Bolt Biotherapeutics, Inc.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1. Description of the Business

Bolt Biotherapeutics, Inc. (the “Company”) is a clinical-stage biopharmaceutical company developing novel immunotherapies for the treatment of cancer. The Company’s pipeline candidates are built on the Company’s deep expertise in myeloid biology and cancer drug development, uniting the targeting precision of antibodies with the power of the innate and adaptive immune system to reprogram the tumor microenvironment for a productive anti-cancer response.

2. Summary of Significant Accounting Policies

Basis of Presentation

The Company’s consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The financial statements for the fiscal years ended December 31, 2025 and 2024 are consolidated and include the accounts of the Company and its subsidiary.

Consolidation

The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiary, Bolt Biotherapeutics Australia PTY LTD (which are referred to herein, collectively, as the Company where context requires). The Company did not hold any assets or generate revenue during and as of the years ended December 31, 2025 and 2024. All intercompany balances and transactions have been eliminated on consolidation.

Out-of-Period Adjustment

On August 7, 2020, the Company executed a non-cancellable lease agreement (the “Chesapeake Master Lease”) for its corporate office, laboratory and vivarium space in Redwood City, California. During the year ended December 31, 2024, the Company recorded an out-of-period adjustment related to an error in lease accounting that occurred in fiscal year 2020 and which was identified during the close process in December 2024. This adjustment corrected an understatement ofoperating lease right-of-use asset of $6.4 million and an understatement of operating lease liabilities of $6.8 million as of December 31, 2024. Additionally, this adjustment resulted in a cumulative impact of $0.4 million in total rent expense, of which $0.3 million is related to research and development expense and $0.1 million is related to general and administrative expense, recorded in the year ended December 31, 2024 which related to prior periods. The Company assessed the materiality of this adjustment on the previously issued annual financial statements in accordance with SEC Staff Accounting Bulletin No. 99. The Company concluded that the out-of-period adjustments were not material to the annual financial statements for the year ended December 31, 2024.

Risks and Uncertainties

The Company is subject to a number of risks similar to other early-stage biopharmaceutical companies, including, but not limited to, changes in any of the following areas that the Company believes could have a material adverse effect on its future financial position or results of operations: risks related to the successful discovery and development of its product candidates, ability to raise additional capital, development of new technological innovations by its competitors, delay or inability to obtain chemical or biological intermediates from such suppliers required for the synthesis of the Company’s product candidates, protection of intellectual property rights, litigation or claims against the Company based on intellectual property rights, and regulatory clearance and market acceptance of the Company’s products.

Global economic and business activities continue to face widespread macroeconomic uncertainties, including pandemics, labor shortages, inflation and monetary supply shifts, recession risks and potential disruptions from major geopolitical conflicts. The Company continues to actively monitor the impact of these macroeconomic factors on its financial condition, liquidity, operations, and workforce. The extent of the impact of these factors on the Company’s operational and financial performance, including its ability to execute its business strategies and initiatives in the expected time frame, will depend on future developments, which are uncertain and cannot be predicted; however, any continued or renewed disruption resulting from these factors could negatively impact the Company’s business.

The Company relies on single source manufacturers and suppliers for the supply of its product candidates. Disruption from these manufacturers or suppliers would have a negative impact on the Company’s business, financial position, and results of operations.

Liquidity and Going Concern

The Company has incurred net losses and negative cash flows from operations since its inception, has an accumulated deficit of$460.8 million and anticipates continuing to incur net operating losses and negative cash flows from operations for the foreseeable future. Under the Company's current plan management believes its cash and cash equivalents and marketable securities of $31.8 million as of December 31, 2025 will not be sufficient for the Company to continue as a going concern for at least one year from the issuance date of these financial statements. The Company believes that this raises substantial doubt about its ability to continue as a going concern within one year after the issuance of the consolidated financial statements.

As a result, the Company will be required to raise additional capital by partnering, selling equity, or other means. There can be no assurance as to whether partnering efforts will be successful or whether additional financing will be available on terms acceptable to the Company, if at all. If sufficient funds on acceptable terms are not available when needed, it would have a negative impact on the Company’s financial condition and could force the Company to delay, limit, reduce, or terminate product development or future commercialization efforts or grant rights to develop and market product candidates that the Company would otherwise plan to develop and market itself.

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The accompanying consolidated financial statements do not reflect any adjustments relating to the recoverability and reclassifications of assets and liabilities that might be necessary if the Company is unable to continue as a going concern.

The Company will need to raise additional capital to continue the advancement of its programs. In the near term, the Company's primary uses of cash will be to fund the completion of key milestones for clinical programs and to fund its operations, including research and development activities and employee salaries. This includes significant costs relating to clinical trials and manufacture of the Company's product candidates. The Company's uses of cash in the long term will be similar as the Company advances its research and development activities and pays employee salaries. Most pharmaceutical products require larger clinical trials as development progresses, and the Company expects its funding requirements to grow with the advancement of its programs. The Company's long-term funding requirements will depend on many factors, which are uncertain but include its portfolio prioritization decisions and the success of its collaborations. In turn, the Company's ability to raise additional capital through equity or partnering will depend on the general economic environment in which it operates and its ability to achieve key milestones.

Reverse Stock Split

On June 6, 2025, the Company effected a 1-for-20 reverse stock split (the “Reverse Stock Split”) of its common stock. The par value per share and the number of authorized shares were not adjusted as a result of the Reverse Stock Split. The shares of common stock underlying outstanding stock options were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased in accordance with the terms of the agreements governing such stock. In addition, the shares available for grants under the Company’s equity incentive plans and employee stock purchase plan were adjusted as a result of the Reverse Stock Split. All references to common stock, options to purchase common stock, common stock share data, per share data, and related information contained in the consolidated financial statements have been retrospectively adjusted to reflect the effect of the Reverse Stock Split for all periods presented.

Use of Estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates and assumptions, including those related to revenue recognition, stock-based compensation, restructuring costs, long-lived assets impairment assessment, and accrued liabilities. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those estimates.

Reclassification

Certain amounts in the accompanying consolidated financial statements were reclassified to conform to the current presentation.

Restructuring charges consist primarily of employee severance costs and related benefits. Liabilities for costs associated with a restructuring activity are recognized when the liability is incurred and are measured at fair value. For one-time employee terminations benefits, the Company recognizes the liability in full on the communication date when future services are not required or amortizes the liability ratably over the service period, if required. The fair value of termination benefits reflects the Company’s estimate of expected utilization of certain Company-funded post-employment benefits. One-time termination benefits include severance, continuation of health insurance coverage for certain employees, and other company funded benefits.

Long-lived Assets Impairment Assessment

Long-lived assets, including operating lease assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The recoverability of assets to be held and used is measured by a comparison of the carrying amount of the asset group to future net cash flows estimated by the Company to be generated by such assets. If such asset group is considered to be impaired, the impairment to be recognized is the amount by which the carrying amount of the asset group exceeds the fair value of the asset group. Any impairment loss is allocated to the long-lived assets of the group on a pro rata basis using the relative carrying amounts of those assets, except that the carrying amount of an individual asset cannot be reduced below its fair value.

