Aligos Therapeutics (ALGS) 10-Q 25 Nov 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Nov. 25, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Registrant Name	Aligos Therapeutics, Inc.
Entity Central Index Key	0001799448
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Trading Symbol	ALGS
Title of 12(b) Security	Common Stock, par value, $0.0001 per share
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		38,117,910
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Tax Identification Number	82-4724808
Entity Address, Address Line One	One Corporate Drive, 2nd Floor
Entity Address, City or Town	South San Francisco
Entity Address, Postal Zip Code	94080
City Area Code	800
Local Phone Number	466-6059
Entity Address, State or Province	CA

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 31,816	$ 69,565
Restricted cash	556	538
Investments in available-for-sale securities, at fair value	23,241
Investments in held-to-maturity securities	15,007	48,098
Other current assets	3,073	2,025
Total current assets	73,693	120,226
Operating lease right-of-use assets	7,054	7,570
Property and equipment, net	8,592	8,517
Other assets	2,844	188
Long-term investments in held-to-maturity securities	0	10,019
Total assets	92,183	146,520
Current liabilities:
Accounts payable	7,682	3,767
Accrued liabilities	9,782	7,599
Operating lease liabilities, current	2,444	2,378
Finance lease liabilities, current	76	74
Total current liabilities	19,984	13,818
Derivative liabilities	620	461
Redeemable convertible preferred stock liabilities	14,560	3,174
Operating lease liabilities, net of current portion	10,696	11,701
Finance lease liabilities, net of current portion	130	178
Other liabilities	295
Total liabilities	46,285	29,332
Commitments and contingencies (Note 12)
Stockholders' deficit:
Common stock, $0.0001 par value; 278,000,000 shares authorized as of September 30, 2020 and December 31, 2019, respectively; 4,104,585 and 3,927,803 shares issued and outstanding as of September 30, 2020 and December 31, 2019, respectively	0	0
Additional paid-in capital	3,620	1,421
Accumulated deficit	(140,320)	(66,197)
Accumulated other comprehensive income (loss)	32	(115)
Total stockholders' deficit	(136,668)	(64,891)
Total liabilities, redeemable convertible preferred stock, and stockholders' deficit	92,183	146,520
Series A
Current liabilities:
Redeemable convertible preferred stock	101,182	100,695
Series B-1
Current liabilities:
Redeemable convertible preferred stock	$ 81,384	$ 81,384

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Common Stock, Par Value	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	278,000,000	278,000,000
Common Stock, Shares, Issued	4,104,585	3,927,803
Common Stock, Shares, Outstanding	4,104,585	3,927,803
Series A
Temporary Equity, Par Value	$ 0.0001	$ 0.0001
Temporary Equity, Shares Authorized	101,962,864	101,962,864
Temporary Equity, Shares Issued	10,857,395	10,819,843
Temporary Equity, Shares Outstanding	10,857,395	10,819,843
Temporary Equity, Liquidation Preference	$ 101,188
Series B-1
Temporary Equity, Par Value	$ 0.0001	$ 0.0001
Temporary Equity, Shares Authorized	77,764,055	77,764,055
Temporary Equity, Shares Issued	8,344,034	8,344,034
Temporary Equity, Shares Outstanding	8,344,034	8,344,034
Temporary Equity, Liquidation Preference	$ 85,005

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating expenses:
Research and development	$ 17,332	$ 11,729	$ 51,809	$ 29,065
General and administrative	4,225	2,775	11,739	6,542
Total operating expenses	21,557	14,504	63,548	35,607
Loss from operations	(21,557)	(14,504)	(63,548)	(35,607)
Interest and other (expense) income, net	(11,740)	453	(10,633)	1,527
Loss before income tax expense	(33,297)	(14,051)	(74,181)	(34,080)
Income tax benefits	0		58
Net loss	(33,297)	(14,051)	(74,123)	(34,080)
Other comprehensive gain (loss):
Unrealized (loss) gain on available-for-sale securities	(105)		132
Unrealized (loss) gain on pension plans	(13)	(38)	15	(85)
Other comprehensive (loss) and income	(118)	(38)	147	(85)
Comprehensive loss	$ (33,415)	$ (14,089)	$ (73,976)	$ (34,165)
Net loss per share, basic and diluted	$ (11)	$ (6.74)	$ (26.20)	$ (18.40)
Weighted average shares of common stock, basic and diluted	3,027,825	2,084,719	2,829,160	1,851,811

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' DEFICIT - USD ($) $ in Thousands	Total	Series A	Series B-1	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2018		$ 100,519	$ 0
Beginning balance, Shares at Dec. 31, 2018		10,806,432	0
Beginning balance at Dec. 31, 2018	$ (13,749)			$ 0	$ 182	$ (13,934)	$ 3
Beginning balance, Shares at Dec. 31, 2018				3,036,574
Issuance of common stock upon exercise of stock options	70				70
Issuance of common stock upon exercise of stock options, Shares				652,527
Stock-based compensation	604	$ 0	$ 0	$ 0	604
Vesting of early exercised common stock options	224	$ 0	$ 0	$ 0	224
Vesting of early exercised common stock options, Shares		0	0	0
Other comprehensive loss (income)	(85)			$ 0	0	0	(85)
Net loss	(34,080)	$ 0	$ 0	0	0	(34,080)	0
Ending balance at Sep. 30, 2019		$ 100,519	$ 0
Ending balance, Shares at Sep. 30, 2019		10,806,432	0
Ending balance at Sep. 30, 2019	(47,016)			$ 0	1,080	(48,014)	(82)
Ending balance, Shares at Sep. 30, 2019				3,689,101
Beginning balance at Jun. 30, 2019		$ 100,519	$ 0
Beginning balance, Shares at Jun. 30, 2019		10,806,432	0
Beginning balance at Jun. 30, 2019	(33,372)			$ 0	635	(33,963)	(44)
Beginning balance, Shares at Jun. 30, 2019				3,036,574
Issuance of common stock upon exercise of stock options	70				70
Issuance of common stock upon exercise of stock options, Shares				652,527
Stock-based compensation	151	$ 0	$ 0	$ 0	151	0	0
Vesting of early exercised common stock options	224				224	0	0
Other comprehensive loss (income)	(38)						(38)
Net loss	(14,051)	0	0	0	0	(14,051)	0
Ending balance at Sep. 30, 2019		$ 100,519	$ 0
Ending balance, Shares at Sep. 30, 2019		10,806,432	0
Ending balance at Sep. 30, 2019	(47,016)			$ 0	1,080	(48,014)	(82)
Ending balance, Shares at Sep. 30, 2019				3,689,101
Beginning balance at Dec. 31, 2019		$ 100,695	$ 81,384
Beginning balance, Shares at Dec. 31, 2019		10,819,843	8,344,034
Beginning balance at Dec. 31, 2019	(64,891)			$ 0	1,421	(66,197)	(115)
Beginning balance, Shares at Dec. 31, 2019				3,927,803
Issuance of Series A redeemable convertible stock upon exercise of Series A warrants		$ 487
Issuance of Series A redeemable convertible stock upon exercise of Series A warrants, Shares		37,552
Issuance of common stock upon exercise of stock options	243			$ 0	243
Issuance of common stock upon exercise of stock options, Shares				176,782
Stock-based compensation	1,674				1,674
Vesting of early exercised common stock options	282				282
Other comprehensive loss (income)	147					0	147
Net loss	(74,123)					(74,123)
Ending balance at Sep. 30, 2020		$ 101,182	$ 81,384
Ending balance, Shares at Sep. 30, 2020		10,857,395	8,344,034
Ending balance at Sep. 30, 2020	(136,668)			$ 0	3,620	(140,320)	32
Ending balance, Shares at Sep. 30, 2020				4,104,585
Beginning balance at Jun. 30, 2020		$ 101,182	$ 81,384
Beginning balance, Shares at Jun. 30, 2020		10,857,395	8,344,034
Beginning balance at Jun. 30, 2020	(104,573)			$ 0	2,300	(107,023)	150
Beginning balance, Shares at Jun. 30, 2020				4,035,978
Issuance of common stock upon exercise of stock options	148				148
Issuance of common stock upon exercise of stock options, Shares				68,607
Stock-based compensation	1,016				1,016
Vesting of early exercised common stock options	156				156
Other comprehensive loss (income)	(118)						(118)
Net loss	(33,297)					(33,297)
Ending balance at Sep. 30, 2020		$ 101,182	$ 81,384
Ending balance, Shares at Sep. 30, 2020		10,857,395	8,344,034
Ending balance at Sep. 30, 2020	$ (136,668)			$ 0	$ 3,620	$ (140,320)	$ 32
Ending balance, Shares at Sep. 30, 2020				4,104,585

