Pfizer's Duchenne Gene Therapy Trial Put On FDA Hold After Patient Death

• In a community letter, Pfizer Inc (NYSE:PFE) informed the Parent Project Muscular Dystrophy of the death of a young man in the Phase Ib trial of its mini-dystrophin gene therapy.
• The event has triggered a halt in screening and dosing and a clinical hold imposed by the FDA.
• Pfizer wrote, "At this time, we do not yet have complete information and are actively working with the trial site investigator to understand what happened."
• The Phase 3 study was testing PF-06939926, Pfizer's AAV9 gene therapy candidate, in both ambulatory and non-ambulatory patients. 
• In January this year, the Company dosed the first participant in the Phase 3 CIFFREO study, which will evaluate the efficacy and safety of investigational gene therapy candidate PF-06939926 in boys with Duchenne muscular dystrophy (DMD). 
• Price Action: PFE shares are down 3.07% at $59.14 during the market session on the last check Tuesday.