Factors that may indicate potential impairment and trigger an impairment test include, but are not limited to, general macroeconomic conditions, conditions specific to the industry and market, an adverse change in legal factors and business climate or operational performance of the business.

Calculating the fair value of a reporting unit, an asset group and an individual asset involves significant estimates and assumptions. These estimates and assumptions include, among others, projected future cash flows, risk-adjusted discount rates, future economic and market conditions, and the determination of appropriate market comparables. Changes in these factors and assumptions used can materially affect the amount of impairment loss recognized in the period the asset was considered impaired.

Concentrations of Credit Risk

Financial instruments that potentially subject the Company to concentration of credit risk consist of cash, cash equivalents and marketable securities. At December 31, 2025 and 2024, most of the Company’s funds were invested with a registered investment manager and custodied at one financial institution, with operating cash kept at a separate financial institution, and account balances may at times exceed federally insured limits. Management believes that the Company is not subject to unusual or significant credit risk beyond the normal credit risk associated with commercial banking relationships.

Cash and Cash Equivalents

The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. As of December 31, 2025 and 2024, cash and cash equivalents consisted primarily of bank deposits and money market funds which were unrestricted as to withdrawal or use.

Allowance for Credit Losses

For available-for-sale securities in an unrealized loss position, the Company first assesses whether it intends to sell, or if it is more likely than not that the Company will be required to sell, the security before 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 through earnings. For available-for-sale securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, market conditions, changes to the underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income (loss) on the statements of operations and comprehensive loss.

The Company elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of its available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within cash and cash equivalents on the Company's 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 the Company considers to be in the period in which it determines the accrued interest will not be collected by the Company.

Marketable Securities

The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the balance sheets, with unrealized gains and non-credit related losses that are determined to be temporary, if any, reported as a component of other comprehensive income (loss) within the statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than three months but less than one year as short-term investments, and those with remaining maturities greater than one year are classified as long-term investments. The Company invests its excess cash balances primarily in corporate debt securities. Realized gains and losses are calculated on the specific identification method and recorded as interest income and were immaterial for all periods presented.

Restricted Cash

As of December 31, 2025 and 2024, the Company had short-term and long-term restricted cash deposited with a financial institution. The restricted cash is held in separate bank accounts to support letter of credit agreements related to the Company’s facility leases which expire in 2031 (see Note 6) and corporate credit card program.

Property and Equipment

Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization begin at the time the asset is placed in service. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets offive years. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives of the assets. Maintenance and repairs are expensed as incurred. Upon sale or retirement of assets, the cost and accumulated depreciation and amortization are removed from the balance sheet and any resulting gain or loss is reflected in the statement of operations and comprehensive loss in the period realized.

Cloud Computing Arrangements

The Company incurs costs to implement cloud computing arrangements hosted by third party vendors. Costs incurred to implement cloud computing service arrangements are capitalized when incurred during the application development phase, and recognized as prepaid and other assets and other non-current assets on the balance sheet. Implementation costs are subsequently amortized over the expected term of the related cloud service. The carrying value of cloud computing implementation costs are tested for impairment when an event or circumstance indicates that the asset might be impaired. Changes in cloud computing arrangement implementation costs are classified within operating activities in the statements of cash flows. The Company does not consider cloud computing agreements to be material to its consolidated financial statements.

Revenue Recognition

Under Accounting Standard Codification Topic 606, Revenue from Contract with Customers (“ASC 606”), the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of ASC 606, the following steps are performed: (i) identification of a contract to provide goods or services to a customer; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration, if any; (iv) where a contract contains multiple performance obligations, the Company must allocate the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) each performance obligation is satisfied.

The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer.

At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied.

As part of the accounting for these arrangements, the Company develops assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company uses key assumptions to determine the stand-alone selling price, which may include development timelines, reimbursement rates for personnel costs, discount rates, and probabilities of technical and regulatory success. The Company evaluates each performance obligation and determines if it is satisfied over time. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price.

The Company constrains the estimates of variable consideration such that it is probable that a significant reversal of previously recognized revenue will not occur in future reporting periods. When determining if variable consideration should be constrained, management considers whether there are factors outside the Company’s control that increase the likelihood of a significant reversal of previously recognized revenue and revenue-related amounts in future reporting periods. These estimates are re-assessed each reporting period as necessary depending on the facts and circumstances of each contract.

If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promised goods or services, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Any change made to estimated progress towards completion of a performance obligation due to changes in the estimated activities required to complete the performance obligation and, therefore, revenue recognized will be recorded as a change in estimate.

The Company receives payments from its collaborators based on billing schedules established in each contract. Upfront payments and other payments may require deferral of revenue recognition to a future period until the Company performs its obligation under its collaboration arrangements. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the payment by the customer is akin to a deposit for research and development services.

To date, all of the Company’s revenue has been derived from its collaboration agreements, see Note 5.

Research and Development Expenses

Research and development costs are charged to expense as incurred. Research and development expenses include certain payroll and personnel expenses, laboratory supplies, consulting costs, external contract research and development expenses, and allocated overhead, including rent, equipment depreciation and utilities. Advance payments for goods or services for future research and development activities are deferred and expensed as the goods are delivered or the related services are performed.

The Company estimates preclinical studies and clinical trial expenses based on the services performed pursuant to contracts with research institutions and clinical research organizations that conduct and manage preclinical studies and trials on the Company’s behalf. 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. These estimates are based on communications with the third-party service providers and the Company’s estimates of accrued expenses and on information available at each balance sheet date. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly.

Research and Development Tax Incentive

The Company is eligible to receive a cash refund from the Australian Taxation Office for eligible research and development (“R&D”) expenditures under the Australian R&D Tax Incentive Program (the “R&D Tax Incentive”). The R&D Tax Incentive is recognized as a reduction to R&D expense when the relevant expenditure has been incurred, the amount can be reliably measured and it is probable that the R&D Tax Incentive will be received. The Company has not recorded any reductions to R&D expense under the R&D Tax Incentive as it is not reasonably assured that the criteria have been met. The Company has not received any cash refunds under this program.

Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that shouldbe determined based on assumptions that market participants would use in pricing an asset or liability. Cash and cash equivalents, restricted cash, marketable debt securities, accounts payable, accrued expenses and other current liabilities are reported at their respective fair values in our balance sheets. The carrying amount of the remaining financial instruments approximate fair value due to their short-term nature. Refer to Note 3 for the methodologies and assumptions used in valuing financial instruments.

Leases

The Company determines whether an arrangement is a lease at inception. Specifically, it considers whether it controls the underlying asset and has the right to obtain substantially all the economic benefits or outputs from the asset. If the contractual arrangement contains a lease, the Company then determines the classification of the lease, operating or finance, using the classification criteria described in Accounting Standard Codification Topic 842, Leases (“ASC 842”). The Company has elected not to separate lease components from non-lease components, such as common area maintenance charges, and instead accounts for the lease and non-lease components as a single component.

