0001564590-21-026071 | 10-Q | XBRL Viewer

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2021	May 07, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Registrant Name	Aligos Therapeutics, Inc.
Entity Central Index Key	0001799448
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		38,153,690
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common Stock, par value, $0.0001 per share
Trading Symbol	ALGS
Security Exchange Name	NASDAQ
Entity File Number	001-39617
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-4724808
Entity Address, Address Line One	One Corporate Drive
Entity Address, Address Line Two	2nd Floor
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	800
Local Phone Number	466-6059
Document Quarterly Report	true
Document Transition Report	false

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 200,362,000	$ 220,383,000
Restricted cash	556,000	560,000
Short-term investments	13,053,000	23,130,000
Other current assets	5,855,000	5,944,000
Total current assets	219,826,000	250,017,000
Operating lease right-of-use assets	6,953,000	6,901,000
Property and equipment, net	7,573,000	8,007,000
Other assets	188,000	377,000
Total assets	234,540,000	265,302,000
Current liabilities:
Accounts payable	2,810,000	3,313,000
Accrued liabilities	12,283,000	16,564,000
Operating lease liabilities, current	2,512,000	2,442,000
Finance lease liabilities, current	45,000	64,000
Deferred revenue from collaborations, current	7,581,000	7,891,000
Total current liabilities	25,231,000	30,274,000
Operating lease liabilities, net of current portion	10,183,000	10,371,000
Finance lease liabilities, net of current portion	130,000	130,000
Other liabilities	267,000	379,000
Deferred revenue from collaborations, net of current portion	3,509,000	4,109,000
Total liabilities	39,320,000	45,263,000
Commitments and contingencies (Note 12)
Stockholders’ equity (deficit):
Common stock, $0.0001 par value; 320,000,000 shares authorized as of March 31, 2021 (unaudited) and December 31, 2020, respectively; 38,147,205 and 38,120,606 shares issued and outstanding as of March 31, 2021 (unaudited) and December 31, 2020, respectively	4,000	4,000
Additional paid-in capital	397,857,000	394,963,000
Accumulated deficit	(202,414,000)	(174,740,000)
Accumulated other comprehensive loss	(227,000)	(188,000)
Total stockholders’ equity	195,220,000	220,039,000
Total liabilities, preferred stock, and stockholders’ equity (deficit)	234,540,000	265,302,000
Preferred Stock
Current liabilities:
Preferred Stock, $0.0001 par value; 10,000,000 shares authorized as of March 31, 2021 and December 31, 2020; no shares issued and outstanding as of March 31, 2021 and December 31, 2020	$ 0	$ 0

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Preferred Stock, Shares Authorized		10,000,000
Preferred Stock, Shares Issued		0
Common Stock, Par Value	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	320,000,000	320,000,000
Common Stock, Shares, Issued	38,147,205	38,120,606
Common Stock, Shares, Outstanding	38,147,205	38,120,606
Preferred Stock
Preferred Stock, Par Value	$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue from collaborations	$ 910
Operating expenses:
Research and development	22,869	$ 17,302
General and administrative	5,781	3,419
Total operating expenses	28,650	20,721
Loss from operations	(27,740)	(20,721)
Interest and other income, net	111	692
Loss before income tax expense	(27,629)	(20,029)
Income tax expense	(45)
Net loss	(27,674)	(20,029)
Other comprehensive gain (loss):
Unrealized gain (loss) on available-for-sale securities	(41)	401
Unrealized gain on pension plans	2	166
Other comprehensive income (loss)	(39)	567
Comprehensive loss	$ (27,713)	$ (19,462)
Net loss per share, basic and diluted	$ (0.74)	$ (7.56)
Weighted average shares of common stock, basic and diluted	37,434,261	2,648,885

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (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, Shares at Dec. 31, 2019		10,819,843	8,344,034
Beginning balance at Dec. 31, 2019		$ 100,695	$ 81,384
Beginning balance, Shares at Dec. 31, 2019				3,927,803
Beginning balance at Dec. 31, 2019	$ (64,891)				$ 1,421	$ (66,197)	$ (115)
Issuance of common stock upon exercise of stock options	18				18
Issuance of common stock upon exercise of stock options, shares				13,672
Issuance of Series A stock upon exercise of Series A warrants		$ 487
Issuance of Series A stock upon exercise of Series A warrants, shares		37,555
Stock-based compensation	331				331
Vesting of early exercised options from existing exercises	63				63
Other comprehensive income	567						567
Net loss	(20,029)					(20,029)
Ending balance, Shares at Mar. 31, 2020		10,857,397	8,344,034
Ending balance at Mar. 31, 2020		$ 101,182	$ 81,384
Ending balance, Shares at Mar. 31, 2020				3,941,476
Ending balance at Mar. 31, 2020	(83,941)				1,833	(86,226)	452
Beginning balance, Shares at Dec. 31, 2020				38,120,606
Beginning balance at Dec. 31, 2020	220,039			$ 4	394,963	(174,740)	(188)
Issuance of common stock upon exercise of stock options	96				96
Issuance of common stock upon exercise of stock options, shares				26,599
Stock-based compensation	2,756				2,756
Vesting of early exercised common stock options	42				42
Other comprehensive income	(39)						(39)
Net loss	(27,674)					(27,674)
Ending balance, Shares at Mar. 31, 2021				38,147,205
Ending balance at Mar. 31, 2021	$ 195,220			$ 4	$ 397,857	$ (202,414)	$ (227)

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (27,674,000)	$ (20,029,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion of discount on investments	37,000	5,000
Amortization of right of use assets	132,000	129,000
Depreciation expense	741,000	331,000
Stock-based compensation	2,756,000	606,000
Change in fair value of derivative liability		(20,000)
Change in fair value of redeemable convertible preferred stock liabilities		(166,000)
Changes in operating assets and liabilities:
Other assets	277,000	(528,000)
Right of use assets		(249,000)
Accounts payable	(502,000)	(304,000)
Accrued liabilities	(4,239,000)	183,000
Operating lease liabilities	(303,000)	(277,000)
Other liabilities	(111,000)
Deferred revenue from collaborations	(910,000)
Net cash and cash equivalents used in operating activities	(29,796,000)	(20,319,000)
Activities in available-for-sale investments:
Purchase of short-term investments		(32,096,000)
Purchase of long term investments		(13,183,000)
Activities in held-to-maturity investments:
Maturities of investments	10,000,000	22,600,000
Purchases of property and equipment	(307,000)	(1,090,000)
Net cash and cash equivalents provided by (used in) investing activities	9,693,000	(23,769,000)
Cash flows from financing activities:
Proceeds from exercise of warrants for series A convertible preferred stock		350,000
Payment of Series B-1 redeemable convertible preferred stock issuance cost		(405,000)
Payments on finance lease	(18,000)	(11,000)
Proceeds from the exercise of common stock option	96,000	18,000
Net cash and cash equivalents provided by (used in) financing activities	78,000	(48,000)
Net decrease in cash, cash equivalents, and restricted cash	(20,025,000)	(44,136,000)
Cash, cash equivalents, and restricted cash, beginning of period	220,943,000	70,103,000
Cash, cash equivalents, and restricted cash, end of period	200,918,000	25,967,000
Reconciliation to amounts on the consolidated balance sheet:
Cash and cash equivalents	200,362,000	25,415,000
Restricted cash	556,000	552,000
Cash, cash equivalents, and restricted cash, end of period	200,918,000	25,967,000
Supplemental disclosures of cash flow information:
Interest paid		2,000
Supplemental disclosures of noncash financing and investing activities:
Leasehold improvement directly paid by landlord		79,000
Mark to market adjustment for available-for-sale investments	41,000	401,000
Acquisition of right of use asset through operating lease obligation	184,000
Change in fair value of derivative liability upon exercise of warrants		137,000
Vesting of early exercised options	42,000	63,000
Property and equipment purchases in accounts payable		399,000
Change in pension obligation	$ (2,000)	$ 166,000

Organization

3 Months Ended

Mar. 31, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Organization

1.	Organization

Description of business

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

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 steatohepatitis (NASH).