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (74,123)	$ (34,080)
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion of discount on investments	181	(786)
Amortization of right of use assets	437	787
Depreciation expense	2,005	868
Stock-based compensation	1,674	604
Change in fair value of derivative liability	296	(294)
Change in fair value of redeemable convertible preferrable stock liabilities	11,387
Changes in operating assets and liabilities:
Other assets	(1,049)	(563)
Right of use assets	0	95
Accounts payable	3,677	(248)
Accrued liabilities	1,875	1,639
Operating lease liabilities	(939)	229
Net cash and cash equivalents used in operating activities	(54,579)	(31,749)
Activities in available-for-sale investments:
Maturities of investments	22,000
Purchase of investments	(45,279)
Activities in held-to-maturity investments:
Maturities of investments	43,100	76,000
Purchase of investments	0	(45,334)
Purchases of property and equipment	(2,003)	(2,065)
Net cash and cash equivalents provided by investing activities	17,818	28,601
Cash flows from financing activities:
Proceeds from exercise of warrants for Series A redeemable convertible preferred stock	350
Payment of Series B-1 redeemable convertible preferred stock issuance cost	(405)
Payments on deferred offering costs	(1,066)
Payments on finance lease	(46)	(27)
Proceeds from the exercise of common stock options	197	295
Net cash and cash equivalents (used in) provided by financing activities	(970)	268
Net decrease in cash, cash equivalents, and restricted cash	(37,731)	(2,880)
Cash, cash equivalents, and restricted cash, beginning of period	70,103	24,547
Cash, cash equivalents, and restricted cash, end of period	32,372	21,667
Reconciliation to amounts on the consolidated balance sheet:
Cash and cash equivalents	31,816	21,130
Restricted cash	556	537
Total cash, cash equivalents, and restricted cash	32,372	21,667
Supplemental disclosures of cash flow information:
Interest paid	4	3
Income taxes paid	0
Supplemental disclosures of noncash financing and investing activities:
Leasehold improvement directly paid by landlord	79	3,990
Equipment acquired through finance lease	0	198
Mark to market adjustment for available-for-sale investments	132
Acquisition of right of use asset through operating lease obligation	0	252
Change in fair value of derivative liability upon exercise of warrants	137
Vesting of early exercised options	283
Receivable from exercise of common stock options	46
Deferred offering costs included in accounts payable and accrued liabilities	1,544
Property and equipment purchases in accounts payable	$ 0	$ 213

Organization

Organization	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Description of b Aligos Therapeutics, Inc. (“Aligos-US”) Aligos-US Aligos is a clinical-stage biopharmaceutical company developing novel therapeutics to address unmet medical needs in viral and liver diseases, including chronic hepatitis B and coronaviruses therapeutics for non-alcoholic 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 nonclinical 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. Reverse stock split On October 8, 2020, the Company’s board of directors approved a 1-for-9.3197 Initial public offering On October 20, 2020, the Company closed its IPO and issued 10,000,000 shares of its common stock at a public offering price of $15.00 per share for net proceeds of $135,400, after deducting underwriting discounts and commissions of $10,500 and estimated expenses of $4,100. In connection with the IPO, all shares of Series A redeemable convertible preferred stock (“Series A”), Series B-1 B-1”) B-2 B-2”) non-voting

Summary of significant accounti

Summary of significant accounting policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of significant accounting policies	2. Summary of significant accounting policies Liquidity The Company has incurred losses and negative cash flows from operations since its inception. As of September 30, 2020 and December 31, 2019, the Company had an accumulated deficit of approximately $140,320 and $66,197, respectively. Since inception through September 30, 2020, the Company has funded operations primarily with the net proceeds from the issuance of redeemable convertible preferred stock and convertible notes. Management expects to continue to incur additional substantial losses in the foreseeable future as a result of expanded research and development activities. As of September 30, 2020, the Company has unrestricted cash, cash equivalents and investments of approximately $70,064. In addition, the Company received net proceeds of approximately net proceeds from its 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. In addition, the Company may seek additional capital to take advantage of favorable market conditions or strategic opportunities even if the Company believes it has sufficient funds for its current or future operating plans. 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 condensed consolidated financial statements are issued. However, the Company’s operating plan may change as a result of many factors currently unknown. The accompanying condensed consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and contemplates the continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the normal course of business. 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 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 Basis of presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. 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 (“FASB”). The condensed consolidated balance sheet as of December 31, 2019 included herein was derived from the audited consolidated financial statements as of that date but does not include all of the information and notes required by U.S. GAAP for complete financial statements. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report on Form 10-Q Principles of consolidation The accompanying condensed consolidated financial statements include Aligos-US Use of estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts in the condensed consolidated financial statements and accompanying notes. The Company regularly evaluates estimates and assumptions related to assets and liabilities, and disclosures of contingent assets and liabilities at the dates of the condensed 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 Unaudited interim financial information The accompanying consolidated balance sheet as of September 30, 2020, the consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019, the consolidated statements of redeemable convertible preferred stock and stockholders’ deficit for the three and nine months ended September 30, 2020 and 2019, and the consolidated statements of cash flows for the nine months ended September 30, 2020 and 2019 are unaudited. The unaudited consolidated interim financial statements have been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s consolidated financial position as of September 30, 2020 and the consolidated results of its operations and cash flows for the three and nine months ended September 30, 2020 and 2019. The consolidated financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2020 and 2019 are unaudited. The consolidated results for the three and nine months ended September 30, 2020 are not necessarily indicative of results to be expected for the year ending December 31, 2020, any other interim periods, or any future year or period. Deferred offering costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process Investments The Company determines the appropriate classification of debt securities at the time of purchase and re-evaluates such designation as of each balance sheet date. Debt securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity, otherwise debt 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 debt securities are reported as a separate component of stockholders’ deficit. 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 (expense) income, net For both held-to-maturity available-for-sale As of September 30, 2020 and December 31, 2019, short-term investments consisted of U.S. Treasury securities with original maturities of less than one year. As of December 31, 2019, long-term investments consisted of U.S. Treasury securities with original maturities of more than one year. 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 Derivative liabilities The Company accounts for certain warrants as liabilities at fair value and adjusts the instruments to fair value at each reporting period. The Company determined that its outstanding warrants are freestanding derivative instruments. The warrants are subject to re-measurement Redeemable convertible preferred stock liability The freestanding instrument related to the commitment by certain preferred stockholders to purchase and the commitment by the Company to sell its redeemable convertible preferred stock in a subsequent closing, contingent upon the achievement of certain developmental milestones or an election by preferred stockholders to waive such milestones, at a fixed price per share, is considered a derivative liability (“Redeemable Convertible Preferred Stock Liability”). The Redeemable Convertible Preferred Stock Liability is measured at fair value as the underlying shares contain liquidation preferences upon certain “deemed liquidation events” that are not solely within the Company’s control and which are considered in-substance The Company’s shares of redeemable convertible preferred stock were assessed at issuance for classification and redemption features requiring bifurcation. The Company presents as temporary equity any stock which (i) the Company undertakes to redeem at a fixed or determinable price on the fixed or determinable date or dates, (ii) is redeemable at the option of the holders, or (iii) has conditions for redemption which are not solely within the control of the Company. The Company’s preferred stock is redeemable upon a deemed liquidation event which the Company determined is not solely within its control and thus has classified shares of preferred stock as temporary equity until such time as the conditions are removed or lapse. Because the occurrence of a deemed liquidation event is not currently probable, the carrying values of the shares of redeemable convertible preferred stock are not being accreted to their redemption values. Subsequent adjustments to the carrying values of the shares of redeemable convertible preferred stock would be made only when a deemed liquidation event becomes probable. Fair value measurements Certain assets and liabilities of the Company are carried at fair value under 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 Level 2 Level 3 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 with service-based vesting, 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 award. The Company has granted certain options with performance-based vesting for which expense is recognized over the explicit service period when achievement of the performance-based milestones is deemed probable. The Company uses judgement to determine whether and, if so, how many awards are deemed probable of vesting at each reporting period. The fair value of stock-based awards with non-market The Company classifies stock-based compensation expense in its condensed 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 complex 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 had been a private company prior to the IPO and lacks company-specific historical and implied fair value information. Therefore, the Board of Directors (the “Board”) of the Company considered numerous objective and subjective factors to determine the fair value of the Company’s common stock options at each meeting in which awards were approved. The factors considered include, but are not limited to (i) the results of contemporaneous independent third-party valuations of the Company’s common stock and the prices, rights, preferences and privileges of the Company’s redeemable convertible preferred stock relative to those of its common stock; (ii) the lack of marketability of the Company’s common stock; (iii) actual operating and financial results; (iv) current business conditions and projections; (v) the likelihood of achieving a liquidity event, such as an initial public offering or sale of the Company, given prevailing market conditions, and (vi) precedent transactions involving the Company’s shares. 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. See Note 9 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 the nine months ended September 30, 2020 and 2019. 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. The Company applies the two-class method The two-class method 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. Recently issued accounting standards 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.

Property and equipment

Property and equipment	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Property and equipment	3. Property and equipment The components of property and equipment as of September 30, 2020 and December 31, 2019 were as follows: September 30, 2020 December 31, 20 19 Leasehold improvements $ 5,647 $ 5,100 Lab equipment 4,747 3,204 Computer equipment 937 890 Furniture and office equipment 459 425 Vehicles 296 296 Asset under construction 19 110 Total, at cost 12,105 10,025 Accumulated depreciation (3,513 ) (1,508 ) Total, net $ 8,592 $ 8,517 Depreciation expense was $708 and $2,005 for the three and nine months ended September 30, 2020, respectively, and September 30, 2019, respectively. Finance leases are also included in property and equipment as vehicles on the condensed consolidated balance sheets (Note 6).

