Gene therapy company Sarepta Therapeutics provided additional data for SRP-5051 in treating Duchenne muscular dystrophy patients who are amenable to exon 51 skipping.
Pictured: Sarepta Sign on a brick building/Sarepta Therapeutics
Sarepta Therapeutics on Monday reported positive data for a Phase II trial of its investigational drug SRP-5051 (vesleteplirsen) for the treatment for Duchenne muscular dystrophy patients amenable to exon 51 skipping.
The Massachusetts-based biotech provided additional details from part B of its Momentum study investigating SRP-5051, a peptide phosphorodiamidate morpholino oligomer (PPMO) treatment, which was investigated in patients between the ages of eight and 21 years.
According to Sarepta, a 30 mg/kg dose of SRP-5051 every four weeks showed a mean dystrophin expression of 5.17% and a mean exon skipping of 11.11% at 28 weeks. The company said the data showed consistent dystrophin expression in both ambulatory and non-ambulatory patients.
The “high-dose” results of the drug also showed a 4.53% mean change from the baseline at 28 weeks and delivered a p-value of less than 0.0001. The lower dosage, marked at 20 mg/kg, had a 2.81% mean dystrophin expression and a 1.60% mean change, resulting in a p-value of 0.0012.
“SRP-5051 dosed every four weeks is showing substantially higher increases in dystrophin and exon skipping compared to eteplirsen dosed weekly,” Sarepta CSO Louise Rodino-Klapac said in a statement. “The data suggest a favorable benefit-risk profile for SRP-5051, and we look forward to discussing the results and next steps with the FDA.”
However, the biotech also reported there were seven “serious” treatment-emergent adverse events in the trial, which were four severe hypomagnesemia events and three serious cases of hypokalemia. Still, Sarepta noted that there had been hypomagnesemia throughout the trial and that no discontinuations related to treatment occurred in the study.
“With effective supplementation and monitoring, we have not seen additional complications from the hypomagnesemia,” study investigator Eugenio Mercuri, head of the neuromuscular unit at Catholic University in Rome, Italy, said in a statement. “The results with SRP-5051 suggest it could play an important role in treating Duchenne patients with a confirmed exon 51-amenable mutation.”
In June 2023, the FDA approved Sarepta’s Elevidys (delandistrogene moxeparvovec-rokl) as the first-ever gene therapy for Duchenne muscular dystrophy (DMD). Elevidys—formerly SRP-9001—was greenlit under the FDA’s accelerated approval pathway for ambulatory patients four to five years of age with a confirmed mutation in the DMD gene.
Tyler Patchen is a staff writer at BioSpace. You can reach him at tyler.patchen@biospace.com. Follow him on LinkedIn.
