Pfizer announced that CIFFREO, a Phase 3 global, multicentre, randomised, double-blind, placebo-controlled study evaluating the investigational mini-dystrophin gene therapy, fordadistrogene movaparvovec, in ambulatory patients with Duchenne muscular dystrophy (DMD) did not meet its primary endpoint of improvement in motor function among boys 4 to 7 years of age treated with the gene therapy compared to placebo. The primary endpoint in the final analysis was assessed by change in the North Star Ambulatory Assessment (NSAA) a year after treatment. Key secondary endpoints, including 10-metre run/walk velocity and time to rise from floor velocity, also did not show a significant difference between participants treated with fordadistrogene movaparvovec and placebo.
The overall safety profile of fordadistrogene movaparvovec in the CIFFREO trial was manageable, with mostly mild to moderate adverse events, and treatment-related serious adverse events generally responding to clinical management. Pfizer will continue to closely monitor all participants enrolled in the study and is evaluating appropriate next steps for the program.
About the Fordadistrogene Movaparvovec Clinical Program
The CIFFREO study is currently on a dosing pause due to a fatal serious adverse event in the Phase 2 DAYLIGHT trial (NCT05429372). DAYLIGHT is a study that evaluates the safety and tolerability of fordadistrogene movaparvovec in participants 2 years to 3 years of age with DMD. Pfizer is actively working to gather additional information on the event to understand the potential cause.
About Duchenne Muscular Dystrophy
Duchenne muscular dystrophy (DMD) is a serious genetic disease characterised by progressive muscle degeneration and weakness. Symptoms usually manifest in early childhood between the ages of 3 and 5. The disease primarily affects boys. Muscle weakness can begin as early as age 3, first affecting the muscles of the hips, pelvic area, thighs, and shoulders, and later the skeletal (voluntary) muscles in the arms, legs, and trunk. By their early teens, patients typically lose their ability to walk and the heart and respiratory muscles are also affected, ultimately resulting in premature death. DMD is the most common form of muscular dystrophy worldwide with an incidence of 1 in every 5,000 live male births.