Investments

Investments	9 Months Ended
	Sep. 30, 2020
Debt Securities, Available-for-sale and Held-to-maturity [Abstract]
Investments	4. Investments As of September 30, 2020 and December 31, 2019, amortized cost, gross unrealized gains and losses, and estimated fair values of total fixed-maturity securities were as follows: September 30, 2020 Amortized Gross Gross Estimated Held-to-maturity U.S. Treasury bonds $ 15,007 $ 56 $ — $ 15,063 Available-for-sale U.S. Treasury bonds 23,109 132 — 23,241 $ 38,116 $ 188 $ — $ 38,304 December 31, 2019 Amortized Gross Gross Estimated Held-to-maturity U.S. Treasury bonds $ 58,117 $ 31 $ (1) $ 58,147 Changes in fair value are related to changes in market interest rates. The Company expects to collect all contractual principal and interest payments. The following is a summary of maturities of securities held-to-maturity available-for-sale Held-to-maturity Available-for-sale Amortized Estimated Amortized Estimated Amounts maturing in: One year or less $ 15,007 $ 15,063 $ 23,109 $ 23,241 Total investments $ 15,007 $ 15,063 $ 23,109 $ 23,241 The Company recorded interest income of $234 and $985 for three and nine months ended September 30, 2020, respectively, and as a component of i

Accrued liabilities

Accrued liabilities	9 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Accrued liabilities	5. Accrued liabilities Accrued liabilities consisted of the following as of: September 30, 2020 December 31, 20 19 Accrued payables $ 4,647 $ 3,113 Accrued compensation 4,353 3,211 Liability with early exercised stock options 650 753 Other 132 522 Total $ 9,782 $ 7,599

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	6. Leases The Company has operating and finance leases for corporate offices, research and development facilities, and certain vehicles. These leases have remaining lease terms of four to eight and a half 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. 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 condensed consolidated balance sheets as of September 30, 2020 and December 31, 2019. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Maturities of lease liabilities as of September 30, 2020 and are as follows: Operating Finance Year ending December 31: 2020 (excluding the nine $ 638 $ 20 2021 2,612 79 2022 2,697 78 2023 2,694 41 2024 2,678 1 Thereafter 6,414 — 17,733 219 Less: imputed interest (4,593 ) (13 ) Present value of lease liabilities 13,140 206 Less: current portion (2,444 ) (76 ) Lease liabilities, net of current portion $ 10,696 $ 130 The components of lease expense were as follows for the three and nine months ended September 30, 2020 and 2019: Three Months Ended Nine Months Ended 2020 2019 2020 2019 Operating lease cost $ 464 $ 568 $ 1,397 $ 1,774 Finance lease cost: Amortization of right-of-use $ 19 $ 11 $ 48 $ 29 Interest on lease liabilities 2 2 7 — Total finance lease cost $ 21 $ 13 $ 55 $ 29 The Company made payments of $637 and $1,885 during the three and nine months ended September 30, 2020, respectively, and $415 and $670 during the three and nine months ended September 30, 2019, respectively, which are included as cash flow from operations on the condensed consolidated statements of cash flows. As of September 30, 2020 and December 31, 2019, $296 of finance lease ROU assets were presented as part of property and equipment on the condensed consolidated balance sheet with accumulated amortization of $94 and $47, respectively. Additional information related to the Company’s leases was as follows as of September 30, 2020 and December 31, 2019: September 30, December 31, Operating Lease: Weighted-average remaining lease term (years) 6.36 7.10 Weighted-average discount rate 9.35 % 9.34 % Finance Lease: Weighted-average remaining lease term (years) 2.92 3.66 Weighted-average discount rate 3.16 % 3.18 %

Derivative liabilities and rede

Derivative liabilities and redeemable convertible preferred stock liability	9 Months Ended
	Sep. 30, 2020
Derivative Liabilities And Redeemable Convertible Preferred Stock Liability [Abstract]
Derivative liabilities and convertible preferred stock liability	7. Derivative liabilities and redeemable convertible preferred stock liability Warrants In connection with the issuance of certain notes, lenders were issued Warrants to purchase 134,112 shares of Series A ten-year The underlying shares issuable upon the exercise of the Warrants were eligible to be exercised into the next round of equity financing. The Warrants became exercisable into shares of Series A for an exercise price of $9.32 per share. There were warrants to purchase 83,149 and 120,701 shares of Series A outstanding as of September 30, 2020 and December 31, 2019, respectively. The Company recorded the Warrants initially at fair value (Note 10) as derivative liabilities on the condensed consolidated balance sheet with the value being allocated to the notes as a debt discount. The fair value of the Warrants was $620 and $461 as of September 30, 2020 and December 31, 2019, respectively. During the nine months ended September 30, 2020, 37,552 Warrants were exercised. No Warrants were exercised during the three months ended September 30, 2020, or during the nine months ended September 30, 2019. As Series A contains a conditional obligation for the Company to repurchase the shares for cash consideration, the Warrants remain outstanding as derivative liabilities with changes in fair value being recorded on the condensed consolidated statements of operations and comprehensive loss. The Company recorded a change in fair value of derivative liabilities of $240 and $296 for the three and nine months ended September 30, 2020, respectively, and $ 154 and $ 294 for the three and nine months ended September 30, 2019, respectively. Redeemable convertible preferred stock liability In connection with the issuance of shares of Series B-1 B-1 B-2 Distinguishing Liabilities from Equity re-measured B-2

Capital stock

Capital stock	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Capital stock	8. Capital stock Common stock On December 23, 2019, pursuant to the Second Amended and Restated Certificate of Incorporation, the total shares of common stock authorized were set to 278,000,000 and the total shares of redeemable convertible preferred stock were set to 212,994,964 with a par value of $0.0001 per share. The total shares of redeemable convertible preferred stock authorized comprised of 101,962,864 shares of Series A, 77,764,055 shares of Series B-1, B-2. The holders of shares of Common Stock are entitled to one vote for each share of Common Stock at all meetings of stockholders. Redeemable convertible preferred stock On August 16, 2018, the Company entered into the Series A Preferred Stock Purchase Agreement for the purchase and sale of Series A for $9.32 per share. The Company received $75,000 in cash proceeds from the initial purchasers. On September 19, 2018, the Company received an additional $20,000 in cash proceeds from subsequent purchasers. Additionally, on the initial closing date, $5,600 in convertible notes plus accrued interest converted into shares of Series A and the notes were subsequently cancelled. The Warrants associated with the convertible notes became exercisable into shares of Series A. Each share of Series A is convertible into Common Stock on a one-for-one On December 23, 2019, the Company entered into the Series B-1 B-2 B-1 B-2 B-1 B-2 Series B-2 B-1, The holders of the Company’s Series A and Series B (collectively, the “Preferred Stock”) had the following rights, preferences, and privileges prior to the completion of the Company’s IPO: (a) Dividends The holders of shares of Preferred Stock, in preference to the holders of Common Stock, shall be entitled to receive, on a pari passu as-if-converted (b) Liquidation preference and redemption In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, the holders of shares of Preferred Stock then outstanding shall be entitled to be paid out of the assets of the Company available for distribution to its stockholders or, in the case of a Deemed Liquidation Event (as defined below), out of the consideration payable to stockholders in such Deemed Liquidation Event or the Available Proceeds (as defined below), before any payment shall be made to the holders of Common Stock by reason of their ownership thereof, an amount per share equal to one (1) times the applicable Original Issue Price of such series of Preferred Stock, plus any dividends declared but unpaid thereon. If upon any such liquidation, dissolution or winding up of the Company or Deemed Liquidation Event, the assets of the Company available for distribution to its stockholders shall be insufficient to pay the holders of shares of Preferred Stock the full amount to which they shall be entitled, the assets or consideration will be distributed ratably among such holders. After the payment in full of all liquidation amounts required to be paid to the holders of shares of Preferred Stock the remaining assets of the Company available for distribution to its stockholders or, in the case of a Deemed Liquidation Event, the consideration not payable to the holders of shares of Preferred Stock or the remaining Available Proceeds, as the case may be, shall be distributed among the holders of the shares of Preferred Stock and Common Stock, pro rata based on the number of shares held by each such holder, treating for this purpose all such securities as if they had been converted to Common Stock immediately prior to such liquidation, dissolution or winding up of the Company; provided, however, that if the aggregate amount which the holders of shares of Preferred Stock are entitled to receive shall exceed one and one-half Each of the following events shall be considered a “Deemed Liquidation Event” unless the holders of at least 67% of the outstanding shares of Preferred Stock (voting as a single class on an as-converted non-strategic B-1 B-2 B-1 B-2 (a) a merger or consolidation in which the Company is a constituent party or a subsidiary of the Company is a constituent party and the Company issues shares of its capital stock pursuant to such merger or consolidation, except (1) any such merger or consolidation involving the Company or a subsidiary in which the shares of capital stock of the Company outstanding immediately prior to such merger or consolidation continue to represent, or are converted into or exchanged for shares of capital stock that represent, immediately following such merger or consolidation, a majority, by voting power, of the capital stock of (a) the surviving or resulting corporation; or (b) if the surviving or resulting corporation is a wholly owned subsidiary of another corporation immediately following such merger or consolidation, the parent corporation of such surviving or resulting corporation; or (2) a merger effected exclusively to change the domicile of the Company; (b) the closing of the sale, in a single transaction or series of related transactions, of equity securities of the Company other than (a) bona fide equity financing, and (b) any transaction in which, the stockholders of the Company prior to such transaction continue to hold at least fifty percent (50%) of the outstanding shares of the surviving corporation; or (c) (1) the sale, lease, transfer, exclusive license or other disposition, in a single transaction or series of related transactions, by the Company or any subsidiary of the Company of all or substantially all the assets of the Company and its subsidiaries taken as a whole, or (2) the sale or disposition (whether by merger, consolidation or otherwise, and whether in a single transaction or a series of related transactions) of one or more subsidiaries of the Company if substantially all of the assets of the Company and its subsidiaries taken as a whole are held by such subsidiary or subsidiaries, except where such sale, lease, transfer, exclusive license or other disposition is to a wholly owned subsidiary of the Company. (c) Conversion Each share of Preferred Stock is convertible into fully paid and non-assessable B-1 B-2 non-strategic B-1 B-2 one-for-one, (d) Voting The holders of Preferred Stock have voting rights equivalent to the number of shares of Common Stock into which their shares of Preferred Stock convert. Except as provided by law or by the other provisions of the amended and restated certificate of incorporation, holders of shares of Preferred Stock shall vote together with the holders of shares of Common Stock as a single class and on an as-converted The holders of record of shares of Series A, exclusively and as a separate class, shall be entitled to elect four (4) directors of the Company, the holders of record of shares of Series B-1 B-2, as-converted