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 reverse stock split (the Reverse Stock Split) of the Company’s common stock and redeemable convertible preferred stock to be consummated prior to the effectiveness of the Company’s planned initial public offering (IPO). The par value and authorized shares of the common stock and redeemable convertible preferred stock were not adjusted as a result of the reverse stock split. All issued and outstanding common stock, options to purchase common stock and per share amounts contained in the financial statements have been retroactively adjusted to give effect to the reverse stock split for all periods presented. The Company filed an amended and restated certificate of incorporation in Delaware on October 9, 2020 that automatically effectuated the Reverse Stock Split without any further action required.

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 $135.4 million, after deducting underwriting discounts and commissions of $10.5 million and expenses of $4.1 million. In connection with the IPO, all shares of Series A redeemable convertible preferred stock (Series A), Series B-1 redeemable convertible preferred stock (Series B-1) and Series B-2 redeemable convertible preferred stock (Series B-2) converted into 19,761,870 shares of voting common stock and 3,092,338 shares of non-voting common stock. On November 5, 2020, the underwriters of the IPO partially exercised their overallotment option by purchasing an additional 1,150,000 shares from the Company, resulting in an additional $16.0 million in net proceeds, after deducting underwriting discounts and commissions of $1.2 million.

Liquidity

The Company has incurred losses and negative cash flows from operations since its inception. As of March 31, 2021 and December 31, 2020, the Company had an accumulated deficit of $202.4 million and $174.7 million, respectively. Management expects to continue to incur additional substantial losses in the foreseeable future as a result of expanded research and development activities.

As of March 31, 2021, the Company has unrestricted cash, cash equivalents and investments of approximately $213.4 million which is available to fund future operations. The Company expects to continue to spend substantial amounts to continue the nonclinical and clinical development of its current and future programs. If the Company is able to gain marketing approval for drug candidates that are being developed, it will require significant additional amounts of cash in order to launch and commercialize such drug candidates. In addition, other unanticipated costs may arise. Because the design and outcome of the Company’s planned and anticipated clinical trials is highly uncertain, the Company cannot reasonably estimate the actual amounts necessary to successfully complete the development and commercialization of any drug candidate the Company may develop.

The Company expects to finance its cash needs through a combination of public or private equity offerings, debt financings, collaborations, strategic alliances, licensing arrangements and other marketing or distribution arrangements. 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, and the Company may need to seek additional funds sooner than planned. Moreover, it is particularly difficult to estimate with certainty the Company’s future expenses given the dynamic nature of its business, the COVID-19 pandemic and the macro-economic environment generally.

The Company’s ability to raise additional funds will depend on financial, economic and other factors, many of which are beyond its control. In particular, the COVID-19 pandemic continues to rapidly evolve and has already resulted in a significant disruption of global financial markets. If the disruption persists or deepens, the Company could be unable to access additional capital, which could negatively affect its ability to consummate certain corporate development transactions or other important, beneficial or opportunistic investments. If additional funds are not available to the Company when needed, on terms that are acceptable to the Company, or at all, the Company may be required to: delay, limit, reduce or terminate nonclinical studies, clinical trials or other research and development activities or eliminate one or more of its development programs altogether; or delay, limit, reduce or terminate its efforts to establish manufacturing and sales and marketing capabilities or other activities that may be necessary to commercialize any future approved products, or reduce the Company’s flexibility in developing or maintaining its sales and marketing strategy.

Summary of significant accounting policies

3 Months Ended

Mar. 31, 2021

Accounting Policies [Abstract]

Summary of significant accounting policies

2.	Summary of significant accounting policies

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 pandemic and the macro-economic environment generally.

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, 2020 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 should be read in conjunction with the audited consolidated financial statements and the related notes thereto as of and for the year ended December 31, 2020, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 23, 2021.

Principles of consolidation

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

Use of estimates

The preparation of the condensed consolidated financial statements in conformity with U.S. 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 assets, lease obligations, impairment of long-lived assets, stock-based compensation, accrued research and development costs, pension liabilities, revenue from collaborations and deferred revenue in the accompanying condensed consolidated financial statements. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from these estimates under different assumptions or conditions.

Unaudited interim financial information

The accompanying consolidated balance sheet as of March 31, 2021, the consolidated statements of operations and comprehensive loss for the three months ended March 31, 2021 and 2020, the consolidated statements of redeemable convertible preferred stock and stockholders’ equity (deficit) for the three months ended March 31, 2021 and 2020, and the consolidated statements of cash flows for the three months ended March 31, 2021 and 2020 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 March 31, 2021 and the consolidated results of its operations and cash flows for the three months ended March 31, 2021 and 2020. The consolidated financial data and other information disclosed in these notes related to the three months ended March 31, 2021 and 2020 are unaudited. The consolidated results for the three months ended March 31, 2021 are not necessarily indicative of results to be expected for the year ending December 31, 2021, any other interim periods, or any future year or period.

Foreign currency

The Company’s foreign subsidiaries use the U.S. dollar as their functional currency, and they initially measure the foreign currency denominated assets and liabilities at the transaction date. Monetary assets and liabilities are then re-measured at exchange rates in effect at the end of each period, and non-monetary assets and liabilities are converted at historical rates. A re-measurement gain was recognized during the three months ended March 31, 2021 and 2020 of $50,000 and $45,000, respectively, and are reflected within interest and other income, net on the consolidated statements of operations and comprehensive loss.

Segment information

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

The Company has $6.3 million and $1.3 million of fixed assets in Aligos-US and Aligos-Belgium, respectively, as of March 31, 2021 and $6.6 million and $1.4 million of fixed assets in Aligos-US and Aligos‑Belgium, respectively as of December 31, 2020.

Cash equivalents

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

Restricted cash

As of March 31, 2021 and December 31, 2020, the restricted cash balance was $556,000 and $560,000, respectively, and was used to secure the letters of credit in relation to the Company’s operating leases and deposits on rental assets (Note 6).

Leases

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

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

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

Property and equipment

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


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

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

Impairment of long-lived assets

The Company regularly reviews the carrying amount of its property, equipment and intangible assets to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. If indications of impairment exist, projected future undiscounted cash flows associated with the asset are compared to the carrying amount to determine whether the asset’s value is recoverable. If the carrying value of the asset exceeds such projected undiscounted cash flows, the asset will be written down to its estimated fair value. No impairment charges were recorded during the three months ended March 31, 2021 or 2020.

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’ equity. Premiums or discounts from par value are amortized to investment income over the life of the underlying investment. The cost of securities sold is determined on a specific identification basis, and realized gains and losses are included in interest and other income, net within the condensed consolidated statements of operations and comprehensive loss.

