Nature of the Business	6 Months Ended
Jun. 30, 2026
Nature of the Business
Nature of the Business	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 FDA 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, the Company is evaluating apitegromab in patients with FSHD with its Phase 2 FORGE trial, which was initiated in the second quarter of 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 following potential apitegromab approvals. 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 and has principal offices 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, performing research and development activities and developing commercialization capabilities to support product sales, marketing and distribution 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 to two 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 June 30, 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.

Nature of the Business

6 Months Ended

Jun. 30, 2026

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 FDA 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, the Company is evaluating apitegromab in patients with FSHD with its Phase 2 FORGE trial, which was initiated in the second quarter of 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 following potential apitegromab approvals.

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 and has principal offices 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, performing research and development activities and developing commercialization capabilities to support product sales, marketing and distribution 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 to two 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 June 30, 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.