Summary of significant accounting policies

9 Months Ended

Sep. 30, 2022

Accounting Policies [Abstract]

Summary of significant accounting policies

2. Summary of significant accounting policies

Unaudited interim financial statements

The accompanying unaudited condensed consolidated financial statements have been prepared by the Company in accordance with GAAP for interim financial reporting and as required by Regulation S-X, Rule 10-01. The unaudited condensed consolidated financial statements have been prepared on the same basis as the Company’s audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the Company’s condensed consolidated balance sheet as of September 30, 2022, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021, the condensed consolidated statement of stockholders’ equity (deficit) as of September 30, 2022 and the condensed consolidated statements of cash flows for the nine months ended September 30, 2022. The financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2022 and 2021 are unaudited. The results for the three and nine months ended September 30, 2022 are not necessarily indicative of results to be expected for the year ending December 31, 2022, any other interim periods, or any future year or period.

Use of estimates

The preparation of the Company's condensed consolidated 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 condensed consolidated financial statements, and the reported amounts of expenses during the reporting period. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, the recognition of research and development expenses, stock-based compensation expense, warrant liabilities and the valuation allowance for deferred tax assets. 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 when there are changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates.

Cash and cash equivalents

The Company considers all highly liquid investments with original maturities of three months or less at the time of purchase to be cash equivalents. Cash equivalents consist primarily of amounts invested in money market accounts.

Short-term marketable securities

The Company invests in short-term marketable securities, primarily money market funds, commercial paper, U.S. treasury securities and corporate debt securities. The Company continually evaluates the credit ratings of its investment portfolio and underlying securities. The Company invests in accordance with its investment policy and invests at the date of purchase in securities with high ratings from top rating agencies. The Company classifies its short-term marketable securities as available-for-sale securities and reports them at fair value in short-term marketable securities on the condensed consolidated balance sheets with related unrealized gains and losses included within accumulated other comprehensive gain (loss) on the condensed consolidated balance sheets. The amortized cost of marketable securities is adjusted for amortization of premiums and accretion of discounts to maturity, which is included in other income on the condensed consolidated statements of operations and comprehensive loss. When the fair value is below the amortized cost of a marketable security, the Company reviews and determines whether the impairment is due to credit-related factors or noncredit-related factors. The credit-related impairment amount is recognized in other income on the condensed consolidated statements of operations and comprehensive loss, with a corresponding allowance for credit losses account in the condensed consolidated balance sheet. Subsequent improvements in expected credit losses are recognized as a reversal of an amount in the allowance account. If the Company has the intent 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 condensed consolidated statements of operations. There were no credit losses recorded during the periods ended September 30, 2022 and December 31, 2021.

Restricted cash

As of September 30, 2022 and December 31, 2021, the Company was required to maintain a separate cash balance of $108 for the benefit of the landlord in connection with the Company’s Gateway office space lease in South San Francisco, California (the “Gateway Lease”), which is classified within other assets (non-current) on the condensed consolidated balance sheets (see Note 12).

Concentrations of credit risk

Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents and short-term marketable securities. Periodically, the Company maintains deposits in accredited financial institutions in excess of federally insured limits. The Company deposits its cash investments in financial institutions that it believes have high credit quality and has not experienced any losses on such accounts and does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships. At September 30, 2022 and December 31, 2021, all of the Company's cash, cash equivalents and short-term investments were held at one accredited financial institution.

Leases

The Company determines whether an arrangement is or contains a lease at inception by assessing whether the arrangement contains an identified asset and whether the Company has the right to control the identified asset. Right-of-use, or ROU, assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Lease liabilities are recognized at the lease commencement date based on the present value of future lease payments over the lease term. ROU assets are based on the measurement of the lease liability and are further adjusted by any lease payments made prior to or on lease commencement, lease incentives received and initial direct costs incurred, as applicable. The Company has elected to not recognize leases with a lease term of one year or less on its balance sheet. Operating lease costs included in the measurement of the lease are recognized on a straight-line basis over the lease term. Variable lease costs are expensed as incurred as an operating expense.

The Company determines the lease classification and the present value of future lease payments at the time of the lease commencement using an incremental borrowing rate that it estimates based upon the Company’s credit risk and term of the lease. The interest rate implicit in lease contracts has not historically been readily determinable and the Company must therefore use the appropriate incremental borrowing rate to measure its leases. To estimate the incremental borrowing rate, a credit rating applicable to the Company is estimated using a synthetic credit rating analysis since the Company does not currently have a rating agency-based credit rating.

Research and development costs

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred to discover, research and develop drug candidates, including personnel expenses, stock-based compensation expense, third-party license fees and external costs including fees paid to consultants, contract manufacturing organizations, or CMOs, and clinical research organizations, or CROs, in connection with drug product manufacturing, nonclinical studies and clinical trials, and other related clinical trial fees, such as for investigator grants, patient screening, laboratory work, clinical trial database management, clinical trial material management and statistical compilation and analysis. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are recorded as prepaid expenses. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered or the services rendered.

