Basis of presentation

The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, and include all adjustments considered necessary for the fair presentation of the Company’s financial position and operating results for the periods presented.

Use of estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. Assets and liabilities reported in the Company’s balance sheets and revenue and expenses reported in the Company's statement of operations and comprehensive (loss) income are affected by estimates and assumptions, which are used for, but are not limited to, measuring and recognizing revenue, including any related constraints, and determining the fair value of assets and liabilities, including the convertible promissory notes, common stock valuation, income tax uncertainties, measurement of stock-based compensation expense, and certain accruals. Actual results could differ from such estimates or assumptions.

Concentration of credit risk and other risks and uncertainties

Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains bank deposits in accounts at two separate federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institution holding its cash to the extent recorded in the balance sheet. The Company has not experienced any losses on its deposits of cash. The Company’s investment policy limits investments to certain types of securities issued by the U.S. government and its agencies, as well as institutions with investment-grade credit ratings and places restrictions on maturities and concentration by type and issuer. As of December 31, 2025 and 2024, the Company had no off-balance sheet concentrations of credit risk.

The Company is also subject to a number of risks similar to other early-stage biopharmaceutical companies, including, but not limited to, the need to obtain adequate additional funding, possible failure of current or future preclinical testing or clinical trials, its reliance on third parties to conduct its preclinical testing or clinical trials, the need to obtain regulatory and marketing approvals for therapeutic candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of therapeutic candidates, the success of efforts to protect its proprietary technology, and the need to secure and maintain adequate manufacturing arrangements with third parties. If the Company does not successfully commercialize or partner any therapeutic candidates, it will be unable to generate product revenue or achieve profitability.

Segment reporting

The Company operates and manages its business as one reportable and operating segment, which is the business of harnessing its understanding of human genetics and variant functionalization to develop small molecule precision medicines. The Company’s chief executive officer, who is the chief operating decision maker, or CODM, reviews financial information on an aggregate basis for allocating resources and evaluating financial performance.

The CODM, in alignment with the Company's overall corporate strategy and goals, analyzes a variety of data to guide segment resource allocation, including program and portfolio scientific data, probability of regulatory and commercial success, and the competitive environment. The CODM also reviews certain financial results included in the segment (loss) income from operations which is reported on the statements of operations and comprehensive (loss) income as total (loss) income from operations. The measure of segment assets is reported on the balance sheets as total assets.

As of December 31, 2025 and 2024, all of the Company’s property and equipment was maintained in the United States. No revenue was generated in the year ended December 31, 2025. For the year ended December 31, 2024, all of the Company’s license revenue was generated in the United States. The following table presents selected financial information with respect to the Company’s single operating segment for the years ended December 31, 2025 and 2024 (amounts in thousands):

Fair value measurement

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date, and establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value.

The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows:

For certain financial instruments, including cash and accounts payable, as well as certain accrued liabilities, the recorded amount approximates estimated fair value due to their relatively short maturity period.

Cash, cash equivalents and restricted cash

The Company considers all highly liquid financial instruments with original maturities of 90 days or less at the date of purchase to be cash equivalents. As of December 31, 2025 and 2024, cash equivalents consisted of money market funds.

Restricted cash is comprised of cash that is restricted as to withdrawal or use under the terms of certain contractual agreements. Restricted cash as of December 31, 2025 and 2024 included $1.1 million as collateral for a letter of credit related to the Company’s headquarters building lease in South San Francisco, California. Restricted cash is classified as a noncurrent asset on the balance sheet. As of December 31, 2025 and 2024, restricted cash consisted of money market funds.

Marketable securities

The Company generally invests its excess cash in money market funds and investment grade short- and long-term fixed income securities. Such investments are included in cash and cash equivalents, marketable securities, current, or marketable securities, non-current, on the balance sheets, are considered available-for-sale, and are reported at fair value with net unrealized gains and losses included as a component of stockholders’ equity.

The Company classifies investments in securities with original maturities over 90 days and remaining maturities of less than one year as marketable securities, current, and investments in securities with remaining maturities of over one year as marketable securities, non-current. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, which is included in interest and other income, net in the statements of operations and comprehensive (loss) income. Realized gains and losses and declines in value determined to be due to credit losses on marketable securities, if any, are included in interest and other income, net.

The Company periodically evaluates the need for an allowance for credit losses. This evaluation includes consideration of several qualitative and quantitative factors, including whether it has plans to sell the security, whether it is more likely than not it will be required to sell any marketable securities before recovery of its amortized cost basis, whether it has the ability and intent to hold the security to maturity and the portion of any unrealized loss that is the result of a credit loss. Factors considered in making these evaluations include quoted market prices, recent financial results and operating trends, implied values from any recent transactions or offers of investee securities, credit quality of debt instrument issuers, expected cash flows from securities, other publicly available information that may affect the value of the marketable security, duration and severity of the decline in value and the Company's strategy and intentions for holding the marketable security.