At the commencement date of a lease, the Company recognizes lease liabilities which represent its obligation to make lease payments, and right-of-use assets (“ROU assets”) which represent its right to use the underlying asset during the lease term. The lease liability is measured at the present value of lease payments over the lease term. As the Company’s leases typically do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date. The incremental borrowing rate is estimated based on the Company's estimated credit rating and available market information for borrowings with similar terms and economic characteristics. The ROU asset is measured at cost, which includes the initial measurement of the lease liability and initial direct costs incurred by the Company and excludes lease incentives. ROU assets are recorded in operating lease ROU assets and lease liabilities are recorded in operating lease liabilities, current and noncurrent in the balance sheets.

Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating lease expense is recognized on a straight-line basis over the lease term. The Company does not recognize lease liabilities and ROU assets for short-term leases with terms of twelve months or less.

The Company accounts for stock-based compensation by measuring and recognizing compensation expense for all share-based payments made to employees and non-employees based on estimated grant-date fair values. For stock-based payments with service conditions only, the Company uses the straight-line method to allocate compensation cost to reporting periods over each award’s requisite service period, which is generally the vesting period. For stock-based payments with both performance and service conditions, the Company recognizes expense based on the fair value of the performance awards over the estimated service period (under the graded vesting method) to the extent the achievement of the related performance criteria is estimated to be probable. The grant date fair value is utilized for restricted stock awards and the fair value of each stock option grant is estimated on the date of grant using the Black-Scholes model. The Black-Scholes model requires the input of subjective assumptions, including expected volatility, expected dividend yield, expected term, risk-free interest rate, and the estimated fair value of the underlying common stock on the date of grant. The Company accounts for forfeitures as they occur.

Income Taxes

The Company accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax reporting bases of assets and liabilities and are measured using enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes.

Realization of deferred tax assets is dependent upon future earnings, the timing and amount of which are uncertain. A valuation allowance is provided against deferred tax assets unless it is more likely than not that they will be realized.

The Company utilizes a two-step approach to recognize and measure uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained upon tax authority examination, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits.

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 potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, stock options, common stock subject to repurchase related to unvested restricted stock awards and early exercise of stock options are considered potentially dilutive securities. Basic and diluted net loss per share is presented in conformity with the two-class method required for participating securities. The Company considers the shares issued upon the early exercise of stock options subject to repurchase to be participating securities because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of early exercised shares subject to repurchase do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for all periods presented as potentially dilutive securities were anti-dilutive.

Comprehensive Loss

Comprehensive loss includes all changes in equity (net assets) during a period from non-owner sources, including unrealized gains and losses on marketable securities. The Company incurred a net unrealized loss on marketable securities of $0.1 million and a net unrealized gain $0.1 million during the years ended December 31, 2025 and 2024, respectively.

Segment Reporting

Operating segments are defined as components of an entity where discrete financial information is evaluated regularly by the chief operating decision maker (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s Chief Executive Officer is its CODM. The Company’s CODM reviews financial information presented on a consolidated basis for the purposes of making operating decisions, allocating resources and evaluating financial performance. As such, the Company has determined that it operates inone operating andone reportable segment. The Company’s long-lived assets are entirely based in the United States.

Recently Adopted Accounting Standards

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which requires enhanced disclosures related to the effective tax rate reconciliation and income taxes paid. The standard is effective for annual periods beginning after December 15, 2024, and may be applied on a prospective or retrospective basis. The Company adoptedthe ASU retrospectively for the period ending December 31, 2025, and it affects only its disclosures and doesnot impact the results of operations or financial condition.

In July 2025, the FASB issued ASU 2025-05, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets, which introduces a practical expedient permitting all entities to assume that current conditions as of the balance sheet date will remain unchanged for the life of the asset when estimating expected credit losses under ASC 606. For entities other than public business entities, the ASU also allows an accounting policy election to consider cash collections received after the balance-sheet date in their estimates. An entity that makes this election must disclose the date through which subsequent collections are evaluated. The ASU is effective for annual reporting periods beginning after December 15, 2025, including interim periods within those years, with early adoption permitted. The Company adoptedthe ASU retrospectively for the period ending December 31, 2025, and it has no impact on its disclosures and doesnot impact the results of operations or financial condition.

Recent Accounting Standards

From time to time, new accounting standards are issued by the Financial Accounting Standards Board (the “FASB”), or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position or results of operations upon adoption.

In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40), which is intended to enhance transparency into the nature and function of expenses, primarily through additional disclosures on certain cost and expenses. ASU 2024-03 should be applied on a prospective basis, and retrospective application is permitted. ASU 2024-03 is effective for annual periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of this guidance; at this time it does not expect it to have a material impact on its consolidated financial statement disclosures.

In May 2025, the FASB issued ASU 2025-04, Revenue from Contracts with Customers (Topic 606) and Compensation—Stock Compensation (Topic 718): Share-Based Consideration Payable to a Customer, to clarify the accounting treatment for equity instruments granted to customers. The guidance is effective for fiscal years beginning after December 15, 2026, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact of this standard on its financial statements and related disclosures; at this time it does not expect it to materially affect its consolidated financial statements.

3. Fair Value Measurements and Fair Value of Financial Instruments

The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows:

Level 1—Quoted prices in active markets for identical assets or liabilities.

Level 2—Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that arenot active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3—Unobservable inputs that are supported by little orno market activity and that are significant to the fair value of the assets or liabilities.

Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability.

During the years ended December 31, 2025 and 2024, financial assets measured on a recurring basis consist of cash invested in money market accounts, short-term investments, and long-term investments. The fair value of short and long-term investments is based upon market prices quoted on the last day of the fiscal period or other observable market inputs. The Company obtains pricing information from its investment manager and generally determines the fair value of investment securities using standard observable inputs, including reported trades, broker/dealer quotes, bids and/or offers.

There were no transfers in or out of Level 3 fair value measurements during the years ended December 31, 2025 and 2024.

Marketable securities, all of which are classified as available-for-sale securities, consisted of the following at December 31, 2025 and 2024 (in thousands):

As of December 31, 2025, the unrealized losses for available-for-sale investments were primarily due to changes in interest rates and not due to increased credit risks associated with specific securities. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost bases of the investments. The Company does not currently intend to sell the investments. As of December 31, 2025, no allowance for credit losses was recorded and the Company did not recognize any impairment losses related to investments.

The tables below show the gross unrealized losses and fair value of the Company's available-for-sale securities with unrealized losses that are not deemed to have credit losses (in thousands), aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31, 2025 and 2024, respectively:

Accrued interest receivable on available-for-sale securities were $0.1 million and $0.3 million at December 31, 2025 and 2024, respectively, which are recorded in cash and cash equivalents line item on the Company's balance sheets. The Company has not written off any accrued interest receivables for the years ended December 31, 2025 and 2024.

At December 31, 2025 and 2024, the fair values of the Company’s assets, which are measured at fair value on a recurring basis, were determined using the following inputs (in thousands):

4. Balance Sheet Components

Property and Equipment, net

Property and equipment, net, consist of the following (in thousands):

Depreciation expense related to property and equipment was$1.3 million and$1.8 million for the years ended December 31, 2025 and 2024, respectively.

