Scholar Rock Holding Corp

1. Nature of the Business

Scholar Rock Holding Corporation and its subsidiaries (collectively, the “Company”) is a global biopharmaceutical company dedicated to improving the lives of children and adults with spinal muscular atrophy (“SMA”) and additional rare, severe and debilitating neuromuscular diseases. As a leader in the biology of the transforming growth factor beta (“TGFβ”) superfamily, the Company’s novel understanding of the molecular mechanisms of growth factor activation enabled the development of a proprietary platform for the discovery and development of monoclonal antibodies that locally and selectively target the precursor, or latent, forms of growth factors. Based on the Company’s innovative, proprietary, and scalable technology platform, the Company is building a world-leading anti-myostatin pipeline.

The Company’s lead product candidates include apitegromab, a subcutaneous formulation of apitegromab, and SRK-439.

Apitegromab is a novel, investigational, fully human monoclonal antibody that inhibits myostatin activation by selectively binding the pro- and latent forms of myostatin in skeletal muscle. Myostatin is a catabolic agent that functions as a negative regulator of muscle mass, therefore inhibition of myostatin results in increased muscle mass and strength. Apitegromab is in development for the treatment of people with SMA and for the treatment of people with facioscapulohumeral muscular dystrophy (“FSHD”).

Positive data from the successful Phase 3 SAPPHIRE study evaluating apitegromab in children and adults with SMA was reported in October 2024. The Company submitted a U.S. Biologics License Application (“BLA”) to the U.S. Food and Drug Administration (“FDA”) in January 2025 and the BLA was granted priority review designation. In September 2025, the Company received a Complete Response Letter (“CRL”) from the FDA related to observations identified during an FDA inspection of a third-party fill-finish facility. The facility was issued a Form 483 by the FDA in July 2025 and the inspection classification of this facility is official action indicated (“OAI”). The observations were related to the facility and were not specific to apitegromab. The CRL did not cite any other approvability concerns, including apitegromab’s efficacy and safety data or the third-party drug substance manufacturer. In November 2025, the Company completed an in-person Type A meeting with the FDA that included participation of representatives from the third-party fill-finish facility. Also in November 2025, the third-party fill-finish facility received a Warning Letter from the FDA. The Company resubmitted the apitegromab BLA in March 2026 with two fill-finish facilities included, which was accepted by the Agency with a September 30, 2026 Prescription Drug User Fee Act (“PDUFA”) action date. In March 2025, the Company submitted to the European Medicines Agency (“EMA”) and received validation of its marketing authorisation application (“MAA”) for apitegromab for the treatment of SMA. If apitegromab is approved by the FDA or EMA, the Company expects to initiate a commercial product launch in the applicable jurisdictions upon approval.

The Company continues to develop apitegromab in SMA with its ongoing long-term extension ONYX trial and its Phase 2 OPAL trial in SMA patients under two years of age, which was initiated in the third quarter of 2025. Additionally, a Phase 2 study evaluating apitegromab in patients with FSHD is expected to initiate in mid-2026.

In addition to the current intravenous (“IV”) formulation, the Company is developing a subcutaneous (“SC”) formulation of apitegromab. A Phase 1 study in healthy volunteers has been completed and demonstrated that SC apitegromab has favorable bioavailability and a comparable pharmacodynamic profile relative to IV administered apitegromab. Further development activities are ongoing, including planned FDA and EMA regulatory engagements.

The Company’s clinical-stage pipeline also includes SRK-439, a novel, investigational, subcutaneously administered fully human anti-pro/latent myostatin antibody that has high inhibitory potency while maintaining selectivity towards myostatin. SRK-439 is being developed for the treatment of patients with rare, severe, and debilitating neuromuscular

diseases. A Phase 1 study of SRK-439 in healthy volunteers is currently underway, with topline data anticipated in the second half of 2026.

