not issue shares for unvested stock options. As of December 31, 2022 and 2021, there were 28,711 and 163,855 shares of Common Stock, respectively, held by employees subject to repurchase at an aggregate price of $0.1 million and $0.3 million, respectively. A corresponding liability was recorded and included in accrued expenses on the consolidated balance sheet as of December 31, 2022 and 2021.

Restricted stock awards

The Company may grant restricted stock purchase awards to the Participants to purchase restricted stock under the Company’s Plan, which are subject to vesting conditions. The purchase prices of the restricted stock are determined by the Board. The Company has a right to repurchase the shares if the Participant’s service period is not fulfilled or upon termination of service at the original per share issuance price. The right of repurchase lapses over a service period which is typically four years with 25% vesting on the first anniversary of the vesting commencement date and 1/48 each month thereafter.

Before the adoption of the Company’s Plan, the Company granted 502,964 restricted stock awards to employees and founders. These restricted stock awards have similar characteristics to the restricted stock awards granted under the Company’s Plan, other than the right of repurchase, which typically lapses over three years with 33% vesting on the first anniversary of the vesting commencement date and 1/36 each month thereafter.

During the years ended December 31, 2022 and December 31, 2021, the Company recorded a total stock-based compensation expense of $0.1 million and $0.4 million, respectively, related to the restricted stock awards. As of December 31, 2022, there was no unrecognized stock-based compensation costs related to outstanding unvested restricted stock awards that are expected to vest.

The following table summarizes the Company’s restricted common stock activity for years ended December 31, 2022 and 2021:


	Number of Awards			Weighted- Average Grant Date Fair Value per Share		Aggregate Fair Value (in $000)

Issued and unvested as of December 31, 2020		408,411		$	1.16	$	473

Restricted stock awards granted		—					—
Restricted stock awards vested		(319,357	)	$	1.12		(356	)
Issued and unvested as of December 31, 2021		89,054		$	1.30	$	117

Restricted stock awards granted		—					—
Restricted stock awards vested		(89,054	)	$	1.30		(117	)

Issued and unvested as of December 31, 2022		0		$	—	$	—

Stock-based compensation expense was allocated as follows for the years ended December 31, 2022 and December 31, 2021:


(in thousands)	2022		2021
Research and development	$	8,006	$	7,554
General and administrative		6,687		5,903
Total	$	14,693	$	13,457

Benefit plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, matching amount		$ 0.9	$ 0.7
Regular Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, matching percentage		1.75%
Net periodic benefit cost		$ 0.3	0.2
Projected benefit obligation		1.1	1.0
Projected benefit obligation, plan assets		1.0	0.9
Net pension liability		0.1	0.1
Actuarial gain (loss)		0.1	0.1
Estimates future benefit payments from 2024 to 2027		0.3
Estimates future benefit payments, 2028 and thereafter		$ 0.9
Regular Pension Plan [Member] \| Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Company contributions	$ 0.2
Top Hat Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan legal yield guarantee percent		1.75%
Net periodic benefit cost		$ 0.2	0.4
Projected benefit obligation		1.7	1.7
Projected benefit obligation, plan assets		1.5	1.2
Net pension liability		0.2	0.5
Actuarial gain (loss)		0.1	$ 0.5
Estimates future benefit payments from 2024 to 2027		0.2
Estimates future benefit payments, 2028 and thereafter		$ 0.6
Top Hat Plan [Member] \| Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Company contributions	$ 0.2

Fair value measurements (Tables)

12 Months Ended

Dec. 31, 2022

Summary of fair value of the financial instruments that are measured at fair value on a recurring basis

The following tables present the fair value of the Company’s financial instruments that are measured or disclosed at fair value on a recurring basis:


	Fair Value Measurements as of December 31, 2022
(in thousands)	Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	81,347	$	—	$	—
Certificates of deposit		-		—		—
U.S. Treasury bonds		44,480		—		—
	$	125,827	$	—	$	—


	Fair Value Measurements as of December 31, 2021
(in thousands)	Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	186,816	$	—	$	—
Certificates of deposit		3,918		—		—
U.S. Treasury bonds		15,110		—		—
	$	205,844	$	—	$	—

Investments - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fixed-Maturity Securities [Member]
Investment In Available For Sale And Held To Maturity Securities [Line Items]
Interest income	$ 1.5	$ 0.2

