Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2023

Summary of Significant Accounting Policies

Note 2. Summary of Significant Accounting Policies

Basis of Presentation

These financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP).

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company evaluates its estimates, including, but not limited to, those related to clinical and preclinical accruals,

manufacturing accruals, fair value of common stock, stock-based compensation, operating lease right-of-use (ROU) assets and liabilities and income taxes. The Company bases its estimates on its historical experience and also on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.

Segments

The Company operates and manages its business as one reportable and operating segment, which is the business of developing covalent small molecule drugs to treat patients with genetically defined cancers and metabolic diseases. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating resources and evaluating financial performance. All long-lived assets are maintained in, and all losses are attributable to, the United States of America.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to a concentration of credit risk, consist primarily of cash, cash equivalents and investments. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company invests in money market funds, U.S. Treasury securities, U.S. government agency securities, corporate notes, commercial paper, and asset backed securities. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents and issuers of investments to the extent recorded in the balance sheet. The Company’s investment policy limits investments to money market funds, certain types of debt securities issued by the U.S. Government and its agencies, corporate notes and commercial paper, and places restrictions on the credit ratings, maturities and concentration by type and issuer. The Company has not experienced any losses on its deposits of cash, cash equivalents and investments.

Other Risks and Uncertainties

The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of preclinical studies, clinical trials and achievement of milestones, uncertainty of regulatory approval of the Company’s potential product candidates, uncertainty of market acceptance of the Company’s product candidates, competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals or sole source suppliers and changes in the Company's operating expenses as a result of these uncertainties and other factors, such as inflation. The Company’s product candidates require approvals from the U.S. Food and Drug Administration and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company is denied approval, approval is delayed or the Company is unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash and cash equivalents. Cash equivalents consist of amounts invested in money market accounts and are stated at fair value. Restricted cash consists of two stand-by letters of credit issued to the Company’s landlord in connection with two of the Company’s leases.

Investments

The Company adopted Accounting Standards Update (“ASU”) 2016-13, Measurement of Credit Losses on Financial Instruments, on January 1, 2023. The Company’s investments have been classified as available-for-sale and carried at estimated fair values and reported in cash equivalents, short-term investments, or long-term investments. Management determines the appropriate classification of the investments at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. Investments with contractual maturities greater than 12 months are considered long-term investments.

For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or whether it is more likely than not that it will be required to sell the security before the recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in interest and other income, net in the statement of operations and comprehensive loss. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the

rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in interest and other income, net.

Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive loss, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in interest and other income, net in the statement operations and comprehensive loss.

For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded in other current assets on the condensed balance sheets.

Property and Equipment, Net

Property and equipment are recorded at cost net of accumulated depreciation. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. The useful lives of property and equipment are as follows:


Computer equipment	3 years
Furniture and fixtures	5 years
Laboratory equipment	5 years
Leasehold improvements	Shorter of remaining lease term or estimated useful life

Upon retirement or sale of the assets, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is recorded to the statements of operations. Repairs and maintenance are expensed as incurred.

Impairment of Long-Lived Assets

Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There was no impairment of long-lived assets during the years ended December 31, 2023, 2022 and 2021.

Research and Development Expenses

The Company expenses research and development costs as they are incurred. Research and development expenses consist primarily of: (i) personnel-related expenses, including salaries, benefits and stock-based compensation expense, for personnel in the Company’s research and development functions; (ii) fees paid to third parties such as contractors, consultants and contract research organizations (CROs), for animal studies and other costs related to preclinical and clinical testing; (iii) costs related to acquiring and manufacturing research and clinical trial materials, including under agreements with third parties such as contract manufacturing organizations (CMOs), and other vendors; (iv) costs related to the preparation of regulatory submissions; (v) expenses related to laboratory supplies and services; and (vi) depreciation of equipment and facilities expenses.

