Scholar Rock's Apitegromab Shows Promise in Preserving Muscle Mass During Weight Loss

Scholar Rock, a biopharmaceutical company focused on the discovery and development of innovative medicines for the treatment of serious diseases, has announced positive results from its Phase 2 Embraze trial. The study evaluated the efficacy of apitegromab, an investigational anti-myostatin antibody, in preserving muscle mass for patients taking GLP-1 weight-loss medications.

Embraze Trial Results: A Breakthrough in Muscle Preservation

The Embraze trial compared the effects of apitegromab with a placebo in patients taking tirzepatide, the active ingredient in Eli Lilly's obesity drug Zepbound. The results were striking:

• Patients receiving apitegromab experienced 85% of weight loss from fat and only 15% from lean mass.
• In contrast, placebo recipients lost 70% from fat and 30% from lean mass.

These findings represent a significant advancement in addressing the challenge of muscle loss associated with rapid weight reduction induced by GLP-1 agonists. The preservation of lean mass is crucial for maintaining overall metabolism and reducing the risk of frailty, particularly in older patients.

Broader Implications for Obesity Treatment

The success of apitegromab in the Embraze trial opens up new possibilities for combination therapies in obesity treatment. Several pharmaceutical companies, including Roche, Regeneron, and Biohaven, are exploring similar approaches targeting the myostatin pathway to combat muscle loss.

While Scholar Rock's primary focus remains on rare neuromuscular diseases, CEO David Hallal suggested that the company may seek partnerships to further develop apitegromab or its follow-on drug SRK-439 for obesity indications. This strategic decision reflects the company's commitment to its core mission while recognizing the potential of its technology in the rapidly expanding obesity market.

Safety Profile and Future Prospects

The Embraze trial also demonstrated a favorable safety profile for apitegromab, with no serious side effects observed and adverse events generally similar between the treatment and placebo groups. This clean safety profile is crucial for potential add-on therapies to GLP-1 agonists.

As the pharmaceutical industry continues to grapple with the challenges of muscle loss in weight management, Scholar Rock's apitegromab represents a promising advance. The company expects an FDA decision on its application for apitegromab in spinal muscular atrophy by September 22, potentially paving the way for broader applications of this innovative therapy.