Braveheart Bio, Inc.

Notes to Condensed Financial Statements (unaudited)

1. Description of Business

Organization

Braveheart Bio, Inc. (the “Company”) was incorporated in the state of Delaware in May 2024 and is located in San Francisco, California. The Company is a clinical-stage biopharmaceutical company dedicated to developing therapeutics to treat hypertrophic cardiomyopathy (“HCM”) and related conditions by targeting overactive proteins within the heart.

On August 7, 2026, the Company completed its initial public offering (“IPO”) of its common stock, par value $0.0001 per share (the “common stock”) in which the Company sold 24,437,500 shares of its common stock, which includes the exercise in full of the underwriters’ option to purchase an additional 3,187,500 shares of common stock, at a public offering price of $18.00 per share, resulting in aggregate gross proceeds of $439.9 million and net proceeds of approximately $404.4 million, after deducting underwriter discounts and commissions of $30.8 million and other offering costs of $4.7 million.

On July 29, 2026, in connection with the IPO, the Company effected a 1-for-4.38 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios of each series of the Company’s redeemable convertible preferred stock. Accordingly, all share and per share amounts for all periods presented in the accompanying unaudited interim condensed financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustments of the redeemable convertible preferred stock conversion ratios throughout this Quarterly Report.

Immediately prior to the closing of the IPO, the Company's outstanding redeemable convertible preferred stock automatically converted into 49,657,532 shares of common stock. Following the closing of the IPO, no shares of redeemable convertible preferred stock were outstanding. In connection with the closing of the IPO, the Company's certificate of incorporation was amended and restated to authorize 500,000,000 shares of common stock, par value $0.0001 per share and 10,000,000 shares of undesignated preferred stock, par value $0.0001 per share.

Liquidity and Capital Resources

Since inception, the Company has devoted substantially all of its resources to research and development activities, business planning, establishing and maintaining its intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these operations. The Company has a limited operating history, and the sales and income potential of its business is unproven. The Company has incurred net losses and negative cash flows from operating activities since its inception and expects to continue to incur net losses into the foreseeable future as it continues the development of its therapeutic candidates.

As of September 30, 2026, the Company had an accumulated deficit of $122.4 million and cash, cash equivalents and investments of $503.5 million. For the nine months ended September 30, 2026 and 2025, the Company had a net loss of $55.8 million and $59.6 million, respectively, and net cash used in operating activities of $46.5 million and $0.7 million, respectively.

The Company has evaluated whether there are conditions and events considered in the aggregate that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that these condensed financial statements are issued. As of November 10, 2026, the issuance date of the condensed financial statements, the Company expects that its cash, cash equivalents and investments will be sufficient to fund its operating expenses and capital expenditure requirements for at least the next twelve months.

The Company will need additional financing to support its continuing operations and pursue its growth strategy. Until such time as the Company can generate significant revenue from product sales, if ever, the Company expects to finance its cash needs through a combination of equity offerings, debt or royalty financings, and collaborations. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into collaborations or other arrangements. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain sufficient funding, the Company will be forced to delay, scale back or discontinue some or all of its research and development programs, product portfolio expansion efforts or commercialization efforts, which could adversely affect its business prospects. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.

2. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying unaudited interim condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("GAAP") and pursuant to the rules and regulations applicable to interim financial reporting. These condensed financial statements should be read in conjunction with the audited financial statements and related notes for the year ended December 31, 2025. The unaudited interim condensed financial statements reflect all adjustments that, in the opinion of management, are necessary for a fair presentation of the results for the interim periods presented. Such adjustments are of a normal recurring nature. The condensed results of operations for the nine months ended September 30, 2026, are not necessarily indicative of the results to be expected for the full year ending December 31, 2026, or for any other future period.

The condensed balance sheet as of December 31, 2025, has been derived from the audited financial statements as of that date.

Use of Estimates

The preparation of condensed financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of income and expenses during the reporting periods. Significant estimates and assumptions are used for, but not limited to, the accruals for research and development expenses, stock-based compensation expense, the determination of fair value of equity instruments, the valuation of equity and liability-classified compensation awards, the fair value of acquired in-process research and development, and income taxes. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.

Cash and Cash Equivalents

Cash and cash equivalents include cash in readily available operating accounts, U.S. Treasury bills, money market funds and deposits with commercial banks. Cash equivalents are defined as short-term, highly liquid investments with original maturities of 90 days or less from the date of purchase.