The Company excludes the applicable accrued interest from both the fair value and amortized cost basis of marketable securities for purposes of identifying and measuring an impairment. Accrued interest receivable on marketable securities is recorded within prepaid expenses and other current assets on the balance sheets. The Company’s accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which is considered to be in the period in which it is determined the accrued interest will not be collected.

Property and equipment, net

Property and equipment are presented at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful life. Depreciation begins at the time the asset is placed in service. Maintenance and repairs that do not improve or extend the life of the assets are charged to expense as incurred and costs of major replacements or improvements are capitalized. Upon disposal of assets, the cost and related accumulated depreciation is removed from the balance sheet and the resulting gain or loss is reflected in the statements of operations and comprehensive (loss) income within interest and other income, net. The Company’s estimated useful lives of its property and equipment are as follows:

Impairment of long-lived assets

The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the asset or asset group may not be recoverable. The recoverability of assets to be held and used is measured by comparing the carrying amount to the estimated undiscounted future cash flows expected to be generated by the asset or asset group. If the carrying amount exceeds the estimated undiscounted future cash flows, an impairment loss is recognized. There have been no such impairments of long-lived assets for the years ended December 31, 2025 and 2024.

Deferred offering costs

The Company defers offering costs consisting of legal, accounting and other fees and costs directly associated with in-process equity financings until such financings are consummated. After consummation of the equity financing, these costs are classified in stockholders’ deficit as a reduction of the additional paid-in capital recorded as a result of the financing. If the in-process financing is abandoned, the deferred offering costs are expensed immediately as a charge to operating expenses in the statements of operations and comprehensive (loss) income. As of December 31, 2024, approximately $4.3 million of deferred offering costs related to the Company’s initial public offering were recorded within other assets in the accompanying balance sheets and upon completion of the Company’s initial public offering in February 2025, the deferred offering costs were recorded as a reduction to the additional paid-in capital within stockholders’ equity (deficit) recorded in the accompanying balance sheets as of December 31, 2025.

Revenue recognition

The Company recognizes revenue in accordance with Accounting Standards Codification (ASC) 606, Revenue from Contracts with Customers, or ASC 606. To determine the appropriate amount and timing of revenue to be recognized under this guidance, the Company performs the following steps: (i) identifies the contract(s) with a customer; (ii) identifies the performance obligations in the contract; (iii) determines the transaction price, including variable consideration, if any; (iv) allocates the transaction price to the performance obligations in the contract; and (v) recognizes revenue when (or as) the entity satisfies a performance obligation.

The Company has entered into arrangements involving the license of intellectual property. Analyzing the license arrangements to identify performance obligations requires the use of judgment. In arrangements that include the license of intellectual property and other promised services, the Company first identifies if the licenses are distinct from the other promises in the arrangement. For the license of intellectual property that is distinct, the Company recognizes revenue from consideration allocated to the license when the license is transferred and the customer is able to benefit from the license. If the license is not distinct, the license is combined with other services into a single performance obligation and the Company recognizes revenue when (or as) the performance obligation is satisfied. Factors that are considered in evaluating whether a license is distinct from other promised services include, for example, whether the counterparty can benefit from the license without the promised service on its own or with other readily available resources and whether the promised service is expected to significantly modify or customize the intellectual property. Promised goods and services that are not material in the context of the contract are not considered performance obligations.

The transaction price is the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. Non-refundable upfront payments are considered fixed consideration and included in the transaction price. At the inception of an arrangement and at each reporting period thereafter, the Company assesses whether it should include development, regulatory, commercial milestones or other forms of variable consideration in the transaction price using the most likely amount method. The Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price. The Company includes the amount of estimated variable consideration, including milestones, in the transaction price to the extent that it is probable that a significant reversal of cumulative revenue recognized will not occur. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of the milestones 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 will affect revenue in the period of adjustment. In addition, we are eligible to receive certain royalties on net sales of licensed products, if successfully commercialized by our licensees. The royalties are dependent on future sales which are at the full discretion of the licensee. We will recognize sales-based milestone payments in the period in which we achieve the milestone under the sales-based royalty exception allowed under accounting rules. Accordingly, we will apply a constraint to these amounts until the future sales have occurred.

For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and if the license is deemed to be the predominant item to which the royalties relate, the Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied.

Amounts received prior to satisfying the revenue recognition criteria are recorded as deferred revenue in the Company’s balance sheets. If the related performance obligation is expected to be satisfied within the next twelve months this will be classified in current liabilities. Amounts recognized as revenue prior to receipt are recorded as contract assets in the Company’s balance sheets. If the Company expects to have an unconditional right to receive consideration in the next twelve months, this will be classified in current assets.