License and collaboration agreements - Additional Information (Detail) - USD ($)			1 Months Ended				12 Months Ended
	Jun. 25, 2020	Dec. 19, 2018	Jan. 31, 2022	Dec. 31, 2020	Jun. 30, 2020	Apr. 30, 2020	Dec. 31, 2022	Dec. 31, 2021	Jun. 30, 2018
Expense related to milestone payments							$ 0	$ 0
Revenue recognized from collaborative arrangements on upfront payment							$ (13,898,000)	(4,359,000)
KU Leuven [Member]
Collaboration expire period	2 years 6 months
Emory license agreement [Member] \| Emory university [Member]
Non-refundable payment					$ 200,000
Long term purchase commitment additional obligation to be paid					35,000
Research plan funding amount					$ 300,000
Research plan expiry period					1 year
Long term purchase commitment period description							The research plan terminates one year from the effective date, with the Company having an option to extend for a second year
Expense related to milestone payments							$ 200,000	200,000
Payments for royalties							0	0
Emory license agreement [Member] \| Emory university [Member] \| Maximum [Member]
Aggregate payments									$ 125,000,000.0
Luxna license agreement [Member] \| Luxna biotech Co Ltd [Member]
Expense related to milestone payments							0	500,000
Payments for royalties							$ 0	0
Luxna license agreement [Member] \| Luxna biotech Co Ltd [Member] \| Maximum [Member]
Aggregate payments		$ 55,500,000
Luxna license agreement [Member] \| Research and Development [Member] \| Luxna biotech Co Ltd [Member]
Upfront license fees paid		$ 600,000
Non-refundable payment						$ 200,000
Katholieke Universiteit Leuven License Agreement [Member] \| Katholieke Universiteit Leuven [Member]
Non-refundable payment	$ 30,000,000.0
Long term purchase commitment period description							Unless terminated earlier by either party, the agreement shall continue until the expiration of the last to expire royalty term, which is the later of the expiration or termination of the last valid patent claim covering the manufacture, use, sale or importation of the licensed product in a particular country or 10 years after the first commercial sale of a licensed product.
First commercial sale of a licensed product period	10 years
Katholieke Universiteit Leuven License Agreement [Member] \| Katholieke Universiteit Leuven [Member] \| Maximum [Member]
Non-refundable payment	$ 32,000,000.0
Merck License and Research Collaboration \| Merck
Upfront payment received			$ 15,000,000	$ 12,000,000
Additional upfront payment received			15,000,000
Merck License and Research Collaboration \| Merck \| Maximum [Member]
Milestone payments and royalties receivable			$ 460,000,000.0	$ 458,000,000.0
Merck License and Research Collaboration First Amendment \| Merck
Revenue recognized from collaborative arrangements on upfront payment							$ 13,900,000	4,400,000
Revenue recognized from collaborative arrangements							$ 0	$ 0

Summary of significant accounting policies

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Summary of significant accounting policies

2. Summary of significant accounting policies

The accompanying consolidated financial statements have been prepared on a basis that contemplates the continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the normal course of business.

Risks and uncertainties

Basis of presentation

Principles of consolidation

Use of estimates

Foreign currency

reflected within interest and other income (expense), net on the consolidated statements of operations and comprehensive loss.

Segment information

Cash equivalents

The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents.

Restricted cash

Investments

As of December 31, 2022 and 2021, investments consisted of Certificates of Deposit and U.S. Treasury securities, with original maturities of up to 1.50 years.

Concentrations of credit risk and significant suppliers

Leases

Property and equipment

Property and equipment is stated at cost less accumulated depreciation, and is depreciated using the straight-line method over the estimated useful life of the asset, which are as follows:


Lab equipment		3 years
Computer equipment		3 years
Furniture and office equipment		3-8 years
Vehicles		4 years
Leasehold improvements		Shorter of the useful life or remaining lease term

Impairment of long-lived assets

Research and development expenses

Collaborative arrangements

Fair value measurements

Level 1—Quoted prices in active markets for identical assets or liabilities.

