CAMBRIDGE, Mass. (TheStreet) -- Duchenne muscular dystrophy is a progressive disease that causes patients to lose muscle function over time. None of the therapies being developed today to treat Duchenne are curative, so the best these still-experimental drugs will do is slow the progression of the disease and give the kids more time outside a wheelchair.
I bring up this reminder about the inevitable muscular deterioration seen with Duchenne because the walking ability of patients treated with Sarepta Therapeutics' (SRPT) experimental drug eteplirsen declined greater at 144 weeks than in previous updates from the phase II study.
Sarepta briefed me on the new eteplirsen phase II study results Wednesday, embargoed until the announcement was made public Thursday morning.
After almost three years, the six Duchenne boys treated with eteplirsen from the beginning of the study reported a maximum loss of 32.2 meters, or about 8.5%, from baseline walking ability, as measured by the six-minute walk test.
For the four Duchenne boys who began the study on placebo but switched over to eteplirsen six months later, the maximum loss of walking ability at 144 weeks was 107.4 meters, or 27%, compared to their baseline.
All 10 boys across both arms of the study -- with an average age of 12 years -- can still walk on their own and only two of the boys have lost muscle function to the point where their score on the six-minute walk test is below 300 meters, said Sarepta CEO Chris Garabedian, in a phone interview.