Leases

The Company determines if an arrangement is a lease at the inception of the arrangement. Operating leases are included in right-of-use assets, operating lease liabilities, current, and operating lease liabilities, net of current portion in its balance sheets. Right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease.

Operating lease right-of-use assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses its incremental borrowing rate based on the information available at the lease commencement date. The operating lease right-of-use assets also include any lease payments made and exclude lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise any such options. Lease expense is recognized on a

straight-line basis over the expected lease term. The Company has elected not to separate lease and non-lease components, such as common area maintenance charges, and instead it accounts for these as a single lease component. Leases with an initial term of 12 months or less are not recorded on the balance sheet, unless they include an option to purchase the underlying asset or to extend the lease that the Company is reasonably certain to exercise.

Convertible promissory notes

From December 2023 through April 2024, the Company issued a total of $40.7 million aggregate principal amount of convertible promissory notes, which contained automatic conversion features triggered upon a qualified preferred stock financing or a qualified public offering. As permitted under Accounting Standards Codification 825, Financial Instruments, or ASC 825, the Company elected the fair value option for recognition of the convertible promissory notes. In accordance with ASC 825, the Company recorded these convertible promissory notes at fair value and remeasured the convertible promissory notes at fair value each reporting period with changes in fair value recorded in the statements of operations and comprehensive (loss) income. As a result of applying the fair value option, direct costs and fees related to the convertible promissory notes were recognized in earnings as incurred and not deferred. The impact of interest expense on the convertible promissory notes is included within the changes in fair value.

The Company recorded a loss of $8.8 million in the statements of operations and comprehensive (loss) income for the year ended December 31, 2024, reflecting the change in the fair value of the convertible promissory notes. In connection with the private placement of Series D convertible preferred stock the Company completed in November 2024, which was a qualified preferred stock financing pursuant to the terms of the convertible promissory notes, the outstanding convertible promissory notes automatically converted into shares of Series D-1 convertible preferred stock, and no convertible promissory notes were outstanding as of December 31, 2024. Accordingly, no change in fair value of convertible promissory notes was recorded in the statements of operations and comprehensive (loss) income for the year ended December 31, 2025.

Redeemable convertible preferred stock

The Company recorded convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The convertible preferred stock included terms allowing for cash redemption by the holders upon the occurrence of certain events, including a deemed liquidation event, which were outside of the Company's control. Therefore, redeemable convertible preferred stock was classified outside of stockholders’ equity (deficit) on the balance sheet as events triggering the redemption were not solely within the Company’s control. No events occurred that triggered redemption of the redeemable convertible preferred stock prior to conversion of the convertible preferred stock to common stock upon the Company’s initial public offering as further described in Note 1, Organization and principal activities.

Research and development expenses

Research and development, or R&D, expenses are recorded in the period that services are rendered or goods are received. R&D expenses consist of personnel related costs, including salaries, benefits and stock-based compensation, related to R&D activities, laboratory supplies and facility costs, as well as fees paid to third parties that conduct certain R&D activities on behalf of the Company. Nonrefundable advance payments for goods or services that will be used or rendered for future R&D activities are capitalized and expensed as the goods are delivered or the related services are performed.

As part of the process of preparing its financial statements, the Company is required to estimate and accrue certain R&D expenses. This process involves the following:

Examples of estimated R&D expenses that the Company may accrue include costs for:

The Company bases its expense accruals related to clinical studies on its estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and CROs that conduct and manage clinical studies on the Company’s behalf. The financial terms of these agreements vary from contract to contract and may result in uneven payment flows. Payments under some of these contracts depend on factors, such as the successful enrollment of patients and the completion of clinical trial milestones. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period.

To date, the Company has not experienced significant changes in its estimates of accrued R&D expenses after a reporting period. However, due to the nature of estimates, there is no assurance that the Company will not make changes to its estimates in the future as it becomes aware of additional information about the status or conduct of its clinical studies and other R&D activities. Such changes in estimates will be recognized as R&D expenses in the period that the change in estimate occurs.

Stock-based compensation expense

The Company recognizes stock-based compensation expense for service-based stock options, employee stock purchases, restricted stock awards, or RSAs, and restricted stock units, or RSUs, on a straight-line basis over the requisite service period. The Company recognizes compensation cost for performance-based awards over the requisite service period when it is determined that the performance condition is probable of being achieved. The Company measures the fair value of service-based stock options and employee stock purchases at the grant date using the Black-Scholes option-pricing model. Inputs to the Black-Scholes option-pricing model include the fair value of its common stock, the expected term of the awards, the expected common stock price volatility over the term of the awards, risk-free interest rates, and the expected dividend yield. The fair value of RSAs and RSUs is determined on the date of grant based on the fair value of the Company’s common stock on that date. Stock-based compensation expense is adjusted for actual forfeitures of unvested awards in the same period as the forfeitures occur.