Stock-based compensation

Income taxes

Net loss per share

Benefit plans

Recently issued accounting standards

Stock-based compensation (Tables)

12 Months Ended

Dec. 31, 2022

Summary of Stock Options

Stock option activity during the year ended December 31, 2022 and 2021 was as follows:


	Number of Options			Weighted- Average Exercise Price per Share		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in $000)

Outstanding as of December 31, 2020		5,488,148		$	11.19		9.57	$	90,335

Granted		482,380		$	20.31
Exercised		(123,621	)	$	3.16				2,338
Forfeited or expired		(154,393	)	$	13.66
Outstanding as of December 31, 2021		5,692,514		$	12.07		8.63	$	16,763

Granted		5,090,824		$	2.58
Exercised		(12,896	)	$	1.57				19
Forfeited or expired		(930,315	)	$	8.72
Outstanding as of December 31, 2022		9,840,127		$	7.49		8.28	$	—
Options vested and expected to vest as of December 31, 2022		9,836,359		$	7.49		8.28	$	—
Options vested and exercisable as of December 31, 2022		3,730,149		$	9.33		7.65	$	—

Summary of Stock Based Compensation Expense Was Allocated

Stock-based compensation expense was allocated as follows for the years ended December 31, 2022 and December 31, 2021:


(in thousands)	2022		2021
Research and development	$	8,006	$	7,554
General and administrative		6,687		5,903
Total	$	14,693	$	13,457

2020 Employee Stock Purchase Plan [Member]

Summary of Assumptions Used to Determine Grant-date Fair Value of Stock Options

The assumptions that the Company used to determine the grant-date fair value of shares granted to participants were as follows, disclosed on a grant date basis:


	2022		2021

Expected term (in years)	0.5 - 2.0 years		0.5 - 2.0 years
Risk-free interest rate	1.54% - 4.62%		0.03% - 0.54%
Dividend yield		—		—
Volatility	57.21% - 73.67		50.41% - 97.14%
Weighted-average estimated fair value of purchase rights	$0.28 - $2.46		$4.13 - $13.49

Restricted Stock [Member]

Summary of Stock Options

The following table summarizes the Company’s restricted common stock activity for years ended December 31, 2022 and 2021:


	Number of Awards			Weighted- Average Grant Date Fair Value per Share		Aggregate Fair Value (in $000)

Issued and unvested as of December 31, 2020		408,411		$	1.16	$	473

Restricted stock awards granted		—					—
Restricted stock awards vested		(319,357	)	$	1.12		(356	)
Issued and unvested as of December 31, 2021		89,054		$	1.30	$	117

Restricted stock awards granted		—					—
Restricted stock awards vested		(89,054	)	$	1.30		(117	)

Issued and unvested as of December 31, 2022		0		$	—	$	—

Stock Option [Member]

Summary of Assumptions Used to Determine Grant-date Fair Value of Stock Options

The assumptions that the Company used to determine the grant-date fair value of stock options granted to Participants were as follows, presented on a weighted-average basis:


	2022			2021
Expected term (in years)		5.95			5.72
Risk-free interest rate		2.20	%		0.99	%
Dividend yield		—			—
Volatility		80.41	%		81.21	%

Stock-based Compensation - Summary of Assumptions Used to Determine Grant-date Fair Value of Stock Options (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected dividend yield	0.00%
2020 Employee Stock Purchase Plan [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected dividend yield
2020 Employee Stock Purchase Plan [Member] \| Minimum [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term (in years)	6 months	6 months
Risk-free interest rate, minimum	1.54%	0.03%
Volatility, minimum	57.21%	50.41%
Weighted-average estimated fair value of purchase rights	$ 0.28	$ 4.13
2020 Employee Stock Purchase Plan [Member] \| Maximum [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term (in years)	2 years	2 years
Risk-free interest rate, maximum	4.62%	0.54%
Volatility, maximum	73.67%	97.14%
Weighted-average estimated fair value of purchase rights	$ 2.46	$ 13.49
Stock Option [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Expected term (in years)	5 years 11 months 12 days	5 years 8 months 19 days
Risk-free interest rate	2.20%	0.99%
Expected dividend yield
Volatility	80.41%	81.21%

Net loss per share (Tables)

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table summarizes the computation of basic and diluted net loss per share of the Company:


		Year Ended December 31,
	2022				2021
Net loss		$	(96,046	)	$	(128,332	)
Weighted average common stock outstanding, basic and diluted			42,695,227			39,855,403
Net loss per share – basic and diluted		$	(2.25	)	$	(3.22	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The Company excluded the following potential shares of Common Stock, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:


		Year Ended December 31,
	2022			2021
Options to purchase common stock			9,840,127		5,692,514
Unvested restricted stock			—		89,054
			9,840,127		5,781,568

Benefit plans

12 Months Ended

Dec. 31, 2022

Retirement Benefits [Abstract]

Benefit plans

13. Benefit plans

Defined contribution plans

The Company established a defined contribution savings plan under Section 401(k) of the Internal Revenue Code. This plan covers substantially all employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. The Company made matching

contributions of $0.9 million and $0.7 million to the plan during the years ended December 31, 2022 and 2021, respectively.

