The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP, and stated in U.S. dollars. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification, or ASC, and Accounting Standards Updates, or ASUs, of the Financial Accounting Standards Board, or FASB.

The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and reported amounts of expenses during the reporting periods. Actual results could differ from those estimates. On an ongoing basis, the Company evaluates its estimates, including those related to accrued research and development expenses, contingent

milestone payments, other long-lived assets, stock-based compensation, and the valuation of deferred tax assets. The Company bases its estimates using historical experience, Company forecasts and future plans, current economic conditions, and information from third-party professionals that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities and recorded amounts of expenses that are not readily apparent from other sources, and adjusts those estimates and assumptions when facts and circumstances dictate.

The Company’s results can also be affected by economic, political, legislative, regulatory and legal actions. Economic conditions, such as recessionary trends, inflation, interest, changes in regulatory laws and monetary exchange rates, and government fiscal policies, can have a significant effect on operations. While the Company maintains reserves for anticipated liabilities, the Company could be adversely affected by civil, criminal, regulatory or administrative actions, claims, or related proceedings.

The Company considers all highly liquid investments with original maturities at the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents are stated at fair value and may include money market funds, corporate debt securities and commercial paper. The Company’s cash equivalents consist of money market fund investments, corporate debt securities, and commercial paper.

The Company invests its excess cash balances in marketable government agency bonds, corporate debt securities and commercial paper. The Company classifies its investments as available-for-sale, reports available-for-sale investments at their fair value at each balance sheet date, and includes any unrealized holding gains and losses (the adjustment to fair value) in accumulated other comprehensive loss, a component of stockholders’ equity. Should there be any realized gains or losses, they will be determined using the specific-identification method and included as other income or expense in the statements of operations.

The Company periodically evaluates whether declines in fair values of its marketable securities below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the marketable security until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or it is more likely than not it will be required to sell any marketable securities before recovery of its amortized cost basis. Impairment assessments are made at the individual security level each reporting period. When the fair value of an available-for-sale security is less than its cost at the balance sheet date, a determination is made as to whether the impairment is other-than-temporary and, if it is other-than-temporary, an impairment loss is recognized in the statements of operations, equal to the difference between the investment’s amortized cost and fair value at such date. The Company did not record any impairment charges related to its marketable securities during the years ended December 31, 2021 and 2020.

The Company classifies its available-for-sale marketable securities as non-current if such instrument’s underlying effective maturity date exceeds 12 months and for which the Company has the intent and ability to hold the investment for a period of greater than 12 months. The Company’s marketable securities at December 31, 2021 and 2020 mature in less than 12 months and are included in short-term investments in the balance sheets.

Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash and cash equivalents and available-for-sale marketable securities. The Company’s investment policy includes guidelines regarding 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 may invest in money market funds, U.S. Treasury securities, corporate debt, U.S. government-related agency securities, commercial paper and certificates of deposit. At December 31, 2021 and 2020, the Company’s cash and cash equivalents were held in financial institutions that management believes are creditworthy. These deposits may exceed federally insured limits. The Company has not experienced any losses historically in these accounts and believes it is not exposed to significant credit risk in its cash and cash equivalents. The Company has no significant off-balance sheet concentrations of credit risk, such as foreign currency exchange contracts, option contracts, or other hedging arrangements.

Property and equipment are stated at cost, subject to adjustments for impairments, less accumulated depreciation and amortization. Depreciation is calculated using the straight-line method over the useful lives of the assets as follows:

Asset		Estimated useful life
Manufacturing and laboratory equipment		Three to five years
Computer hardware		Three to five years
Office furniture and equipment		Three to five years

Leasehold improvements are amortized over the shorter of their useful lives or the related lease term. Maintenance and repairs that do not improve or extend the life of the respective asset are expensed to operations as incurred. Manufacturing and laboratory equipment received is classified as construction in progress until placed into service, at which time depreciation commences. 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 results of operations.

The Company evaluates whether current facts or circumstances indicate that the carrying values of its long-lived assets may not be recoverable. If such facts or circumstances are determined to exist, an estimate of the sum of the undiscounted future cash flows of these assets is compared to the carrying value the assets to determine whether impairment exists. If the assets are determined to be impaired, the loss is measured based on the difference between the sum of the undiscounted future cash flows and the carrying value of the assets. No impairment losses were recorded during the years ended December 31, 2021 or 2020.