Stock-based compensation

Stock-based compensation	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Stock-based compensation	9. Stock-based compensation 2018 Equity incentive plan The Company’s 2018 Equity Incentive Plan, as amended, (the “Plan”), allows for the Company to issue restricted stock awards and restricted stock units, and to grant incentive stock options or non-qualified non-qualified 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. Options may vest over periods determined by the Board, generally 48 months (“Time-Vesting Options”), or vest upon the achievement of a certain performance condition (“Performance-Vesting Options”). 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. Of the option awards outstanding as of September 30, 2020, 1,711,065 were Time-Vesting Options, with an unamortized expense balance of $3,463, to be amortized over a weighted average period of 2.88 years. Of the option awards outstanding as of September 30, 2020, 434,977 were Performance-Vesting Options. On September 30, 2020, the Company has determined that the vesting condition associated with the Performance-Vesting Options became probable. Therefore, the Company has recognized compensation expense under the accelerated attribution method measured at the grant date fair value. In September 2020, terms of certain Performance-Vesting Options were modified. The performance condition for these options was removed and they became fully vested. The Company recognized a total of $203 of incremental compensation expense as a result of the modification. The total unrecognized expense for Performance-Vesting options was $629 as of September 30, 2020, which will be recognized over a weighted-average period of 3.30 years. During the three and nine months ended September 30, 2020, the Company’s stock option compensation expense was approximately $926 and $1,403, respectively. During the three and nine months ended September 30, 2019, stock option compensation expense was $60 and $203, respectively. There was no recognized tax benefit in either of the periods. Stock option activity during the nine months ended September 30, 2020 is as follows: Time-Vesting Options Performance-Vesting Options Shares subject Weighted- Shares subject Weighted- Weighted- (years) Aggregate Outstanding as of January 1, 2020 346,872 $ 1.30 — $ — 9.01 $ 744 Granted 1,552,942 3.45 454,994 3.45 Exercised (156,783 ) 2.25 (20,017 ) 3.45 1,786 Forfeited (31,966 ) 1.30 — Outstanding as of September 30, 2020 1,711,065 $ 3.16 434,977 $ 3.45 9.30 $ 19,888 Options vested and expected to vest as of September 30, 2020 2,137,351 $ 2.84 434,977 $ 3.45 9.15 $ 24,554 Options vested and exercisable as of September 30, 2020 1,337,277 $ 3.36 71,670 $ 3.45 9.38 $ 12,859 The weighted-average grant date fair value of both Time-Vesting Options and Performance-Vesting Options granted was $2.23 per share during the three and nine months ended September 30, 2020. The Company did not grant any Time-Vesting Options or Performance-Vesting Options during the three months ended September 30, 2020. 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 shares of restricted stock to employees and founders. These shares of restricted stock 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 three and nine months ended September 30, 2020, the Company recorded a total stock-based compensation expense of $90 and $271, respectively, related to the restricted stock awards. During the three and nine months ended September 30, 2019, the Company recorded stock-based compensation expense related to restricted stock awards of $91 and $401, respectively. As of September 3 0 The following table summarizes the Company’s restricted common stock activity for the nine months ended September 30, 2020: Number Weighted- Aggregate Fair Value Issued and unvested as of January 1, 2020 827,192 $ 1.01 $ 834 Restricted stock awards vested (314,093 ) 0.86 271 Issued and unvested as of September 30, 2020 513,099 $ 1.10 $ 563 Stock-based compensation expense was allocated as follows for the three and nine months ended September 30, 2020 and 2019: Three months ended September 30, Nine months ended September 30, 2020 2019 2020 2019 Research and development $ 331 $ 97 $ 652 $ 368 General and administrative 685 54 1,022 236 $ 1,016 $ 151 $ 1,674 $ 604 During the nine months ended September 30, 2020, the Company issued 52,062 shares of common stock, upon exercise of unvested stock options or purchases for unvested restricted stock awards. As of September 30, 2020 and December 31, 2019, there were 441,198 and 577,124 shares of Common Stock held by employees subject to repurchase at an aggregate price of $650 and $753, respectively. A corresponding liability was recorded and included in accrued expenses on the condensed consolidated balance sheet as of September 30, 2020 and December 31, 2019, respectively.

Fair value

Fair value	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair value	10. Fair value 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 Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 31,816 $— $ — Held-to-maturity U.S. Treasury bonds 15,063 — — Available-for-sale U.S. Treasury bonds 23,241 — — Liabilities: Derivative liabilities — — (620 ) Redeemable convertible preferred stock liability — — (14,560 ) $ 70,120 $ — $ (15,180) Fair Value Measurements Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 69,565 $ — $ — Held-to-maturity U.S. Treasury bonds 58,147 — — Liabilities: Derivative liabilities — — (461 ) Redeemable convertible preferred stock liability — — (3,174 ) $ 127,712 $ — $ (3,635 ) The derivative liability in the table above refers to the fair value of Warrants (Note 7). The fair values of the Warrants were determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. In order to determine the fair value of the Warrants, the Company utilized a probability-weighted multi-scenario Black-Scholes option-pricing model to determine the fair value of the Warrants by accounting for the probability of multiple possible outcomes, including deemed liquidation events, as best estimated by the management. Estimates and assumptions impacting the fair value measurement including the fair value of the underlying shares of Series A, the remaining contractual or expected term of the Warrants, risk-free interest rate, expected dividend yield and expected volatility of the price of the underlying preferred stock on an as converted basis. The Company considered the probability of a deemed liquidation event in determining the remaining expected term of the Warrants, which was used as an input to the probability-weighted multi-scenario Black-Scholes option-pricing model adopted in 2019. The Company lacks company-specific historical and implied volatility information of its stock since there is currently no market. Therefore, it estimated its expected stock volatility based on the historical volatility of publicly traded guideline companies for a term equal to the remaining contractual or expected term of the Warrants. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining contractual or expected term of the Warrants. The Company estimated no expected dividend yield based on the fact that the Company has never paid or declared dividends and does not intend to do so in the foreseeable future. The Warrants were measured at fair value under the following assumptions: September 30, December 31, 2020 2019 Exercise price $ 9.32 $ 9.32 Term (in years) 0.32 2.00 - 3.00 Risk-free interest rate 0.10 % 1.63 % Dividend yield — — Volatility 120.00 % 75.00 % The significant unobservable inputs used in the fair value measurement of the Warrants are the remaining expected term, which considers the timing of a liquidation event that would net settle the awards before their contractual term expires, and the equity volatility, which is a statistical measure of the dispersion of returns for a given security. Significant increases (decreases) in the term would result in significantly higher (lower) fair value measurements. Significant increases (decreases) in the volatility would result in significantly higher (lower) fair value measurements. The following table sets forth a summary of changes in fair value of the Company’s derivative liability and redeemable convertible preferred stock liability for which fair value was determined by Level 3 inputs: Derivative Redeemable Convertible Balance as of December 31, 2019 $ 461 $ 3,174 Exercise of warrants (137 ) — Change in fair value 296 11,386 Balance as of September 30, 2020 $ 620 $ 14,560 In order to determine the fair value of the Redeemable Convertible Preferred Stock Liability, the Company used a probability-weighted multi-scenario Black Scholes hybrid valuation method that accounts for the probability of achieving milestones as estimated by the management. The Redeemable Convertible Preferred Stock Liability was measured at fair value under the following assumption as of September 30, 2020: September 30, December 31, 2020 2019 Exercise price $ 11.21 $ 11.21 Term (in years) 0.02-0.75 1.27 Risk-free interest rate 0.08%-0.11 % 1.55 % Dividend yield — — Volatility — % 60.00 % The significant unobservable inputs used in the fair value measurement of the redeemable convertible preferred stock liability include the probability of milestone achievement and/or milestone achievement waiver, the Series B-2 B-2

License and collaboration agree

License and collaboration agreements	9 Months Ended
	Sep. 30, 2020
License and collaboration agreements [Abstract]
License and collaboration agreements	11. 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, sublicensable 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. 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 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, sublicensable 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. 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). one-time non-refundable 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. know-how know-how know-how know-how, know-how non-commercial low-to-mid-single

Commitments and contingencies

Commitments and contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
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 September 30, 2020 and December 31, 2019.​​​​​​​

Net loss per share

Net loss per share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net loss per share	13. Net loss per share The following table summarizes the computation of basic and diluted net loss per share of the Company: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Net loss $ (33,297) $ (14,051) $ (74,123) $ (34,080) Weighted average common stock outstanding, basic and diluted 3,027,825 2,084,719 2,829,160 1,851,811 Net loss per share—basic and diluted $ (11.00) $ (6.74) $ (26.20) $ (18.40) The Company’s potentially dilutive securities, which include redeemable convertible preferred stock, a forward contract to issue preferred stock, 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: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Redeemable c 19,201,429 10,806,432 19,201,429 10,806,432 Forward contract to issue redeemable convertible preferred stock 3,569,630 — 3,569,630 — Options to purchase common stock 2,586,195 1,028,327 2,586,195 1,028,327 Unvested restricted stock 513,078 931,893 513,078 931,893 Warrants to purchase preferred stock 83,149 134,112 83,149 134,112 25,953,481 12,900,764 25,953,481 12,900,764

