Pfizer Inc. today announced that its investigational gene therapy candidate (PF-06939926) being developed to treat Duchenne muscular dystrophy (DMD) received Fast Track designation from the U.S. Food and Drug Administration (FDA).

PF-06939926 is currently being evaluated to determine the safety and efficacy of this gene therapy in boys with DMD.
Fast Track is a process designed to facilitate the development, and expedite the review, of new drugs that are intended to treat or prevent serious conditions that have the potential to address an unmet medical need. This designation was granted based on data from the Phase 1b study that indicated that the intravenous administration of PF-06939926 was well-tolerated during the infusion period and dystrophin expression levels were sustained over a 12-month period.

“The FDA’s decision to grant our investigational gene therapy PF-06939926 Fast Track designation underscores the urgency to address a significant unmet treatment need for Duchenne muscular dystrophy,” said Brenda Cooperstone, MD, Chief Development Officer, Rare Disease, Pfizer Global Product Development. “DMD is a devasting condition and patients, and their parents, are waiting desperately for treatment options. We are working to advance our planned Phase 3 program as quickly as possible.”

DMD is a devastating and life-threatening X-linked disease that is caused by mutations in the gene encoding dystrophin, which is needed for proper muscle membrane stability and function. Patients present with muscle degeneration that progressively worsens with age to the extent that they require wheelchair assistance when they are in their early teens, and unfortunately, usually succumb to their disease by the time they are in their late twenties. It is estimated that there are ~10-12,000 individuals affected with DMD in the US.