Boundless Bio, Inc.

Organization and Basis of Presentation

Description of Business

Boundless Bio, Inc. (Boundless Bio or the Company) is a clinical-stage oncology company dedicated to unlocking a new paradigm in cancer therapeutics that addresses the significant unmet need in patients with oncogene amplified tumors by interrogating extrachromosomal DNA (ecDNA), a root cause of oncogene amplification observed in 14 to 17% of cancer patients. The Company was focused on identifying targets essential for ecDNA functionality in oncogene amplified cancer cells, then designing and developing small molecule drugs called ecDNA-directed therapeutic candidates (ecDTx) to inhibit those targets, with the aim to prevent cancer cells from using chromosomal instability and ecDNA amplification biology to grow, adapt, and become resistant to existing therapies.

The Company was incorporated in the state of Delaware on April 10, 2018 and is headquartered in La Jolla, California.

Merger Agreement with Serapha Bio, Inc.

On June 22, 2026, Boundless Bio entered into an Agreement and Plan of Merger (the Merger Agreement) with Serapha Bio, Inc. (Serapha) and Boulder Merger Sub Corp., a wholly owned subsidiary of Boundless Bio (Merger Sub). Upon the terms and subject to the satisfaction of the conditions described in the Merger Agreement, Merger Sub will be merged with and into Serapha, with Serapha surviving as a wholly owned subsidiary of Boundless Bio (the Merger). The transaction is intended to qualify for federal income tax purposes as (i) a “reorganization” within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended (the Code), and/or (2) an exchange of shares of Serapha capital stock for Boundless Bio common stock under Section 351(a) of the Code.

Upon closing, Serapha's existing stockholders are expected to own approximately 96.31% of the combined company, and Boundless Bio's existing stockholders are expected to own approximately 3.69%, in each case on a fully diluted basis. Prior to closing, Boundless Bio may declare a special cash dividend to its current stockholders to the extent its net cash is estimated, based on a reasonable, good faith approximation, to exceed zero at closing.

The transaction requires approval from stockholders of both companies, as well as continued Nasdaq listing of Boundless Bio’s common stock, effectiveness of a Form S-4 registration statement, and receipt of at least $200 million in gross proceeds from related financings by Serapha, among other closing conditions. In connection with the Merger, Boundless Bio stockholders will also be asked to approve a reverse stock split and an increase in authorized shares. Either party may terminate the agreement under certain circumstances, in which case a termination fee of $1.0 million may be payable by the terminating party.

In connection with the Merger, on June 23, 2026, the Company committed to a reduction in workforce of approximately 75% and communicated the plan to affected employees. The Company recognized a charge of approximately $2.8 million for the three and six months ended June 30, 2026, of which approximately $1.5 million was recorded in research and development expense and approximately $1.3 million was recorded in general and administrative expense. The Company hadno associated liability as of December 31, 2025. During the six months ended June 30, 2026, the Company charged $2.8 million to expense and made no cash payments, resulting in a liability of $2.8 million recorded in accrued compensation as of June 30, 2026. The Company estimates aggregate one-time charges of approximately $3.0 million to $5.0 million, with the remainder to be recognized as the related services are rendered or the applicable conditions are met, in the second half of 2026.

The transaction is expected to close in the fourth quarter of 2026. Following completion of the Merger, the combined company plans to focus on advancing SERP-01, an investigational in vivo base editing therapy for Alpha-1 Antitrypsin Deficiency, and does not intend to continue development of any of Boundless Bio’s legacy product candidates.

If the Merger is not completed, Boundless Bio may continue to explore development opportunities for its ecDTx and pursue other strategic alternatives, including collaborations, financing opportunities or a transaction similar to the proposed Merger, or liquidation.