Subsequent events

Subsequent events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent events	14. Subsequent events In preparing the interim financial statements as of September 30, 2020 and for the three and nine months then ended, the Company evaluated subsequent events Series B-2 On October 6, 2020, the Company issued 3,569,630 shares of Series B-2 following the achievement of certain milestones stated in the Series B Purchase Agreement. Warrants to purchase Series A redeemable convertible preferred stock Prior to the completion of the Company’s IPO, all Warrants to purchase Series A were exercised. Non-voting In October 2020, certain holders of the Company’s redeemable convertible preferred stock elected to have such shares convert into 3,092,338 shares of non-voting non-voting non-voting. non-voting non-voting non-voting 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 initially reserved for issuance 4,426,822 shares of common stock pursuant to 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 will enable eligible employees of the Company to purchase shares of common stock at a discount to fair market value. The Company initially reserved for issuance 368,901 shares of common stock pursuant to the 2020 ESPP. First dosage in Phase 1a/b clinical trial for ALG-000184 On October 30, 2020, the Company dosed its first subject in a first-in-human ALG-000184-201.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Liquidity	Liquidity The Company has incurred losses and negative cash flows from operations since its inception. As of September 30, 2020 and December 31, 2019, the Company had an accumulated deficit of approximately $140,320 and $66,197, respectively. Since inception through September 30, 2020, the Company has funded operations primarily with the net proceeds from the issuance of redeemable convertible preferred stock and convertible notes. Management expects to continue to incur additional substantial losses in the foreseeable future as a result of expanded research and development activities. As of September 30, 2020, the Company has unrestricted cash, cash equivalents and investments of approximately $70,064. In addition, the Company received net proceeds of approximately net proceeds from its 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. In addition, the Company may seek additional capital to take advantage of favorable market conditions or strategic opportunities even if the Company believes it has sufficient funds for its current or future operating plans. 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 condensed consolidated financial statements are issued. However, the Company’s operating plan may change as a result of many factors currently unknown. The accompanying condensed consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and contemplates the continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the normal course of business.
Risks and uncertainties	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 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
Basis of presentation, continued	Basis of presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. 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 (“FASB”). The condensed consolidated balance sheet as of December 31, 2019 included herein was derived from the audited consolidated financial statements as of that date but does not include all of the information and notes required by U.S. GAAP for complete financial statements. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report on Form 10-Q
Principles of consolidation	Principles of consolidation The accompanying condensed consolidated financial statements include Aligos-US
Use of estimates	Use of estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts in the condensed consolidated financial statements and accompanying notes. The Company regularly evaluates estimates and assumptions related to assets and liabilities, and disclosures of contingent assets and liabilities at the dates of the condensed 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
Unaudited interim financial information	Unaudited interim financial information The accompanying consolidated balance sheet as of September 30, 2020, the consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019, the consolidated statements of redeemable convertible preferred stock and stockholders’ deficit for the three and nine months ended September 30, 2020 and 2019, and the consolidated statements of cash flows for the nine months ended September 30, 2020 and 2019 are unaudited. The unaudited consolidated interim financial statements have been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s consolidated financial position as of September 30, 2020 and the consolidated results of its operations and cash flows for the three and nine months ended September 30, 2020 and 2019. The consolidated financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2020 and 2019 are unaudited. The consolidated results for the three and nine months ended September 30, 2020 are not necessarily indicative of results to be expected for the year ending December 31, 2020, any other interim periods, or any future year or period.
Deferred offering costs	Deferred offering costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process
Investments	Investments The Company determines the appropriate classification of debt securities at the time of purchase and re-evaluates such designation as of each balance sheet date. Debt securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity, otherwise debt 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 debt securities are reported as a separate component of stockholders’ deficit. 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 (expense) income, net For both held-to-maturity available-for-sale As of September 30, 2020 and December 31, 2019, short-term investments consisted of U.S. Treasury securities with original maturities of less than one year. As of December 31, 2019, long-term investments consisted of U.S. Treasury securities with original maturities of more than one year.
Property and equipment
Impairment of long-lived assets
Research and development expenses	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
Derivative liabilities	Derivative liabilities The Company accounts for certain warrants as liabilities at fair value and adjusts the instruments to fair value at each reporting period. The Company determined that its outstanding warrants are freestanding derivative instruments. The warrants are subject to re-measurement
Redeemable convertible preferred stock liability	Redeemable convertible preferred stock liability The freestanding instrument related to the commitment by certain preferred stockholders to purchase and the commitment by the Company to sell its redeemable convertible preferred stock in a subsequent closing, contingent upon the achievement of certain developmental milestones or an election by preferred stockholders to waive such milestones, at a fixed price per share, is considered a derivative liability (“Redeemable Convertible Preferred Stock Liability”). The Redeemable Convertible Preferred Stock Liability is measured at fair value as the underlying shares contain liquidation preferences upon certain “deemed liquidation events” that are not solely within the Company’s control and which are considered in-substance The Company’s shares of redeemable convertible preferred stock were assessed at issuance for classification and redemption features requiring bifurcation. The Company presents as temporary equity any stock which (i) the Company undertakes to redeem at a fixed or determinable price on the fixed or determinable date or dates, (ii) is redeemable at the option of the holders, or (iii) has conditions for redemption which are not solely within the control of the Company. The Company’s preferred stock is redeemable upon a deemed liquidation event which the Company determined is not solely within its control and thus has classified shares of preferred stock as temporary equity until such time as the conditions are removed or lapse. Because the occurrence of a deemed liquidation event is not currently probable, the carrying values of the shares of redeemable convertible preferred stock are not being accreted to their redemption values. Subsequent adjustments to the carrying values of the shares of redeemable convertible preferred stock would be made only when a deemed liquidation event becomes probable.
Fair value measurements	Fair value measurements Certain assets and liabilities of the Company are carried at fair value under 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 Level 2 Level 3
Stock-based compensation	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 with service-based vesting, 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 award. The Company has granted certain options with performance-based vesting for which expense is recognized over the explicit service period when achievement of the performance-based milestones is deemed probable. The Company uses judgement to determine whether and, if so, how many awards are deemed probable of vesting at each reporting period. The fair value of stock-based awards with non-market The Company classifies stock-based compensation expense in its condensed 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 complex 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 had been a private company prior to the IPO and lacks company-specific historical and implied fair value information. Therefore, the Board of Directors (the “Board”) of the Company considered numerous objective and subjective factors to determine the fair value of the Company’s common stock options at each meeting in which awards were approved. The factors considered include, but are not limited to (i) the results of contemporaneous independent third-party valuations of the Company’s common stock and the prices, rights, preferences and privileges of the Company’s redeemable convertible preferred stock relative to those of its common stock; (ii) the lack of marketability of the Company’s common stock; (iii) actual operating and financial results; (iv) current business conditions and projections; (v) the likelihood of achieving a liquidity event, such as an initial public offering or sale of the Company, given prevailing market conditions, and (vi) precedent transactions involving the Company’s shares. 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. See Note 9 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 the nine months ended September 30, 2020 and 2019.
Net loss per share	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. The Company applies the two-class method The two-class method 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.
Recently issued accounting standards	Recently issued accounting standards 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.

Property and equipment (Tables)

Property and equipment (Tables)	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	The components of property and equipment as of September 30, 2020 and December 31, 2019 were as follows: September 30, 2020 December 31, 20 19 Leasehold improvements $ 5,647 $ 5,100 Lab equipment 4,747 3,204 Computer equipment 937 890 Furniture and office equipment 459 425 Vehicles 296 296 Asset under construction 19 110 Total, at cost 12,105 10,025 Accumulated depreciation (3,513 ) (1,508 ) Total, net $ 8,592 $ 8,517

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Securities, Available-for-sale and Held-to-maturity [Abstract]
Summary of Available For Sale and Held to Maturity Securities Amortized Cost Gross Unrealized Gains Losses and Fair Value	As of September 30, 2020 and December 31, 2019, amortized cost, gross unrealized gains and losses, and estimated fair values of total fixed-maturity securities were as follows: September 30, 2020 Amortized Gross Gross Estimated Held-to-maturity U.S. Treasury bonds $ 15,007 $ 56 $ — $ 15,063 Available-for-sale U.S. Treasury bonds 23,109 132 — 23,241 $ 38,116 $ 188 $ — $ 38,304 December 31, 2019 Amortized Gross Gross Estimated Held-to-maturity U.S. Treasury bonds $ 58,117 $ 31 $ (1) $ 58,147
Summary of Debt Securities Available for Sale and Held to Maturity	The following is a summary of maturities of securities held-to-maturity available-for-sale Held-to-maturity Available-for-sale Amortized Estimated Amortized Estimated Amounts maturing in: One year or less $ 15,007 $ 15,063 $ 23,109 $ 23,241 Total investments $ 15,007 $ 15,063 $ 23,109 $ 23,241

Accrued liabilities (Tables)

Accrued liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Summary of Accrued Liabilities	Accrued liabilities consisted of the following as of: September 30, 2020 December 31, 20 19 Accrued payables $ 4,647 $ 3,113 Accrued compensation 4,353 3,211 Liability with early exercised stock options 650 753 Other 132 522 Total $ 9,782 $ 7,599

