Sarepta Therapeutics announced
their confirmatory study of eteplirsen has begun and the first patient has been dosed.
The open-label study, 4658-301 (PROMOVI), is designed to evaluate the efficacy and safety of eteplirsen in Duchenne muscular dystrophy patients over 48 weeks (30 mg/kg once a week) in up to 39 sites across the United States. Approximately 160 patients will be involved. The study will enroll 60-80 boys, aged 7-16 years with genotypes amenable to exon 51 skipping who will be treated with eteplirsen, while an additional 60-80 patients with genotypes not amenable to exon 51 skipping will serve as a concurrent control group. The primary endpoint will be the 6 minute walk test but other efficacy and safety parameters will be included. The study will be powered to show a benefit on the 6-minute walk test compared with the untreated control group.
Edward Kaye, M.D., Sarepta’s Chief Medical Officer said:
“This confirmatory study with eteplirsen in ambulatory patients is an important step in the process of confirming the promising clinical results we achieved in our previous studies 201/202,” adding, “By evaluating a larger population of boys and examining both functional and biochemical endpoints, we expect to further support the evidence of eteplirsen’s potential benefit to patients.”
Susan Apkon, M.D., Principal Investigator at Seattle Children’s Hospital added:
“The commencement of this study is a significant achievement for the DMD community. Eteplirsen shows great potential as an important therapeutic, and I am delighted to be a part of this larger confirmatory study to further understand the impact that eteplirsen may have on families dealing with this terrible disease.”
Last week, Sarepta announced
the start of a non-confirmatory study examining the safety and efficacy of eteplirsen in non-ambulatory patients with Duchenne muscular dystrophy. That announcement plus today’s are positive signs following the tumultuous relationship that seemed to be present between the company and the FDA.
About Duchenne Muscular Dystrophy
Duchenne muscular dystrophy is a progressive muscle disorder caused by the lack of functional dystrophin protein. Patients with Duchenne muscular dystrophy lose the ability to walk as early as age 10 and experience life-threatening lung and heart complications in their late teens and twenties.
There are an estimated 35,000 patients with Duchenne in the United States and Europe but the population has many subsets based on mutations of the dystrophin gene.
There are currently no treatments for these patients but several drugs are in late stage clinical development, including Both Sarepta’s eteplirsen and Prosensa’s drisaperson
which should be effective in the same 13% of the Duchenne population who would benefit from exon 51 skipping therapy (i.e., those with mutations near exon 51 of the dystrophin gene) and PTC Therapeutics’ ataluren
which should be effective in another 13% subset who have nonsense mutations in the dystrophin gene. Lilly’s tadalafil
is also in a phase 3 clinical trial.