ATM Offering

On April 1, 2025, the Company entered into an Open Market Sale Agreement SM (the Sales Agreement) with Jefferies LLC (the Agent), under which the Company may, from time to time, sell shares of the Company’s common stock in “at the market” (ATM) offerings through or to the Agent, as sales agent or principal. The shares of common stock will be offered and issued pursuant to the Company’s shelf registration statement on Form S-3 (File No. 333-286302), including the Sales Agreement prospectus contained therein, filed with the Securities and Exchange Commission (SEC) on April 1, 2025 and declared effective by the SEC on April 10, 2025. Pursuant to the Sales Agreement prospectus, the Company may sell shares of its common stock having an aggregate offering price ofup to $14.5 million. Sales of the shares of common stock, if any, will be made at prevailing market prices at the time of sale, or as otherwise agreed with the Agent. The Agent will receive a commission from the Company of up to 3.0% of the gross proceeds of any shares of common stock sold under the Sales Agreement. The Company is not obligated to sell, and the Agent is not obligated to buy or sell, any shares of common stock under the Sales Agreement. No assurance can be given that the Company will sell any shares of common stock under the Sales Agreement, or, if it does, as to the price or amount of shares of common stock that it sells or the dates when such sales will take place. As of June 30, 2026, no shares had been sold under the Sales Agreement.

Liquidity

Since the Company commenced operations in 2018, it has devoted substantially all of its efforts and resources to organizing and staffing the Company, business planning, raising capital, building its proprietary Spyglass platform, discovering its ecDTx, developing its ecDNA diagnostic, establishing its intellectual property portfolio, conducting research, preclinical studies, and clinical trials, establishing arrangements with third parties for the manufacture of its ecDTx and related raw materials, and providing other general and administrative support for these operations. The Company does not have any products for sale and has not generated any revenue to date. The Company has funded its operations primarily from the sale and issuance of shares of its convertible preferred stock and common stock, including the net proceeds from the initial public offering (IPO) of its common stock completed on April 2, 2024.

As of June 30, 2026, the Company had cash, cash equivalents, and short-term investments of $72.6 million. During the six months ended June 30, 2026, the Company terminated its long-term headquarters lease effective May 31, 2026, involving a cash payment of approximately $10.0 million to the landlord, with the landlord separately retaining the Company's security deposit of approximately $0.5 million. See Note 7 —Lease Agreements for further information regarding the lease termination. Based on its current operating plan, and without giving effect to the anticipated pre-closing cash dividend or the proposed Merger, the Company believes that its existing cash, cash equivalents, and short-term investments will be sufficient to fund its operations for at least twelve months from the issuance date of these unaudited condensed financial statements.

Since inception, the Company has incurred significant operating losses and negative cash flows from its operations and expects that it will continue to do so into the foreseeable future as it assesses potential development of, seeks regulatory approval for, and potentially commercializes its ecDTx, utilizes third parties to manufacture its ecDTx and related raw materials, potentially identifies additional development opportunities for its ecDTx, seeks to expand its therapeutic pipeline, and expands and protects its intellectual property. If the Company obtains regulatory approval for any of its ecDTx, it expects to incur significant commercialization expenses related to product sales, marketing, manufacturing, and distribution. The Company does not expect to generate any revenue from product sales until it successfully completes development of and obtains regulatory approval for one or more of its ecDTx, which the Company expects will take several years and may never occur. In May 2025, Boundless Bio announced that it discontinued the monotherapy arm and combination arms of BBI-355 with third-party targeted therapies in the POTENTIATE trial based on initial trial data. Boundless Bio had been continuing to investigate BBI-355 in combination with BBI-825; however, in January 2026, following a strategic portfolio review, Boundless Bio elected to cease enrollment of the POTENTIATE trial due to market considerations, clinical data, and prioritization of its BBI-940 program. In June 2026, Boundless Bio announced that based on preliminary exposure data obtained in the early dose escalation cohorts of the KOMODO-1 clinical trial, Boundless Bio believed that the observed pharmacokinetic exposure data did not support continued clinical development of BBI-940. As of June 30, 2026, the Company had an accumulated deficit of $296.9 million, and, during the six months ended June 30, 2026, the Company incurred a net loss of $37.2 million and had negative cash flows from operations of $35.9 million. If the Merger is not completed and the Company decides to develop any current or future ecDTx, it will need to acquire a substantial amount of additional funding until such time as it is able to generate significant revenues to fund its research and development activities and operations. Accordingly, the Company expects to finance its cash requirements through equity offerings, debt financings, or other capital sources, including potential collaborations, licenses, and other similar arrangements. There can be no assurance that the Company will be successful in acquiring additional funding or that any additional funding would be sufficient to continue operations in future periods.