Defined benefit plans—regular pension plan

ASC Topic 715, Compensation—Retirement Benefits, requires an employer to: (a) recognize in its statement of financial position an asset for a plan’s overfunded status or a liability for a plan’s under-funded status; (b) measure a plan’s assets and its obligations that determine its funded status as of the end of the employer’s fiscal year; and (c) recognize changes in the funded status of a defined benefit post retirement plan in the year in which the changes occur. Accordingly, the Company is required to report changes in its funded status on its consolidated statement of stockholders’ deficit and consolidated statement of operations and comprehensive loss.

Aligos-Belgium offers its employees a regular pension plan in the form of a defined contribution plan (the Regular Pension Plan), which contains a 1.75% legally required minimum rate of return for the participants. The Regular Pension Plan does not meet all the requirements that are needed for recognition of the plans as a defined contribution plan. The Company therefore recognizes the Regular Pension Plan as a defined benefit plan.

The Company measures the fair value of the Regular Plan assets by using Level 3 inputs, unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of assets, including pricing models, discounted cash flow methodologies and similar techniques.

The net periodic benefit cost of the Pension Plan was $0.3 million and $0.2 million, and is recognized in accrued liabilities on the consolidated balance sheet as of December 31, 2022 and 2021, respectively. As of December 31, 2022, the projected benefit obligation was $1.1 million, the plan assets were $1.0 million and the net pension liability was $0.1 million. As of December 31, 2021, the projected benefit obligation was $1.0 million, the plan assets were $0.9 million, and the net pension liability was $0.1 million. The Company has recorded the unfunded amount as a liability in its consolidated balance sheet at December 31, 2022 and 2021, under the accrued liabilities caption. The unrealized actuarial gain and loss on pension benefits, net of tax, at December 31, 2022 and 2021 was $0.1 million and $0.1 million, respectively. These amounts were reflected in other comprehensive loss under the caption gain (loss) on pension plans. The Company expects to make contributions to the Pension Plan of approximately $0.2 million during 2023. The Company estimates future benefit payments from 2024 to 2027 to be $0.3 million, and from 2028 thereafter to be $0.9 million.

Defined benefit plans—Top Hat Plan

In Aligos-Belgium, the Company established a pension bonus complementary plan (the Top Hat Plan), where the bonus payments to each participant are added to the Top Hat Plan. The annual contributions to this plan are based on performance and determined on a discretionary basis by the Company. The Top Hat Plan contains a legal yield guarantee of 1.75%. The Top Hat Plan became effective as of January 1, 2019.

In 2019, the Company accounted for the Top Hat Plan in accordance with ASC 715—Compensation—Retirement Benefits, once it became effective. The Top Hat Plan does not meet all the requirements that are needed for recognition as a defined contribution plan. The Company therefore recognizes the Top Hat Plan as a defined benefit plan.

The net periodic benefit cost of the Top Hat Plan was $0.2 million and $0.4 million, and is recognized in accrued liabilities on the consolidated balance sheet as of December 31, 2022 and 2021, respectively. As of December 31, 2022, the projected benefit obligation was $1.7 million, the plan assets were $1.5 million and the net pension liability was $0.2 million. As of December 31, 2021, the projected benefit obligation was $1.7 million, the plan assets were $1.2 million, and the net pension liability was $0.5 million. The Company has recorded the unfunded amount as a liability in its consolidated balance sheet at December 31, 2022 and 2021, under the accrued liabilities caption. The unrealized actuarial gain and loss on pension benefits, net of tax, at December 31, 2022 and 2021 was $0.1 million and $0.5 million, respectively. These amounts were reflected in other comprehensive loss under the caption gain (loss) on pension plans. The Company expects to make contributions to the Pension Plan of approximately $0.2 million during 2023. The Company estimates future benefit payments from 2024 to 2027 to be $0.2 million, and from 2028 thereafter to be $0.6 million.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section S99
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=21916913&loc=d3e273930-122802