The fair value of awards that contain market-based conditions is measured using a Monte-Carlo option pricing model at the date of grant using similar input assumptions as the Black-Scholes model while incorporating Level 3 inputs related to probability estimates of the market conditions being satisfied. Compensation expense related to awards with a market-based condition is recognized regardless of whether the market condition is ultimately satisfied, and compensation expense is not reversed if the achievement of the market condition does not occur.

Income taxes

The Company accounts for income taxes using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns subject to a determinable valuation allowance.

Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse.

In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. In the event the Company determines that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, it would make an adjustment to the valuation allowance that would reduce the provision for income taxes. Conversely, in the event that all or part of the net deferred tax assets are determined not to be realizable in the future, an adjustment to the valuation allowance would be charged to earnings in the period when such determination is made. As of December 31, 2025 and 2024, the Company recorded a full valuation allowance on its deferred tax assets.

The Company recognizes uncertain income tax positions at the largest amount that is more likely than not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. Changes in recognition or measurement are reflected in the period in which judgment occurs. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of the provision for income tax.

Foreign currency transaction gain (loss)

Gains and losses arising from transactions and remeasurement of balances denominated in currencies other than U.S. dollars are recorded in interest and other income, net on the statement of operations and comprehensive (loss) income. The Company recorded immaterial losses and gains on foreign currency transactions for the years ended December 31, 2025 and 2024, respectively.

Comprehensive (loss) income

Comprehensive (loss) income is defined as a change in equity of a business enterprise during a period, resulting from transactions from non-owner sources. Comprehensive income for the year ended December 31, 2025 consists of net unrealized gains on available-for-sale debt securities. The Company did not have any transactions that would be reported separately to derive comprehensive (loss) income during the year ended December 31, 2024.

Net (loss) income per share

Net (loss) income per share attributable to common stockholders is calculated using the two-class method required for companies with participating securities. The Company considered its convertible preferred stock to be participating securities as the holders were entitled to receive noncumulative dividends in the event that a dividend is paid on common stock.

Basic net (loss) income per share attributable to common stockholders is computed by dividing net (loss) income attributable to common stockholders by the weighted-average number of common shares outstanding during the period less common shares subject to vesting or forfeiture, without consideration for potentially dilutive securities. In September 2025, the Company completed the Private Placement, pursuant to which the Company issued the Pre-Funded Warrants to purchase 5,231,090 shares of its common stock. The Pre-Funded Warrants are exercisable immediately at an exercise price of $0.001 per share and do not expire. The Company included the Pre-Funded Warrants in the computation of basic net loss per share, as applicable, since their exercise price is negligible and they may be exercised at any time. See Note 6, Capital structure, for further discussion of the Private Placement.

Diluted net (loss) income per share is computed by dividing net (loss) income by the weighted-average number of common shares and the number of common shares that would be issued assuming exercise and conversion of all potentially dilutive instruments. In calculating diluted net (loss) income per share, the Company applies the more dilutive of the two-class method or the if-converted method to the redeemable convertible preferred stock, applies the treasury stock method to equity awards, and applies the if-converted method to the convertible promissory notes, if dilutive.

Distributed and undistributed earnings are allocated to participating securities based on their participation rights and are subtracted from net income in determining net income attributable to common stockholders for basic and diluted net income per share, only in periods of net income.

Commitments and contingencies

Liabilities for loss contingencies arising from claims, assessments, litigation, fines, and penalties and other sources are recorded if and when it is probable that a liability has been incurred and the amount can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred.

Emerging growth company status

The Company is an emerging growth company, or EGC, as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards.

Recently adopted accounting pronouncements

In December 2023, the Financial Accounting Standards Board, or FASB, issued ASU 2023-09, Improvements to Income Tax Disclosures, which requires incremental income tax disclosures on an annual basis for all public entities. The amendments require that public business entities disclose specific categories in the rate reconciliation and provide additional information for reconciling items meeting a quantitative threshold. The amendments also require disclosure of income taxes paid to be disaggregated by jurisdiction, and disclosure of income tax expense disaggregated by federal, state, and foreign. The Company adopted the new standard retrospectively as of December 31, 2025. The impact was limited to the Company’s income tax-related disclosures in Note 13, Income Taxes.

New accounting pronouncements—Not yet adopted

In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures, which will require additional expense disclosures for all public entities. The amendments require that at each interim and annual reporting period, an entity will disclose certain disaggregated expenses included in each relevant expense caption, as well as the total amount of selling expenses and, in annual periods, an entity’s definition of selling expenses. ASU 2024-03 is effective for annual reporting periods beginning with the fiscal year ending December 31, 2027, and interim periods thereafter, with early adoption permitted. The Company expects the adoption of this standard to result in increased disclosures in its financial statements.