Pfizer announces phase 3 trial of Duchenne muscular dystrophy treatment

Pfizer revealed plans to open sites in the U.S. for a phase 3 study evaluating an investigational mini-dystrophin gene therapy in ambulatory patients with Duchenne muscular dystrophy.

The announcement comes after the FDA lifted its clinical hold on the investigational new drug application for fordadistrogene movaparvovec when Pfizer addressed the agency’s requests regarding the potency assay.

“Duchenne muscular dystrophy is a devastating disease with very limited treatment options, and we believe that gene therapy has the potential to significantly impact disease progression,” Brenda Cooperstone, chief development officer for rare disease at Pfizer Global Product Development, said in a company press release.

The global phase 3 study, CIFFREO, had been initiated in 11 countries before pausing in December 2021 to implement a protocol amendment, which followed a fatal serious adverse event in a phase 1b study in the non-ambulatory cohort.

Regulatory authorities in the U.K., Canada, Taiwan, Spain and Belgium have approved restarting the phase 3 study, and additional global reviews are underway. Pending regulatory feedback, Pfizer anticipates that nearly all CIFFREO sites will open by the end of June 2022.

“We thank the participants in our clinical trials and their families, as well as the broader Duchenne community, for their ongoing trust and collaboration as we work to advance our investigational gene therapy,” Cooperstone said in the release.