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Summary of Maturities of Lease Liabilities	Maturities of lease liabilities as of September 30, 2020 and are as follows: Operating Finance Year ending December 31: 2020 (excluding the nine $ 638 $ 20 2021 2,612 79 2022 2,697 78 2023 2,694 41 2024 2,678 1 Thereafter 6,414 — 17,733 219 Less: imputed interest (4,593 ) (13 ) Present value of lease liabilities 13,140 206 Less: current portion (2,444 ) (76 ) Lease liabilities, net of current portion $ 10,696 $ 130
Summary of Components of lease Expense	The components of lease expense were as follows for the three and nine months ended September 30, 2020 and 2019: Three Months Ended Nine Months Ended 2020 2019 2020 2019 Operating lease cost $ 464 $ 568 $ 1,397 $ 1,774 Finance lease cost: Amortization of right-of-use $ 19 $ 11 $ 48 $ 29 Interest on lease liabilities 2 2 7 — Total finance lease cost $ 21 $ 13 $ 55 $ 29
Summary of Additional Information Related to the Leases	Additional information related to the Company’s leases was as follows as of September 30, 2020 and December 31, 2019: September 30, December 31, Operating Lease: Weighted-average remaining lease term (years) 6.36 7.10 Weighted-average discount rate 9.35 % 9.34 % Finance Lease: Weighted-average remaining lease term (years) 2.92 3.66 Weighted-average discount rate 3.16 % 3.18 %

Stock-based compensation (Table

Stock-based compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Summary of Stock Options	Stock option activity during the nine months ended September 30, 2020 is as follows: Time-Vesting Options Performance-Vesting Options Shares subject Weighted- Shares subject Weighted- Weighted- (years) Aggregate Outstanding as of January 1, 2020 346,872 $ 1.30 — $ — 9.01 $ 744 Granted 1,552,942 3.45 454,994 3.45 Exercised (156,783 ) 2.25 (20,017 ) 3.45 1,786 Forfeited (31,966 ) 1.30 — Outstanding as of September 30, 2020 1,711,065 $ 3.16 434,977 $ 3.45 9.30 $ 19,888 Options vested and expected to vest as of September 30, 2020 2,137,351 $ 2.84 434,977 $ 3.45 9.15 $ 24,554 Options vested and exercisable as of September 30, 2020 1,337,277 $ 3.36 71,670 $ 3.45 9.38 $ 12,859
Summary of Stock Based Compensation Expense Was Allocated	Stock-based compensation expense was allocated as follows for the three and nine months ended September 30, 2020 and 2019: Three months ended September 30, Nine months ended September 30, 2020 2019 2020 2019 Research and development $ 331 $ 97 $ 652 $ 368 General and administrative 685 54 1,022 236 $ 1,016 $ 151 $ 1,674 $ 604
Restricted Stock [Member]
Summary of Stock Options	The following table summarizes the Company’s restricted common stock activity for the nine months ended September 30, 2020: Number Weighted- Aggregate Fair Value Issued and unvested as of January 1, 2020 827,192 $ 1.01 $ 834 Restricted stock awards vested (314,093 ) 0.86 271 Issued and unvested as of September 30, 2020 513,099 $ 1.10 $ 563

Fair value (Tables)

Fair value (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
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 Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 31,816 $— $ — Held-to-maturity U.S. Treasury bonds 15,063 — — Available-for-sale U.S. Treasury bonds 23,241 — — Liabilities: Derivative liabilities — — (620 ) Redeemable convertible preferred stock liability — — (14,560 ) $ 70,120 $ — $ (15,180) Fair Value Measurements Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 69,565 $ — $ — Held-to-maturity U.S. Treasury bonds 58,147 — — Liabilities: Derivative liabilities — — (461 ) Redeemable convertible preferred stock liability — — (3,174 ) $ 127,712 $ — $ (3,635 )
Summary of warrants were measured at fair value	The Warrants were measured at fair value under the following assumptions: September 30, December 31, 2020 2019 Exercise price $ 9.32 $ 9.32 Term (in years) 0.32 2.00 - 3.00 Risk-free interest rate 0.10 % 1.63 % Dividend yield — — Volatility 120.00 % 75.00 %
Summary of changes in fair value for which fair value was determined by Level 3 inputs	The following table sets forth a summary of changes in fair value of the Company’s derivative liability and redeemable convertible preferred stock liability for which fair value was determined by Level 3 inputs: Derivative Redeemable Convertible Balance as of December 31, 2019 $ 461 $ 3,174 Exercise of warrants (137 ) — Change in fair value 296 11,386 Balance as of September 30, 2020 $ 620 $ 14,560
Summary of redeemable convertible preferred stock liability measured at fair value	The Redeemable Convertible Preferred Stock Liability was measured at fair value under the following assumption as of September 30, 2020: September 30, December 31, 2020 2019 Exercise price $ 11.21 $ 11.21 Term (in years) 0.02-0.75 1.27 Risk-free interest rate 0.08%-0.11 % 1.55 % Dividend yield — — Volatility — % 60.00 %

Net loss per share (Tables)

Net loss per share (Tables)	9 Months Ended
	Sep. 30, 2020
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: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Net loss $ (33,297) $ (14,051) $ (74,123) $ (34,080) Weighted average common stock outstanding, basic and diluted 3,027,825 2,084,719 2,829,160 1,851,811 Net loss per share—basic and diluted $ (11.00) $ (6.74) $ (26.20) $ (18.40)
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: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Redeemable c 19,201,429 10,806,432 19,201,429 10,806,432 Forward contract to issue redeemable convertible preferred stock 3,569,630 — 3,569,630 — Options to purchase common stock 2,586,195 1,028,327 2,586,195 1,028,327 Unvested restricted stock 513,078 931,893 513,078 931,893 Warrants to purchase preferred stock 83,149 134,112 83,149 134,112 25,953,481 12,900,764 25,953,481 12,900,764

Organization - Additional Infor

Organization - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Nov. 05, 2020	Oct. 20, 2020	Oct. 15, 2020	Oct. 08, 2020	Sep. 30, 2020	Dec. 31, 2019
Nature Of Operations [Line Items]
Reverse stock split				1-for-9.3197
Common Stock, Shares, Issued					4,104,585	3,927,803
Subsequent Event [Member]
Nature Of Operations [Line Items]
Sale of stock net consideration received on the transaction	$ 151,443
Common Stock, Shares, Issued	11,150,000
Subsequent Event [Member] | Conversion Of Stock Voting Shares [Member]
Nature Of Operations [Line Items]
Temporary equity shares converted into permanent equity		19,761,870
Subsequent Event [Member] | Conversion Of Stock Non Voting Shares [Member]
Nature Of Operations [Line Items]
Temporary equity shares converted into permanent equity		3,092,338
Subsequent Event [Member] | IPO [Member]
Nature Of Operations [Line Items]
Stock issued during the period new issues shares			10,000,000
Sale of stock issue price per share			$ 15
Sale of stock net consideration received on the transaction			$ 135,400
Underwriting discounts and commissions			10,500
Offer expenses			$ 4,100
Subsequent Event [Member] | Over-Allotment Option [Member]
Nature Of Operations [Line Items]
Sale of stock net consideration received on the transaction	$ 16,043
Underwriting discounts and commissions	$ 1,208
Common Stock, Shares, Issued	1,150,000

Summary of significant accoun_3

Summary of significant accounting policies - Additional Information (Detail) - USD ($) $ in Thousands	Nov. 05, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Financing Sources [Line Items]
Retained earnings accumulated deficit		$ 140,320		$ 66,197
Cash, cash equivalents excluding restricted cash		31,816	$ 21,130	69,565
Deferred offering costs		2,610		$ 0
Other than temporary impairment losses, investments		0	0
Impairment of long lived assets		$ 0	$ 0
Common stock shares issued		4,104,585		3,927,803
Subsequent Event [Member]
Financing Sources [Line Items]
Common stock shares issued	11,150,000
Sale of stock net consideration received on the transaction	$ 151,443

Property and equipment - Summar

Property and equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total, at cost	$ 12,105	$ 10,025
Accumulated depreciation	(3,513)	(1,508)
Total, net	8,592	8,517
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	5,647	5,100
Lab equipment [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	4,747	3,204
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	937	890
Furniture and office equipment [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	459	425
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	296	296
Asset under construction [Member]
Property, Plant and Equipment [Line Items]
Total, at cost	$ 19	$ 110

Property and equipment - Additi

Property and equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 708	$ 387	$ 2,005	$ 868

Investments - Summary of Availa

Investments - Summary of Available For Sale and Held to Maturity Securities Amortized Cost Gross Unrealized Gains Losses and Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Available For Sale And Held To Maturity Securities Amortised Cost Gross Unrealised Gains Losses And Fair Value [Line Items]
Held-to-maturity securities, Amortized Cost	$ 38,116
Held-to-maturity securities, Gross Unrealized Gain	188
Held-to-maturity securities, Gross Unrealized Loss	0
Held-to-maturity securities, Estimated Fair Value	38,304
Available-for-sale securities, Amortized Cost	23,109
Available-for-sale securities, Estimated Fair Value	23,241
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]
Held-to-maturity securities, Amortized Cost	15,007	$ 58,117
Held-to-maturity securities, Gross Unrealized Gain	56	31
Held-to-maturity securities, Gross Unrealized Loss	0	(1)
Held-to-maturity securities, Estimated Fair Value	15,063	$ 58,147
Available-for-sale securities, Amortized Cost	23,109
Available-for-sale securities, Gross Unrealized Gain	132
Available-for-sale securities, Gross Unrealized Loss	0
Available-for-sale securities, Estimated Fair Value	$ 23,241

Investments - Summary of Debt S

Investments - Summary of Debt Securities Available for Sale and Held to Maturity (Detail) $ in Thousands	Sep. 30, 2020USD ($)
Debt Securities, Available-for-sale and Held-to-maturity [Abstract]
Held-to-Maturity, Amortized Cost, One year or less	$ 15,007
Held-to-Maturity, Fair Value, One year or less	15,063
Available-for-Sale, Amortized Cost, One year or less	23,109
Available-for-Sale, Fair Value, One year or less	23,241
Held-to-maturity, Amortized Cost, Total investments	15,007
Held-to-maturity, Fair Value, Total investments	15,063
Available-for-sale, Amortized Cost, Total investments	23,109
Available-for-sale, Fair Value, Total investments	$ 23,241