For both held-to-maturity and available-for-sale investments, the Company periodically reviews each individual security position that has an unrealized loss, or impairment, to determine if that impairment is other-than-temporary. If the Company believes an impairment of a security position is other than temporary, based on available quantitative and qualitative information as of the report date, the loss will be recognized as other income in the Company’s condensed consolidated statements of operations and a new cost basis in the investment is established. No impairment charges were recorded during the three months ended March 31, 2021 and 2020.

As of March 31, 2021 and December 31, 2020, short-term investments consisted of U.S. Treasury securities with original maturities of less 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 prepayments for goods or services that will be used or rendered for future research and development activities are expensed as incurred. In-process research and development (IPR&D) expense represents the costs to acquire technologies to be used in research and development that have not reached technological feasibility or have no alternative future uses and thus are expensed as incurred. IPR&D expense also includes upfront license fees and milestones paid to collaborators for technologies with no alternative use.

Collaborative arrangements

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

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

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

During the three months ended March 31, 2021 and 2020, no milestones were met and no royalties were due; therefore, the Company did not pay or expense any milestone or royalties.

Fair value measurements

Certain assets and liabilities of the Company are carried at fair value under U.S. GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

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

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

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

Stock-based compensation

The Company’s stock-based awards consist of restricted stock awards and stock options. For stock-based awards issued to employees and nonemployees 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 performance conditions is estimated on the grant date. The Company records expense for awards with service-based vesting using the straight-line method and for awards with performance conditions utilizing an accelerated attribution method. The Company accounts for forfeitures as they occur.

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 three months ended March 31, 2021 and 2020.

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 to calculate its basic and diluted net loss per share as the Company has issued shares that meet the definition of participating securities. The two-class method is an earnings allocation formula that treats a participating security as having rights to earnings that otherwise would have been available to common stockholders. The Company’s participating securities contractually entitle the holders of such shares to participate in dividends; but do not contractually require the holders of such shares to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss, such losses are not allocated to such participating securities.

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

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

3 Months Ended

Mar. 31, 2021

Property Plant And Equipment [Abstract]

Property and equipment

3.	Property and equipment

The components of property and equipment as of March 31, 2021 and December 31, 2020 were as follows:

	March 31, 2021			December 31, 2020
Leasehold improvements	$	5,660		$	5,655
Lab equipment		5,145			4,833
Computer equipment		978			942
Furniture and office equipment		459			459
Vehicles		296			296
Asset under construction		19			65
Total, at cost		12,557			12,250
Accumulated depreciation		(4,984	)		(4,243	)
Total, net	$	7,573		$	8,007

Depreciation expense was $741,000 for the three months ended March 31, 2021, and $331,000 for the three months ended March 31, 2020, respectively. Finance leases are also included in property and equipment as vehicles on the condensed consolidated balance sheets (Note 6).

Investments

3 Months Ended

Mar. 31, 2021

Debt Securities Available For Sale And Held To Maturity [Abstract]

Investments

4.	Investments

As of March 31, 2021 and December 31, 2020, amortized cost, gross unrealized gains and losses, and estimated fair values of total fixed-maturity securities were as follows:

	March 31, 2021
			Gross		Gross
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gain		Loss		Fair Value
Available-for-sale securities
U.S. Treasury bonds		13,026		27		-		13,053
	$	13,026	$	27	$	-	$	13,053

	December 31, 2020
			Gross		Gross
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gain		Loss		Fair Value
Held-to-maturity securities:
U.S. Treasury bonds		10,002		14		-		10,016
Available-for-sale securities
U.S. Treasury bonds		13,060		68		-		13,128
	$	23,062	$	82	$	-	$	23,144

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 and available-for-sale as of March 31, 2021:

	Available-for-sale
	Amortized Cost		Estimated Fair Value
Amounts maturing in:
One year or less	$	13,026	$	13,053
Total investments	$	13,026	$	13,053

The Company recorded interest income of $105,000 for three months ended March 31, 2021, and $468,000 for the three months ended March 31, 2020, respectively, as a component of interest and other income, net on the Company’s condensed consolidated statement of operations and comprehensive loss.

Accrued liabilities

3 Months Ended

Mar. 31, 2021

Payables And Accruals [Abstract]

Accrued liabilities

5.	Accrued liabilities

Accrued liabilities consisted of the following as of:

	March 31,		December 31,
	2021		2020
Accrued payables	$	6,927	$	7,274
Accrued compensation		3,941		8,554
Liability with early exercised stock options		528		569
Other		887		167
Total	$	12,283	$	16,564

Leases

3 Months Ended

Mar. 31, 2021

Leases [Abstract]

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 March 31, 2021 and December 31, 2020. Lease expense for lease payments is recognized on a straight-line basis over the lease term.

Maturities of lease liabilities as of March 31, 2021 and are as follows:

	Operating Lease			Finance Lease
Year ending December 31:
2021, remainder	$	2,026		$	59
2022		2,799			78
2023		2,754			41
2024		2,678			1
2025		2,772			-
Thereafter		3,642			-
Less: imputed interest		(3,976	)		(4	)
Present value of lease liabilities		12,695			175
Less: current portion		(2,512	)		(45	)
Lease liabilities net of current portion	$	10,183		$	130

The components of lease expense were as follows for the three months ended March 31, 2021 and 2020:

	Three Months Ended
	March 31,
	2021		2020
Operating lease cost	$	469	$	462
Finance lease cost:
Amortization of right-of-use assets	$	18	$	17
Interest on lease liabilities		1		2
Total finance lease cost	$	19	$	19

The Company made payments of $638,000 during the three months ended March 31, 2021, respectively, and $607,000 during the three months ended March 31, 2020, respectively, which are included as cash flow from operations on the condensed consolidated statements of cash flows.

As of March 31, 2021 and December 31, 2020, $296,000 of finance lease ROU assets were presented as part of property and equipment on the condensed consolidated balance sheet with accumulated amortization of $126,000 and $107,000, respectively.

Additional information related to the Company’s leases was as follows as of March 31, 2021 and December 31, 2020:

	March 31,			December 31,
	2021			2020
Operating Lease:
Weighted-average remaining lease term (years)		5.83			5.97
Weighted-average discount rate		9.38	%		9.35	%
Finance Lease:
Weighted-average remaining lease term (years)		2.44			2.68
Weighted-average discount rate		3.14	%		3.15	%

Derivative liabilities and redeemable convertible preferred stock liability

3 Months Ended

Mar. 31, 2021

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. The Warrants have a coverage percentage of 25% of the principal amount of the notes and have a ten-year expiration date from the applicable closing date of April 20, 2018 or June 6, 2018.

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.

The Company recorded the Warrants initially at fair value (Note 10) as derivative liabilities on the consolidated balance sheet with the value being allocated to the notes as a debt discount. The fair value of the Warrants upon issuance on April 20, 2018 and June 6, 2018, was $0.7 million and $238,000, respectively. The fair value of the Warrants was $0 and $0 as of March 31, 2021 and December 31, 2020, respectively as, due to the IPO in October 2020, all outstanding warrants were automatically exercised for the issuance of Common Stock, and upon that exercise, such warrants were no longer outstanding.