As the Company focuses its strategy on rare neuromuscular diseases, the Company is currently seeking partnerships for its additional programs. These programs include: SRK-181, a Phase 2-ready investigational inhibitor of latent TGFβ1 in development for the treatment of patients with solid tumors that are resistant to anti-PD-(L)1 antibody therapies; SRK-373, an investigational, highly selective inhibitor of the latent TGFβ1 isoform with selective activity in the fibrotic extracellular matrix, in preclinical development for the treatment of fibrotic diseases; and SRK-256, an investigational inhibitor of RGMc, or hemojuvelin, in preclinical development for the treatment of iron-restricted anemias. The Company is also seeking partners to further evaluate the potential for myostatin inhibition in combination with GLP-1 weight loss approaches following its positive Phase 2 EMBRAZE study, demonstrating proof-of-concept in the ability of apitegromab to drive statistically significant preservation of lean mass during tirzepatide-induced weight loss.

Beyond these clinical-stage product candidates, the Company’s early-stage pipeline includes additional preclinical programs intended for the treatment of patients with rare, severe, and debilitating neuromuscular diseases. The Company was originally formed in May 2012. Its principal offices are in Cambridge, Massachusetts.

Since its inception, the Company’s operations have focused on research and development of monoclonal antibodies that selectively inhibit activation of growth factors for therapeutic effect, as well as establishing the Company’s intellectual property portfolio and performing research and development activities. The Company has primarily financed its operations through various equity financings, the exercise of stock options and warrants, as well as research and development collaboration agreements and the Company’s debt facility (Note 11).

Revenue generation activities have been limited totwo collaborations, both containing research services and the issuance of a license. No revenues have been recorded from the sale of any commercial product.

The Company is subject to a number of risks similar to other life science companies, including, but not limited to, successful discovery and development of its drug candidates, raising additional capital, development by its competitors of new technological innovations, protection of proprietary technology and regulatory approval and market acceptance of the Company’s product candidates. The Company anticipates that it will continue to incur significant operating losses for the next several years as it continues to develop and seek regulatory approval for its product candidates.

The Company believes that its existing cash, cash equivalents and marketable securities as of March 31, 2026 will be sufficient to allow the Company to fund its current operations through at least a period of one year after the date these financial statements are issued.

2. Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

The significant accounting policies used in preparation of the unaudited condensed consolidated financial statements are described in the Company’s audited consolidated financial statements as of and for the year ended December 31, 2025, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K. There have been no material changes to the significant accounting policies previously disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

Unaudited Interim Financial Information

The condensed consolidated financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The unaudited condensed consolidated financial statements include the accounts of Scholar Rock Holding Corporation and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. In the opinion of management, the information furnished reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair presentation of the results for the reported interim periods. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to

certain estimates or to identify matters that require additional disclosure. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or any other interim period.

Use of Estimates

The preparation of financial statements in accordance with accounting principles generally accepted in the U.S. (“GAAP”) requires management to make estimates and judgments that may affect the reported amounts of assets and liabilities and related disclosures of contingent assets and liabilities at the date of the financial statements and the related reporting of revenues and expenses during the reporting period. Management bases its estimates on historical experience and on various assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates.

Cash, Cash Equivalents and Restricted Cash

The following table reconciles cash, cash equivalents and restricted cash per the balance sheet to the statement of cash flows (in thousands):

The Company’s restricted cash is associated with a letter of credit related to its lease at 301 Binney Street in Cambridge, Massachusetts and a collateral account associated with a corporate credit card program.

Recently Adopted Accounting Pronouncements

In December 2023, the FASB issued ASU 2023-09,Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”), which enhances the transparency of income tax disclosures to provide information to investors to better assess how a company’s operations and related tax risks, tax planning and operational opportunities affect its tax rate and prospects for future cash flows. This requires public entities to disclose additional categories in the rate reconciliation regarding federal and state income taxes and provide more details surrounding reconciling items if a quantitative threshold is met. The Company adopted ASU 2023-09 on January 1, 2025, which did not have a material impact on the financial statements and related disclosures.

Recently Issued Accounting Pronouncements

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(“ASU 2024-03”), and in January 2025, the FASB issued ASU No. 2025-01,Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date. ASU 2024-03 requires additional disclosure of the nature of expenses included in the income statement as well as disclosures about specific types of expenses included in the expense captions presented in the income statement. ASU 2024-03, as clarified by ASU 2025-01, is effective for public companies for annual periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is still evaluating the impact on its disclosures in future years as a result of the adoption of ASU 2024-03.