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Available For Sale And Held To Maturity Securities [Member]
Investment In Available For Sale And Held To Maturity Securities [Line Items]
Interest income	$ 234	$ 345	$ 985	$ 1,308

Accrued liabilities - Summary o

Accrued liabilities - Summary of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued payables	$ 4,647	$ 3,113
Accrued compensation	4,353	3,211
Liability with early exercised stock options	650	753
Other	132	522
Total	$ 9,782	$ 7,599

Leases - Additional Informatio

Leases - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Operating lease remaining lease term	4 years		4 years
Finance lease remaining lease term	8 years		8 years
Finance lease right of use assets	$ 296		$ 296		$ 296
Finance lease right of use assets accumulated amortization	94		94		$ 47
Operating lease, payments	$ 637		$ 1,885
Cash flow from operations		$ 415		$ 670
Maximum [Member]
Operating lease option to extend			8 years
Minimum [Member]
Operating lease option to extend			5 years

Leases - Summary of Maturities

Leases - Summary of Maturities of Lease Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of maturities of lease liabilities table [Line Items]
2020 (excluding the nine months ended September 30, 2020)	$ 638
2021	2,612
2022	2,697
2023	2,694
2024	2,678
Thereafter	6,414
Lessee, Operating Lease, Liability, to be Paid	17,733
Less: imputed interest	(4,593)
Present value of lease liabilities	13,140
Less: current portion	(2,444)	$ (2,378)
Lease liabilities net of current portion	10,696	11,701
2020 (excluding the nine months ended September 30, 2020)	20
2021	79
2022	78
2023	41
2024	1
Thereafter	0
Finance Lease, Liability, Payment, Due	219
Less: imputed interest	(13)
Present value of lease liabilities	206
Less: current portion	(76)	(74)
Lease liabilities net of current portion	$ 130	$ 178

Leases - Summary of Components

Leases - Summary of Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating lease cost	$ 464	$ 568	$ 1,397	$ 1,774
Finance lease cost:
Amortization of right-of-use assets	19	11	48	29
Interest on lease liabilities	2	2	7	0
Total finance lease cost	$ 21	$ 13	$ 55	$ 29

Leases - Summary of Additional

Leases - Summary of Additional Information Related to the leases (Detail)	Sep. 30, 2020	Dec. 31, 2019
Schedule of additional information related to the leases [Abstract]
Weighted-average remaining lease term (years)	6 years 4 months 9 days	7 years 1 month 6 days
Weighted-average discount rate	9.35%	9.34%
Weighted-average remaining lease term (years)	2 years 11 months 1 day	3 years 7 months 27 days
Weighted-average discount rate	3.16%	3.18%

Derivative liabilities and re_2

Derivative liabilities and redeemable convertible preferred stock liability - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Dec. 23, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Aug. 16, 2018
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Warrants issued expiry period				10 years
Changes in fair value of the warrants				$ 137
Change in fair value of redeemable convertible preferrable stock liabilities				$ 11,387
Class of warrant or right, number of securities called by warrants or rights		134,112		134,112
Percentage of principal amount of notes covered by warrants		25.00%		25.00%
warrants issued closing date				Apr. 20, 2018
Derivative Financial Instruments, Liabilities [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Warrants exercised		$ 0		$ 37,552	$ 0
Changes in fair value of the warrants		240	$ 154	296	$ 294
Derivative Financial Instruments, Liabilities [Member] | Warrant [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Fair value of the warrants		$ 620		620		$ 461
Mandatorily Redeemable Preferred Stock [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Redeemable convertible preferred stock liability at a fair value						$ 3,174
Change in fair value of redeemable convertible preferrable stock liabilities				$ 11,387
Redeemable Convertible Preferred Stock shares issued		0		0
Maximum [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
warrants issued closing date				Jun. 6, 2018
Series A Preferred Stock [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Warrants exercise price per share		$ 9.32		$ 9.32
Warrants outstanding		83,149		83,149		120,701
Sale of stock issue price per share							$ 9.32
Series B Two Preferred Stock [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	3,569,630
Sale of stock issue price per share	$ 11.20563
Series B Two Preferred Stock [Member] | Mandatorily Redeemable Preferred Stock [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Change in fair value of redeemable convertible preferrable stock liabilities				$ 11,750

Capital stock - Additional Info

Capital stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2020	Dec. 23, 2019	Sep. 19, 2018	Aug. 16, 2018	Sep. 30, 2020	Dec. 31, 2019
Number of shares of common stock authorized	278,000,000	278,000,000			278,000,000	278,000,000
Number of shares of preferred stock authorized		212,994,964
Preferred stock authorized par value		$ 0.0001
Common stock voting right		one
Sale of stock net consideration received on Series A Preferred Stock	$ 75,000
Preferred Stock, Conversion split					one-for-one	one-for-one
Series A Preferred Stock [Member]
Number of shares of preferred stock authorized	101,962,864	101,962,864			101,962,864	101,962,864
Sale of stock issue price per share				$ 9.32
Sale of stock, consideration received on transaction			$ 20,000	$ 75,000
Series B Preferred Stock [Member]
Number of shares of preferred stock authorized	77,764,055				77,764,055	77,764,055
Sale of stock, consideration received on transaction		$ 125,000
Percent of voting rights for special events	33.00%				33.00%
Series B One Preferred Stock [Member]
Number of shares of preferred stock authorized		77,764,055
Sale of stock issue price per share		$ 10.18690
Sale of stock, consideration received on transaction		$ 85,000
Stock issuance costs	$ 442
Sale of stock, number of shares issued in transaction		8,344,034
Series B Two Preferred Stock [Member]
Number of shares of preferred stock authorized		33,268,045
Sale of stock issue price per share		$ 11.20563
Sale of stock, number of shares issued in transaction		3,569,630
Cummulative stock issued	0				0
Series A [Member]
Stock issued during period value				5,600
Stock issuance costs				$ 194
Preferred Stock [Member]
Percent of voting rights for special events	67.00%				67.00%

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2019USD ($)	Dec. 31, 2019$ / sharesshares
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [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.
Share based compensation expense		$ 1,016	$ 151	$ 1,674	$ 604
Share based compensation expense recognized tax benefit		0	0	$ 0	0
Restricted stock awards expiry date				10 years
Common stock, upon exercise of stock options		$ 148	70	$ 243	70
Shares of common stock held by employees subject to repurchase | shares				441,198		577,124
Share price | $ / shares	$ 650	$ 650		$ 650		$ 753
Stock Option [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Common stock, upon exercise of stock options				$ 52,062
Time Vesting Options [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Share based payment unamortised share based payment expenses	$ 3,463	$ 3,463		$ 3,463
Share based payment expenses amortized over a weighted average period				2 years 10 months 17 days
Share based payments weighted-average grant date fair value | $ / shares		$ 2.23
Share based payments options outstanding | shares	1,711,065	1,711,065		1,711,065		346,872
Performance Shares [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Share based payment unamortised share based payment expenses	$ 629	$ 629		$ 629
Share based payment expenses amortized over a weighted average period				3 years 3 months 18 days
Share based compensation expense		$ 926	60	$ 1,403	203
Share based payments weighted-average grant date fair value | $ / shares				$ 2.23
Share based payments options outstanding | shares	434,977	434,977		434,977
Restricted Stock [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Share based payment unamortised share based payment expenses	$ 542	$ 542		$ 542
Share based payment expenses amortized over a weighted average period				1 year 4 months 9 days
Share based compensation expense		$ 90	$ 91	$ 271	$ 401
Restricted stock awards granted | shares				502,964
Restricted stock awards rights vesting percentage				33.00%
Restricted stock awards expiry date				3 years
Restricted stock awards rights vesting				1/36
Less than 10% | Minimum [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Exercise price for incentive stock options as of fair market value	1
More Than 10% | Maximum [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Exercise price for incentive stock options as of fair market value	1.10
2018 Equity incentive Plan
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Share based payment Common stock shares authorised | shares	4,913,665	4,913,665		4,913,665
Share based payment awards granted | shares				4,238,874
Common stock available for future issuances | shares	674,791	674,791		674,791

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Stock Options (Detail) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Weighted average remaining contractual term Outstanding	9 years 3 months 18 days	9 years 3 days
Weighted average remaining contractual term options vested and expected to vest	9 years 1 month 24 days
Weighted average remaining contractual term Options vested and exercisable	9 years 4 months 17 days
Aggregate Intrinsic Value - Options outstanding | $	$ 744
Aggregate Intrinsic Value - Exercised | $	1,786
Aggregate Intrinsic Value - Options outstanding | $	19,888	$ 744
Aggregate Intrinsic Value, options vested and expected to vest | $	24,554
Aggregate Intrinsic Value, Options vested and exercisable | $	$ 12,859
Time Vesting Options [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share subject to options - Beginning balance | shares	346,872
Share subject to option Granted | shares	1,552,942
Share subject to option Exercised | shares	(156,783)
Share subject to option Forfeited | shares	(31,966)
Share subject to options - Ending balance | shares	1,711,065	346,872
Share subject to Options Vested and expected to vest | shares	2,137,351
Share subject to Options vested and exercisable | shares	1,337,277
Weighted average exercise price - Beginning balance | $ / shares	$ 1.30
Weighted average exercise price Granted | $ / shares	3.45
Weighted average exercise price Exercised | $ / shares	2.25
Weighted average exercise price Forfeited | $ / shares	1.30
Weighted Average Exercise Price - Ending balance | $ / shares	3.16	$ 1.30
Weighted average exercise price Options vested and expected to vest | $ / shares	2.84
Weighted average exercise price options vested and exercisable | $ / shares	$ 3.36
Performance Shares [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share subject to option Granted | shares	454,994
Share subject to option Exercised | shares	(20,017)
Share subject to options - Ending balance | shares	434,977
Share subject to Options Vested and expected to vest | shares	434,977
Share subject to Options vested and exercisable | shares	71,670
Weighted average exercise price Granted | $ / shares	$ 3.45
Weighted average exercise price Exercised | $ / shares	3.45
Weighted Average Exercise Price - Ending balance | $ / shares	3.45
Weighted average exercise price Options vested and expected to vest | $ / shares	3.45
Weighted average exercise price options vested and exercisable | $ / shares	$ 3.45
Restricted Stock [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Number of awards - Beginning balance | shares	827,192
Number of awards, vested | shares	(314,093)
Number of awards - Ending balance | shares	513,099	827,192
Weighted average granted fair date value - Beginning balance | $ / shares	$ 1.01
Weighted average granted fair date value, vested | $ / shares	0.86
Weighted average granted fair date value - Ending balance | $ / shares	$ 1.10	$ 1.01
Aggregate intrinsic value - Beginning balance | $	$ 834
Aggregate intrinsic value, Vested | $	271
Aggregate intrinsic value - Ending balance | $	$ 563	$ 834