No warrants were exercised during the three months ended March 31, 2021, or during the three months ended March 31, 2020. As Series A contained a conditional obligation for the Company to repurchase the shares for cash consideration, the Warrants were exercised as of the IPO date, with changes in fair value being recorded on the consolidated statements of operations and comprehensive loss. The Company recorded a change in fair value of derivative liabilities of $0 and $20,000 for the three months ended March 31, 2021 and March 31, 2020, respectively.

Redeemable convertible preferred stock liability

In connection with the issuance of shares of Series B-1 (Note 8), the Series B-1 preferred stockholders committed to purchase and the Company committed to sell 3,569,630 shares of Series B-2 at a price of $11.20563 per share in a subsequent closing, contingent upon the achievement of certain developmental milestones or a receipt of a waiver of achievement of the milestones. The Redeemable Convertible Preferred Stock Liability is considered a freestanding instrument that qualifies as a liability under ASC Topic 480, Distinguishing Liabilities from Equity as the Company is committed to issue an instrument that ultimately may require a transfer of assets. The liability is accounted for at fair value and re-measured at each reporting date (Note 10). On the date of the initial closing, the Company recorded the Redeemable Convertible Preferred Stock Liability at a fair value of $3.2 million. As of March 31, 2021 and December 31, 2020, all of the Series B-2 shares were issued and then, as a result of the IPO, converted to shares of common stock. The Company recorded a change in fair value of the liability of $0 and $166,000 during the three months ended March 31, 2021 and 2020.

Capital stock

3 Months Ended

Mar. 31, 2021

Equity [Abstract]

Capital stock

8.	Capital stock

Common stock

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

The holders of shares of 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 $75.0 million in cash proceeds from the initial purchasers. On September 19, 2018, the Company received an additional $20.0 million in cash proceeds from subsequent purchasers. Additionally, on the initial closing date, $5.6 million 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 basis. In connection with the issuance of Series A, the Company incurred $194,000 in issuance costs which have offset amounts reported as temporary equity as of December 31, 2019. As of December 31, 2020, in connection with the Company’s IPO, all shares of Series A converted into Common Stock.

On December 23, 2019, the Company entered into the Series B-1 and Series B-2 Preferred Stock Purchase Agreement (the Series B Purchase Agreement), pursuant to which the investors committed to invest an aggregate amount of up to $125.0 million for the issuance and sale of shares of Series B-1 and Series B-2 (collectively, the Series B), at a price of $10.18690 and $11.20563 per share, respectively. The Company issued 8,344,034 shares of Series B-1 for cash proceeds of $85.0 million at the initial closing. The investors also committed to purchase and the Company committed to sell 3,569,630 shares of Series B-2 in a subsequent closing (the Second Closing), contingent upon achievement by the Company of certain development milestones or a receipt of a waiver of achievement of the milestones. No shares of Series B-2 were issued as of March 31, 2021. In connection with the issuance of Series B-1, the Company incurred $442,000 in issuance costs which have offset amounts reported as temporary equity as of December 31, 2019.

Prior to the IPO, the Company issued 3,569,630 shares of Series B-2, which upon the closing of the IPO converted into common stock. In connection with the Company’s IPO, all shares of Series B-1 converted into common stock. As of December 31, 2020, there was 10,000,000 shares of preferred stock authorized and no preferred stock issued.

Stock-based compensation

3 Months Ended

Mar. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-based compensation

9.	Stock-based compensation

Stock options

During the periods ended March 31, 2021 and 2020, the Company’s stock option compensation expense was approximately $2.7 million and $240,000, respectively, and there was no recognized tax benefit in either of the periods. As of March 31, 2021, unamortized expense balance was $37.1 million, to be amortized over a weighted average period of 3.21 years.

Stock option activity during the three months ended March 31, 2021 is as follows:

	Time-based options
	Shares subject to options			Weighted- average exercise price		Weighted- average remaining contractual term (years)		Aggregate Intrinsic Value
Outstanding as of January 1, 2021		5,488,148		$	11.19	9.57		$	90,335
Granted		59,500		$	26.46
Exercised		(26,207	)	$	3.50			$	92
Cancelled		(5,718	)	$	3.01
Outstanding as of March 31, 2021		5,515,723		$	11.40		9.35	$	62,548

Options vested and expected to vest as of March 31, 2021		5,460,481		$	11.48		9.35	$	61,485
Options vested and exercisable as of March 31, 2021		752,171		$	6.36		8.98	$	12,321

The weighted-average grant date fair value of options granted was $17.33 per share during the three months ended March 31, 2021.

Restricted stock awards

During the three months ended March 31, 2021 and 2020, the Company recorded a total stock-based compensation expense of $90,000 and $90,000 related to the restricted stock awards. As of March 31, 2021, unrecognized stock-based compensation expense related to outstanding unvested shares of restricted stock that are expected to vest were approximately $421,000, expected to be recognized over a weighted-average period of 1.00 years.

The following table summarizes the Company’s restricted common stock activity for the three months ended March 31, 2021:

	Number of Awards			Weighted- Average Grant Date Fair Value		Aggregate Fair Value
Issued and unvested as of January 1, 2021		408,411			1.15		470
Restricted stock awards granted		—			—		—
Restricted stock awards vested		(104,700	)		0.86		(90	)
Issued and unvested as of March 31, 2021		303,711			1.25		380

Stock-based compensation expense was allocated as follows for the three months ended March 31, 2021 and 2020:

	March 31, 2021		March 31, 2020
Research and development	$	1,709	$	172
General and administrative		1,047		159
Total	$	2,756	$	331

During the three months ended March 31, 2021, the Company issued 317,456 shares of common stock, upon exercise of unvested stock options or purchases for unvested restricted stock awards. As of March 31, 2021 and December 31, 2020, there were 338,358 and 396,522 shares of Common Stock held by employees subject to repurchase at an aggregate price of $0.5 million and $0.6 million, respectively. A corresponding liability was recorded and included in accrued expenses on the condensed consolidated balance sheet as of March 31, 2021 and December 31, 2020, respectively.

Fair value

3 Months Ended

Mar. 31, 2021

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 as of March 31, 2021
	Level 1		Level 2		Level 3
Assets:
Cash equivalents		200,362		-		-
U.S. Treasury bonds		13,053		-		-
	$	213,415	$	-	$	-

	Fair Value Measurements as of December 31, 2020
	Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	220,383	$	-	$	-
U.S. Treasury bonds		23,144		-		-
	$	243,527	$	-	$	-

- Definition

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

+ References + Details

License and collaboration agreements

3 Months Ended

Mar. 31, 2021

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

As consideration for the Emory License Agreement, the Company paid an upfront license fee of $290,000 and issued the Emory Convertible Note of $600,000. As discussed in Note 8, upon issuance of the Series A in August 2018, the Emory Convertible Note and unpaid accrued interest was cancelled and converted into shares of Series A at a conversion price of $9.32 per share.

In June 2020, the Company amended the license agreement with Emory. Pursuant to the amended license agreement, Emory granted the Company additional patent rights to certain compounds targeting the treatment or prevention of HBV. As consideration for the additional rights, the Company made a one-time, non-refundable payment to Emory in the amount of $150,000, with an additional obligation to pay up to a maximum of $35,000. On the same date, the Company entered into a collaboration agreement with Emory, with the initial research plan pertaining to the synthesis and evaluation of the compounds licensed through the additional patent rights granted in the amended license agreement. The research plan terminates one year from the effective date, with the Company having an option to extend for a second year. In connection with the research plan, the Company will provide Emory funding up to $270,000 per year.