3. Fair Value of Financial Assets and Liabilities

The following tables summarize the assets and liabilities measured at fair value on a recurring basis at March 31, 2026 and December 31, 2025 (in thousands):

Level 1 assets include investments in money market funds, U.S. treasury obligations and government agency securities that are valued using quoted market prices in active markets. There wereno transfers of assets between fair value measurement levels during the three months ended March 31, 2026 or 2025.

The carrying amounts reflected in the balance sheets for prepaid expenses and other current assets, accounts payable, and accrued expenses approximate their fair values at March 31, 2026 and December 31, 2025, due to their short-term nature.

4. Marketable Securities

The following table summarizes the Company’s investments as of March 31, 2026 (in thousands):

The following table summarizes the Company’s investments as of December 31, 2025 (in thousands):

The Company believes that U.S. treasury obligations and government agency securities are subject to minimal credit risk. As a result, the Company did not record any charges for credit-related impairments for its available-for-sale securities for the three months ended March 31, 2026.

5. Prepaid Expenses and Other Current Assets

At March 31, 2026 and December 31, 2025, prepaid expenses and other current assets consist of the following (in thousands):

At March 31, 2026 and December 31, 2025, other long-term assets consist of the following (in thousands):

6. Accrued Expenses

At March 31, 2026 and December 31, 2025, accrued expenses consist of the following (in thousands):

7. Common Stock

The Company’s amended and restated certificate of incorporation was amended to increase the number of authorized shares of common stock to 300,000,000 in June 2024.

The Company has had a sales agreement in place during various time periods with Jefferies LLC (“Jefferies”) with respect to an at-the-market (“ATM”) offering program. Under this program, the Company is able to offer and sell, from time to time at its sole discretion, shares of its common stock through Jefferies as its sales agent. In an ATM offering, exchange-listed companies incrementally sell newly issued shares into the secondary trading market through a designated broker-dealer at prevailing market prices. The current sales agreement with Jefferies, entered into in

November 2022, allows for the sale of shares of common stock from time to time in “at the market” offerings through Jefferies as the Company’s sales agent. The Company sold 2,576,299 shares of its common stock under the ATM program during the three months ended March 31, 2026, generating net proceeds of$111.8 million. Of this amount,$13.8 million was received in April 2026 and was classified as a receivable and included in “Prepaid expenses and other current assets” in the consolidated balance sheets as of March 31, 2026.

The Company has issued pre-funded warrants to purchase common stock, as well as warrants to purchase common stock as part of its financing activities. Both the pre-funded warrants and warrants meet the conditions for equity classification and are recorded as a component of stockholders’ equity within additional paid-in capital. In October 2024, June 2022 and November 2020, the Company issued 353,983,25,510,205 and 2,179,487 pre-funded warrants, respectively. During the three months ended March 31, 2026 and 2025,6,804,082 and 0, respectively, of the Company’s pre-funded warrants were exercised. As of March 31, 2026, the Company has 10,558,065 pre-funded warrants outstanding. In June 2022, the Company also issued 10,459,181 warrants with an exercise price of$7.35, which expired on December 31, 2025. All of the common warrants outstanding associated with the June 2022 financing were exercised prior to their expiry. None of the Company’s common warrants were exercised during the three months ended March 31, 2026 and 2025.

In October 2025, the Company issued 250,000 warrants with an exercise price of $28.59 for non-employee services. Warrants issued to non-employees in connection with providing services meet the conditions for equity classification and are recorded as a component of stockholders’ equity within additional paid in capital. There wereno exercises of the warrants issued for non-employee services during the three months ended March 31, 2026.

Shares Reserved For Future Issuance

As of March 31, 2026, the Company had common shares reserved for issuance as follows:

8. Equity-Based Compensation

The Company recorded equity-based compensation expense related to all equity-based awards, which was allocated as follows in the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2026 and 2025 (in thousands):

During the three months ended March 31, 2026 and 2025, the Company entered into separation agreements with certain employees. Per the separation terms, certain stock option awards and RSUs were amended and may provide for

continued vesting, accelerated vesting, and extended time to exercise vested options. As a result, equity-based compensation expense during the three months ended March 31, 2026 and 2025 includes $0.1 million and $4.0 million, respectively, related to the modification of certain equity awards.