Sale of Property and Equipment, net

During the year ended December 31, 2025, the Company sold certain laboratory equipment. As a result, the Company recorded proceeds of $1.0 million and incurred a gain on disposal of $0.3 million.

Prepaids and Other Current Assets and Other Non-current Assets

Prepaids and other current assets and other non-current assets consist of the following (in thousands):

As of December 31, 2025 and 2024, cloud computing arrangement implementation costs consisted of deferred costs ofzero andzero, respectively, and associated accumulated amortization of$0.2 million and$0.4 million, respectively.

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following (in thousands):

5. Collaborations

Joint Development and License Agreement with Toray Industries, Inc. (“Toray”)

In March 2019, the Company entered into a Joint Development and License Agreement (the “Toray Agreement”) with Toray Industries, Inc. (“Toray”) to jointly develop and commercialize a Boltbody™ immune-stimulating antibody conjugate (“ISAC”) containing Toray’s proprietary antibody to treat cancer. The Company determined that the Toray Agreement is a contract with a customer and should be accounted for under ASC 606. In conjunction with the Toray Agreement, the Company entered into a Series T Convertible Preferred Stock Purchase Agreement (the “Series T Agreement”) for the issuance of 35,875 shares of Series T convertible preferred stock to Toray. These contracts have been evaluated together and the consideration in excess of the fair value of the Series T convertible preferred stock of $1.5 million has been allocated to the Toray Agreement and included in the total consideration for collaboration revenue. In February 2021, in connection with the Company’s initial public offering (“IPO”), all outstanding shares of Series T convertible preferred stock were converted into shares of the Company’s common stock.

In the Toray Agreement, the Company has identified one bundled performance obligation which includes the license rights, research and development services and services associated with participation on a joint steering committee. The transaction price includes the $1.5 million allocated from the Series T convertible preferred stock and $2.1 million of estimated variable consideration related to compensation for research and development services at the agreed upon full-time employee rate and third-party costs. Collaboration revenue is recognized over time proportionate to the costs that the Company has incurred to perform the services using an input method as a measure of progress towards satisfying the performance obligation, which is based on project hours. Amounts are billed based on estimated variable consideration in the quarter ahead of performance and are trued up on the subsequent quarter’s invoice following the work performed. The cumulative effect of revisions to estimated hours to complete the Company’s performance obligation will be recorded in the period in which changes are identified and amounts can be reasonably estimated. As of December 31, 2025 and 2024, receivables of $45,000 and $7,500 related to research and development services performed under the Toray Agreement were recorded as part of the prepaid expenses and other current assets line item on the balance sheet. Deferred revenue allocated to the unsatisfied performance obligation is recorded as a contract liability on the balance sheet and will be recognized over time as the services are performed. As of December 31, 2025, contract liabilities totaling $0.8 million at period-end were recorded in deferred revenue with $0.3 million in current liabilities and $0.5 million in non-current liabilities on the balance sheet based on the forecasted periods of performance. As of December 31, 2024, contract liabilities totaling $0.9 million at period-end were recorded in deferred revenue with $0.4 million in current liabilities and $0.5 million in non-current liabilities on the balance sheet based on the forecasted periods of performance.

The following table presents changes in the Company's contract liability (in thousands):

The Company recorded $0.3 million and $0.9 million revenue during the years ended December 31, 2025 and 2024, respectively. The Toray Agreement includes both fixed and variable considerations. Under the Toray Agreement, the Company will be compensated for early-stage development and manufacturing activities based on agreed full-time equivalent rates and actual out of pocket costs through the completion of the first Phase 1 clinical trial for the collaboration product candidate and Toray is entitled to reimbursement for 50% of such development costs from the Company’s share of revenues collected from the sale or licensing of collaboration products. Although the legal term of the agreement is until collaboration products are no longer sold in the territories covered under the agreement, the parties have present enforceable rights and obligations through the end of the first Phase 1 clinical trial, after which both parties can opt out of continued development under the agreement. As such, the accounting term of the Toray Agreement is considered to terminate upon completion of the first Phase 1 clinical trial. After the conclusion of the first Phase 1 clinical trial, the parties will share equally all costs of development activities necessary for obtaining regulatory approval of collaboration products in the indications in the territories covered under the agreement, unless either party elects to opt out of its co-funding obligations or reduce them by half, which election can be on a region-by-region basis or for the territories covered under the agreement as a whole. Such optional additional items will be accounted for as contract modifications when development advances past certain milestones and the parties both exercise their opt-in rights.

Oncology Research and Development Collaboration with Genmab A/S (“Genmab”)

In May 2021, the Company entered into a License and Collaboration Agreement (the “Genmab Agreement”) with Genmab A/S (“Genmab”). Together, the companies will evaluate Genmab antibodies in combination with the Company’s ISAC technology, with the goal of discovering and developing next-generation ISACs for the treatment of cancer. Under this research collaboration, the companies evaluated multiple ISAC concepts to identify up to three clinical candidates for development. Genmab will fund the research, along with the preclinical and clinical development of these candidates through initial clinical proof of concept. Under the Genmab Agreement, the Company received an upfront payment of $10.0 million. The Company determined that the Genmab Agreement is a contract with a customer and should be accounted for under ASC 606. In conjunction with the Genmab Agreement, the Company entered into a stock purchase agreement (the “Genmab SPA”) for the issuance of 41,052 shares of the Company’s common stock to Genmab for a total purchase price of $15.0 million. These contracts have been evaluated together and the consideration in excess of the fair value of the common stock of $1.4 million has been allocated to the Genmab Agreement and included in the total consideration for collaboration revenue.

In the Genmab Agreement, the Company has identified one bundled performance obligation that includes the license rights, research and development services and services associated with participation on a joint research committee. The transaction price includes the $10.0 million upfront payment, the $1.4 million allocated from the Genmab SPA, and $12.4 million of estimated variable consideration related to compensation for research and development services at the agreed upon full-time employee rate and third-party costs. Collaboration revenue is recognized over time proportionate to the costs that the Company has incurred to perform the services using an input method as a measure of progress towards satisfying the performance obligation, which is based on project hours. Compensation for the research and development services are billed in the quarter based on actual hours incurred to satisfy the performance obligation. The cumulative effect of revisions to estimated hours to complete the Company’s performance obligation will be recorded in the period in which changes are identified and amounts can be reasonably estimated. As of December 31, 2025 and December 31, 2024, receivables of $0.6 million and $0.8 million, respectively, related to research and development services performed under the Genmab Agreement were recorded as part of the prepaid expenses and other current assets line item on the balance sheet. Deferred revenue allocated to the unsatisfied performance obligation is recorded as a contract liability on the balance sheet and will be recognized over time as the services are performed. As of December 31, 2025, contract liabilities totaling $1.2 million were recorded in deferred revenue with $0.1 million in current liabilities and $1.1 million in non-current liabilities on the balance sheet based on the forecasted periods of performance. As of December 31, 2024, contract liabilities totaling $5.7 million were recorded in deferred revenue with $2.6 million in current liabilities and $3.1 million in non-current liabilities on the balance sheet based on the forecasted periods of performance.