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (o)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (p)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-URI http://asc.fasb.org/topic&trid=2235017

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 60
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39689-114964

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (q)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

+ Details

Consolidated balance sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 81,347	$ 186,816
Restricted cash	115	164
Short-term investments	44,480	3,918
Other current assets	7,603	13,526
Total current assets	133,545	204,424
Operating lease right-of-use assets	7,698	8,789
Property and equipment, net	4,816	6,180
Long-term investments		15,110
Other assets	634	866
Total assets	146,693	235,369
Current liabilities:
Accounts payable	4,737	3,015
Accrued liabilities	16,039	25,394
Operating lease liabilities, current	3,035	2,769
Finance lease liabilities, current	108	138
Deferred Revenue from customers, current	467
Deferred Revenue from collaborations, current	8,743	7,641
Total current liabilities	33,129	38,957
Operating lease liabilities, net of current portion	9,201	11,287
Finance lease liabilities, net of current portion	230	261
Long term liabilities		133
Deferred revenue from customers	233
Total liabilities	42,793	50,638
Commitments and contingencies (Note 12)
Stockholders’ equity:
Preferred Stock, $0.0001 par value; 10,000,000 shares authorized as of December 31, 2022 and 2021, respectively; no shares issued and outstanding as of December 31, 2022 and 2021, respectively.
Common stock, $0.0001 par value; 320,000,000 shares authorized as of December 31, 2022 and 2021, respectively; 42,922,980 and 42,690,229 shares issued and outstanding as of December 31, 2022 and 2021, respectively	4	4
Additional paid-in capital	502,613	487,347
Accumulated deficit	(399,118)	(303,072)
Accumulated other comprehensive income	401	452
Total stockholders’ equity	103,900	184,731
Total liabilities, redeemable convertible preferred stock, and stockholders’ equity	$ 146,693	$ 235,369

Income taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Schedule of Components of Current Provision for Income Taxes

The components of the current provision for income taxes were as follows for the years ended December 31, 2022 and 2021:


(in thousands)	2022		2021
Current:
State	$	—	$	—
Federal		—		—
Foreign		106		143
Total current provision for income taxes	$	106	$	143

Deferred:
State	$	—	$	—
Federal		—		—
Foreign		—		—
Total deferred provision for income taxes	$	—	$	—

Schedule of Expected Income Tax (Benefit) Computed Using Federal Statutory Income Tax Rate to Company's Effective Income Tax Rate


	2022			2021
Income tax computed at federal statutory rate		21.00	%		21.00	%
State taxes, net of federal benefit		6.95	%		6.91	%
R&D credit carryovers		1.25	%		0.90	%
Change in valuation allowance		-26.32	%		-27.42	%
Stock based compensation		-1.08	%		-1.19	%
Permanent differences		-1.91	%		-0.31	%
Change in fair value of derivatives		0.00	%		0.00	%
Effective income tax rate		-0.11	%		-0.11	%

Schedule of Deferred Tax Assets And Liabilities

The components of the deferred tax assets and liabilities were as follows at December 31:


(in thousands)	2022			2021
Deferred tax assets:
Net operating loss carryforward	$	82,775		$	72,425
Operating lease liabilities		4,057			4,622
Tax credits		8,025			6,177
Other accruals and reserves		1,398			1,461
Stock-based compensation		2,055			1,216
Deferred revenue		27			2,140
Capitalized SEC 174 costs		14,138			—
Other		253			22
		112,728			88,063
Valuation allowance		(109,560	)		(84,288	)
Net deferred tax assets	$	3,168		$	3,775
Deferred tax liabilities:
Right of use assets	$	(2,803	)	$	(3,205	)
Stock-based compensation		—			—
Property and equipment		(365	)		(570	)
Total deferred tax liabilities	$	(3,168	)	$	(3,775	)
Total deferred income taxes	$	—		$	—

Summary of Changes to Unrecognized Tax Benefits


(in thousands)	2022			2021
Balance, beginning of the period	$	2,441		$	1,536
Increase related to prior year positions		687			63
Increase / (decrease) related to current year positions		(28	)		842
Balance, ending of the period	$	3,100		$	2,441