Available-for-Sale Securities

The Company classifies its investments in debt securities as available-for-sale. Debt securities that do not meet the definition of cash equivalents are classified as short-term or long-term investments based on their remaining maturity at each balance sheet date. Securities maturing within one year are included in short-term investments, and those maturing in more than one year are included in long-term investments. Accordingly, securities initially classified as long-term investments are reclassified to short-term investments when their remaining maturity becomes one year or less.

The Company records its available-for-sale securities at estimated fair value in the condensed balance sheets. Unrealized gains and losses, if any, are reported as a component of other comprehensive loss in the condensed statements of operations and comprehensive loss and are included in accumulated other comprehensive loss, a separate component of stockholders’ equity.

Any premium arising at purchase is amortized, and any discount arising at purchase is accreted, to maturity using the effective interest method. Amortization of premiums and accretion of discounts are recorded in interest income in the condensed statements of operations and comprehensive loss.

Fair Value Measurements

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

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

• Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

• Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques.

The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy (see Note 4). The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities.

Operating Leases

The Company accounts for leases in accordance with ASC 842, Leases. The Company entered into its first lease agreement in January 2026 (see Note 7). The Company determines if an arrangement is a lease at inception. Operating lease right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset during the lease term, and operating lease liabilities represent the Company’s obligation to make lease payments. ROU assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the remaining lease term. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. Lease expense is recognized on a straight-line basis over the lease term.

Property and Equipment

Property and equipment, net consists of lab equipment, computer equipment, furniture and fixtures, and leasehold improvements, which are recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets (three toseven years, or, for leasehold improvements, the shorter of the remaining lease term or the estimated useful life). Repairs and maintenance costs are expensed as incurred.

Deferred Offering Costs

The Company incurred certain legal, accounting, and other third party fees that were directly related to the Company’s IPO that closed in August 2026. Such costs were recorded in stockholders’ equity (deficit) as a reduction to the proceeds received from the IPO.

Stock-Based Compensation – Liability-Classified Awards

Restricted stock awards that include a vesting condition that is not related to service, performance or market conditions are classified as liabilities. The Company measures these awards at fair value using a Monte Carlo simulation model and remeasures them at each reporting date until they are reclassified to equity or settled. Compensation cost is recognized over the derived service period and the Company does not update the derived service period after the initial measurement date (see Note 9).

Recently Issued Accounting Standards Not Yet Adopted

In November 2024, the FASB issued ASU No. 2024-03, Income Statement—Reporting Comprehensive Income (Topic 220): Disaggregation of Income Statement Expenses. This ASU requires enhanced disaggregation of certain expense categories in the notes to the financial statements. The guidance is effective for annual periods beginning after December 15, 2026, and interim periods within annual reporting periods beginning after December 15, 2027, with early adoption permitted, and the standard may be applied on either a prospective or retrospective basis. The Company is currently evaluating the impact of this standard on its financial statements.

In September 2025, the FASB issued ASU No. 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. This ASU removes references to project stages from the guidance on internal-use software costs, clarifies the threshold for beginning to capitalize those costs, and supersedes the separate guidance for website development costs. The guidance is effective for annual periods beginning after December 15, 2027, and interim periods within those annual reporting periods, with early adoption permitted. The Company is currently evaluating the impact of this standard on its financial statements.

3. Related Party Transactions

Financial Accounting Standards Board (FASB) ASC 850, Related Party Disclosures (FASB ASC 850) requires that transactions with related parties that would make a difference in decision making shall be disclosed so that users of the financial statements can evaluate their significance.

Hengrui Pharmaceuticals Exclusive License Agreement

The Company entered into an Exclusive License Agreement (the “License Agreement”) with Jiangsu Hengrui Pharmaceuticals Co., Ltd. (“Hengrui”) in September 2025, as described in the Company’s audited financial statements for the year ended December 31, 2025. Hengrui is a related party of the Company as a result of its ownership of 7,420,091 shares of the Company’s common stock, representing approximately 8.3% of the Company’s issued common stock as of September 30, 2026. During the nine months ended September 30, 2026, the Company incurred related party expenses of $7.0 million in connection with the License Agreement for the completed manufacturing technology transfer milestone and initial echo data transfer milestone, which were recorded within research and development expense on the condensed statement of operations and comprehensive loss. The manufacturing technology transfer milestone of $6.0 million was paid as of September 30, 2026. The initial echo data transfer milestone of $1.0 million was recorded within accrued expenses on the condensed balance sheet as of September 30, 2026. During the nine months ended September 30, 2026, the Company also incurred related party expenses of $0.4 million for drug supply purchases from Hengrui, which was recorded within research and development expense on the condensed statement of operations and comprehensive loss and within accrued expenses on the condensed balance sheet. As of September 30, 2026, the accrued license milestone of $3.0 million recorded as of December 31, 2025 has been paid.