Accrued Research and Development Expenses

The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing development, which are significant components of research and development expenses. A substantial portion of the Company’s ongoing research and development activities is conducted by third-party service providers, CROs and CMOs. The Company’s contracts with the CROs and CMOs generally include fees such as initiation fees, reservation fees, costs related to animal studies and safety tests, verification run costs, materials and reagents expenses, investigator fees, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, or stage of completion and actual

timeline (start-date and end-date) of the services and the agreed-upon fees to be paid for such services. Through December 31, 2023, there have been no material differences from the Company’s estimated accrued research and development expenses to actual expenses.

Stock-Based Compensation

The Company accounts for stock-based compensation by measuring and recognizing compensation expense for all share-based awards made to employees, non-employees and directors based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over the requisite service period, which is generally the vesting period, and estimates the fair value of share-based awards to employees, non-employees and directors using the Black-Scholes option-pricing model. The Company uses the “simplified” method to estimate the expected term. The Company utilizes this method as our stock options qualify as "plain-vanilla" options. The Company accounts for forfeitures as they occur. The fair value of restricted stock awards is based on grant-date fair value. The fair value of each purchase under the employee stock purchase plan (ESPP) is estimated at the beginning of the offering period using the Black-Scholes option pricing model and recorded as expense over the service period using the straight-line method.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented.

Leases

The Company determines if an arrangement is a lease at inception in accordance with Accounting Standard Codification 842, “Leases” (ASC 842). As of December 31, 2023, the Company's lease population consisted of real estate leases and the Company did not have finance leases.

Operating leases are included in operating lease right-of-use (ROU) assets, current operating lease liabilities and non-current operating lease liabilities on the Company’s balance sheet. 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. 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. As most of the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of those lease payments. The Company determines the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to the Company. The determination of the Company’s incremental borrowing rate requires management judgment including the development of a synthetic credit rating and cost of debt as the Company currently does not carry any debt. The Company believes that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in the estimated amounts to vary. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. Lease incentives are recognized prospectively, on reimbursement, as reduction to the right-of-use asset and lease liabilities over the lease term. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease cost is recognized on a straight-line basis over the expected lease term. Variable lease costs represent payments that are dependent on usage, a rate or index. Variable lease cost primarily relates to common area maintenance charges. Lease agreements that include lease and non-lease components are accounted for as a single lease component. The Company has elected to apply the short-term lease exception for all lease agreements with a noncancelable term of less than 12 months.

Income Taxes

The Company began providing for income taxes under the asset and liability method in December 2020 upon conversion from a limited liability company into a corporation. Current income tax expense or benefit represents the amount of income taxes expected to be payable or refundable for the current year. Deferred income tax assets and liabilities are determined based on differences between the financial statement reporting and tax basis of assets and liabilities and net operating loss and credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when such items are expected to reverse. Deferred income tax assets are reduced, as necessary, by a valuation allowance when management determines it is more likely than not that some or all the tax benefits will not be realized.

The Company accounts for uncertain tax positions in accordance with ASC No. 740 Income Taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still

subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.

The Company includes any penalties and interest expense related to income taxes as a component of income tax expense, as necessary.

Recent Accounting Pronouncements - Adopted

In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss methodology, which will result in more timely recognition of credit losses. The measurement of expected credit losses is based on historical experience, current conditions, and reasonable and supportable forecasts that affect collectability. This ASU also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. This ASU is effective for fiscal years beginning after December 15, 2022 and interim periods within those fiscal years. The Company adopted ASU 2016-13 on January 1, 2023, using the modified retrospective approach, and no cumulative effect adjustment to accumulated deficit was needed as of the adoption date. Additionally, no prior period amounts were adjusted and continue to be reported in accordance with the legacy other-than-temporary impairment model. The adoption of ASU 2016-13 did not have a material impact on the Company’s financial statements.

Recent Accounting Pronouncements - Not Yet Adopted

In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2023-09, “Income Taxes - Improvements to Income Tax Disclosures” requiring enhancements and further transparency to certain income tax disclosures, most notably the tax rate reconciliation and income taxes paid. This ASU is effective for fiscal years beginning after December 15, 2024 on a prospective basis and retrospective application is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s financial statements and related disclosures.