Scholar Rock Holdings Shares Surge After Positive Trial Results

Shares of Scholar Rock Holdings skyrocketed 320% on Monday following the announcement of positive results from its Phase 3 SAPPHIRE clinical trial for apitegromab, a treatment for spinal muscular atrophy (SMA).

The trial met its primary endpoint, showing statistically significant improvements in motor function as measured by the Hammersmith Functional Motor Scale Expanded (HFMSE).

Scholar Rock explained in its press release that 30.4% of patients receiving apitegromab experienced a greater than three-point improvement compared to only 12.5% of those on a placebo.

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

The company plans to submit a U.S. Biologics License Application and European Union marketing authorization application in the first quarter of 2025.

Scholar Rock also noted that no new safety findings were observed in the SAPPHIRE clinical trial, and the safety profile was consistent with that observed in the Phase 2 TOPAZ clinical trial.

Following the news, Truist analysts issued a note stating that the study showed a clinically meaningful improvement of 1.8 points compared to placebo, reinforcing the unmet need for effective SMA treatments. They reiterated a Buy rating for Scholar Rock and raised the price target from $20 to $36 per share.

“We see this as a validation of the company’s TGFbeta platform and their strategy to evaluate anti-myostatin (a drug that improves muscle) on top of a drug that targets the genetic cause of the disease,” said Truist. “We also see these data as a positive read-through to the company’s obesity program with readout in 2Q2025,” they added. As a reminder, while apitegromab is being evaluated in a Phase 2 trial, the company plans to develop SRK-439, a next-gen anti-myostatin drug engineered specifically for CVD in obesity.