Research and development costs are expensed as incurred. The Company’s research and development expenses consist primarily of costs incurred for the development of its product candidates and include expenses incurred under agreements with contract manufacturing organizations, or CMOs, contract research organizations, or CROs, investigative sites and consultants to conduct clinical trials and preclinical and non-clinical studies, costs to acquire, develop and manufacture supplies for clinical trials and other studies, salaries and related costs, including stock-based compensation, depreciation and other allocated facility-related and overhead expenses.

The Company records accruals for estimated costs of preclinical and clinical studies and manufacturing development. The Company’s clinical and manufacturing development activities are conducted by third-party service providers, including CROs and CMOs. The financial terms of these contracts are subject to negotiation, which vary by contract and may result in payments that do not match the periods over which materials or services are provided. The Company accrues the costs incurred under the agreements based on an estimate of actual work completed in accordance with the agreements. In the event the Company makes advance payments for goods or services that will be used or rendered for future research and development activities, the payments are deferred and capitalized as a prepaid expense and recognized as expense as the goods are received or the related services are rendered. Such payments are evaluated for current or non-current classification based on when they are expected to be realized. If the Company does not identify costs that have begun to be incurred or if the Company underestimates or overestimates the level of services performed or the costs of these services, actual expenses could differ from the Company’s estimates. To date, the Company has not experienced significant changes in its estimates of preclinical studies, clinical trial and manufacturing accruals.

Costs to secure and maintain patents covering the Company’s technology and product candidates are expensed as incurred and are classified as general and administrative expenses in the statements of operations.

The Company classified convertible preferred stock outside of stockholders’ equity (deficit) on its balance sheet as of December 31, 2019, as the requirements of triggering a deemed liquidation event were not within the Company’s control. In the event of a deemed liquidation event, the proceeds from the event would have been distributed in accordance with liquidation preferences of such securities.

The Company would have adjusted the carrying value of the convertible preferred stock to their redemption values when it became probable a redemption event would occur. Prior to the completion of the IPO on September 24, 2020, all of the outstanding shares of convertible preferred stock automatically converted into 13,085,913 shares of common stock. Subsequent to the closing of the IPO on September 29, 2020, there were no shares of convertible preferred stock outstanding.

The Company’s Series C convertible preferred stock included features the Company determined were not clearly and closely related to the equity host. These features were therefore bifurcated and accounted for separately as a freestanding derivative liability on the balance sheet at its estimated fair value. This derivative liability was a result of certain investors’ rights to purchase from the Company, on the same terms as the Series C Preferred Stock Purchase Agreement executed in July 2019, additional shares of Series C convertible preferred stock in subsequent tranches based on the achievement of certain development milestones, or the Preferred Stock Tranche Obligation. At initial recognition, the Company recorded this derivative as a liability on the balance sheet at its estimated fair value. The derivative was subject to remeasurement at each balance sheet date until its expiration in September 2020, with changes in fair value recognized in change in fair value of Preferred Stock Tranche Obligation on the Company’s statements of operations.

Stock-based compensation expense related to stock options and warrants granted to employees, directors and non-employees is recognized based on the grant-date estimated fair values of the awards using the Black-Scholes option pricing model, or Black-Scholes. The valuation of restricted stock units, or RSUs, is determined at the date of grant using the Company’s closing stock price. The value is recognized as expense ratably over the requisite service period, which is generally the vesting term of the award. The Company adjusts the expense for actual forfeitures as they occur.

The Company uses the liability method to account for income taxes. Under this method, deferred tax assets and liabilities are determined based on temporary differences between the financial statement carrying amounts of existing assets and liabilities and their tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized.

The Company assesses the likelihood of deferred tax assets being realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. For the Company, the ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which the temporary differences representing net future deductible amounts become deductible. Based on the Company’s operations to date and the uncertainty as to the timing and amount of future taxable income, the Company has recorded a full valuation allowance in all periods and for all jurisdictions.

