Two Sarepta Therapeutics medication for treating totally different genetic subsets of sufferers with Duchenne muscular dystrophy failed the confirmatory research required of their accelerated FDA approvals. Sarepta executives say there’s nonetheless a path for conventional FDA approval, nevertheless it would possibly depend on regulatory flexibility that the company has proven towards the corporate and different builders of therapies for uncommon ailments.
Sarepta’s Vyondys 53, accepted in 2019, and Amondys 45, accepted in 2021, each obtained their speedy regulatory nods based mostly on scientific trial outcomes displaying remedy led to larger ranges of dystrophin, a key muscle protein that Duchenne sufferers lack. However these antisense oligonucleotide medication had been nonetheless required to bear testing in an extended and bigger confirmatory research designed to evaluate sufferers on a variety of muscle perform measures.
After Monday’s market shut, Sarepta reported preliminary Section 3 outcomes displaying remedy with the Duchenne medication led to numerically higher however not statistically vital enchancment on the primary aim measuring the time it takes for a affected person to climb 4 steps. Sarepta stated the destructive consequence of the nine-year research was as a result of Covid-19 pandemic, throughout which 43% of impacted members had consecutive missed doses of the once-weekly infused medication. On common, research members missed eight consecutive doses.
Excluding knowledge from the 57 members whose double-blind dosing interval overlapped with the pandemic, Sarepta stated outcomes present a 30% discount in illness development in comparison with placebo over two years as measured in line with the four-step take a look at. Talking throughout a Monday night convention name, Sarepta CEO Doug Ingram acknowledged that excluding the 57 Covid-impacted research members reduces the facility of the research. However he stated the change for the remaining 168 sufferers is clinically significant. Ingram added that it’s vital to take a protracted view of the Duchenne medication.
“One of many good issues about having these therapies commercially obtainable for therefore lengthy is that we get to see what occurs over the long run,” Ingram stated. “You take a look at [Vyondys] for six years, and these youngsters are seeing actually virtually three years of delay in being in a wheelchair and the time to air flow is considerably totally different.”
Medication that fails confirmatory research can have their advertising authorization revoked. Ingram doesn’t see that occuring to Vyondys and Amondys based mostly on Sarepta’s prior discussions with the FDA. Based on Ingram, the company stated the usual for withdrawing advertising authorization is “solely in a situation the place no related analyses would affirm scientific profit.” He added that the scientific trial and actual world proof proceed to assist affected person profit. The corporate plans to debate with the FDA transitioning the Duchenne medication’ standing to conventional regulatory approvals.
Sarepta didn’t disclose outcomes for the trial’s secondary targets. However Louise Rodino-Klapac, the corporate’s president, R&D and technical operations, stated that these targets, which embody extra measures of muscle perform in addition to organic endpoints, might be offered at a future medical assembly.
Sarepta has had a tough yr. Three sufferers who obtained Sarepta gene therapies died in 2025. Two of those sufferers obtained Sarepta’s Elevidys, a Duchenne gene remedy that controversially transformed its accelerated approval to a standard one final yr regardless of failing its confirmatory scientific trial. All three fatalities had been attributed to acute liver failure. Elevidys stays obtainable to Duchenne sufferers who can nonetheless stroll, however not for these whose illness has progressed to the purpose the place they’re non-ambulatory. Discussions with the FDA are ongoing concerning adjustments to the Elevidys immunosuppression routine to cut back the liver harm threat.
Sarepta’s monetary report for the third quarter of 2025 exhibits $399.4 million in income, down 14.5% in comparison with the identical interval within the prior yr. The corporate attributed the decrease income to the discount in Elevidys shipments. That places extra strain on Sarepta’s chronically administered Duchenne therapies to generate income, however monetary analysts don’t share the corporate’s optimism about these medication. In a word despatched to buyers Tuesday, William Blair analyst Sami Corwin stated the Section 3 research’s failure to fulfill its primary aim is a destructive improvement.
“Regardless of administration’s confidence that Vyondys 53 and Amondys 45 is not going to lose advertising authorization consequently, we’re extra skeptical, and assume the inventory’s response (down 37% after hours) suggests buyers are additionally involved about the way forward for these two merchandise,” Corwin wrote.
Picture: Dina Mariani, Getty Photos