Stock-based Compensation - Su_2

Stock-based Compensation - Summary of Stock Based Compensation Expense Was Allocated (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	$ 1,016	$ 151	$ 1,674	$ 604
Research and Development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	331	97	652	368
General and Administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	$ 685	$ 54	$ 1,022	$ 236

Fair value - Summary of Fair Va

Fair value - Summary of Fair Value of the Financial Instruments that are Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Assets:
Held-to-maturity securities	$ 38,304
Available-for-sale securities	23,241
Redeemable convertible preferred stock liability [Member]
Liabilities:
Redeemable convertible preferred stock liability		$ (3,174)
Level 1 [Member]
Liabilities:
Fair value, net asset (Liability)	70,120	127,712
Level 1 [Member] | Derivative liabilities [Member]
Liabilities:
Derivative liabilities	0	0
Level 1 [Member] | Redeemable convertible preferred stock liability [Member]
Liabilities:
Redeemable convertible preferred stock liability	0	0
Level 1 [Member] | Money market funds [Member]
Assets:
Cash equivalents	31,816	69,565
Level 1 [Member] | US Treasury securities [Member]
Assets:
Held-to-maturity securities	15,063	58,147
Available-for-sale securities	23,241
Level 2 [Member]
Liabilities:
Fair value, net asset (Liability)	0	0
Level 2 [Member] | Derivative liabilities [Member]
Liabilities:
Derivative liabilities	0	0
Level 2 [Member] | Redeemable convertible preferred stock liability [Member]
Liabilities:
Redeemable convertible preferred stock liability	0	0
Level 2 [Member] | Money market funds [Member]
Assets:
Cash equivalents	0	0
Level 2 [Member] | US Treasury securities [Member]
Assets:
Held-to-maturity securities	0	0
Available-for-sale securities	0
Level 3 [Member]
Liabilities:
Fair value, net asset (Liability)	15,180	3,635
Level 3 [Member] | Derivative liabilities [Member]
Liabilities:
Derivative liabilities	(620)	(461)
Level 3 [Member] | Redeemable convertible preferred stock liability [Member]
Liabilities:
Redeemable convertible preferred stock liability	(14,560)	(3,174)
Level 3 [Member] | Money market funds [Member]
Assets:
Cash equivalents	0	0
Level 3 [Member] | US Treasury securities [Member]
Assets:
Held-to-maturity securities	0	$ 0
Available-for-sale securities	$ 0

Fair value - Summary of Warrant

Fair value - Summary of Warrants Measured at Fair Value (Detail) - Warrant [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Warrants Were Measured at Fair Value [Line Items]
Exercise price	$ 9.32	$ 9.32
Term (in years)	3 months 25 days
Risk-free interest rate	0.10%	1.63%
Dividend yield	0.00%	0.00%
Volatility	120.00%	75.00%
Maximum [Member]
Schedule Of Warrants Were Measured at Fair Value [Line Items]
Term (in years)		3 years
Minimum [Member]
Schedule Of Warrants Were Measured at Fair Value [Line Items]
Term (in years)		2 years

Fair value - Summary of Changes

Fair value - Summary of Changes in Fair Value for Fair Value was Determined by Level 3 Inputs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule Of Changes in Fair Value [Line Items]
Change in fair value			$ 137
Derivative financial instruments liabilities [Member]
Schedule Of Changes in Fair Value [Line Items]
Exercise of warrants	$ 0		37,552	$ 0
Change in fair value	240	$ 154	296	$ 294
Mandatorily redeemable preferred stock [Member]
Schedule Of Changes in Fair Value [Line Items]
Beginning balance- Redeemable Convertible Preferred Stock Liability			3,174
Level 3 [Member] | Derivative financial instruments liabilities [Member]
Schedule Of Changes in Fair Value [Line Items]
Beginning balance-Derivative Liabilities			461
Exercise of warrants			(137)
Change in fair value			296
Ending balance-Derivative Liabilities	620		620
Level 3 [Member] | Mandatorily redeemable preferred stock [Member]
Schedule Of Changes in Fair Value [Line Items]
Beginning balance- Redeemable Convertible Preferred Stock Liability			3,174
Exercise of warrants			0
Change in fair value			11,386
Ending balance -Redeemable Convertible Preferred Stock Liability	$ 14,560		$ 14,560

Fair value - Summary of Redeema

Fair value - Summary of Redeemable Convertible Preferred Stock Liability Measured at Fair Value (Detail) - Mandatorily redeemable preferred stock [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Schedule of redeemable convertible preferred stock liability measured at fair value [Line Iteam]
Exercise price	$ 11.21	$ 11.21
Term (in years)		1 year 3 months 7 days
Risk-free interest rate		1.55%
Dividend yield	0.00%	0.00%
Volatility	0.00%	60.00%
Maximum [Member]
Schedule of redeemable convertible preferred stock liability measured at fair value [Line Iteam]
Term (in years)	9 months
Risk-free interest rate	0.11%
Minimum [Member]
Schedule of redeemable convertible preferred stock liability measured at fair value [Line Iteam]
Term (in years)	7 days
Risk-free interest rate	0.08%

License and collaboration agr_2

License and collaboration agreements - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 25, 2020	Apr. 30, 2020	Dec. 19, 2018	Sep. 30, 2020
Non-refundable payment					$ 4,500
KU leuven [Member]
Colabrations expire period		2 years 6 months
Luxna biotech Co Ltd [Member] | Luxna license agreement [Member]
Non-refundable payment			$ 200
Emory university [Member] | Emory license agreement [Member]
Non-refundable payment	$ 150
Long term purchase commitment additional obligation to be paid	35
Research plan funding amount	$ 270
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.
Katholieke universiteit leuven [Member] | Katholieke universiteit leuven license agreement [Member]
Non-refundable payment		$ 30,000
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 [Member] | Katholieke universiteit leuven license agreement [Member] | Maximum [Member]
Non-refundable payment		$ 32,000
NASH [Member] | Oligonucleotides [Member] | Luxna biotech Co Ltd [Member] | Luxna license agreement [Member]
Product selection period				8 years
Hepatocellular carcinoma [Member] | Oligonucleotides [Member] | Luxna biotech Co Ltd [Member] | Luxna license agreement [Member]
Product selection period				3 years

Commitments and contingencies -

Commitments and contingencies - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingent liabilities	$ 0	$ 0

Net loss per share - Schedule o

Net loss per share - Schedule of Earnings Per Share Basic and Diluted (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share, Basic and Diluted [Abstract]
Net loss	$ (33,297)	$ (14,051)	$ (74,123)	$ (34,080)
Weighted average common stock outstanding, basic and diluted	3,027,825	2,084,719	2,829,160	1,851,811
Net loss per share - basic and diluted	$ (11)	$ (6.74)	$ (26.20)	$ (18.40)

Net loss per share - Schedule_2

Net loss per share - Schedule of Antidilutive Securities Excluded From Computation of Earnings Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	25,953,481	12,900,764	25,953,481	12,900,764
Redeemable convertible preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	19,201,429	10,806,432	19,201,429	10,806,432
Forward contract to issue redeemable convertible preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	3,569,630	0	3,569,630	0
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	2,586,195	1,028,327	2,586,195	1,028,327
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	513,078	931,893	513,078	931,893
Warratns to purchase preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	83,149	134,112	83,149	134,112

Subsequent events - Additional

Subsequent events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Nov. 05, 2020	Oct. 20, 2020	Oct. 06, 2020	Dec. 23, 2019	Sep. 30, 2020	Oct. 15, 2020
Subsequent Event [Line Items]
Common stock voting rights				one
Payments made upon acheivement of certain development and regulatory milestone					$ 4,500
Subsequent Event [Member]
Subsequent Event [Line Items]
Sale of stock, net consideration received on the transaction	$ 151,443
Subsequent Event [Member] | Conversion Of Stock Non Voting Shares [Member]
Subsequent Event [Line Items]
Common stock voting rights		4.99
Subsequent Event [Member] | 2020 Equity Incentive Plan [Member]
Subsequent Event [Line Items]
Common stock shares reserved for future issuance						4,426,822
Subsequent Event [Member] | 2020 Employee Stock Purchase Plan [Member]
Subsequent Event [Line Items]
Common stock shares reserved for future issuance						368,901
SeriesB Two Preferred Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Sale of Stock, Number of Shares Issued in Transaction			3,569,630
Sale of stock, issue price per share			$ 11.20563
Sale of stock, net consideration received on the transaction			$ 40,000