Other Related Party Transactions

During the nine months ended September 30, 2026, the Company incurred related party expenses of $0.2 million in connection with fees to certain directors, and board and committee members. These expenses are included within general and administrative expense on the condensed statement of operations and comprehensive loss. As of September 30, 2026, $0.1 million of these expenses are accounted for within accounts payable or accrued expenses on the condensed balance sheet.

4. Fair Value Measurements

Assets measured at fair value on a recurring basis are as follows (in thousands):

There have been no transfers between fair value levels during the nine months ended September 30, 2026. Money market funds are valued at the closing price reported by the fund sponsor from an actively-traded exchange. The Company obtains the fair value of its Level 2 cash equivalents and short-term investments from third-party pricing services. The pricing services utilize industry standard valuation models whereby all significant inputs, including benchmark yields, reported trades, broker/dealer quotes, issuer spreads, bids, offers, or other market-related data, are observable.

5. Marketable Securities

Marketable securities consisted of available-for-sale securities as follows (in thousands):

During the three and nine months ended September 30, 2026, the Company purchased $227.9 million in short-term investments and $154.6 million in long-term investments. There wereno sales or maturities of available-for-sale debt securities during the three and nine months ended September 30, 2026.

The Company's money market mutual fund holdings are highly liquid and invested primarily in short-term U.S. Treasury bills and obligations guaranteed by the U.S. government. The Company’s portfolio of available-for-sale debt securities consists primarily of U.S. Treasury securities. These securities are classified as short- term investments when remaining effective maturities are one year or less from the balance sheet date, and as long-term investments when maturities exceed one year from the balance sheet date. As of September 30, 2026, the Company’s long-term investments had contractual maturities of less than two years.

As of September 30, 2026, the Company’s available-for-sale securities had gross unrealized losses of $0.7 million. Management determined that the gross unrealized losses on the Company's available-for-sale securities as of September 30, 2026 were primarily attributable to current economic and market conditions and not credit risk. As of September 30, 2026, no allowance for credit losses was recorded for available-for-sale securities. It is neither management's intention to sell nor is it more likely than not that the Company will be required to sell any investments prior to recovery of their amortized cost basis, which is expected to be at maturity.

There wereno available-for-sale securities in an unrealized loss position for greater than one year as of September 30, 2026, and the Company heldno available-for-sale securities as of December 31, 2025.

Accrued interest receivable on the Company's available-for-sale securities was $1.4 million at September 30, 2026, and is included in prepaid expenses and other current assets on the condensed balance sheet.

6. Balance Sheet Details

Accrued Expenses

Accrued expenses consist of the following (in thousands):

7. Commitments and Contingencies

Legal Proceedings

In the event the Company becomes subject to claims or suits arising in the ordinary course of business, the Company would accrue an estimated liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated.

The Company has not recorded any such liabilities as of September 30, 2026.

Hengrui License Agreement – Contingent Obligations

As described in Note 3 to our audited financial statements for the year ended December 31, 2025, the Company is obligated to make contingent cash payments to Hengrui upon the achievement of specified milestones. During the nine months ended September 30, 2026, the Company has incurred $7.0 million related to specified milestones. The Company will continue to evaluate the probability of remaining contingent milestone and royalty payments at each reporting period.

The flipping transaction provision described in Note 3 to our audited financial statements for the year ended December 31, 2025, remains in effect through March 3, 2027 (18 months from the September 3, 2025, effective date of the License Agreement). As of September 30, 2026, no flipping transaction has occurred.

Operating Lease

Effective January 2026, the Company executed a sublease agreement (the “Sublease”) with Aperture Group, LLC, for office space located in San Francisco, California. The Company determined the Sublease is an operating lease. The initial term of the Sublease is approximately 24 months and the commencement date occurred in January 2026. Lease payments total approximately $0.4 million annually, exclusive of operating expenses including utilities, common area maintenance, insurance, and property taxes.

Upon commencement of the Sublease in January 2026, the Company recognized an operating lease right-of-use asset of $0.8 million and a corresponding operating lease liability of $0.8 million, based on the present value of the remaining minimum lease payments using an incremental borrowing rate of 7.65%.

Rent expense was $0.1 million and $0.3 million for the three and nine months ended September 30, 2026, respectively.