In 2024, as part of the Company’s ongoing collaboration with Genmab, the Company reassessed the related variable consideration. In alignment with the Company’s latest forecast and strategic objectives, Genmab agreed to take on an increased share of the activities originally planned as joint efforts, further optimizing resource allocation and enhancing operational efficiency. As a result, the Company’s variable consideration was significantly reduced, impacting the recognized revenue for the year ended December 31, 2024. The Company’s previously recognized revenue was not subject to reversal; however, the Company adjusted its forward-looking revenue projections accordingly. While this resulted in no recognized revenue in the three-month period ending December 31, 2024, the Company continued to perform services under the Genmab collaboration agreement during the year ended December 31, 2025.

The following table presents changes in the Company’s contract liability (in thousands):

The Company recorded $7.4 million and $3.3 million in revenue earned during the years ended December 31, 2025 and 2024, based on services performed under the Genmab Agreement during the period. Under the Genmab Agreement, the Company will be compensated for agreed research and development services and third party costs through initial clinical proof of concept of the therapeutic candidates, which also represents the period of time both parties have enforceable rights and obligations. As such, the accounting term of the Genmab Agreement is considered to terminate upon completion of the initial clinical proof of concept of the therapeutic candidates, after which Genmab has the option to develop and commercialize up to three therapeutic candidates and the Company has the option to participate in development and commercialization of one candidate. The Genmab Agreement includes optional additional items which will be accounted for as contract modifications after initial clinical proof of concept of the therapeutic candidates. With respect to each candidate for which a party has exercised its program opt-in rights and has exclusive global rights, the other party is eligible to receive potential development and sales-based milestone payments and tiered royalties, subject to certain customary reductions, the amount of all such considerations will vary based on the market potential of the applicable territory for which such party has exercised its program opt-in rights. Under the Genmab Agreement, the Company is eligible to receive total potential milestone payments of up to $125.0 million in development milestones and $160.0 million in sale milestones per therapeutic candidate exclusively developed and commercialized by Genmab, along with tiered royalties at rates from a single-digit to mid-teens percentage based on net sales of each therapeutic candidate. However, given the current phase of development of therapeutic candidates under the Genmab Agreement, the Company cannot estimate the probability or timing of achieving these milestones, and, therefore, has excluded all milestone and royalty payments from the transaction prices of the agreement.

The Company expects its collaboration revenue to vary from period to period and the Company may have periods of little to no activity depending on the development timeline and activities with our collaboration partners. The Company's BDC-4182 ongoing clinical trial is expected to provide insights that may be relevant to its current collaboration with Genmab and as a result, the Company does not expect to perform additional research and development activities until the companies evaluate the impact of the BDC-4182 clinical trial results. The Company remains committed to executing on this agreement and will continue to reassess its revenue recognition estimates as new information becomes available.

Oncology Research and Development Collaboration with Innovent Biologics, Inc. (“Innovent”)

In March 2024, the Company entered into an amended and restated license and collaboration agreement with Innovent Biologics, Inc. (the “Amended Innovent Agreement”), which amended the original license and collaboration agreement with Innovent Biologics, Inc. ("Innovent") dated August 25, 2021 (the “Original Innovent Agreement”). Under the Original Innovent Agreement, the Company and Innovent leveraged Innovent’s proprietary therapeutic antibody portfolio and antibody discovery capability against undisclosed oncology targets in combination with the Company's Boltbody ISAC technology and myeloid biology expertise to create new candidates for cancer treatments. Innovent funded the initial research, along with the preclinical development of these candidates through the contract modification date. Under the Original Innovent Agreement, the Company received an upfront payment of $5.0 million and was compensated for research and development services, including third-party costs and employee utilization.

As part of the Amended Innovent Agreement, Innovent paid the Company a one-time payment of $4.7 million to be relieved from certain future funding and developmental obligations under the Original Innovent Agreement. Additionally, the Company secured exclusive worldwide rights to ISAC programs utilizing specified antibodies against two tumor antigen targets and assumed all future development and commercialization costs for any such ISAC program. Under the Amended Innovent Agreement, the Company has the right, but not the obligation, to further develop and commercialize the ISAC programs. Innovent and its affiliates are eligible to receive total potential milestones payments of up to $112.7 million, as well as royalties in low single digits on global net sales. The Company determined that the Amended Innovent Agreement no longer meets the criteria under ASC 606. Therefore, $2.5 million of deferred revenue allocated to the unsatisfied performance obligation as of the contract modification date, was recognized as revenue and the $4.7 million one-time payment received was recognized as other income on the consolidated statement of operations and comprehensive loss in the first quarter of 2024.

The following table presents changes in the Company’s contract liability (in thousands):

The Company hadno contract liability balance as of December 31, 2025 and 2024, respectively. The Company hadzero and $3.4 million revenue earned during the years ended December 31, 2025 and 2024, respectively, based on services performed to satisfy the performance obligation under the Innovent collaboration during the periods.

6. Commitments and Contingencies

Leases

The Company has operating leases for its corporate office, laboratory and vivarium space in Redwood City, California. On August 7, 2020, the Company executed a non-cancellable lease agreement for 71,646 square feet of space (the “Chesapeake Master Lease”), which consist of 25,956 square feet under an existing lease and 45,690 square feet of additional space, for its corporate office, laboratory and vivarium space in Redwood City, California. The Chesapeake Master Lease has an initial term often years from the commencement date, with anoption to extend the lease for an additional eight-year term. The Chesapeake Master Lease contains rent escalation, and the Company is also responsible for certain operating expenses and taxes throughout the lease term.

In addition, the Company is entitled to up to $4.8 million of tenant improvement allowance, which was paid directly by the landlord to various vendors. Upon execution of the non-cancellable lease agreement, the Company took control of 10,000 square feet of space. The remaining 35,690 square feet of additional office, laboratory and vivarium space commenced in June 2021.

Sublease Arrangements

A sublease agreement to sublease 10,500 square feet commenced in June 2021 and amended in August 2022 to expand the subleased premises to 11,655 square feet in the first year and further increase to 13,743 square feet in the second year. In addition, the expiration date of the second sublease was also amended to the expiration date of the Chesapeake Master Lease. The sublease has an early termination option under which both the Company and the sublessee have the right to terminate the sublease prior to the expiration date by providing at least fifteen months written notice to the other party. The subtenant does not have anoption to extend the sublease term. Rent for this sublease is subject to scheduled annual increases and the subtenant is responsible for certain operating expenses and taxes throughout the term under the sublease agreement.

On March 10, 2025, the Company entered into another sublease agreement under its Chesapeake Master Lease to sublease 11,773 square feet. The Company’s sublease term expires thirty-six months from the commencement date, with options for renewal. The sublessee has a one-time right to terminate the sublease agreement no earlier than twenty-four months after the commencement date by providing at least nine months written notice to the other party. The subtenant is responsible for certain operating expenses and taxes throughout the term under the sublease agreement. On August 4, 2025, the Company entered into an amendment to this sublease agreement to increase the subtenant's sublease square feet to 11,975 and to increase the subtenant's base rent for the premises. All other terms in the agreement remained the same.

