Pfizer said Wednesday afternoon that a closely watched gene therapy for Duchenne muscular dystrophy failed to slow the disease’s progression in a Phase 3 trial.
This is now the second large, randomized, placebo-controlled trial of a Duchenne gene therapy to fail to reach its primary endpoint, a composite scale of muscle function designed specifically for the rare disease. A similar study of a Sarepta gene therapy failed last year, although the company pointed to secondary measures as evidence that its treatment was still slowing the fatal, muscle-wasting condition.
Pfizer said that in its study, which enrolled 99 boys between ages 4 and 7 and followed them for a year, its gene therapy did not show any difference on those key secondary endpoints.