Foreign currency transaction gains and losses related to the purchase of contract manufacturing services are included as a component of research and development expense. The Company recorded net foreign currency transaction losses of $1,273 and $1,214 within research and development expense during the three and nine months ended September 30, 2022, respectively.

Costs incurred in obtaining technology licenses are charged immediately to research and development expense if the technology licensed has not reached technological feasibility and has no alternative future uses.

Research contract costs and accruals

The Company has entered into various research and development and other agreements with commercial firms, researchers and others for provisions of goods and services. These agreements are generally cancelable, and the related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or clinical trials, including the phase or 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 materially from the Company's estimates.

Stock-based compensation

The Company measures all stock-based awards granted to employees and nonemployees based on the fair value on the date of the grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award, on a straight-line basis. The Company recognizes stock-based compensation expense for awards that contain performance-based conditions using the accelerated attribution method when management determines it is probable that the performance condition will be satisfied. The Company accounts for forfeitures as they occur.

The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of

the option, and the Company's expected dividend yield. The Company went public in June 2019 and accordingly, lacks sufficient company-specific historical and implied volatility information for its shares traded in the public markets. Therefore, it estimates its expected share price volatility based on the historical volatility of publicly traded peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded share 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. Expected dividend yield is based on the fact that the Company has never paid cash dividends on common stock and does not expect to pay any cash dividends in the foreseeable future. The fair value of each common stock award is estimated on the date of grant based on the fair value of the Company's common stock on that same date.

Compensation expense for purchases under the Employee Stock Purchase Plan is recognized based on the fair value of the common stock estimated based on the closing price of our common stock as reported on the date of offering, less the purchase discount percentage provided for in the plan.

The Company classifies stock-based compensation expense in its condensed consolidated statement of operations and comprehensive loss in the same manner in which the award recipient's payroll costs are classified or in which the award recipient's service payments are classified.

Loan Payable

The Company initially reviews loan payables to identify the units of account for recognition purposes. The Company identifies the units of account by identifying each freestanding financial instrument included in the debt arrangement. For freestanding equity-linked financial instruments that are not in the form of shares, liability classification is used if the instrument embodies an obligation to repurchase the Company’s shares that may require the use of cash or other assets or the instrument may require the issuance of a variable number of the Company’s shares with a monetary value that is predominately based on a fixed value, based on variations in variables other than the fair value of the Company’s stock, or based on variations inversely related to the fair value of the Company’s stock. The Company will then review for embedded features within the debt instrument to evaluate whether the embedded features require bifurcation from the debt host instrument. Embedded features typically include conversion or exchange features, redemption features, or other embedded features. The identified embedded feature is bifurcated from the debt host instrument if the criteria in ASC 815-15-25-1 are met. Debt arrangements are classified on the consolidated balance sheet as current if the obligation of the debt arrangement is reasonably expected to be liquidated within 12 months. Loan payable is recorded net of debt discount which comprises issuance costs, customary closing and end of term charge or final fees, and the fair value of additional warrants issued in conjunction with the loan payable. Debt discount is amortized over the term of the loan payable using the effective interest method, and is recorded to interest expense on the consolidated statements of operations (see Note 6).

Warrant Liabilities

The Company accounts for warrants anticipated to be issued in the future under the Loan Agreement as liabilities and measures them at fair value using the Black-Scholes valuation model. The warrants are subject to remeasurement at each prospective balance sheet date, with any changes in the fair value recorded in the consolidated statements of operations.

Comprehensive loss

Comprehensive loss includes net loss as well as other changes in stockholders' equity (deficit) that result from transactions and economic events other than those with stockholders. The Company’s comprehensive loss is comprised of net loss and changes in unrealized gains and losses on its short-term marketable securities.

Recently adopted accounting pronouncements

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) ("ASU 2016-13"), which introduced a new methodology for accounting for credit losses on financial instruments, including available-for-sale debt securities. The Company adopted ASU 2016-03 as of January 1, 2021. For available-for-sale debt securities with unrealized losses, those losses are recognized as allowances rather than reductions in the amortized cost of the underlying security. The adoption of ASU 2016-03 did not have a material impact on the Company's condensed consolidated financial statements.

In August 2020, the FASB issued ASU No. 2020-06, “Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging— Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity”, or ASU 2020-06. ASU 2020-06 simplifies the accounting for convertible instruments by eliminating the requirement to separate embedded conversion features from the host contract when the conversion features are not required to be accounted for as derivatives under Topic 815, Derivatives and Hedging, or that do not result in substantial premiums accounted for as paid-in capital. The Company adopted ASU 2020-06 on January 1, 2022, on a modified retrospective basis. The adoption of ASU 2020-06 did not have a material impact on the Company's condensed consolidated financial statements.