Basis of Presentation

The accompanying unaudited condensed financial statements have been prepared in accordance with United States generally accepted accounting principles (U.S. GAAP) and the requirements of the SEC for interim reporting. As permitted under those rules, certain footnote disclosures or other financial information that are normally required by U.S. GAAP have been condensed or omitted. The condensed financial statements are presented in U.S. dollars. Any reference in these notes to applicable guidance is meant to refer to U.S. GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Updates (ASU) promulgated by the Financial Accounting Standards Board (FASB).

The condensed balance sheet as of June 30, 2026, the condensed statements of operations and comprehensive loss for the six months ended June 30, 2026 and 2025, the condensed statements of stockholders’ equity for the six months ended June 30, 2026 and 2025, and the condensed statements of cash flows for the six months ended June 30, 2026 and 2025 are unaudited. These unaudited condensed financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments and the effects of the transactions described herein, necessary to present fairly the Company’s financial position, results of operations, and cash flows for the interim period presented. The financial data and the other financial information contained in these notes to the condensed financial statements are also unaudited. The results of operations for the six months ended June 30, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026 or for any other future annual or interim period. The condensed balance sheet as of December 31, 2025 included herein was derived from the audited financial statements as of that date. The unaudited condensed financial statements and these notes thereto should be read in conjunction with the Company’s audited financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025 filed with the SEC on March 9, 2026 (the Company's 2025 10-K).

Summary of Significant Accounting Policies

The Company’s significant accounting policies are disclosed in Note 2 to the audited financial statements included in the Company’s 2025 10-K. There were no material changes to the Company’s significant accounting policies during the six months ended June 30, 2026.

The Company qualifies as an “emerging growth company” (EGC) as defined in the Jumpstart Our Business Startups Act of 2012, as amended (JOBS Act). The JOBS Act permits EGCs such as the Company to take advantage of an extended transition period to comply with new or revised financial accounting standards applicable to public companies until those standards would otherwise apply to nonpublic companies. The Company has elected not to “opt out” of such extended transition period, which means that when an accounting standard is issued or revised and it has different application dates for public or nonpublic companies, the Company can adopt the new or revised standard at the time nonpublic companies adopt the new or revised standard and can do so until such time that it either (i) irrevocably elects to “opt out” of such extended transition period or (ii) no longer qualifies as an EGC.

Segment Reporting

Operating segments are identified as components of an enterprise about which discrete financial information is available for evaluation by the chief operating decision-maker (CODM) in making decisions regarding resource allocation and assessing performance. The Company operates and manages its business asone reporting andone operating segment, which is the business of designing and developing ecDTx, for which no revenue has been recorded. All of the Company’s long-lived assets are located in the United States. The Company’s CODM is its Chief Executive Officer. For purposes of assessing the Company’s financial performance and making resource allocation decisions, the CODM reviews total expenses, as well as expenses by nature.

Recent Accounting Pronouncements Not Yet Adopted

In November 2024, the FASB issued ASU No. 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. The new guidance requires more detailed information about specified types of expenses (including purchases of inventory, employee compensation, depreciation, amortization, and depletion) in commonly presented expense captions on the face of the statement of operations on an annual and interim basis. This guidance is effective for the Company for annual periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027. The new standard permits early adoption and can be applied prospectively or retrospectively. The Company is evaluating the effect that this guidance will have on its financial statements and related disclosures.

Fair Value Measurements

The following tables summarize the Company’s financial assets measured at fair value on a recurring basis and their respective input levels based on the fair value hierarchy described in Note 2 to the audited financial statements included in the Company’s 2025 10-K (in thousands):

(1)

Included in cash and cash equivalents on the balance sheets.

(2)

Included in short-term investments on the balance sheets.

(1)

Included in cash and cash equivalents on the balance sheets.

(2)

Included in short-term investments on the balance sheets.