The following table summarizes the Company’s unrecognized equity-based compensation expense as of March 31, 2026:

Restricted Stock Units

The following table summarizes the Company’s RSU activity for the current year:

The total fair value of RSUs vested during the three months ended March 31, 2026 and 2025 was $26.3 million and $28.3 million, respectively.

Performance Stock Units

The following table summarizes the Company’s PSU activity for the current year:

The Company has granted various PSUs to certain employees. Depending on the terms of the PSUs and the outcome of the pre-established performance criteria, which may include a market condition, performance condition and/or time-based vesting, the recipient may ultimately earn the target number of PSUs granted or a specified multiple thereof at the end of the vesting period.

The total fair value of PSUs vested during the three months ended March 31, 2026 was $12.0 million. No PSUs vested during the three months ended March 31, 2025.

Stock Options

The following table summarizes the Company’s stock option activity for the current year:

Using the Black-Scholes option pricing model, the weighted average grant date fair value of options granted during the three months ended March 31, 2026 and 2025 was $39.53 and $30.02, respectively.

The following weighted average assumptions were used in determining the fair value of options granted in the three months ended March 31, 2026 and 2025:

9. Leases

Operating Lease

In November 2019, the Company entered into a lease of office and laboratory space at 301 Binney Street in Cambridge, Massachusetts to be used as its new corporate headquarters (the “Lease”). The expiration date of the Lease was originally in August 2025 and included anoption to extend the term bytwo years. The base rent under the original Lease was $6.9 million per year, subject to an annual increase of 3.5%. Variable lease payments include the Company’s allocated share of costs incurred and expenditures made by the landlord in the operation and management of the building. The Lease included incentives of $14.1 million in the form of an allowance for tenant improvements related to the design and build out of the space. In connection with the Lease, the Company has secured a letter of credit for $2.3 million which renews automatically each year.

In May 2024, the Company entered into the First Amendment (the “Lease Amendment”) to the Lease to extend the term for approximatelytwo years, commencing on August 19, 2025 (the “First Extension Term”) with the base rent to start at approximately $6.2 million per year, followed by a 3% annual increase. Pursuant to the Lease Amendment, the Company also has anoption to extend the term of the Lease byfive years, upon the expiration of the First Extension Term.

In October 2025, the Company entered into a lease of office space in Zug, Switzerland (the “Switzerland Lease”). The Switzerland Lease commencement date was January 1, 2026, which is when the Company gained access to the space under the terms of the lease. The Switzerland Lease has an expiration date of December 31, 2029, with a minimum term oftwelve months. The base rent under the Switzerland lease is CHF 276,000 per year.

Other information related to the leases are as follows (in thousands, except lease term and discount rate):

10. Commitments and Contingencies

Legal Proceedings

The Company, from time to time, may be party to litigation arising in the ordinary course of its business. The Company was not subject to any material legal proceedings during the three months ended March 31, 2026 and 2025.

11. Debt

On October 16, 2020, the Company entered into a Loan and Security Agreement with Oxford Finance LLC (“Oxford”) and Silicon Valley Bank (“SVB”) for $50.0 million (the “Loan and Security Agreement”), which was amended in 2022 to increase the Company’s borrowing capacity.

On February 10, 2025, the Company entered into an Amended and Restated Loan and Security Agreement with Oxford (such agreement, as amended, the “Existing Loan Agreement”). The Existing Loan Agreement consolidated the existing outstanding loan tranches solely with Oxford and amends and restates in its entirety that certain Loan and Security Agreement, as amended. In conjunction with the Existing Loan Agreement, the Company was required to pay$0.9 million, which included$0.5 million to SVB for the final payment on the outstanding tranche.

On September 29, 2025, the Company received $50.0 million from the next available tranche under the Existing Loan Agreement, bringing the total borrowings to $100.0 million.

On February 27, 2026, the Company terminated the Existing Loan Agreement and entered into a Financing Agreement (the “Financing Agreement”) with certain funds managed by Blue Owl Capital Corporation (“Blue Owl”). Concurrently with the entry into the Financing Agreement, the Company also entered into a Pledge and Security Agreement (the “Security Agreement,” together with the Financing Agreement, the “2026 Loan Agreement”) with Blue Owl. The Financing Agreement contains customary representations, warranties and covenants. The Company is also required to maintain a minimum unrestricted cash balance of at least 60% of the aggregate outstanding principal amount, unless certain milestones are met and maintained.