Net loss per share - Schedule of Antidilutive Securities Excluded From Computation of Earnings Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	9,840,127	5,781,568
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	9,840,127	5,692,514
Unvested restricted stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		89,054

Stock-based Compensation - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Oct. 15, 2020 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based payment exercise price description	The exercise price for incentive stock options is at least 100% of the fair market value on the date of grant for stockholders owning less than 10% of the voting power of all classes of stock, or at least 110% of the fair market value for stockholders owning more than 10% of the voting power of all classes of stock. Options generally expire in 10 years and vest over periods determined by the Board, generally 48 months.
Share based compensation expense \| $	$ 14,693,000	$ 13,457,000
Share based compensation expense recognized tax benefit \| $	$ 0	$ 0
Shares of common stock held by employees subject to repurchase	28,711	163,855
Aggregate price for share repurchase \| $	$ 100,000	$ 300,000
Less than 10% [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price for incentive stock options as of fair market value	1
More Than 10% [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price for incentive stock options as of fair market value	1.10
Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period	10 years
Common stock vesting period	48 months
Share based compensation expense \| $	$ 13,400,000	$ 12,200,000
Share based payment unamortised share based payment expenses \| $	$ 28,300,000
Share based payment expenses amortized over a weighted average period	2 years 3 months 3 days
Share based payments weighted-average grant date fair value \| $ / shares	$ 1.80	$ 13.76
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period	3 years
Share based compensation expense \| $	$ 100,000	$ 400,000
Restricted stock awards rights vesting percentage	33.00%
Restricted stock awards rights vesting	1/36
Restricted stock awards granted	502,964
2018 Equity incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based payment Common stock shares authorised	4,913,665
Share based payment awards granted	4,279,693
Common stock available for future grant	0
2018 Equity incentive Plan [Member] \| Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period	4 years
Restricted stock awards rights vesting percentage	25.00%
Restricted stock awards rights vesting	1/48
2020 Incentive Award Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based payment awards granted	8,967,670
Common stock available for future grant	562,010
2020 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock available for future grant	265,465		368,901
Share based compensation expense \| $	$ 1,300,000	$ 800,000

Net loss per share

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Net loss per share

14. Net loss per share

The following table summarizes the computation of basic and diluted net loss per share of the Company:


		Year Ended December 31,
	2022				2021
Net loss		$	(96,046	)	$	(128,332	)
Weighted average common stock outstanding, basic and diluted			42,695,227			39,855,403
Net loss per share – basic and diluted		$	(2.25	)	$	(3.22	)

The Company’s potentially dilutive securities, which include options to purchase common stock and unvested restricted stock, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of shares of Common Stock outstanding used to calculate both basic and diluted net loss per share is the same. The Company excluded the following potential shares of Common Stock, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:


		Year Ended December 31,
	2022			2021
Options to purchase common stock			9,840,127		5,692,514
Unvested restricted stock			—		89,054
			9,840,127		5,781,568

Leases - Summary of Maturities of Lease Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Operating Lease
2023	$ 3,425
2024	3,305
2025	3,418
2026	3,534
2027	1,170
Lessee, Operating Lease, Liability, to be Paid	14,852
Less: imputed interest	(2,616)
Present value of lease liabilities	12,236
Less: current portion	(3,035)	$ (2,769)
Lease liabilities net of current portion	9,201	11,287
Finance Lease
2023	189
2024	64
2025	63
2026	42
Finance Lease, Liability, Payment, Due	358
Less: imputed interest	(20)
Present value of lease liabilities	338
Less: current portion	(108)	(138)
Lease liabilities net of current portion	$ 230	$ 261

Leases (Tables)

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Summary of Maturities of Lease Liabilities

Maturities of lease liabilities as of December 31, 2022, were as follows:


(in thousands)	Operating Lease			Finance Lease
Year ending December 31:
2023	$	3,425		$	189
2024		3,305			64
2025		3,418			63
2026		3,534			42
2027		1,170			—
Thereafter		-			—
		14,852			358
Less: imputed interest		(2,616	)		(20	)
Present value of lease liabilities		12,236			338
Less: current portion		(3,035	)		(108	)
Lease liabilities net of current portion	$	9,201		$	230

Summary of Components of lease Expense

The components of lease expense were as follows for the years ended December 31, 2022 and 2021:


(in thousands)	2022		2021
Operating lease cost	$	2,504	$	1,990
Finance lease cost:
Amortization of right-of-use assets		108		107
Interest on lease liabilities		13		15
Total finance lease cost	$	121	$	122
Short-term lease cost	$	—	$	89

Summary of Additional Information Related to the Leases

Additional information related to the Company’s leases was as follows as of December 31:


	2022			2021
Operating Lease:
Weighted-average remaining lease term (years)		4.21			5.18
Weighted-average discount rate		9.04	%		9.08	%
Finance Lease:
Weighted-average remaining lease term (years)		3.26			3.83
Weighted-average discount rate		5.15	%		4.86	%

Consolidated statements of operations and comprehensive loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue from collaborations	$ 13,907	$ 4,359
Operating expenses:
Research and development	85,077	104,153
General and administrative	26,410	28,527
Total operating expenses	111,487	132,680
Loss from operations	(97,580)	(128,321)
Interest and other income, net	1,640	132
Loss before income tax expense	(95,940)	(128,189)
Income tax expense	(106)	(143)
Net loss	(96,046)	(128,332)
Other comprehensive (loss) and income:
Gains on pension plans	6	749
Losses on available for sale investments	(57)	(109)
Comprehensive loss	$ (96,097)	$ (127,692)
Net loss per share, basic and diluted	$ (2.25)	$ (3.22)
Weighted average shares of common stock, basic and diluted	42,695,227	39,855,403

Stock-based Compensation - Summary of Stock Options (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Stock Option [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Number of options - Beginning balance	5,692,514	5,488,148
Number of options, Granted	5,090,824	482,380
Number of options, Exercised	(12,896)	(123,621)
Number of options, Forfeited or expired	(930,315)	(154,393)
Number of options - Ending balance	9,840,127	5,692,514	5,488,148
Number of options vested and expected to vest	9,836,359
Number of options vested and exercisable	3,730,149
Weighted average exercise price per share - Beginning balance	$ 12.07	$ 11.19
Weighted average exercise price per share Granted	2.58	20.31
Weighted average exercise price per share Exercised	1.57	3.16
Weighted average exercise price per share Forfeited or expired	8.72	13.66
Weighted Average Exercise Price Per Share - Ending balance	7.49	$ 12.07	$ 11.19
Weighted average exercise price Options per share vested and expected to vest	7.49
Weighted average exercise price options per share vested and exercisable	$ 9.33
Weighted- Average Remaining Contractual Term, Outstanding	8 years 3 months 10 days	8 years 7 months 17 days	9 years 6 months 25 days
Weighted- Average Remaining Contractual Term, Options vested and expected to vest	8 years 3 months 10 days
Weighted- Average Remaining Contractual Term, Options vested and exercisable	7 years 7 months 24 days
Aggregate Intrinsic Value - Options outstanding		$ 16,763	$ 90,335
Aggregate Intrinsic Value - Exercised	$ 19	$ 2,338
Restricted Stock [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Number of awards - Beginning balance	89,054	408,411
Restricted stock awards granted	502,964
Number of awards, vested	(89,054)	(319,357)
Number of awards - Ending balance	0	89,054	408,411
Weighted average granted fair date value per share - Beginning balance	$ 1.30	$ 1.16
Weighted average granted fair date value per share, vested	$ 1.30	1.12
Weighted average granted fair date value per share - Ending balance		$ 1.30	$ 1.16
Aggregate Fair Value, Beginning balance	$ 117	$ 473
Aggregate Fair Value, vested	$ (117)	(356)
Aggregate Fair Value, Ending balance		$ 117	$ 473

Accrued liabilities - Summary of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued compensation	$ 6,297	$ 6,329
Accrued payables	8,203	17,554
Liability for early exercised stock options	66	276
Other	1,473	1,235
Total	$ 16,039	$ 25,394

Fair value measurements - Summary of Fair Value of the Financial Instruments that are Measured at Fair Value on a Recurring Basis (Detail) - Level 1 [Member] - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets:
Cash equivalents	$ 81,347	$ 186,816
Fair value, assets	125,827	205,844
U.S. Treasury bonds [Member]
Assets:
Fair value, assets	$ 44,480	15,110
Certificates of deposit [Member]
Assets:
Cash equivalents		$ 3,918