Financial statement effects of uncertain tax positions are recognized when it is more likely than not, based on the technical merits of the position, that it will be sustained upon examination. The Company evaluates uncertain tax positions on a regular basis. The evaluations are based on a number of factors, including changes in facts and circumstances, changes in tax law, correspondence with tax authorities during the course of an audit, and effective settlement of audit issues. Interest and penalties related to unrecognized tax benefits would be included within the income tax provision.

The Company calculates basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for participating securities. While it was outstanding, the Company considered its convertible preferred stock to be participating securities as, in the event a dividend was paid on common stock, the holders of convertible preferred stock and unvested shares of common stock would have been entitled to receive dividends on a basis consistent with the common stockholders. The net loss attributable to common stockholders was not allocated to the convertible preferred stock as the holders of those securities did not have a contractual obligation to share in losses. Cumulative dividends on preferred stock were added to net loss to arrive at net loss available to common stockholders.

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 common shares outstanding during the period, without consideration of potential dilutive securities. Diluted net loss per share is calculated by dividing net loss by the weighted-average number of shares of common stock and potential dilutive common stock equivalents outstanding during the period if the effect is dilutive. Potentially dilutive securities include warrants, stock options, RSUs and convertible preferred stock. Likewise, adjustments to the denominator are required to reflect the related dilutive shares. In all periods presented, the Company’s outstanding stock options, RSUs, convertible preferred stock, common stock warrants, and the potential issuance of additional preferred shares from the Preferred Stock Tranche Obligation were excluded from the calculation of diluted net loss per share because their effects were antidilutive and the

development milestones for the issuance of additional shares from the Preferred Stock Tranche Obligation were not achieved prior to its expiration in September 2020.

In August 2019, the Company engaged a consulting firm managed by the then acting chief financial officer of the Company for professional services related to finance and other administrative functions. For the year ended December 31, 2020, the costs incurred under this arrangement totaled $657,000 and were recorded as general and administrative expense in the accompanying statement of operations. The Company terminated its relationship with this entity in September 2020.

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, or CODM, in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is its chief executive officer. The Company has determined it operates in one segment.

Comprehensive loss is defined as the change in equity of a business enterprise during a period arising from transactions and other events and circumstances from non-owner sources. The Company’s comprehensive loss is comprised of changes in unrealized (loss) gain on available-for-sale securities.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), as amended, with guidance regarding the accounting for and disclosure of leases. The update requires lessees to recognize the liabilities related to all leases, including operating leases, with a term greater than 12 months on the balance sheet. This update also requires lessees and lessors to disclose key information about their leasing transactions. As an emerging growth company, this standard is effective for the Company for fiscal years beginning after December 15, 2021, and interim periods within annual periods beginning after December 15, 2022. Early adoption is permitted. The Company adopted this standard on January 1, 2022 and has performed an analysis on the impact of this standard and does not expect that this standard will have a material impact on its results of operations or cash flows, but that it will have a material impact on the Company’s assets and liabilities as a result of the recognition of right-of-use asset and lease liabilities. The Company also expects to elect the “package of practical expedients”, which permits the Company to not reassess under this standard its prior conclusions about lease identification, lease classification and initial direct costs. In addition, the Company expects to elect the short-term lease recognition exemption for all leases that qualify.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires measurement and recognition of expected credit losses for financial assets. In April 2019, the FASB issued a clarification to ASU 2016-13 within ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments, which modified the accounting for available-for-sale securities. As an emerging growth company, ASU 2016-13 is effective for the Company for fiscal years beginning after December 15, 2022, with early adoption permitted. The Company is currently assessing the potential impact of adopting ASU 2016-13 on its financial statements and financial statement disclosures.

In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which removes certain exceptions and amends certain requirements in the existing income tax guidance to ease accounting requirements. As an emerging growth company, this standard is effective for the Company for fiscal years beginning after December 15, 2021, and interim periods within annual periods beginning after December 15, 2022, and must be applied on a retrospective basis. The Company is currently evaluating the impact of this new guidance on its financial statements and financial statement disclosures but does not expect this new guidance to have a material impact on its financial statements and financial statement disclosures.