Future minimum annual obligations under the Sublease, to be recognized over a weighted-average remaining term of 1.2 years, are as follows (in thousands):

8. Convertible Preferred Stock and Stockholders’ Equity (Deficit)

Convertible Preferred Stock

Redeemable Convertible Preferred Stock

During the nine months ended September 30, 2026, the Company issued 60,000,000 shares of Series A redeemable convertible preferred stock at a price of $1.00 per share in a third closing under the Series A Preferred Stock Purchase Agreement, which granted certain investors the right to purchase these additional shares upon approval by the Board of Directors. This third closing occurred on April 24, 2026, and the Company received $60.0 million in gross proceeds. In connection with this additional closing, the Company recorded a deemed dividend of $3.6 million, representing the excess of the estimated fair value of the Series A redeemable convertible preferred stock issued over the $1.00 per share purchase price. The deemed dividend increased the carrying value of the Series A redeemable convertible preferred stock and increased net loss attributable to common stockholders in the computation of net loss per share (see note 10). Immediately prior to the closing of the Company’s IPO, all 217,500,000 outstanding shares of Series A redeemable convertible preferred stock automatically converted into 49,657,532 shares of common stock (see note 1).

Common Stock

As of September 30, 2026, the Company was authorized to issue 500,000,000 shares of $0.0001 par value common stock. As of September 30, 2026,89,867,737 shares of common stock were issued and 82,069,077 shares of common stock were outstanding. The difference represents 7,798,660 shares of unvested restricted common stock, which are issued but not outstanding for accounting purposes until vested.

Common stock reserved for future issuance consisted of the following:

9. Equity Incentive Plan and Stock-Based Compensation

Stock Options

On May 5, 2026, the Company entered into an amendment to the 2025 Stock Option and Grant Plan (the “2025 Plan”), pursuant to which the number of shares of common stock available for issuance thereunder was increased to 14,576,068 shares, representing an increase of 2,191,781 shares. On June 24, 2026, the Company’s board of directors adopted, and the Company’s stockholders approved, the 2026 Stock Option and Incentive Plan (the “2026 Plan”) and the 2026 Employee Stock Purchase Plan (the “2026 ESPP”) (together, the “Stock Plans”), which became effective on August 4, 2026 in connection with the Company's IPO. The Company initially reserved 10,761,900 and 894,100 shares of common stock for issuance under the 2026 Plan and the 2026 ESPP, respectively. The 2026 Plan has replaced the 2025 Plan and the shares reserved for future issuance under the 2025 Plan ceased to be available for issuance at the time the 2026 Plan became effective. The 2025 Plan will continue to govern outstanding equity awards granted thereunder and any shares underlying outstanding stock awards granted under the 2025 Plan that subsequently expire or are repurchased, forfeited, cancelled, or withheld will return to the 2026 Plan and be reserved and available for issuance.

A summary of the Company’s stock option activity for the nine months ended September 30, 2026, under the 2025 Plan and 2026 Plan is as follows (in thousands, except share and per share data and years):

Exercisable options reflect the number of options vested as of the date reported. The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the Company’s common stock for all options that were in-the-money as of September 30, 2026.

The weighted-average grant date fair value of options granted during the nine months ended September 30, 2026, was $8.56 per share. There wereno options granted during the nine months ended September 30, 2025.

The Company recorded stock-based compensation expense related to stock options as follows (in thousands):

As of September 30, 2026, the unrecognized compensation cost related to outstanding stock options was $45.4 million and is expected to be recognized as expense over a weighted-average period of approximately 3.7 years.

The assumptions used in the Black-Scholes option pricing model to determine the fair value of the option grants issued for the nine months ended September 30, 2026, were as follows:

Restricted Stock Awards

As of September 30, 2026, the Company recorded $0.1 million in other long-term liabilities on the condensed balance sheet related to unvested awards that the Company has the option to repurchase.

A summary of the Company’s restricted stock activity under the 2025 Plan for the nine months ended September 30, 2026, is as follows:

Restricted Stock Award Modification

In July 2026, the Company’s board of directors modified the vesting criteria for 1.7 million shares of restricted stock awards for an executive officer with certain market-based conditions. Under the modified terms, subject to the executive’s continued employment through the vesting dates, the awards vest intwo equal tranches upon the achievement of stock price hurdles, set as specified multiples of the original issuance price of the Series A redeemable convertible preferred stock, within specified periods following the Company’s public listing. In addition, vesting cannot occur before the later of a specified period following the Company’s public listing and the public disclosure of top-line results from a Phase 3 clinical study conducted by Hengrui. If the shares underlying the award have not vested by the tenth anniversary of the closing of the Company’s Series A financing, the Company has the right, but not the obligation, to repurchase such shares at the original per share purchase price.