Sublease income from both agreements was approximately $1.4 million and $0.8 million for each of the years ended December 31, 2025 and 2024.

Finance right-of-use leases used to finance capital equipment, such as printers or ozone generators, were immaterial as of December 31, 2025 and 2024,

The weighted-average remaining lease term and discount rate related to the Company’s lease liabilities as of December 31, 2025 were 5.4 years and 11.9%, respectively, for the operating leases. The weighted-average remaining lease term and discount rate related to the Company’s lease liabilities as of December 31, 2024 were 6.4 years and 11.9%, respectively, for the operating leases. The Company lease discount rates are based on estimates of its incremental borrowing rate, as the discount rates implicit in the Company’s leases cannot be readily determined. As the Company does not have any outstanding debt, the Company estimates the incremental borrowing rate based on its estimated credit rating and available market information.

Cash required as security for our operating leases is secured by a letter of credit on behalf of the lessor in the amount of approximately $1.5 million and $1.6 million and is recorded as restricted cash on the balance sheet as of December 31, 2025 and 2024, respectively.

The components of lease expense were as follows (in thousands):

Supplemental cash flow information related to leases was as follows (in thousands):

The following is a schedule by year for future maturities of the Company’s operating lease liabilities and sublease income to be received as of December 31, 2025 (in thousands):

Lease Impairment

In June 2024, the Company conducted an impairment assessment following its May 2024 announcement and restructuring plan. As part of this evaluation, the Company assessed whether these events constituted a triggering event that could impact the carrying value of its long-lived assets. The Company concluded that a triggering event had occurred but determined that no impairment charge was necessary.

In December 2024, the Company both abandoned a portion of its Chesapeake Master Lease and initiated efforts to sublease this space, which indicated the carrying amount may not be recoverable and constituted a triggering event under ASC 360 for this asset group. In performing the impairment assessment, the Company utilized the income approach using a discounted cash flow methodology to estimate fair values of its right-of-use assets.

The carrying value of the asset grouping was compared to its estimated fair value. The analysis measured the undiscounted cash flows over the remaining lease term, by utilizing key market based assumptions such as rent, lease terms, commissions and fees, and a discount rate. It also considered current market lease rates and applied a discount rate of 8.0%. These represented Level 3 nonrecurring fair value measurements. Based on these analyses, the Company recognized pre-tax long-lived asset impairment charges of $1.5 million on the right-of-use assets, disclosed as a separate line item on the consolidated income statement, during the year ended December 31, 2024.

In December 2025, the Company conducted an impairment assessment following its October 2025 announcement and restructuring plan. As part of this evaluation, the Company assessed whether this event constituted a triggering event that could impact the carrying value of its long-lived assets. The Company concluded that a triggering event had occurred but determined that no impairment charge was necessary.

License and Equity Agreement

In May 2015, the Company entered into a license agreement (as amended, the “Stanford Agreement”), with The Board of Trustees of the Leland Stanford Junior University (“Stanford”). The Stanford Agreement provides the Company exclusive licenses to certain inventions. As consideration, the Company issued Stanford shares of its common stock and a limited right to purchase equity in future financing. Dr. Edgar G. Engleman, a founder and member of the board of directors of the Company, who is a professor at Stanford, was issued shares of common stock as part of the Company’s Series A financing in September 2016. As a result of Dr. Engleman’s board service and affiliation with Stanford,

Stanfordand Dr. Engleman were previously considered related parties. Additionally, the Company is required by the Stanford Agreement to make milestone payments up to an aggregate of$0.4 million for the first licensed product that meets certain patent issuance, clinical and regulatory milestones, and an additional milestone payment of $0.2 million for each additional regulatory approval. The Company also agreed in the Stanford Agreement to pay Stanford tiered royalties on the Company’s and its sublicensees’ net sales of licensed products, if any, at low single-digit percentage rates, subject to certain reductions. Dr. Engleman is entitled to receive a share of any royalties that the Company pays to Stanford under the Stanford Agreement with respect to the covered intellectual property. In May 2024, Dr. Engleman resigned from the board of directors of the Company. As a result, Stanford and Dr. Engleman are no longer considered related parties as of the date of his resignation. No royalty payments have been made to date.

Guarantees and Indemnifications

In the normal course of business, the Company enters into agreements that contain a variety of representations and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves claims that may be made against the Company in the future. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations. As of December 31, 2025, the Company did not have any material indemnification claims that were probable or reasonably possible and consequently had not recorded related liabilities.

Other Commitments

The Company enters into agreements in the normal course of business, including with contract research organizations for clinical trials, contract manufacturing organizations for certain manufacturing services, and vendors for preclinical studies and other services and products for operating purposes, which are generally cancelable upon written notice.

From time to time, we might be subject to various legal proceedings relating to claims arising out of our operations. The outcome of litigation is inherently uncertain. If one or more legal matters were resolved against us in a reporting period for amounts above management’s expectations, our business, results of operations, financial position and cash flows for that reporting period could be materially adversely affected. We are not currently involved in any material legal proceedings, the ultimate disposition of which could have a material adverse effect on our operations, financial condition or cash flows.

Securities Class Action

On July 2, 2024, a securities class action complaint was filed against the Company and certain of its directors and executive officers (collectively, the "Defendants") in the United States District Court for the Northern District of California, captioned Nesterenko v. Bolt Biotherapeutics, Inc. et al., Case No. 3:24-cv-03985, purportedly on behalf of a class of individuals who purchased or otherwise acquired the Company’s common stock between February 5, 2021 and May 14, 2024. The complaint alleged that Defendants made false and/or misleading statements in violation of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended. The complaint sought unspecified monetary damages and other relief. On October 3, 2024, the court appointed a lead plaintiff, appointed lead plaintiff's counsel, and ordered the parties to submit a proposed briefing schedule for the filing of an amended complaint and the Company’s response thereto, which the parties submitted on October 23, 2024. On January 17, 2025, the lead plaintiff voluntarily dismissed the case, bringing the legal proceedings to a close.

7. Restructuring

May 2024 Restructuring

On May 14, 2024, the Company announced a strategic pipeline prioritization and restructuring plan pursuant to which it reduced overall operating expenses and discontinued developing trastuzumab imbotolimod in order to focus on the Company’s Phase 1 asset, BDC-3042, a dectin-2 agonist antibody, and the Company's next generation ISAC platform including new clinical candidate, BDC-4182, a Boltbody ISAC targeting claudin 18.2. The restructuring plan reduced the Company’s workforce by approximately 50%. The Company recorded a total restructuring charge of $3.6 million, which consisted of $2.9 million of one-time termination benefits such as severance costs and related benefits and $0.7 million of non-cash stock-based compensation expense. Cash payments of $0.7 million were made during the year ended December 31, 2025. Severance payments commenced in July 2024 and extended through July 2025. The following table provides details on the Company's restructuring and other charges (in thousands):

In June 2024, the Company assessed whether the restructuring plan constituted a triggering event indicating potential impairment of its long-lived assets, including operating lease right-of-use assets and property and equipment. Based on this evaluation, the Company determined that while impairment indicators were present, no impairment charge was necessary at that time.