The Company has agreed to pay Emory up to an aggregate of $125.0 million upon the achievement of specified development, regulatory, and commercial milestones, and all ongoing patent costs. During the three months ended March 31, 2021, the Company had $80,000 expenses related to milestone payments. The Company also agreed to pay Emory tiered single-digit royalties on worldwide annual net sales of licensed products, on a quarterly basis and calculated on a product-by-product basis. With respect to licensed products containing any of a specified subset of the licensed compounds, such royalties range from a mid-single digit to a high-single digit percentage rate. With respect to licensed products which do not contain such compounds, the royalties span a range of percentage rates within the mid-single digits if a Phase 1 clinical trial is initiated for the product within three years of the effective date of the Emory License Agreement, and range from a low-single digit to a mid-single digit rate if a Phase 1 clinical trial is initiated more than three years after the effective date. During the three months ended March 31, 2021 and 2020, the Company made no payments associated with royalties and recognized no expense or accruals.

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. As consideration for this agreement, the Company paid an upfront license fee of $600,000, which was recorded as research and development expense during the period from inception through December 31, 2018 and the year ended December 31, 2019.

In April 2020, the Company amended the license agreement with Luxna. Pursuant to the amended license agreement, Luxna granted the Company an exclusive, worldwide license under the licensed patents to research, develop, make, have made and commercialize products containing oligonucleotides targeting three families of viruses: orthomyxoviridae, paramyxoviridae, and coronaviridae (a family which includes SARS-CoV-2). As consideration for the amended license agreement, the Company paid Luxna a one-time non-refundable fee of $200,000 in April 2020.

The Company is obligated to make payments to Luxna, in aggregate, totaling up to but no more than $55.5 million upon the achievement of specified development, regulatory, and commercial milestones. During the three months ended March 31, 2021 and 2020, the Company recognized no expenses related to milestone payments. The Company is also required to pay Luxna a low-single digit royalty percentage on net sale of applicable products, if any. During the three months ended March 31, 2021 and 2020, the Company made no payments associated with royalties.

Agreement with Katholieke Universiteit Leuven (KU Leuven)

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

Agreement with Merck

In December 2020, the Company and Merck & Co. entered into an exclusive License and Research Collaboration Agreement under which Merck and the Company agreed to apply the Company’s oligonucleotide platform technology to discover, research, optimize and develop oligonucleotides directed against a NASH target and up to one additional liver-targeted cardiometabolic and/or fibrosis target. Under the terms of the agreement, the Company received an upfront payment from Merck and may receive an additional upfront payment after finalization of a research plan for such additional target. With respect to each collaboration target, the Company will be eligible for up to $458.0 million in development and commercialization milestones as well as tiered royalties on net sales. The Company will be primarily responsible for designing, preparing and evaluating the oligonucleotide molecules and delivering optimized lead molecules, and Merck will be responsible for subsequent research, clinical development and commercialization efforts. The Company determined that the Merck agreement falls within the scope of ASC 808 and we analogized to ASC 606 for the accounting of payments such as upfront payments and other milestones. During the three months ended March 31, 2021 the Company recognized $910,000 of revenue from collaborative arrangements related to milestone payments. During the three months ended March 31, 2020 the Company did not recognize any revenue from collaborative arrangements.

Commitments and contingencies

3 Months Ended

Mar. 31, 2021

Commitments And Contingencies Disclosure [Abstract]

Commitments and contingencies

12.	Commitments and contingencies

From time to time, the Company may have certain contingent liabilities, including legal matters that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. The Company had no contingent liabilities requiring accrual as of March 31, 2021 and December 31, 2020.

Income taxes

3 Months Ended

Mar. 31, 2021

Income Tax Disclosure [Abstract]

Income taxes

13. Income taxes

The Company has a history of losses and expected to record a loss in 2021. The Company continues to maintain a full valuation allowance its net deferred tax assets.

- Definition

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

+ References + Details

Net loss per share

3 Months Ended

Mar. 31, 2021

Earnings Per Share [Abstract]

Net loss per share

14.	Net loss per share

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

	Three Months Ended
	March 31,
	2021			2020
Net loss	$	(27,674	)	$	(20,029	)
Weighted average common stock outstanding, basic and diluted		37,434,261			2,648,885
Net loss per share - basic and diluted	$	(0.74	)	$	(7.56	)

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
	March 31,
	2021		2020
Convertible preferred stock		-		19,201,432
Forward contract to issue redeemable convertible preferred stock		-		3,569,630
Options to purchase common stock		5,504,150		2,435,535
Unvested restricted stock		303,697		722,486
Warrants to purchase preferred stock		-		83,146
		5,807,847		26,012,229

Subsequent events

3 Months Ended

Mar. 31, 2021

Subsequent Events [Abstract]

Subsequent events

15.	Subsequent events

In preparing the interim financial statements as of March 31, 2021 and for the three months then ended, the Company evaluated subsequent events for recognition and measurement purposes. The Company concluded that no events or transactions have occurred that require disclosure in the accompanying financial statements.

Summary of significant accounting policies (Policies)

3 Months Ended

Mar. 31, 2021

Accounting Policies [Abstract]

Risks and uncertainties

Basis of presentation

Principles of consolidation

Use of estimates

Unaudited interim financial information

Foreign currency

Segment information

Cash equivalents

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

Restricted cash

Leases

Property and equipment

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


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

Impairment of long-lived assets

Investments

As of March 31, 2021 and December 31, 2020, short-term investments consisted of U.S. Treasury securities with original maturities of less than one year.

Research and development expenses

Collaborative arrangements

During the three months ended March 31, 2021 and 2020, no milestones were met and no royalties were due; therefore, the Company did not pay or expense any milestone or royalties.

Fair value measurements

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

Stock-based compensation

Net loss per share

Recently issued accounting standards

Summary of significant accounting policies (Tables)

3 Months Ended

Mar. 31, 2021

Accounting Policies [Abstract]

Summary of Estimated Useful Life of Asset

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


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

Property and equipment (Tables)

3 Months Ended

Mar. 31, 2021

Property Plant And Equipment [Abstract]

Summary of Property and Equipment

The components of property and equipment as of March 31, 2021 and December 31, 2020 were as follows:

	March 31, 2021			December 31, 2020
Leasehold improvements	$	5,660		$	5,655
Lab equipment		5,145			4,833
Computer equipment		978			942
Furniture and office equipment		459			459
Vehicles		296			296
Asset under construction		19			65
Total, at cost		12,557			12,250
Accumulated depreciation		(4,984	)		(4,243	)
Total, net	$	7,573		$	8,007

Investments (Tables)

3 Months Ended

Mar. 31, 2021

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 March 31, 2021 and December 31, 2020, amortized cost, gross unrealized gains and losses, and estimated fair values of total fixed-maturity securities were as follows:

	March 31, 2021
			Gross		Gross
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gain		Loss		Fair Value
Available-for-sale securities
U.S. Treasury bonds		13,026		27		-		13,053
	$	13,026	$	27	$	-	$	13,053

	December 31, 2020
			Gross		Gross
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gain		Loss		Fair Value
Held-to-maturity securities:
U.S. Treasury bonds		10,002		14		-		10,016
Available-for-sale securities
U.S. Treasury bonds		13,060		68		-		13,128
	$	23,062	$	82	$	-	$	23,144