Because vesting also depends on the timing of the public disclosure of clinical results from a study conducted by a third party, which is not a service, performance or market condition, the awards were classified as liabilities as of the modification date. No compensation cost was recognized for the original awards because the change-in-control condition was not considered probable. No compensation cost was recognized at the modification date because vesting of the modified awards also required the Company’s public listing, which was not considered probable until the Company completed its initial public offering on August 7, 2026. The fair value of the awards, determined using a Monte Carlo simulation model, was $25.2 million at the modification date and $28.1 million as of September 30, 2026. Significant assumptions used in the model were expected volatility of 98.4% at the modification date and 89.1% as of September 30, 2026, based on the historical volatility of a group of comparable publicly traded entities; risk-free interest rates of 4.31% and 4.88%, respectively; an expected dividend yield ofzero; and vesting end terms through the end of each tranche’s market condition period in September 2028 and September 2029. The awards are remeasured to fair value at each reporting date until they are reclassified to equity or settled, and compensation expense is recognized on a straight-line basis over the derived service period of each tranche, approximately 0.8 and 1.0 years from the modification date.

Other Restricted Stock Awards

In addition to grants under the 2025 Plan, the Company has also granted RSAs outside of the 2025 Plan. The shares were issued under the terms of restricted stock purchase agreements, and unvested shares are subject to repurchase by the Company upon the holder’s termination of his or her relationship with the Company at the original purchase price per share.

A summary of the Company’s restricted stock activity outside of the 2025 Plan for the nine months ended September 30, 2026, is as follows:

The total fair value of all RSAs vested during the nine months ended September 30, 2026, was $1.2 million.

The Company recorded stock-based compensation expense related to RSAs as follows (in thousands):

Stock-based compensation expense for RSAs for the three and nine months ended September 30, 2026 includes $6.1 million related to the modified RSAs described above. This expense is included in general and administrative expense in the condensed statements of operations and comprehensive loss, and the related share-based liability of $6.1 million is included in other current liabilities on the condensed balance sheet.

As of September 30, 2026, the unrecognized compensation cost related to all outstanding RSAs was $6.4 million and is expected to be recognized over a weighted-average period of approximately 2.9 years, in addition to $21.9 million of total unrecognized stock-based compensation expense related to the modified executive RSAs, which we expect to recognize over a remaining weighted-average period of 0.8 years. No stock-based compensation expense related to RSAs was recorded for the three and nine months ended September 30, 2025.

2026 Employee Stock Purchase Plan

No offerings have been authorized to date under the 2026 ESPP.

10. Net loss per share

The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per share data):

The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been antidilutive are as follows:

(1)As of September 30, 2026, excluded from this amount are 10,702 shares underlying vested common stock options with a weighted average exercise price of $0.04, which have been included in the computation of basic and diluted net loss per share on the date all necessary conditions have been satisfied for issuance, which is the date any service based vesting conditions have been met, as they represent shares issuable for little or no cash consideration upon the satisfaction of certain conditions pursuant to ASC 260-10-45-13.

11. Income Taxes

As of September 30, 2026, there have been no material changes to the Company’s uncertain tax positions or its assessment regarding the realizability of its deferred tax assets as compared to December 31, 2025. The Company continues to maintain a full valuation allowance on its net deferred tax assets as it has determined that it is more likely than not that these deferred tax assets will not be realized. For the three and nine months ended September 30, 2026, the Company’s effective tax rate differed from the U.S. federal statutory rate of 21% primarily due to the full valuation allowance maintained against its deferred tax assets.

12. Segment Reporting

The Company operates and manages its business asone reportable and operating segment, which is the business of developing therapeutics to treat hypertrophic cardiomyopathy. The Company’s chief operating decision maker (“CODM”) is the chief executive officer, who assesses performance of the segment based on net loss, which includes evaluating the progress of ongoing research and development. The measure of segment assets is reported on the balance sheet as total assets. All long-lived assets are maintained in the

United States. The following table contains information on segment profit or loss, including significant segment expenses (in thousands):

(a)Other primarily includes consultants, legal, insurance expenses and subscriptions.

13. Subsequent Events

The Company has evaluated subsequent events through the date the condensed financial statements were issued. No subsequent events occurring after the balance sheet date were identified that require recognition or disclosure in the financial statements.