8-K: Scholar Rock Announces Positive Phase 3 Results for SMA Treatment and Upsized Public Offering

Scholar Rock reported positive topline data from its Phase 3 SAPPHIRE trial for apitegromab in SMA, achieved its primary endpoint, and completed a $345 million public offering.

Summary

• Scholar Rock announced positive topline results from the Phase 3 SAPPHIRE trial of apitegromab for Spinal Muscular Atrophy (SMA), showing a statistically significant improvement in motor function compared to placebo.
• The trial met its primary endpoint with a mean difference of 1.8 points on the HFMSE scale for patients receiving apitegromab compared to placebo.
• The company is on track to submit a Biologics License Application (BLA) in the U.S. and a Marketing Authorisation Application (MAA) in the European Union in the first quarter of 2025.
• Enrollment for the Phase 2 EMBRAZE trial of apitegromab in obesity is complete, with topline data expected in the second quarter of 2025.
• Scholar Rock successfully completed a $345 million public offering to fund the planned commercial launch of apitegromab in SMA and advance other programs.
• The company reported a net loss of $64.5 million for the third quarter of 2024, compared to a net loss of $42.4 million for the same period in 2023.
• Research and development expenses increased to $48.7 million for the quarter, up from $30.3 million in the prior year, due to costs associated with the ONYX and EMBRAZE trials and the development of SRK-439.
• As of September 30, 2024, Scholar Rock had approximately $139.1 million in cash, cash equivalents, and marketable securities, which increases to $463.5 million on a pro forma basis including the recent offering, extending the cash runway into the fourth quarter of 2026.

Sentiment

Score: 9

Explanation: The document is highly positive due to the successful Phase 3 trial results, the significant capital raise, and the clear path to commercialization. The company is well-positioned for future growth and success.

Positives

• The positive results from the Phase 3 SAPPHIRE trial validate the potential of apitegromab as a transformative treatment for SMA.
• The successful completion of the $345 million public offering provides substantial funding for the commercial launch of apitegromab and further development of the pipeline.
• The completion of enrollment in the Phase 2 EMBRAZE trial for obesity indicates progress in the cardiometabolic program.
• The company has a strong cash position, extending the runway into the fourth quarter of 2026.
• Apitegromab has shown consistent clinically meaningful benefit across all age groups (2-21) with a favorable safety profile.

Negatives

• The company reported a net loss of $64.5 million for the third quarter of 2024, which is an increase compared to the $42.4 million loss in the same quarter of 2023.
• Research and development expenses have increased significantly, primarily due to the ONYX and EMBRAZE trials and the development of SRK-439.
• The company did not record any revenue for the quarter ended September 30, 2024, or for the quarter ended September 30, 2023.

Risks

• The regulatory approval of apitegromab is not guaranteed, and the full results from the Phase 3 SAPPHIRE trial may differ from the topline data.
• Clinical trial data from ongoing studies may not be consistent with previous results.
• The company is dependent on third parties for the development and manufacture of product candidates.
• There is competition from other companies developing treatments for similar conditions.
• The company needs to manage expenses and obtain additional funding to support its business activities.

Future Outlook

Scholar Rock is preparing for the commercial launch of apitegromab in the U.S. in the fourth quarter of 2025 and plans to expand to selected European countries. The company is also advancing its pipeline, including the EMBRAZE trial for obesity and the development of SRK-439.

Management Comments

• Jay Backstrom, M.D., MPH, President and Chief Executive Officer, stated that the positive SAPPHIRE trial results underscore apitegromab's potential to redefine the standard of care for patients with SMA.
• Dr. Backstrom also noted that the results reinforce the broader potential of their selective myostatin inhibition strategy.
• Ted Myles, Chief Operating Officer and Chief Financial Officer, mentioned that the company is advancing its mission from a position of strength, supported by the recent public offering and successful SAPPHIRE data.

Industry Context

The announcement is significant in the context of the SMA treatment landscape, where there is a need for therapies that directly target muscle atrophy. The positive results from the SAPPHIRE trial position apitegromab as a potential competitor to existing treatments like nusinersen and risdiplam, which primarily target the SMN gene. The company is also expanding into the obesity market, which is a large and growing area of unmet need.

Comparison to Industry Standards

• The 1.8-point improvement in HFMSE seen in the SAPPHIRE trial is clinically meaningful and compares favorably to the natural history of SMA, where patients typically experience a decline in motor function over time.
• Existing SMA treatments like Spinraza (nusinersen) and Evrysdi (risdiplam) primarily address the underlying genetic cause of SMA by increasing SMN protein levels, but do not directly target muscle atrophy. Apitegromab's muscle-targeted approach offers a complementary mechanism of action.
• The company's expansion into obesity with apitegromab and SRK-439 is aligned with the growing interest in therapies that can preserve lean muscle mass during weight loss, which is a key challenge with current GLP-1 receptor agonists.
• The company's approach to myostatin inhibition is similar to that of other companies such as Acceleron Pharma (now part of Merck), which developed sotatercept, a TGF-beta ligand trap, for pulmonary arterial hypertension. However, Scholar Rock's focus on selective inhibition of myostatin and its proand latent forms is a differentiating factor.

Management Changes

Stakeholder Impact

• Shareholders will benefit from the positive clinical trial results and the increased financial stability of the company.
• Patients with SMA will potentially have access to a new and effective treatment option.
• Employees will be involved in the commercial launch of apitegromab and the advancement of other programs.
• Customers (healthcare providers and patients) will have access to a new treatment option for SMA.
• Suppliers and creditors will benefit from the company's increased financial strength.

Next Steps

• Submit a U.S. Biologics License Application (BLA) and a European Union Marketing Authorisation Application (MAA) for apitegromab in the first quarter of 2025.
• Prepare for the commercial launch of apitegromab in the U.S. in the fourth quarter of 2025.
• Report topline data from the Phase 2 EMBRAZE trial for apitegromab in obesity in the second quarter of 2025.
• Initiate the OPAL clinical trial in SMA patients under two years old in mid-2025.
• File an IND for SRK-439 for the treatment of obesity in 2025.

Key Dates

Keywords

Spinal Muscular Atrophy, SMA, apitegromab, myostatin inhibitor, Phase 3 trial, SAPPHIRE trial, Biologics License Application, BLA, Marketing Authorisation Application, MAA, obesity, EMBRAZE trial, SRK-439, public offering, clinical trial, motor function, HFMSE, muscle-targeted therapy, cardiometabolic, SRK-181, immuno-oncology