FDA Rejects Scholar Rock's SMA Drug, Citing Manufacturing Issues at Novo-Owned Facility

Scholar Rock's bid to introduce the first muscle-targeted treatment for spinal muscular atrophy (SMA) has hit a roadblock as the U.S. Food and Drug Administration (FDA) rejected its application for apitegromab. The decision, communicated through a complete response letter (CRL), cited manufacturing concerns at a third-party facility in Indiana, now owned by Novo Nordisk.

Manufacturing Setback at Former Catalent Site

The FDA's rejection stems from observations made during a general site inspection of the Indiana facility, which Novo Nordisk acquired from Catalent as part of a larger $16.5 billion deal finalized in December 2024. Scholar Rock emphasized that the issues identified were not specific to apitegromab's production and that the CRL did not raise concerns about the drug's efficacy or safety.

The facility in question, referred to as Catalent Indiana, performs fill-finish services for apitegromab. In early August, the site submitted a response to address the FDA's concerns and has continued to implement corrective actions, updating the regulatory agency accordingly.

This setback is not isolated to Scholar Rock. The same Bloomington, Indiana facility has been linked to regulatory delays for other pharmaceutical companies, including Regeneron, which faced a two-month delay for its high-dose version of Eylea in 2023 and subsequent holdups for two other Eylea-related decisions in 2025.

Apitegromab's Potential Impact on SMA Treatment

Apitegromab represents a novel approach to SMA treatment, targeting muscle growth and preservation. If approved, it would complement existing therapies that focus on preventing motor neuron loss but do not directly address muscle deterioration. These current treatments include Novartis's Zolgensma, Biogen's Spinraza, and Roche's Evrysdi, all of which have achieved blockbuster status.

Clinical trials have shown promising results for apitegromab when used in combination with standard SMA therapies. In Phase 3 testing, the drug demonstrated significant improvements in motor function compared to typical care alone. Kenneth Hobby, President of Cure SMA, highlighted the urgent need for treatments addressing muscle strength and motor function in the SMA community, emphasizing their importance for patient independence and quality of life.

Scholar Rock's Path Forward

Despite this setback, Scholar Rock remains committed to bringing apitegromab to market. The company plans to resubmit its Biologics License Application (BLA) once the manufacturing issues are resolved, expecting an expedited review from the FDA.

David Hallal, Scholar Rock's chairman and CEO, stated, "We are continuing to work closely with Catalent Indiana on the FDA's manufacturing observations so that we can resubmit the apitegromab BLA as soon as possible."

The company reported a cash balance of $295 million as of June 30, 2025, with its financial runway extending into 2027. While the U.S. launch faces delays, Scholar Rock is also pursuing approval in Europe, with expectations to launch there in 2026. Analysts remain optimistic about apitegromab's potential, with Jefferies projecting peak sales to reach $1.8 billion.