The Company’s money market funds are classified as Level 1 because they are valued using quoted market prices. The Company’s investments consist of available-for-sale securities and are classified as Level 2 because their value is based on valuations using significant inputs derived from or corroborated by observable market data. No Level 3 assets were held during the periods presented.

There wereno transfers of assets between fair value levels for any period presented.

Investments

The following tables summarize investments accounted for as available-for-sale securities (in thousands):

On June 30, 2026 and December 31, 2025, the remaining contractual maturities of all the Company’s available-for-sale investments were less than 12 months. As of June 30, 2026 and December 31, 2025, the Company has not established an allowance for credit losses for any of its available-for-sale securities.

As of June 30, 2026, there were eighteen available-for-sale securities with an estimated fair value of $49.4 million in gross unrealized loss positions. As of December 31, 2025, there wereno available-for-sale securities in a gross unrealized loss position. Based on its review of these investments, the Company believes that the unrealized losses are attributable to changes in market interest rates and not to credit-related factors and therefore were not other-than-temporary in nature.

Property and Equipment

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

Depreciation and amortization expense related to property and equipment was $1.3 million and $1.5 million for the three and six months ended June 30, 2026, respectively, and $0.3 million and $0.6 million for the three and six months ended June 30, 2025, respectively.

In connection with the termination of the Company's headquarters lease effective May 31, 2026 (see Note 7 —Lease Agreements), the Company shortened the estimated useful lives of the leasehold improvements at that facility to coincide with the termination date. This change in estimate resulted in additional depreciation expense of approximately $0.8 million during the three and six months ended June 30, 2026.

Separately, in connection with the Merger and the Company's decision to wind down its research and development activities, the Company reassessed the estimated useful lives of certain property and equipment that are no longer expected to be used over their previously estimated service periods. As a result of shortening these useful lives, the Company recognized additional accelerated depreciation of approximately $0.3 million during the three and six months ended June 30, 2026, which is included in operating expenses in the condensed statements of operations and comprehensive loss.

In connection with the same facility exit, the Company determined that certain furniture and fixtures and laboratory equipment located at the facility would not be relocated and would be disposed of. The Company concluded these circumstances indicated that the carrying amounts of the affected assets may not be recoverable and, as the assets were not expected to generate future cash flows, wrote them down to their estimated fair value. The Company recognized impairment losses of $1.4 million on furniture and fixtures and $0.2 million on laboratory equipment, totaling $1.6 million, for the three and six months ended June 30, 2026, of which approximately $1.1 million was recorded in research and development expense and approximately $0.5 million was recorded in general and administrative expense in the condensed statements of operations and comprehensive loss. No impairment losses were recognized for the three and six months ended June 30, 2025.

Accounts Payable and Accrued Liabilities

Accounts payable and accrued liabilities consisted of the following (in thousands):

Lease Agreements

2024 Lease

The Company was a party to a non-cancellable facility lease for approximately 80,168 square feet of laboratory and office space in San Diego, California (the 2024 Lease). The 2024 Lease had an initial lease term of 120 months, which commenced in November 2024, and provided the Company with the right to extend the term for an additional 60 months at expiry, which was not included in the lease term used for measurement. The 2024 Lease included obligations to make base rent payments and additional variable lease payments for the Company's allocated share of variable costs associated with the operation and management of the property, which included utilities, property taxes, common area maintenance, and amenities costs. The 2024 Lease provided for a rent abatement period through July 2025.

The Company recorded an operating lease liability based on the present value of the lease payments using an estimated incremental borrowing rate of approximately 8.3%, as the 2024 Lease did not have a stated rate and the implicit rate was not readily determinable, and a corresponding right-of-use (ROU) asset. Management exercised judgment in estimating the incremental borrowing rate and in determining the lease term. The renewal option was evaluated at lease commencement and excluded from the lease term, as the Company was not reasonably certain to exercise the option.

The Company was required to maintain a security deposit under the 2024 Lease in the form of a standby letter of credit, which was collateralized by a restricted cash deposit of approximately $0.5 million. In April 2026, in connection with the termination described below, the Landlord drew on the letter of credit, and the related restricted cash was released. As of June 30, 2026, the Company hadno restricted cash associated with the 2024 Lease.

