While exact figures are unknown, the Centers for Disease Control estimates that 1 in every 5,600 to 7,700 males aged 5-24 suffers from Duchenne muscular dystrophy. By the age of 24, survival rates drop to 58%. There is an average delay of 2.5 years from the time symptoms are noticed to diagnosis, with the diagnosis occurring around 5 years of age. This is a devastating illness with a measurable effect on the population and, despite extensive research, a cure has yet to be discovered.
Sarepta Therapeutics continues to pursue a new experimental muscle disorder drug called eteplirsen, which was deemed “premature” by the U.S. Food and Drug Administration (FDA) in 2013 due to lack of sufficient trial data. We presented the story in an earlier blog post. The FDA has now indicated that safety and efficacy data from studies without placebo groups could support an approval application.
The company is encouraged that a new set of safety and efficacy data will allow them to move forward. The data, from studies they conducted without the generally required placebo groups, can be compared with existing historical data from DMD patients to provide adequate evidence of safety and efficacy.
“Currently we have 2018 as the year of launch for eteplirsen, but this timeline could shave as much as 2+ years off that projection,” says analyst Edward Nash.
The drug, a targeted new treatment for DMD, enhances the protein dystrophin, a protein DMD patients lack and could provide significant symptom relief for many of these patients. Since DMD has few treatment options, one would expect that accelerated approval would be granted, as has happened for other illness treatments for serious diseases. However, Sarepta still has to conduct larger trials so that they can increase evidence to back up their initial findings.
They still face an uphill battle, as many efforts to develop DMD treatments have been refused by the FDA. Competitor Prosensa Holding NV is developing a rival drug called drisapersen that claims to work in a similar fashion to dystrophin, but it has failed to help DMD patients in a recent late-stage trial. These failures are less than helpful for approval for competitors moving forward, but Sarepta is still hopeful that this alternate path offered by the FDA will enable them to get the new treatment on the market.
While the future of this treatment is still somewhat clouded, the potential is incredible and indications are that, before too long, we could actually see a new and viable treatment for this disorder. The video shows additional trial results for eteplirsen.