Summary of significant accounting policies | 2. 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 Revenue from Contracts with Customers 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. |