Lease Termination and Facility Exit Costs

In April 2026, the Company entered into an Agreement for Termination of Lease and Voluntary Surrender of Premises (the Termination Agreement) with ARE-10933 North Torrey Pines, LLC (the Landlord), pursuant to which the parties agreed to terminate the 2024 Lease for the Company's headquarters facility, located at 10955 Alexandria Way, San Diego, California, effective May 31, 2026. The original lease term, which would have run through October 2034, was shortened by approximately 100 months. In connection with the early termination, the Company paid a non-refundable termination payment of $10.0 million to the Landlord on April 10, 2026, and the Landlord retained the Company's security deposit (in the form of a letter of credit) of approximately $0.5 million. Total termination consideration was $10.5 million.

The early termination was accounted for as a lease modification that shortened the lease term under ASC 842. As of the modification date, the Company remeasured the lease liability to $11.7 million, representing the present value of the remaining lease payments, including the $10.5 million termination consideration, and reduced the ROU asset by an amount equal to the change in the lease liability. Because the ROU asset remained positive after the adjustment, no gain or loss was recognized at the modification date. The termination consideration is recognized as operating lease cost over the two-month wind-down period ended May 31, 2026 through amortization of the modified ROU asset, resulting in wind-down operating lease cost of $6.2 million included in operating expenses in the condensed statements of operations for the three and six months ended June 30, 2026.

In connection with the early termination, the Company shortened the estimated useful lives of leasehold improvements at the facility to coincide with the May 31, 2026 termination date, resulting in accelerated depreciation of approximately $0.8 million included in operating expenses in the condensed statements of operations. The Company also recognized impairment losses on furniture and fixtures of $1.4 million and laboratory equipment of $0.2 million, as these assets will not be relocated from the facility. These impairment losses, totaling $1.6 million, are included inoperating expenses in the condensed statements of operations for the three and six months ended June 30, 2026.

Cash outflows related to the early termination and wind-down totaled approximately $11.2 million during the six months ended June 30, 2026, consisting of the $10.0 million termination payment and $1.2 million of monthly rent for the April–May wind-down period, and are classified within operating activities in the condensed statements of cash flows. The Landlord's $0.5 million draw on the letter of credit collateralizing the Company's security deposit is reflected as a reduction in restricted cash within the reconciliation of cash, cash equivalents, and restricted cash.

By the May 31, 2026 termination date, the modified ROU asset had been fully amortized and the modified operating lease liability had been fully settled. Accordingly, the Company hadno ROU asset or operating lease liability related to the 2024 Lease as of June 30, 2026.

New Headquarters Lease

In April 2026, the Company entered into a lease for approximately 10,822 square feet of office and laboratory space in La Jolla, California (the 2026 Lease), to serve as its successor headquarters facility. The 2026 Lease has a term of 12 months and provides for fixed rent of approximately $56,000 per month, with the Company's allocated share of operating costs (including utilities, property taxes, common area maintenance, and similar charges) treated as variable lease payments. The Company paid a security deposit of approximately $77,000, which is recorded within prepaid expenses and other current assets in the condensed balance sheet as of June 30, 2026.

Because the 2026 Lease has a term of 12 months or less and does not include an option to purchase the underlying asset that the Company is reasonably certain to exercise, the Company elected the short-term lease exception under ASC 842-20-25-2. Accordingly, the Company didnot record a ROU asset or lease liability for the 2026 Lease and recognizes lease payments as short-term lease cost on a straight-line basis over the lease term.

Lease Cost

Lease expense for the three months ended June 30, 2026 and 2025 totaled approximately $6.7 million and $2.4 million, respectively, consisting of operating lease cost of approximately $6.2 million and $1.8 million, short-term lease cost of approximately $46,000 and $0, and variable lease cost of approximately $0.4 million and $0.6 million, respectively. Lease expense for the six months ended June 30, 2026 and 2025 totaled approximately $9.2 million and $4.7 million, respectively, consisting of operating lease cost of approximately $8.1 million and $3.7 million, short-term lease cost of approximately $46,000 and $0, and variable lease cost of approximately $1.1 million and $1.0 million, respectively.