Summary of Debt Securities Available for Sale and Held to Maturity

The following is a summary of maturities of securities held-to-maturity and available-for-sale as of March 31, 2021:

	Available-for-sale
	Amortized Cost		Estimated Fair Value
Amounts maturing in:
One year or less	$	13,026	$	13,053
Total investments	$	13,026	$	13,053

Accrued liabilities (Tables)

3 Months Ended

Mar. 31, 2021

Payables And Accruals [Abstract]

Summary of Accrued Liabilities

Accrued liabilities consisted of the following as of:

	March 31,		December 31,
	2021		2020
Accrued payables	$	6,927	$	7,274
Accrued compensation		3,941		8,554
Liability with early exercised stock options		528		569
Other		887		167
Total	$	12,283	$	16,564

Leases (Tables)

3 Months Ended

Mar. 31, 2021

Leases [Abstract]

Summary of Maturities of Lease Liabilities

Maturities of lease liabilities as of March 31, 2021 and are as follows:

	Operating Lease			Finance Lease
Year ending December 31:
2021, remainder	$	2,026		$	59
2022		2,799			78
2023		2,754			41
2024		2,678			1
2025		2,772			-
Thereafter		3,642			-
Less: imputed interest		(3,976	)		(4	)
Present value of lease liabilities		12,695			175
Less: current portion		(2,512	)		(45	)
Lease liabilities net of current portion	$	10,183		$	130

Summary of Components of lease Expense

The components of lease expense were as follows for the three months ended March 31, 2021 and 2020:

	Three Months Ended
	March 31,
	2021		2020
Operating lease cost	$	469	$	462
Finance lease cost:
Amortization of right-of-use assets	$	18	$	17
Interest on lease liabilities		1		2
Total finance lease cost	$	19	$	19

Summary of Additional Information Related to the Leases

Additional information related to the Company’s leases was as follows as of March 31, 2021 and December 31, 2020:

	March 31,			December 31,
	2021			2020
Operating Lease:
Weighted-average remaining lease term (years)		5.83			5.97
Weighted-average discount rate		9.38	%		9.35	%
Finance Lease:
Weighted-average remaining lease term (years)		2.44			2.68
Weighted-average discount rate		3.14	%		3.15	%

Stock-based compensation (Tables)

3 Months Ended

Mar. 31, 2021

Summary of Stock Options

Stock option activity during the three months ended March 31, 2021 is as follows:

	Time-based options
	Shares subject to options			Weighted- average exercise price		Weighted- average remaining contractual term (years)		Aggregate Intrinsic Value
Outstanding as of January 1, 2021		5,488,148		$	11.19	9.57		$	90,335
Granted		59,500		$	26.46
Exercised		(26,207	)	$	3.50			$	92
Cancelled		(5,718	)	$	3.01
Outstanding as of March 31, 2021		5,515,723		$	11.40		9.35	$	62,548

Options vested and expected to vest as of March 31, 2021		5,460,481		$	11.48		9.35	$	61,485
Options vested and exercisable as of March 31, 2021		752,171		$	6.36		8.98	$	12,321

Summary of Stock Based Compensation Expense Was Allocated

Stock-based compensation expense was allocated as follows for the three months ended March 31, 2021 and 2020:

	March 31, 2021		March 31, 2020
Research and development	$	1,709	$	172
General and administrative		1,047		159
Total	$	2,756	$	331

Restricted Stock [Member]

Summary of Stock Options

The following table summarizes the Company’s restricted common stock activity for the three months ended March 31, 2021:

	Number of Awards			Weighted- Average Grant Date Fair Value		Aggregate Fair Value
Issued and unvested as of January 1, 2021		408,411			1.15		470
Restricted stock awards granted		—			—		—
Restricted stock awards vested		(104,700	)		0.86		(90	)
Issued and unvested as of March 31, 2021		303,711			1.25		380

Fair value (Tables)

3 Months Ended

Mar. 31, 2021

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 as of March 31, 2021
	Level 1		Level 2		Level 3
Assets:
Cash equivalents		200,362		-		-
U.S. Treasury bonds		13,053		-		-
	$	213,415	$	-	$	-

	Fair Value Measurements as of December 31, 2020
	Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	220,383	$	-	$	-
U.S. Treasury bonds		23,144		-		-
	$	243,527	$	-	$	-

Net loss per share (Tables)

3 Months Ended

Mar. 31, 2021

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
	March 31,
	2021			2020
Net loss	$	(27,674	)	$	(20,029	)
Weighted average common stock outstanding, basic and diluted		37,434,261			2,648,885
Net loss per share - basic and diluted	$	(0.74	)	$	(7.56	)

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
	March 31,
	2021		2020
Convertible preferred stock		-		19,201,432
Forward contract to issue redeemable convertible preferred stock		-		3,569,630
Options to purchase common stock		5,504,150		2,435,535
Unvested restricted stock		303,697		722,486
Warrants to purchase preferred stock		-		83,146
		5,807,847		26,012,229

Organization - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Nov. 05, 2020	Oct. 20, 2020	Oct. 08, 2020	Mar. 31, 2021	Dec. 31, 2020
Nature Of Operations [Line Items]
Reverse stock split			1-for-9.3197
Common Stock, Shares, Issued				38,147,205	38,120,606
Accumulated deficit				$ 202,414	$ 174,740
Unrestricted cash, Cash equivalent and short term investment				$ 213,400
Conversion Of Stock Voting Shares [Member]
Nature Of Operations [Line Items]
Temporary equity shares converted into permanent equity		19,761,870
Conversion Of Stock Non Voting Shares [Member]
Nature Of Operations [Line Items]
Temporary equity shares converted into permanent equity		3,092,338
IPO
Nature Of Operations [Line Items]
Stock issued during the period new issues shares		10,000,000
Sale of stock issue price per share		$ 15.00
Sale of stock net consideration received on the transaction		$ 135,400
Underwriting discounts and commissions		10,500
Offer expenses		$ 4,100
Over-Allotment Option [Member]
Nature Of Operations [Line Items]
Sale of stock net consideration received on the transaction	$ 16,000
Underwriting discounts and commissions	$ 1,200
Common Stock, Shares, Issued	1,150,000

Summary of significant accounting policies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2021 USD ($) Segment	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($)
Financing Sources [Line Items]
Re-measurement gain (loss)	$ 50,000	$ 45,000
Number of reportable segments \| Segment	1
Revenue from collaborations	$ 910,000
Property and equipment, net	$ 7,573,000			$ 8,007,000
Cash equivalent qualification, description	The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents.
Restricted cash	$ 556,000			560,000
Impairment of long lived assets	0	0
Other than temporary impairment losses, investments	0	0	$ 0
Royalties due	0
Expenses on milestone payments		$ 0
Dividends, common stock, cash	$ 0
Expected dividend yield	0.00%
US
Financing Sources [Line Items]
Property and equipment, net	$ 6,300,000			6,600,000
Belgium
Financing Sources [Line Items]
Property and equipment, net	1,300,000			$ 1,400,000
Product [Member]
Financing Sources [Line Items]
Revenue from collaborations	$ 0

Summary of significant accounting policies - Summary of Estimated Useful Life of Asset (Detail)	3 Months Ended
	Mar. 31, 2021
Lab Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Furniture and Office Equipment [Member] \| Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	3 years
Furniture and Office Equipment [Member] \| Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	8 years
Vehicles [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	4 years
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of asset	Shorter of the useful life or remaining lease term

