The U.S. Food and Drug Administration on Friday approved ISEMBYLD (apitegromab-mstn) from Scholar Rock (NASDAQ:SRRK) for spinal muscular atrophy (SMA) in adults and pediatric patients aged 2 years and older.
The decision makes ISEMBYLD the first muscle-targeted therapy to demonstrate motor function improvement in individuals already taking an SMN2-targeted drug.
The FDA also awarded Scholar Rock a Rare Pediatric Disease Priority Review Voucher following the decision.
Mechanism Of Action And Disease Impact
SMA is a severe, rare neuromuscular disorder that causes irreversible loss of motor neurons and progressive muscle wasting.
The decline reduces motor function and limits personal independence. As a fully human monoclonal IgG4 antibody, ISEMBYLD targets promyostatin and latent myostatin to inhibit myostatin activation and block its signaling pathway.
Phase 3 SAPPHIRE Study Delivers Robust Results
Patients aged 2 to 12 years receiving 10 mg/kg (recommended dose) of ISEMBYLD alongside SMN2-targeted therapy achieved a 2.2-point improvement on the Hammersmith Functional Motor Scale-Expanded (HFMSE) at 1 year, compared to those receiving SMN2-targeted therapy alone.
Furthermore, 34.2% of ISEMBYLD-treated participants experienced a 3-point or greater HFMSE increase, versus 13.5% in the control group.
Safety Profile And Long-Term Extension
More than 500 individuals participated in global clinical studies for apitegromab, with some receiving treatment for over 7 years.
98% of SAPPHIRE participants chose to join the ONYX long-term extension study.
ISEMBYLD U.S. commercial launch underway, with product available to ship in the coming days.
SRRK Stock Price Activity: Scholar Rock Holding shares were up 6.48% at $59.00 during premarket trading Monday, according to Benzinga Pro data.
Photo: Shutterstock
Recent Comments