Scholar Rock Stock Soars on Promising Spinal Muscular Atrophy Treatment Results

Shares of Scholar Rock Holdings surged by 320% on Monday after the company reported positive outcomes from its Phase 3 SAPPHIRE clinical trial for apitegromab, a treatment aimed at spinal muscular atrophy (SMA).

The trial successfully met its primary endpoint, demonstrating statistically significant improvements in motor function, assessed by the Hammersmith Functional Motor Scale Expanded (HFMSE). According to Scholar Rock, 30.4% of patients treated with apitegromab experienced a three-point improvement, compared to only 12.5% of patients receiving a placebo.

Dr. Jay Backstrom, the President and CEO of Scholar Rock, expressed excitement about the trial results, stating, “The results clearly demonstrate robust and clinically meaningful improvement in motor function in patients with SMA.”

The company plans to file a U.S. Biologics License Application and a marketing authorization application in the European Union in the first quarter of 2025. Scholar Rock noted that no new safety concerns were reported during the SAPPHIRE clinical trial, indicating that the safety profile remained consistent with that observed in the earlier Phase 2 TOPAZ clinical trial.

In response to the news, analysts from Truist highlighted that the study indicated a clinically meaningful improvement of 1.8 points compared to the placebo, emphasizing the ongoing need for effective treatments for SMA. They reaffirmed a Buy rating for Scholar Rock and raised the price target from $20 to $36 per share.

Truist commented, “We see this as a validation of the company’s TGFbeta platform and their strategy to assess anti-myostatin treatments alongside drugs that target the genetic causes of the disease.” They also mentioned that the data could positively influence the company’s obesity program, with results expected in the second quarter of 2025. Notably, while apitegromab is under investigation in a Phase 2 trial, Scholar Rock has plans to develop SRK-439, a next-generation anti-myostatin drug specifically designed to address cardiovascular issues in obesity.