Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Basis of Presentation and Use of Estimates The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and in these accompanying notes. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors and assumptions that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates, which include but are not limited to estimates of revenue, accrued research and development expenses, the valuation of common stock in connection with the issuance of stock-based awards prior to the completion of the IPO, and income taxes. Changes in estimates are recorded in the period in which they become known. Principles of Consolidation The consolidated financial statements include the accounts of Atea Pharmaceuticals, Inc. and its wholly- owned subsidiary, Atea Pharmaceuticals Securities Corporation. All intercompany amounts have been eliminated in consolidation. Revenue Recognition Through December 31, 2021, all of the Company’s revenue was collaboration revenue generated from the Roche License Agreement. Until receipt in November 2021 of the notice from Roche that Roche was terminating the Roche License Agreement effective February 2022, the Company recognized collaboration revenue over the expected performance period based on its measure of progress towards the completion of certain activities referred to as its Combined Performance Obligation. The Company concluded that the notice of termination represents a contract modification for accounting purposes. The Company further concluded that upon receipt of the notice of termination, the Combined Performance Obligation has been completely satisfied. As a result, the Company recognized all remaining deferred revenue as collaboration revenue within the consolidated statements of operations and comprehensive income for the year ended December 31, 2021 (see Note 3, Collaboration Revenue, for a detailed discussion). The Company analyzes its collaboration arrangements to assess whether they are within the scope of Accounting Standards Codification ASC Topic 808, Collaborative Arrangements (“ Research and Development Revenue from Contracts with Customers To determine the appropriate amount of revenue to be recognized for arrangements that the Company determines are within the scope of ASC 606, it performs the following steps: (i) identify the contract(s) with the customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) each performance obligation is satisfied. ASC 606 requires significant judgment and estimates and results in changes to, but not limited to: (i) the determination of the transaction price, including estimates of variable consideration, (ii) the allocation of the transaction price, including the determination of estimated selling price, and (iii) the pattern of recognition, including the application of proportional performance as a measure of progress on service-related promises and application of point-in-time recognition for supply-related promises. The transaction price is generally comprised of an upfront payment due at contract inception and variable consideration in the form of payments for the Company’s services and materials and milestone payments due upon the achievement of specified events. Other payments the Company could be entitled to include tiered royalties earned when customers recognize net sales of licensed products. The Company considers the existence of any significant financing component within its arrangements and has determined that a significant financing component does not exist in its arrangements as substantive business purposes exist to support the payment structure other than to provide a significant benefit of financing. The Company measures the transaction price based on the amount of consideration to which it expects to be entitled in exchange for transferring the promised goods and/or services to the customer. The Company utilizes either the expected value method or the most likely amount method to estimate the amount of variable consideration, depending on which method is expected to better predict the amount of consideration to which the Company will be entitled. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. With respect to arrangements that include payments for a development or regulatory milestone payment, the Company evaluates whether the associated event is considered probable of achievement and estimate the amount to be included in the transaction price using the most likely amount method. Milestone payments that are not within the Company’s control or the customer’s, such as those dependent upon receipt of regulatory approval, are not considered to be probable of achievement until the triggering event occurs. At the end of each reporting period, the Company re-evaluates the probability of achievement of each milestone and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment. For arrangements that include sales-based royalties, including milestone payments based upon the achievement of a certain level of product sales, wherein the license is deemed to be the sole or predominant item to which the payments relate, the Company recognizes revenue upon the later of: (i) when the related sales occur or (ii) when the performance obligation to which some or all of the payment has been allocated has been satisfied (or partially satisfied). Consideration that would be received for optional goods and/or services is excluded from the transaction price at contract inception. The Company generally allocates the transaction price to each performance obligation based on a relative standalone selling price basis. The Company develops assumptions that require judgment to determine the standalone selling price for each performance obligation in consideration of applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer and estimated research and development costs. However, in certain instances, the Company allocates variable consideration entirely to one or more performance obligation if the terms of the variable consideration relate to the satisfaction of the respective performance obligation and the amount allocated is consistent with the amount the Company would expect to receive for the satisfaction of the respective performance obligation. The Company recognizes revenue based on the amount of the transaction price that is allocated to each respective performance obligation when or as the