Property and equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total, at cost	$ 12,557	$ 12,250
Accumulated depreciation	(4,984)	(4,243)
Total, net	7,573	8,007
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Total, at cost	5,660	5,655
Lab equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	5,145	4,833
Computer equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	978	942
Furniture and office equipment [Member]
Property Plant And Equipment [Line Items]
Total, at cost	459	459
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	$ 65

Property and equipment - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Property Plant And Equipment [Abstract]
Depreciation expense	$ 741,000	$ 331,000

Investments - Summary of Available For Sale and Held to Maturity Securities Amortized Cost Gross Unrealized Gains Losses and Fair Value (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule Of Available For Sale And Held To Maturity Securities Amortised Cost Gross Unrealised Gains Losses And Fair Value [Line Items]
Available-for-sale securities, Amortized Cost	$ 13,026
Available-for-sale securities, Gross Unrealized Gain	27
Available-for-sale securities, Estimated Fair Value	13,053
Total Held-to-maturity securities and Available for-sale securities Amortized Cost		$ 23,062
Total Held-to-maturity securities and Available for-sale securities Gross Unrealized Gain		82
Total Held-to-maturity securities and Available for-sale securities Estimated Fair Value		23,144
U.S. Treasury bonds [Member]
Schedule Of Available For Sale And Held To Maturity Securities Amortised Cost Gross Unrealised Gains Losses And Fair Value [Line Items]
Available-for-sale securities, Amortized Cost	13,026	13,060
Available-for-sale securities, Gross Unrealized Gain	27	68
Available-for-sale securities, Estimated Fair Value	$ 13,053	13,128
Held-to-maturity securities, Amortized Cost		10,002
Held-to-maturity securities, Gross Unrealized Gain		14
Held-to-maturity securities, Estimated Fair Value		$ 10,016

Investments - Summary of Debt Securities Available for Sale and Held to Maturity (Detail) $ in Thousands	Mar. 31, 2021 USD ($)
Debt Securities Available For Sale And Held To Maturity [Abstract]
Available-for-Sale, Amortized Cost, One year or less	$ 13,026
Available-for-sale, Amortized Cost, Total investments	13,026
Available-for-Sale, Estimated Fair Value, One year or less	13,053
Available-for-sale, Estimated Fair Value, Total investments	$ 13,053

Investments - Additional Information (Detail) - USD ($)	3 Months Ended
Investments - Additional Information (Detail) - USD ($)	Mar. 31, 2021	Mar. 31, 2020
Fixed-Maturity Securities [Member]
Investment In Available For Sale And Held To Maturity Securities [Line Items]
Interest income	$ 105,000	$ 468,000

Accrued liabilities - Summary of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued payables	$ 6,927	$ 7,274
Accrued compensation	3,941	8,554
Liability with early exercised stock options	528	569
Other	887	167
Total	$ 12,283	$ 16,564

Leases - Additional Information (Detail) - USD ($)	3 Months Ended
Leases - Additional Information (Detail) - USD ($)	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Lessee Lease Description [Line Items]
Operating lease, payments	$ 638,000	$ 607,000
Finance lease right of use assets	296,000		$ 296,000
Finance lease right of use assets accumulated amortization	$ 126,000		$ 107,000
Minimum [Member]
Lessee Lease Description [Line Items]
Operating and finance lease remaining lease term	4 years
Operating lease option to extend	5 years
Maximum [Member]
Lessee Lease Description [Line Items]
Operating and finance lease remaining lease term	8 years 6 months
Operating lease option to extend	8 years

Leases - Summary of Maturities of Lease Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Operating Lease
2021, remainder	$ 2,026
2022	2,799
2023	2,754
2024	2,678
2025	2,772
Thereafter	3,642
Less: imputed interest	(3,976)
Present value of lease liabilities	12,695
Less: current portion	(2,512)	$ (2,442)
Lease liabilities net of current portion	10,183	10,371
Finance Lease
2021, remainder	59
2022	78
2023	41
2024	1
Less: imputed interest	(4)
Present value of lease liabilities	175
Less: current portion	(45)	(64)
Lease liabilities net of current portion	$ 130	$ 130

Leases - Summary of Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lease Cost [Abstract]
Operating lease cost	$ 469	$ 462
Finance lease cost:
Amortization of right-of-use assets	18	17
Interest on lease liabilities	1	2
Total finance lease cost	$ 19	$ 19

Leases - Summary of Additional Information Related to the leases (Detail)	Mar. 31, 2021	Dec. 31, 2020
Schedule Of Additional Information Related To The Leases [Abstract]
Weighted-average remaining lease term (years)	5 years 9 months 29 days	5 years 11 months 19 days
Weighted-average discount rate	9.38%	9.35%
Weighted-average remaining lease term (years)	2 years 5 months 8 days	2 years 8 months 4 days
Weighted-average discount rate	3.14%	3.15%

Derivative liabilities and redeemable convertible preferred stock liability - Additional Information (Detail) - USD ($)			3 Months Ended
	Oct. 19, 2020	Dec. 23, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Aug. 16, 2018	Jun. 06, 2018	Apr. 20, 2018
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Class of warrant or right, number of securities called by warrants or rights			134,112
Percentage of principal amount of notes covered by warrants			25.00%
Warrants issued expiry period			10 years
Warrants issued closing date			Apr. 20, 2018
Changes in fair value of the warrants				$ 137,000
Derivative Financial Instruments, Liabilities [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Changes in fair value of the warrants			$ 0	$ 20,000
Derivative Financial Instruments, Liabilities [Member] \| Warrant [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Fair value of warrants upon issuance							$ 238,000	$ 700,000
Fair value of the warrants			$ 0		$ 0
Mandatorily Redeemable Preferred Stock [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Redeemable convertible preferred stock liability at a fair value		$ 3,200,000
Series A
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Warrants exercise price per share			$ 9.32
Sale of stock issue price per share						$ 9.32
Series A \| Derivative Financial Instruments, Liabilities [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Warrants exercised			0	0
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	3,569,630
Sale of stock issue price per share		$ 11.20563
Change in fair value of liability			$ 0	$ 166,000
Maximum [Member]
Derivative Liabilities And Convertible Preferred Stock Liability [Line Items]
Warrants issued closing date			Jun. 06, 2018

Capital stock - Additional Information (Detail) - USD ($)					12 Months Ended
	Oct. 19, 2020	Dec. 23, 2019	Sep. 19, 2018	Aug. 16, 2018	Dec. 31, 2019	Mar. 31, 2021	Dec. 31, 2020	Oct. 20, 2020
Number of shares of common stock authorized						320,000,000	320,000,000	320,000,000
Number of shares of preferred stock authorized							10,000,000	10,000,000
Preferred stock authorized par value								$ 0.0001
Common stock voting right		one
Preferred Stock, Conversion split				one-for-one
Preferred Stock, Shares Issued							0
Voting Common Stock [Member]
Number of shares of common stock authorized								300,000,000
Non-Voting Common Stock [Member]
Number of shares of common stock authorized								20,000,000
Series A Preferred Stock [Member]
Sale of stock issue price per share				$ 9.32
Sale of stock, consideration received on transaction			$ 20,000,000	$ 75,000,000
Series A [Member]
Conversion of convertible notes to redeemable convertible preferred stock				5,600,000
Stock issuance costs				$ 194,000
Series B Preferred Stock [Member]
Sale of stock, consideration received on transaction		$ 125,000,000
Series B One Preferred Stock [Member]
Sale of stock issue price per share		$ 10.18690
Sale of stock, consideration received on transaction		$ 85,000,000
Stock issuance costs					$ 442,000
Sale of Stock, Number of Shares Issued in Transaction		8,344,034
Series B Two Preferred Stock [Member]
Sale of stock issue price per share		$ 11.20563
Sale of Stock, Number of Shares Issued in Transaction	3,569,630	3,569,630
Cummulative stock issued						0

Stock-based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 2,756,000	$ 331,000
Share based compensation expense recognized tax benefit	$ 0	0
Shares of common stock held by employees subject to repurchase	338,358		396,522
Share price	$ 500,000		$ 600,000
Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 2,700,000	240,000
Share based payment unamortized share based payment expenses	$ 37,100,000
Share based payment expenses amortized over a weighted average period	3 years 2 months 15 days
Share based payments weighted-average grant date fair value	$ 17.33
Common stock issued upon exercise of stock options	317,456
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 90,000	$ 90,000
Share based payment unamortized share based payment expenses	$ 421,000
Share based payment expenses amortized over a weighted average period	1 year

Stock-based Compensation - Summary of Stock Options (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Stock Option [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Number of options - Beginning balance	5,488,148
Number of options, Granted	59,500
Number of options, Exercised	(26,207)
Number of options, Cancelled	(5,718)
Number of options - Ending balance	5,515,723	5,488,148
Number of options vested and expected to vest	5,460,481
Number of options vested and exercisable	752,171
Weighted average exercise price - Beginning balance	$ 11.19
Weighted average exercise price Granted	26.46
Weighted average exercise price Exercised	3.50
Weighted average exercise price Cancelled	3.01
Weighted Average Exercise Price - Ending balance	11.40	$ 11.19
Weighted average exercise price Options vested and expected to vest	11.48
Weighted average exercise price options vested and exercisable	$ 6.36
Weighted- Average Remaining Contractual Term, Outstanding	9 years 4 months 6 days	9 years 6 months 25 days
Weighted- Average Remaining Contractual Term, Options vested and expected to vest	9 years 4 months 6 days
Weighted- Average Remaining Contractual Term, Options vested and exercisable	8 years 11 months 23 days
Aggregate Intrinsic Value - Options outstanding		$ 90,335
Aggregate Intrinsic Value - Exercised	$ 92
Aggregate Intrinsic Value - Options outstanding	62,548
Aggregate Intrinsic Value, options vested and expected to vest	61,485
Aggregate Intrinsic Value, Options vested and exercisable	$ 12,321
Restricted Stock [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Number of awards - Beginning balance	408,411
Number of awards, granted	0
Number of awards, vested	(104,700)
Number of awards - Ending balance	303,711	408,411
Weighted average granted fair date value - Beginning balance	$ 1.15
Weighted average granted fair date value, vested	0.86
Weighted average granted fair date value - Ending balance	$ 1.25	$ 1.15
Aggregate intrinsic value - Beginning	$ 470
Aggregate intrinsic value, Vested	(90)
Aggregate intrinsic value - Ending balance	$ 380	$ 470

Stock-based Compensation - Summary of Stock Based Compensation Expense Was Allocated (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	$ 2,756	$ 331
Research and Development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	1,709	172
General and Administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated Share Based Compensation Expense	$ 1,047	$ 159

Fair value - Summary of Fair Value of the Financial Instruments that are Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Level 1 [Member]
Assets:
Cash equivalents	$ 200,362	$ 220,383
Fair value, assets	213,415	243,527
Level 1 [Member] \| U.S. Treasury bonds [Member]
Assets:
U.S. Treasury bonds	13,053	23,144
Level 2 [Member]
Assets:
Cash equivalents	0	0
Fair value, assets	0	0
Level 2 [Member] \| U.S. Treasury bonds [Member]
Assets:
U.S. Treasury bonds	0	0
Level 3 [Member]
Assets:
Cash equivalents	0	0
Fair value, assets	0	0
Level 3 [Member] \| U.S. Treasury bonds [Member]
Assets:
U.S. Treasury bonds	$ 0	$ 0

License and collaboration agreements - Additional Information (Detail) - USD ($)		1 Months Ended		3 Months Ended		11 Months Ended	12 Months Ended
	Jun. 25, 2020	Jun. 30, 2020	Apr. 30, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2020	Dec. 19, 2018	Aug. 16, 2018	Jun. 30, 2018
Expense related to milestone payments				$ 0
KU Leuven [Member]
Collaboration expire period	2 years 6 months
Emory license agreement [Member] \| Emory university [Member]
Non-refundable payment		$ 150,000
Long term purchase commitment additional obligation to be paid		35,000
Research plan funding amount		$ 270,000
Research plan expiry period		1 year
Long term purchase commitment period description				The research plan terminates one year from the effective date, with the Company having an option to extend for a second year.
Expense related to milestone payments				$ 80,000
Payments for royalties				0	$ 0
Expense or accruals recognized related to royalties				0	0
Emory license agreement [Member] \| Emory university [Member] \| Maximum [Member]
Aggregate payments											$ 125,000,000
Emory license agreement [Member] \| Series A \| Emory university [Member]
Debt instrument, conversion price										$ 9.32
Luxna license agreement [Member] \| Luxna biotech Co Ltd [Member]
Expense related to milestone payments				0	0
Payments for royalties				$ 0	0
Luxna license agreement [Member] \| Luxna biotech Co Ltd [Member] \| Maximum [Member]
Aggregate payments									$ 55,500,000
Katholieke Universiteit Leuven License Agreement [Member] \| Katholieke Universiteit Leuven [Member]
Non-refundable payment	$ 30,000,000
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 License Agreement [Member] \| Katholieke Universiteit Leuven [Member] \| Maximum [Member]
Non-refundable payment	$ 32,000,000
Merck License and Research Collaboration [Member] \| Merck [Member]
Revenue recognized from collaborative arrangements				$ 910,000	$ 0
Merck License and Research Collaboration [Member] \| Merck [Member] \| Maximum [Member]
Milestone payments and royalties receivable								$ 458,000,000
Research and Development [Member] \| Emory license agreement [Member] \| Emory university [Member]
Upfront license fees paid				290,000
Convertible notes issued for purchasing license				$ 600,000
Research and Development [Member] \| Luxna license agreement [Member] \| Luxna biotech Co Ltd [Member]
Upfront license fees paid						$ 600,000	$ 600,000
Non-refundable payment			$ 200,000

Commitments and contingencies - Additional Information (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Contingent liabilities	$ 0	$ 0

Net loss per share - Schedule of Earnings Per Share Basic and Diluted (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share Basic And Diluted [Abstract]
Net loss	$ (27,674)	$ (20,029)
Weighted average shares of common stock, basic and diluted	37,434,261	2,648,885
Net loss per share, basic and diluted	$ (0.74)	$ (7.56)

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

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

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669625-108580

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794

+ Details

Net loss per share - Schedule of Antidilutive Securities Excluded From Computation of Earnings Per Share (Detail) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	5,807,847	26,012,229
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		19,201,432
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
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	5,504,150	2,435,535
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	303,697	722,486
Warrants 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		83,146