The 2026 Loan Agreement provides for up to $350.0 million (each, a “Term Loan” and together, the “Term Loans”), of which $100.0 million of the initial term loan (the “Initial Term Loan”) was received in February 2026. In addition, the Financing Agreement includes an uncommitted incremental term loan facility that requires the consent of Blue Owl in an aggregate principal amount not to exceed $200.0 million. Deferred financing costs related to undrawn debt are included in “Other long-term assets” in the consolidated balance sheets. The Company used the proceeds of the Initial Term Loan upon the closing under the 2026 Loan Agreement to repay all outstanding obligations, totaling $103.7 million, which included $2.0 million related to the final payment and $1.0 million related to the prepayment fee, under the Existing

Loan Agreement with Oxford and upon such repayment, terminated the Existing Loan Agreement. The amount repaid by the Company included $100.0 million of outstanding indebtedness plus accrued and unpaid interest as of February 27, 2026 and fees. The Company recognized a loss on extinguishment of debt of $3.3 million in connection with the termination of the Existing Loan Agreement. As a result of the termination, all credit commitments under the Existing Loan Agreement were terminated and all security interests and guarantees executed in connection with the Existing Loan Agreement were released.

On March 31, 2026, the Company received $100.0 million from the next available tranche under the 2026 Loan Agreement. To date, the Company has received $200.0 million of Term Loans. The additional delayed draw term loan commitment in an aggregate principal amount not to exceed $150.0 million will be available from the date of FDA approval for apitegromab in SMA until the date that is the earliest of the full usage thereof, termination thereof and September 30, 2027, which may be borrowed by the Company at its sole option upon satisfying certain customary conditions, including satisfaction of the minimum cash covenant (if applicable).

The outstanding principal of the Term Loan interest at a rate per annum on the basis of a 360 day year equal to (a) in the case of Term Loans bearing interest based on the base rate defined in the Financing Agreement, the sum of (i) the base rate (and which base rate will not be less than 2.00%) plus (ii)4.00% and (B) in the case of Term Loans bearing interest based on the three-month forward-looking term secured overnight financing rate as published by CME Group Benchmark Administration Limited (the “Term SOFR”), the sum of (i) three-month Term SOFR (subject to 1.00% per annum floor), plus (ii)5.00%. Accrued interest is payable quarterly, on any date of prepayment of the Term Loans and at maturity.

The maturity date of the Term Loan is the earlier of February 26, 2032 and the date the Term Loans shall otherwise become due and payable in full under the Financing Agreement. The Company may, at its option, prepay at any time the Term Loans on any Business Day in whole or in part. In certain instances and during certain time periods, these prepayments, together with certain mandatory prepayments and payments of the Term Loans resulting from the exercise of remedies under the Financing Agreement, will be subject to customary prepayment fees.

12. Net Loss per Share

The Company calculates basic net loss per share by dividing net loss by the weighted average number of common shares outstanding. The weighted average number of common shares used in the basic and diluted net loss per share calculation includes the pre-funded warrants issued in connection with the Company’s November 2020, June 2022 and October 2024 follow-on offerings as the pre-funded warrants are exercisable at any time for nominal cash consideration. The Company has generated a net loss in all periods presented, so the basic and diluted net loss per share are the same, as the inclusion of the potentially dilutive securities would be anti-dilutive.

The following table sets forth the outstanding common stock equivalents, presented based on amounts outstanding at each period end, that have been excluded from the calculation of diluted net loss per share for the periods indicated because their inclusion would have been anti-dilutive:

13. Segment Reporting

The Company operates and manages its business on a consolidated basis as asingle reportable andsingle operating segment for the purposes of assessing performance and making operating decisions. The Company’s chief executive officer, who is the chief operating decision maker (“CODM”), reviews the Company’s financial information on a

consolidated basis for purposes of evaluating financial performance and allocating resources. When evaluating the Company’s financial performance, the CODM regularly reviews net loss. The CODM considers net loss in making decisions on how to allocate resources. Net loss is used to monitor budget versus actual results in an effort to refine forecasts and control costs. The measure of segment assets is reported on the balance sheet as total consolidated assets. All of the Company’s long-lived assets are held in the United States.

The following table presents significant expense information about the Company’s operating segment: