The US Food and Drug Administration (FDA) has granted accelerated approval to Sarepta Therapeutics’ first-of-its-kind Duchenne muscular dystrophy (DMD) gene therapy.
The one-time treatment, Elevidys (delandistrogene moxeparvovec-rokl), is specifically indicated for use in ambulatory patients aged between four and five years, with a confirmed mutation in the DMD gene.
Sarepta was initially seeking approval for all ambulatory patients with DMD, a rare and serious neuromuscular genetic disease that occurs in approximately one in every 3,500 to 5,000 newborn males worldwide.
The disease is caused by a change or mutation in the gene that encodes instructions for dystrophin, which is required to strengthen and protect muscles.
Over time, this causes progressive loss of muscle strength, with most patients requiring full-time use of a wheelchair by their early teens. Eventually, increasing difficulty in breathing due to respiratory muscle dysfunction requires ventilation support, and cardiac dysfunction can lead to heart failure.
Elevidys is designed to address the underlying cause of DMD through the targeted production of functional components of dystrophin in muscle tissue.
The accelerated approval of the therapy was based on data from a mid-stage clinical trial in which Elevidys was able to produce a mini version of the dystrophin protein, but did not improve patient clinical outcomes such as motor function.
Doug Ingram, Sarepta’s president and chief executive officer, said the approval was a “watershed moment for the treatment of Duchenne”.
“Elevidys is the first and only gene therapy approved for Duchenne, and this approval brings us closer to our goal of bringing forward a treatment that provides the potential to alter the trajectory of this degenerative disease,” he said.
Consistent with the accelerated approval pathway, which allows the FDA to approve treatments for serious conditions where there is an unmet medical need, Sarepta said it has “committed to the completion of a confirmatory trial”.
Ingram said: “Our confirmatory trial, EMBARK, should read out in the fourth quarter of this year. If [it] confirms the benefits seen in our prior trials, Sarepta will move rapidly to submit a Biologics License Application supplement to expand the approved label as broadly as good science permits.”