FDA Rejects Scholar Rock's SMA Drug Due to Manufacturing Concerns

Scholar Rock's bid to introduce the first muscle-targeted treatment for spinal muscular atrophy (SMA) has hit a significant roadblock. The U.S. Food and Drug Administration (FDA) has rejected the company's application for apitegromab, citing manufacturing issues at a third-party facility.

Regulatory Setback for Promising SMA Treatment

The FDA's complete response letter (CRL) to Scholar Rock pointed to observations from a general site inspection of a contract manufacturing facility in Indiana. This facility, formerly owned by Catalent, was recently acquired by Novo Nordisk as part of a larger $16.5 billion deal.

Scholar Rock emphasized that the FDA's concerns were not specific to apitegromab's production and did not relate to the drug's efficacy or safety. The company's chairman and CEO, David Hallal, 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."

Impact on Scholar Rock and SMA Treatment Landscape

The rejection delays a potentially groundbreaking treatment for SMA, a disease that causes progressive muscle weakness. Apitegromab, an infused monoclonal antibody, aims to address muscle deterioration in SMA patients, complementing existing therapies that focus on preventing motor neuron loss.

Kenneth Hobby, President of Cure SMA, highlighted the drug's importance: "Muscle strength and motor function are significant unmet needs for many in the SMA community and are fundamental to independence. A gain in motor function can allow someone to participate in important activities of daily living from self-care to work and social interactions."

Despite this setback, Scholar Rock remains optimistic about apitegromab's future. The company reported a cash balance of $295 million as of June 30, with its financial runway extending into 2027. Jefferies analyst Amy Li projects peak sales for apitegromab to reach $1.8 billion.

Broader Implications for the Pharmaceutical Industry

This rejection underscores ongoing challenges in pharmaceutical manufacturing and regulatory compliance. The Indiana facility involved in this case has been linked to previous regulatory issues, including delays in FDA decisions for Regeneron's high-dose version of Eylea and its blood cancer bispecific odronextamab.

The incident also highlights the complex relationships between drug developers, contract manufacturing organizations, and regulatory bodies. As the pharmaceutical industry continues to rely heavily on outsourced manufacturing, ensuring consistent quality and regulatory compliance across the supply chain remains a critical challenge.