October 2025 Restructuring

On October 1, 2025, the Company announced a restructuring plan pursuant to which it reduced overall operating expenses to preserve cash. The restructuring plan included a reduction of the Company’s current workforce by approximately 20 employees, or approximately 50% of the Company’s workforce. The Company recorded a total restructuring charge of $1.5 million in connection with the reduction-in-force, primarily consisting of severance payments, employee benefits, and related costs. The Company expects that the $1.5 million represents the total restructuring charges to be incurred in connection with the plan and does not anticipate incurring any additional material charges.

The following table provides details on the Company's restructuring and other charges (in thousands):

In December 2025, the Company assessed whether the October 2025 restructuring plan constituted a triggering event indicating potential impairment of its long-lived assets, including operating lease right-of-use assets and property and equipment. Based on this evaluation, the Company determined that although impairment indicators were present, no impairment charge was necessary at that time.

8. Common Stock

Shelf Registration and At-The-Market Equity Offering

On March 30, 2022, the Company filed a shelf registration statement on Form S-3 (the "Registration Statement"). Pursuant to the Registration Statement, the Company may offer and sell securities having an aggregate public offering price of up to $250.0 million. In connection with the filing of the Registration Statement, the Company also entered into a sales agreement with Cowen and Company, LLC ("Cowen"), as sales agent or principal, pursuant to which the Company may issue and sell shares of its common stock for an aggregate offering price of up to $75.0 million under an at-the-market (the “ATM”) offering program. Pursuant to the ATM, the Company will pay Cowen a commission rate equal to 3.0% of the gross proceeds from the sale of any shares of common stock. The Company is not obligated to make any sales of shares of its common stock under the ATM. Subsequently, the ATM expired as of March 29, 2025. As of December 31, 2025 and 2024, no shares of the Company's common stock had been sold under this ATM.

Common Stock Reserved for Future Issuance

The following shares of common stock were reserved for future issuance:

9. Stock-Based Compensation

2021 Equity Incentive Plan and 2021 Employee Stock Purchase Plan

In January 2021, the Company’s board of directors adopted the 2021 Equity Incentive Plan (the “2021 Plan”) and the Company’s stockholders approved the 2021 Plan. The 2021 Plan authorized issuance of up to 403,750 shares of common stock and it became effective upon the execution of the underwriting agreement for the Company’s IPO. In addition, the number of shares of common stock reserved for issuance under the 2021 Plan automatically increases on the first day of January of each calendar year that commences after the 2021 Plan became effective and continuing through and including January 1, 2031, in an amount equal to 5% of the total number of shares of the Company’s common stock outstanding on December 31, or a lesser number of shares determined by the Company's board of directors or compensation committee. As a result, common stock reserved for issuance under the 2021 Plan was increased by 95,849 shares on January 1, 2025. In connection with the workforce reduction described in Note 7 “Restructuring”, the Company entered into consulting agreements with certain officers of the Company, pursuant to which a total of 80,785 stock options previously granted to the officers were canceled on July 15, 2024.

In addition, in January 2021, the Company’s board of directors and stockholders adopted the 2021 Employee Stock Purchase Plan (the “ESPP”). The ESPP authorized issuance of up to 21,000 shares of common stock and it became effective upon the execution of the underwriting agreement for the Company’s IPO. The ESPP permits participants to purchase common stock through payroll deductions of up to 15% of their eligible compensation. Employees purchase shares of common stock at a price per share equal to 85% of the lower of the fair market value at the start or end of six-month purchase periods within thetwo-year offering period. In addition, the number of shares of common stock reserved for issuance under the ESPP automatically increases on January 1 of each calendar year that commences after the ESPP became effective and continuing through and including January 1, 2031, by the lesser of (1)1% of the total number of shares of the Company's common stock outstanding on December 31 of the preceding calendar year, (2)42,000 shares, and (3) a number of shares determined by the Company's board of directors. As a result, common stock reserved for issuance under the 2021 ESPP was increased by 19,169 shares on January 1, 2025. During the years ended December 31, 2025 and 2024,3,623 and 9,161 shares were issued under the ESPP, respectively.

Performance and Service-Based Stock Options

In September 2020, the compensation committee of the Company’s board of directors granted 26,300 options to employees that would commence vesting upon the closing of the Series C-2 financing and generally vest monthly over 48 months (the “Performance Awards”). The Company recognizes expense based on the fair value of the Performance Awards over the estimated service period (under the graded vesting method) to the extent the achievement of the related performance criteria is estimated to be probable. The Company determined that the financing milestone was achieved during January 2021. Accordingly, the Company recognized stock-based compensation expenses related to the Performance Awards of approximately zero and $35,000 for the years ended December 31, 2025 and 2024, respectively. The weighted-average grant date fair value of the Performance Awards was $64.80 per share.

The following table summarizes the stock option activity during the year ended December 31, 2025:

The intrinsic value of options exercised waszero for both years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, there was approximately$0.8 million of unrecognized stock-based compensation related to unvested stock options, which the Company expects to recognize over a weighted-average period of 1.8 years.

The fair value of each option grant was estimated on the date of grant using the Black-Scholes option-pricing model with the following assumptions:

Expected Term–The expected term of options granted represents the period of time that the options are expected to be outstanding. Due to the lack of historical exercise history, the expected term of the Company’s employee stock options has been determined utilizing the simplified method for awards that qualify as plain-vanilla options, which use the midpoint between the vesting date and the expiration date of each option.

Expected Volatility–The estimated volatility was based on the historical volatility of the common stock of a group of publicly traded companies deemed comparable to the Company.

Risk-Free Interest Rate–The risk-free interest rate is the implied yield in effect at the time of the option grant based on U.S. Treasury securities with contract maturities equal to the expected term of the Company’s stock options.

Dividend Rate–The Company has not paid any cash dividends on common stock since inception and does not anticipate paying any dividends in the foreseeable future. Consequently, an expected dividend yield of zero was used.

Fair Value of Common Stock– The fair value of the Company’s common stock is determined by the closing price, on the date of grant, of its common stock, which is traded on the Nasdaq Capital Market.

The following table summarizes the components of stock-based compensation expense recognized in the Company’s statement of operations and comprehensive loss (in thousands):

Repricing of Stock Options

On December 12, 2025, the Board of Directors of the Company approved amendments to certain outstanding stock options to purchase shares of the Company’s common stock to reduce the per-share exercise price of such options to the closing price of the Company’s common stock on the Nasdaq Capital Market on December 12, 2025, which was $5.44 (the “Repricing”).

The Repricing applied to (i) outstanding stock options granted under the Company’s 2015 Equity Incentive Plan that were held by eligible employees and service providers who affirmatively consented to the Repricing and (ii) outstanding stock options granted under the Company’s 2021 Equity Incentive Plan, which were repriced without requiring participant consent (collectively, the “Eligible Options”). The Eligible Options included options held by certain executive officers and non-employee directors. Only options with an exercise price per share greater than $5.44 immediately prior to the Repricing were eligible to participate.

