Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the valuation of stock-based awards and the accrual of research and development expenses. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates as there are changes in circumstances, facts and experience. Actual results may differ from those estimates or assumptions. Unaudited interim financial information The consolidated balance sheet at December 31, 2022, was derived from audited consolidated financial statements but does not include all disclosures required by GAAP. The accompanying unaudited consolidated financial statements as of March 31, 2023, and for the three months ended March 31, 2023 and 2022, have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in the consolidated financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2022, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, on file with the SEC. In the opinion of management, these consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the Company’s financial position as of March 31, 2023, and results of operations for the three months ended March 31, 2023 and 2022, and cash flows for the three months ended March 31, 2023 and 2022. The Company’s results of operations for the three months ended March 31, 2023, are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2023. Concentrations of credit risk and of significant suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company’s investments are comprised of commercial paper and corporate bonds of corporations and U.S. Treasury and U.S. government agency debt securities. As of March 31, 2023 and December 31, 2022, the Company maintained cash, cash equivalents and marketable securities balances in excess of federally insured limits. However, the Company mitigates credit risk by maintaining a diversified portfolio, placing its cash with high credit quality financial institutions and limiting the amount of investment exposure as to institution, maturity and investment type. The Company is dependent on third-party vendors for the manufacturing of its product candidates. In particular, the Company relies, and expects to continue to rely, on a small number of vendors to manufacture materials and components required for the production of its product candidates. These programs could be adversely affected by a significant interruption in the manufacturing process. Fair value measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—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 and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above (see Note 4). The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities. Marketable securities The Company’s marketable securities (non-equity instruments) are classified as available-for-sale and are carried at fair value, with the unrealized gains and losses reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses are based on the specific identification method and are included as a component of other income (expense), net in the consolidated statements of operations and comprehensive loss. The Company classifies its marketable securities with maturities beyond one year as short-term, based on their highly liquid nature and because such marketable securities are available for current operations. Effective January 1, 2023, when the fair value is below the amortized cost of a marketable security, an estimate of expected credit losses is made. The credit-related impairment amount is recognized in the consolidated statements of operations and comprehensive loss. Credit losses are recognized through the use of an allowance for credit losses account in the consolidated balance sheet and subsequent improvements in expected credit losses are recognized as a reversal of an amount in the allowance account. If the Company intends to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis, then the allowance for the credit loss is written-off and the excess of the amortized cost basis of the asset over its fair value is recorded in the consolidated statements of operations and comprehensive loss. There were no credit losses recorded during the three months ended March 31, 2023. Net income (loss) per share Basic net income (loss) per common share is computed by dividing the net income (loss) by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) per common share is computed by dividing net income (loss) 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 and unvested restricted stock units. For periods in which the Company reported a net loss, diluted net loss per common share is the same as basic net loss per common share, since dilutive common shares are not assumed to have been issued if their affect is anti-dilutive. The Company has two classes of common stock outstanding: Class A common stock and Class B common stock. The rights of the holders of Class A and Class B common stock are substantially identical, except with respect to voting and conversion. Each share of Class B common stock is convertible into one share of Class A common stock at the option of the holder at any time, subject to the ownership limitations provided for in the Company’s amended and restated certificate of incorporation. The Company allocates undistributed earnings attributable to common stock between the common stock classes on a one-to-one basis when computing net income (loss) per share. As a result, basic and diluted net income (loss) per share of Class A common stock and share of Class B common stock are equivalent. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: As of March 31, 2023 2022 Unvested restricted common stock — 21,129 Options to purchase common stock 8,505,182 6,250,433 8,505,182 6,271,562 Recently adopted accounting pronouncements Effective January 1, 2023 , the Company adopted ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments for the year ended December 31, 2023. The new standard adjusts the accounting for assets held at amortized cost basis, including marketable securities accounted for as available for sale, and trade receivables. The standard eliminates the probable initial recognition threshold and requires an entity to reflect its current estimate of all expected credit losses. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net amount expected to be collected. The adoption of this standard did no t have a material impact on the Company’s consolidated financial statements and related disclosures. |