performance obligation is satisfied by transferring a promised good or service to the customer. For performance obligations that are satisfied at a point in time, the Company recognizes revenue when control of the goods and/or services is transferred to the customer. For performance obligations that are satisfied over time, the Company recognizes revenue by measuring the progress toward complete satisfaction of the performance obligation using a single method of measuring progress which depicts the performance in transferring control of the associated goods and/or services to the customer. The Company generally uses input methods to measure the progress toward the complete satisfaction of performance obligations satisfied over time. With respect to arrangements containing a license to its intellectual property that is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from amounts allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. Significant management judgment is required in determining the level of effort required under an arrangement and the period over which the Company is expected to complete its performance obligations under an arrangement. The Company evaluate s the measure of progress each reporting period and, if necessary, adjust s the measure of performance and related revenue recognition. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment. Contract costs The Company recognizes as an asset the incremental costs of obtaining a contract with a customer if the costs are expected to be recovered. The Company has elected the practical expedient in ASC 340, Other Assets and Deferred Costs Cash and Cash Equivalents The Company considers all highly-liquid investments purchased with maturities of 90 days or less at acquisition to be cash equivalents. Cash and cash equivalents include bank demand deposits and money market funds that invest in U.S. government and U.S. government agency obligations. Cash equivalents are reported at fair value. Concentrations of Credit Risk and Significant Suppliers Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash and cash equivalents. The Company maintains its cash and cash equivalents with a financial institution that management believes is creditworthy. The Company’s investment policy includes guidelines on the quality of the financial institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs. Fair Value Measurements Assets and liabilities recorded at fair value on a recurring basis in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability 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. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2—Observable inputs (other than quoted prices included in Level 1) that are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determination of fair value of the assets or liabilities. Cash, cash equivalents and restricted cash are Level 1 assets which are comprised of funds held in checking and money market accounts. Cash, cash equivalents and restricted cash were recorded at fair value as disclosed in Note 4 . The carrying amounts of accounts payable , accrued expenses and unbilled other receivables approximate their fair values due to their short-term maturities. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation and amortization. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the asset. The Company estimates the useful life of its assets as follows: Asset Estimated useful life Laboratory equipment Five years Office furniture and fixtures Five years Computer hardware Two years Leasehold improvements Shorter of useful life or remaining lease term Maintenance and repairs that do not improve or extend the life of the respective asset are expensed to operations as incurred. Upon disposal of an asset, the related cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the consolidated statements of operations. Other Assets Other assets consist of a right-of-use asset of $161 and bank deposits of $305, classified as restricted cash, to collateralize two letters of credit. Impairment of Long-lived Assets The Company reviews long-lived assets when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparing the book value of the assets to the estimated undiscounted future net cash flows that the asset is expected to generate. If the estimated undiscounted future net cash flows are less than the book value, the asset is impaired, and the impairment loss to be recognized in income is measured as the amount by which the book value of the asset exceeds its fair value, which is measured based on the estimated discounted future net cash flows that the asset is expected to generate. No impairment losses were recorded during the years ended December 31, 2021, 2020 and 2019. Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses consist principally of costs associated with outsourced research and development activities, including preclinical and clinical development, manufacturing and research conducted by contract research organizations and academic institutions, employee compensation, including stock-based compensation and consulting expenses together with related expenses, professional fees and facility and overhead costs. Facility and overhead costs primarily include the allocation of rent, utility and office-related expenses attributable to research and development personnel. In circumstances where amounts have been paid in advance or in excess of costs incurred, the Company records a prepaid expense, which is expensed as services are performed or goods are delivered. The Company has entered into various research and development contracts with third parties. These agreements are generally cancelable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase of completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. Patent Costs Costs to secure and maintain the Company’s patents are expensed as incurred and are classified as general and administrative expenses in the Company’s consolidated statements of operations. Stock-based Compensation Stock-based compensation expense is classified in the consolidated statement of operations in the same manner in which the award recipient’s payroll costs or service payments are classified. Stock-based awards granted to employees and non-employees are measured based on the estimated fair value of the awards using the Black-Scholes option pricing model (“Black-Scholes”). Stock-based compensation expense with respect to awards with service conditions is recognized using the straight-line method over the service period. Stock-based compensation with respect to awards with performance conditions is recognized when satisfaction of the performance conditions is probable. Stock-based compensation is based on awards ultimately expected to vest and, as such, it is reduced by forfeitures. The Company accounts for forfeitures as they occur. Black-Scholes requires the use of subjective assumptions which determine the fair value of stock-based awards. These assumptions include: Fair value of common stock Prior to the IPO, because there was no public market for the Company’s common stock, the fair value of the Company’s common stock underlying stock-based awards was estimated on each grant date by the board of directors. The Company developed an estimate on each grant date of the fair value of its common stock based on valuations from an independent third-party valuation firm using information known to the Company on the date of grant and a review of any recent events and their potential impact on the estimated fair value per share of the common stock. The third-party valuations of the Company’s common stock were determined in accordance with the guidelines outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation, or the Practice Aid. The assumptions used to determine the estimated fair value of the Company’s common stock were based on numerous objective and subjective factors, combined with management judgment, including: • external market conditions affecting the pharmaceutical and biotechnology industry and trends within the industry; • the Company’s stage of development and business strategy; • the rights, preferences and privileges of the Company’s then-outstanding redeemable convertible preferred stock relative to those of its common stock; • the prices at which the Company sold shares of its then-outstanding redeemable convertible preferred stock; • the Company’s financial condition and operating results, including its levels of available capital resources; • the progress of the Company’s research and development efforts; • equity market conditions affecting comparable public companies; and • general U.S. market conditions and the lack of marketability at the time of the Company’s common stock. The Practice Aid identifies various available methods for allocating enterprise value across classes and series of capital stock to determine the estimated fair value of common stock at each valuation date. In accordance with the Practice Aid, the Company considered the following methods: • Option Pricing Method . Under the option pricing method (“OPM”), shares are valued by creating a series of call options with exercise prices based on the liquidation preferences and conversion terms of each equity class. The estimated fair values of the then-outstanding preferred stock and common stock were inferred by analyzing these options. • Probability -Weighted Expected Return Method. The probability-weighted expected return method (“ PWERM ”) , is a scenario-based analysis that estimates value per share based on the probability-weighted present value of expected future investment returns, considering each of the possible outcomes available to the Company , as well as the economic and control rights of each share class. Based on the Company’s early stage of development and other relevant factors, the Company determined that OPM method as well as a hybrid approach of the OPM and the PWERM methods were the most appropriate methods for allocating its enterprise value to determine the estimated fair value of its common stock. In determining the estimated fair value of the Company’s common stock, its board of directors also considered the fact that its stockholders could not freely trade its common stock in the public markets. Accordingly, the Company applied discounts to reflect the lack of marketability of its common stock based on the weighted-average expected time to liquidity. The estimated fair value of the Company’s common stock at each grant date reflected a non-marketability discount partially based on the anticipated likelihood and timing of a future liquidity event. Upon the completion of the Company’s initial public offering, the fair value of its common stock is based on the daily closing quoted market price of its common stock. Risk-free interest rate —The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of a stock-based award. Expected term —The expected term represents the period that stock-based awards are expected to be outstanding. Given the Company’s lack of specific history, the expected term for option grants is determined using the simplified method. The simplified method deems the term to be the average of the time-to-vesting and the contractual life of the stock-based awards. Expected volatility —Since the Company was privately held through October 29, 2020 and did not have any trading history for its common stock, the expected volatility was estimated based on the average volatility for comparable publicly traded biotechnology companies over a period equal to the expected term of the stock-based awards. The comparable companies were chosen based on their similar size, stage in the life cycle or area of specialty. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Expected dividend yield —The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero. The Company also accounts for any modifications to share based payments in accordance with ASC Topic 718, Compensation – Stock Compensation Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax base. Deferred tax assets are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities. Valuation allowances are established to reduce deferred tax assets where, based upon the available evidence, the Company concludes that it is more-likely-than-not that the deferred tax assets will not be realized. In evaluating its ability to recover deferred tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income. Reserves are provided for tax benefits for which realization is uncertain. Such benefits are only recognized when the underlying tax position is considered more-likely-than-not to be sustained on examination by a taxing authority. Interest and penalties related to uncertain tax positions are recognized in the provision of income