Except as described below, the Eligible Options remain subject to their original terms and conditions following the Repricing, including the number of shares underlying the options, vesting schedules and expiration dates. With respect to Eligible Options that were incentive stock options (“ISOs”), the Repricing resulted in the following consequences under U.S. federal income tax rules governing ISOs: (i) thetwo-year holding period for ISO qualification restarted on the date of the Repricing, and (ii) the $100,000 annual ISO exercisability limitation was recalculated as of the Repricing Date. To the extent the aggregate fair market value of shares underlying ISOs that first become exercisable in any calendar year exceeds $100,000 (determined based on the applicable exercise prices), the portion of such options in excess of the limit will be treated as non-statutory stock options.

As of the date of the Repricing, the total number of shares underlying all Eligible Options was approximately 438,000 shares. For the year ended December 31, 2025, the Company recognized incremental stock-based compensation expense totaling $0.5 million associated with the Repricing, which is included in research and development and general and administrative expense on the statement of operations. The change was treated as a modification under ASC 718, Stock Compensation, in which the fair value of the Eligible Options was remeasured at the modification date and compared to the fair value of the modified award immediately prior to the modification, with the difference resulting in incremental stock-based compensation expense. The incremental stock-based compensation expense was calculated using the Black-Scholes option-pricing model.

Restricted Stock Units

In December 2021, the Company issued 16,800 restricted stock units ("RSUs") under the 2021 Plan at a grant date fair value of $90.20 per share. These RSUs vested in equal quarterly installments over three years, subject to the employee's continued employment with, or services to, the Company on each vesting date. Each RSU represented the right to receive one share of the Company's common stock if the applicable vesting conditions were satisfied. As of December 31, 2024, all such RSUs had vested and the shares thereunder issued.

In October 2025, the Company issued 249,500 RSUs under the 2021 Plan at a grant date fair value of $5.61 per share. These RSUs vest on September 15, 2026, subject to the employee's continued employment with, or services to, the Company on the vesting date. Each RSU represents the right to receive one share of the Company's common stock when and if the applicable vesting conditions are satisfied.

The following table summarizes the activity of the restricted stock units during the year ended December 31, 2025:

The intrinsic value of RSUs was $1.4 million andzero during years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, total unrecognized stock-based compensation expense relating to unvested restricted stock unitswas$1.1 million and the weighted-average remaining vesting period was 0.7 years.

As of December 31, 2025,249,500 RSUs were unvested and outstanding.

10. Net Loss Per Share

The following table sets forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders, which excludes shares which are legally outstanding, but subject to repurchase by the Company (in thousands, except share and per share amounts):

Potentially dilutive shares to be issued under the ESPP as of December 31, 2025 and 2024 were not included in the calculation of diluted net loss per share because they would be anti-dilutive and were immaterial. In addition, potential dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalent shares):

11. 401(k) Savings Plan

The Company established a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code of 1986, as amended. The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pretax basis. Beginning in 2021, the Company makes matching contributions of up to 3% of the eligible employees’ compensation to the 401(k) plan. During the years ended December 31, 2025 and 2024, the Company made contributions to the 401(k) plan of $0.3 million and $0.5 million, respectively.

12. Segment Reporting

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 (CODM), in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is its chief executive officer. Based on the information used by the CODM to allocate resources, the Company has determined it operates inone segment. The Company’s operating segment generates revenue from its collaboration agreements as described in Note 5.

The CODM assesses performance for the Company’s operating segment and decides how to allocate resources based on the Company’s cash runway and Net Loss that also is reported on the Consolidated Statements of Operations and Comprehensive Loss Income as Net Loss. Net loss is used to monitor budget versus actual results. 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. For the year ended December 31, 2025 and 2024, all of the Company’s revenue was generated and incurred in the United States.

Please refer to the consolidated financial statements for further information related to these measures of segment performance. In addition, research and development and general and administrative expenses are significant segment expenses regularly provided to the CODM with the following categories:

(Note A) Other segment expense include depreciation expense and other miscellaneous expenses.

13. Income Taxes

For financial reporting purposes, income (loss) before provision for income taxes, includes the following components (in thousands):

The Company hasnot recorded any income tax expense for the years ended December 31, 2025 and 2024. Additionally, the Company hasnot paid any income taxes for the years ended December 31, 2025 and 2024, respectively.

A reconciliation of the Company’s effective tax rate and federal statutory tax rate is summarized as follows (in thousands):

State income taxes in California comprise the majority of the state income taxes, net of federal effect category for the years ended December 31, 2025 and 2024, respectively.

Deferred income taxes reflect the net tax effects of loss and credit carryforwards and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets for federal and state income taxes are as follows (in thousands):

A valuation allowance is required to be established when it is more likely than not that all or a portion of a deferred tax asset will not be realized. Realization of deferred tax assets is dependent upon future earnings, the timing and amount of which are uncertain. A full review of all positive and negative evidence needs to be considered. The Company has established a full valuation allowance against the net deferred tax assets as of December 31, 2025 and 2024 due to historical losses and uncertainty surrounding the use of such assets. The valuation allowance increased by $6.7 million between December 31, 2025 and December 31, 2024 primarily due to the generation of operating losses.

As required under ASU 2023-09, the Company has included only the portion of the valuation allowance related to federal deferred tax assets in the "change in valuation allowance" line of the rate reconciliation. The following table presents a reconciliation of the total change in the valuation allowance (in thousands):

As of December 31, 2025, the Company has net operating loss, or NOL, carryforwards for federal and state income tax purposes of $294.6 million and $351.1 million, respectively. The federal NOL carryforwards generated prior to 2018 and state NOL carryforwards, if not utilized, will expire beginning in 2035. Federal NOL carryforwards aggregating $290.2 million are not subject to expiration.

The Company has research credit carryforwards for federal and state income tax purposes of approximately $12.3 million and $7.0 million, respectively, as of December 31, 2025. The federal credits begin to expire in 2038 and the state credits can be carried forward indefinitely.

Utilizationof some of the federal and state NOL and credit carryforwards may be subject to annual limitations due to the change in ownership provisions of the Internal Revenue Code of 1986 and similar state provisions. The annual limitation may result in the expiration of NOL and credit carryforwards before utilization. The Company has performed a Section

382 study as of September 30, 2023 and expects approximately$2.8 million of federal research and development tax credits and $51.0 million of California NOL carryforwards to expire unused due to Section 382 limitations.

The Company files tax returns in the United States, California and various states. The Company is not currently under examination in any of these jurisdictions and all of the Company’s tax years remain effectively open to examination due to NOL carryforwards.

The Company recognizes a tax benefit from uncertain tax positions when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. Due to the existence of the full valuation allowance, future changes in unrecognized tax benefits will not impact the Company’s effective tax rate.

The following table summarizes the activity in the Company’s gross unrecognized tax benefits (in thousands):

During the years ended December 31, 2025 and 2024, no interest or penalties were required to be recognized relating for unrecognized tax benefits. In the event the Company should need to recognize interest and penalties related to unrecognized income tax liabilities, this amount will be recorded as an accrued liability and an increase to income tax expense.