FDA Approves First Muscle-Targeting Treatment for Spinal Muscular Atrophy

FDA Approves First Muscle-Targeting Treatment for Spinal Muscular Atrophy

The US Food and Drug Administration (FDA) has approved Scholar Rock’s Isemblyd (apitegromab), making it the first approved treatment for spinal muscular atrophy (SMA) that directly targets muscle function.

SMA is an inherited neuromuscular disease that causes progressive muscle weakness and loss of movement.

Isemblyd has been approved for patients aged two years and older and is intended to be used alongside existing standard SMA treatments.

What makes Isemblyd different is that it works directly on the muscles rather than focusing only on the nerve-related mechanisms of the disease.

The drug blocks activation of myostatin, a protein that naturally limits muscle growth. By doing so, Isemblyd may help improve muscle strength and physical function.

The FDA approval was based on results from the Phase III SAPPHIRE trial. After one year, patients receiving Isemblyd together with standard SMA therapy showed significant improvements in motor function compared with those receiving standard treatment alone.

The FDA had previously declined to approve the drug following findings from an inspection of a third-party manufacturing facility. Those concerns were related to the manufacturing site and not to the safety or effectiveness of Isemblyd itself.

Following approval, Scholar Rock is introducing patient support programmes designed to help with insurance coverage, financial assistance and access to treatment.

The company said Isemblyd is expected to be available for shipment in the coming days and may be administered either at home or in infusion centres.

Analysts expect myostatin-inhibiting medicines to become an important area of growth in the SMA treatment market over the coming years.