taxes. Comprehensive Income (Loss) Comprehensive income (loss) includes net income (loss) as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with equity holders. The Company did not have any items of comprehensive income or loss other than net income (loss) for the years ended December 31, 2021, 2020 and 2019. Net Income (Loss) Per Share Attributable to Common Stockholders Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted net income per share attributable to common stockholders is computed by dividing the diluted net income attributable to common stockholders by the weighted average number of common shares outstanding for the period, including potential dilutive common shares assuming the dilutive effect of outstanding stock options. Prior to the Company’s IPO, basic and diluted net loss per share attributable to common stockholders was determined using the two-class method, which is required for participating securities. The Company considered its convertible preferred stock to be participating securities as, in the event a dividend is paid on common stock, the holders of convertible preferred stock would be entitled to receive dividends on a basis consistent with the common stockholders. Under the two-class method, the net loss attributable to common stockholders is not allocated to the convertible preferred stock as the holders of the convertible preferred stock do not have a contractual obligation to share in losses. Under the two-class method, basic 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 shares of common stock. Due to net losses for the years ended December 31, 2020 and 2019, basic and diluted net loss per share attributable to common stockholders were the same, as the effect of all potentially dilutive securities would have been anti-dilutive . In-process Research and Development Assets In-process research and development assets that are acquired in a transaction that does not qualify as a business combination under GAAP and that do not have an alternative future use are expensed in the period in which the assets are acquired. Segments Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the chief operating decision maker (the “CODM”), in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is its chief executive officer, who manages and allocates resources to the operations on a total company basis. Accordingly, there is a single SEC Filing Status Based on its public float as of June 30, 2021, the Company became a large accelerated filer, and lost emerging growth company status, as of December 31, 2021. As of December 31, 2021, the Company is required to adopt new or revised accounting standards when they are applicable to public companies that are not emerging growth companies and is required to comply with the auditor attestation requirements Section 404(b) of the Sarbanes-Oxley Act. Recently Issued Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standard Board (“FASB”) or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise disclosed below, the Company does not believe that the adoption of recently issued standards have or may have a material impact on its consolidated financial statements and disclosures. Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02” or “ASC 842”) beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. In July 2018, an amendment was made that allows companies the option of using the effective date of the new standard as the initial application date (at the beginning of the period in which the new standard is adopted, rather than at the beginning of the earliest comparative period). This update includes a short-term lease exception for leases with a term of 12 months or less, in which a lessee can make an accounting policy election not to recognize the associated lease assets and lease liabilities on its balance sheet. Additionally, in March 2019, the FASB issued ASU 2019-01 (“ASU No. 2019-01”). ASU No. 2019-01 clarifies the transition guidance related to interim disclosures provided in the year of adoption. Lessees will continue to differentiate between finance leases (previously referred to as capital leases) and operating leases, using classification criteria that are substantially similar to the previous guidance. For lessees, the recognition, measurement, and presentation of expenses and cash flows arising from a lease did not significantly change from previous U.S. GAAP. The modified retrospective method includes several optional practical expedients that entities may elect to apply, as well as transition guidance specific to nonstandard leasing transactions. The Company adopted the new standard effective January 1, 2021 using the modified retrospective method as of the beginning of the period of the adoption. The Company has elected the package of practical expedients permitted in ASC Topic 842. Accordingly, the Company accounted for its existing operating lease as an operating lease under the new guidance, without reassessing (a) whether the contracts contain a lease under ASC Topic 842, (b) whether classification of the operating leases would be different in accordance with ASC Topic 842, or (c) whether the unamortized initial direct costs would have met the definition of initial direct costs in ASC Topic 842 at lease commencement. The adoption of this standard resulted in the recording of operating lease liabilities and right-of-use assets on the Company’s consolidated balance sheet (see Note 7). The adoption of the standard did not have a material effect on the Company’s consolidated statements of operations and comprehensive income (loss), consolidated statements of cash flows or consolidated statements of convertible preferred stock and stockholders’ equity (deficit). In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception (“ASU 2017-11”) . The adoption of this standard did not have a material impact on the Company’s consolidated financial position and results of operations. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Statements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes The Company adopted the standard effective January 1, 2021. The adoption of the standard did not have a material effect on the Company’s consolidated balance sheets, consolidated statements of operations and comprehensive income (loss), consolidated statements of cash flows or consolidated statement of stockholders’ equity (deficit). |