The Company paid approximately $13.4 million and $0.1 million for amounts included in the measurement of its operating lease liabilities for the six months ended June 30, 2026 and 2025, respectively (2026 consisting of the $10.5 million termination consideration and $2.9 million of monthly rent); all such amounts were included within operating activities in the condensed statements of cash flows.

Lease Commitments

As of June 30, 2026, the Company hadno operating lease ROU assets or operating lease liabilities recorded in its condensed balance sheet, as the 2024 Lease was terminated effective May 31, 2026 and the 2026 Lease qualifies for the short-term lease exception. Accordingly, the Company had no future undiscounted operating lease payment obligations, weighted-average remaining lease term, or weighted-average discount rate to disclose as of June 30, 2026.

As of December 31, 2025, the 2024 Lease was the Company's only lease. The operating lease liability was $49.0 million, the weighted-average remaining lease term was 8.8 years, and the weighted-average discount rate was 8.3%.

Commitments and Contingencies

Contracts

The Company enters into contracts in the normal course of business with various third parties for preclinical research studies, clinical trials, testing, manufacturing, and other services. These contracts generally provide for termination upon notice and are cancellable without significant penalty or payment and do not contain any minimum purchase commitments.

Indemnification Agreements

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners, and other parties with respect to certain matters including, but not limited to, losses arising out of breach of agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with its officers and members of its board of directors that require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as officers or directors. The maximum potential future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs because of these indemnification agreements. The Company has not accrued any liabilities related to such indemnification agreements in its financial statements as of June 30, 2026 or December 31, 2025 because it determined the likelihood of incurring a payment obligation pursuant to such agreements was not probable.

Litigation

Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties, and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. There are no matters currently outstanding for which any liabilities have been accrued. The Company was not a defendant in any lawsuit for the six months ended June 30, 2026 or the year ended December 31, 2025.

Common Stock

Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consisted of the following (in thousands):

Stock-Based Compensation

Equity Incentive Plan

In March 2024, the Company’s board of directors adopted, and the Company’s stockholders approved, the 2024 Incentive Award Plan (the Plan), which became effective in connection with the IPO and has a term often years. As of June 30, 2026, a total of 5,068,078 shares of common stock were authorized for issuance under the Plan, which includes a January 1, 2026 increase of 1,120,362 shares, pursuant to the evergreen provision of the Plan. See Note 10 to the audited financial statements included in the Company’s 2025 10-K for a description of the evergreen provision of the Plan. On June 30, 2026,2,724,148 of these shares were available for grant under the Plan.

Prior to the adoption of the Plan, the Company had awarded common stock options under the 2018 Equity Incentive Plan (as amended, the Predecessor Plan). Under the provisions of the Plan, the shares subject to awards issued under the Predecessor Plan that were outstanding as of March 27, 2024, the effective date of the Plan, and that are subsequently cancelled or forfeited, will become available for issuance under, and will increase the number of shares that may be issued under, the Plan.

Repricing of Outstanding Options

In August 2024, the compensation committee of the Company’s board of directors, as administrator of the Plan and the Predecessor Plan, approved an option repricing (2024 Repricing), which was effective on August 19, 2024 (the Repricing Effective Date). The repricing applied to options to purchase up to an aggregate of 3,484,346 shares of the Company’s common stock with an exercise price per share in excess of the closing price per share of the Company’s common stock on the Repricing Effective Date, held by eligible employees of the Company that were granted under the Plan or the Predecessor Plan and were outstanding as of the Repricing Effective Date (the Repriced Options). As of June 30, 2026, Repriced Options to purchase up to an aggregate of 2,208,476 shares of the Company’s common stock remained outstanding. See Note 10 to the audited financial statements included in the Company’s 2025 10-K for a description of the 2024 Repricing.

Option Modifications in Connection with the Merger

On June 22, 2026, in connection with the entry into the Merger Agreement (see Note 1 —Organization and Basis of Presentation), the Company amended all outstanding stock options granted under the Plan and the Predecessor Plan. The amendment (i) accelerated the vesting of all unvested options such that they became fully vested and exercisable as of June 22, 2026, (ii) extended the post-termination exercise period of the options until the later of (A) March 31, 2027 or, if the closing of the Merger occurs prior to that date, the date three months following the closing of the Merger, and (B) such later date provided in the applicable option agreement, and (iii) accelerated the premium end date applicable to the Repriced Options under the 2024 Repricing to June 22, 2026. The amendment affected options to purchase 5,945,008 shares of common stock held by 48 holders.

The Company accounted for the amendment as a modification under ASC 718 and recognized $2.0 million of stock-based compensation expense in connection with the amendment during the three and six months ended June 30, 2026, of which $1.5 million was recorded in general and administrative expense and $0.5 million was recorded in research and development expense. Total incremental compensation cost resulting from the modification was $0.4 million. The remainder consists of previously unrecognized compensation cost accelerated by the amendment, net of compensation cost previously recognized for options that were not expected to vest under their original terms, and of compensation cost measured at the modification-date fair value of those options. Fair values were estimated using a Black-Scholes option-pricing model with the following weighted-average assumptions as of the modification date: expected term of 0.8 years, expected volatility of 98.8%, risk-free interest rate of 4.0%, and expected dividend yield of 0%.

Stock Options

Stock option activity under the Plan and the Predecessor Plan and certain other related information is as follows (in thousands except weighted-average exercise price and remaining term):

Aggregate intrinsic value in the above table is the difference between the estimated fair value of the Company’s common stock as of either June 30, 2026 or December 31, 2025, and the exercise price of stock options that had exercise prices below that value.

For the Repriced Options, the weighted-average prices and intrinsic value information in the table above is calculated based on the exercise price per share that applied immediately prior to the Repricing Effective Date.

During the six months ended June 30, 2026, the total intrinsic value of stock options exercised was approximately $14,000. No options were exercised during the six months ended June 30, 2025.

Employee Stock Purchase Plan

The Company maintains the 2024 Employee Stock Purchase Plan (the ESPP). As of June 30, 2026,492,641 shares of common stock were available for issuance under the ESPP. The Company issued and sold 34,610 and 85,568 shares under the ESPP during the six months ended June 30, 2026 and 2025, respectively.

As of June 30, 2026, unrecognized compensation cost related to the ESPP was approximately $0.3 million. In connection with the Merger, the Company has suspended the ESPP and halted participant payroll deductions, and expects that a substantial portion of this cost will not be recognized.

Stock-Based Compensation Expense

Stock-based compensation expense, including the expense related to the ESPP, as recorded in the accompanying condensed statements of operations and comprehensive loss was as follows (in thousands):

As of June 30, 2026, there wasno unrecognized compensation cost related to outstanding stock options, as the vesting of all outstanding options was accelerated in full on June 22, 2026 in connection with the Merger.

The weighted-average assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted during the periods indicated were as follows:

The weighted-average grant date per share fair value of options granted during the three months ended June 30, 2026 and 2025 were $1.12 and $0.89, respectively, and the weighted-average grant date per share fair value of options granted during the six months ended June 30, 2026 and 2025 were $1.05 and $1.89, respectively.

Net Loss Per Common Share

The following table summarizes the calculation of basic and diluted net loss per common share attributable to common stockholders (in thousands, except per share data):

The Company excluded the following potential shares of its common stock, presented based on amounts outstanding at each period end, from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect (in thousands):

Segment Information

The CODM reviews the budget versus actual expense by nature of expense. The following table sets forth the Company’s segment loss disclosure for the three and six months ended June 30, 2026 and 2025 (in thousands):

(1)

Includes expenses such as software licenses, database subscriptions, lab service contracts, travel, and other costs.

(2)

Includes expenses such as travel, investor relations services, software licenses, employee training and development, and other costs.

Subsequent Events

The Company has evaluated subsequent events through August 7, 2026, the date on which these unaudited condensed financial statements were issued.

See Note 1 —Organization and Basis of Presentation for a description of the Merger Agreement entered into by the Company on June 22, 2026.

Other than the events described above and elsewhere in these condensed financial statements, the Company is not aware of any subsequent events requiring recognition or disclosure.