Pfizer Update on Clinical Trial
May 7, 2024
We are deeply saddened to share that a patient participating in our Phase 2 DAYLIGHT study for Duchenne muscular dystrophy has passed away suddenly. On behalf of everyone at Pfizer, we extend our sympathies to his family, friends, and those closest to his care.
We do not yet have complete information and are actively working with the trial site investigator to understand what happened. The patient received the investigational gene therapy, fordadistrogene movaparvovec, in early 2023.
Initial dosing for the placebo-controlled, randomized Phase 3 CIFFREO trial, which utilizes a crossover trial design, was also completed in 2023. We have decided to pause dosing associated with the cross-over portion of CIFFREO, and we are working with regulators and the independent external Data Monitoring Committee as we learn more about this event. Other than this pause in dosing, trial activities are continuing as scheduled.
Both the DAYLIGHT and CIFFREO trials are investigating fordadistrogene movaparvovec in patients with DMD, in different age cohorts: DAYLIGHT in boys 2 years to less than 4 years of age, and CIFFREO in boys 4 to less than 8 years of age. Beyond CIFFREO, the dosing pause does not apply to other ongoing trials in the fordadistrogene movaparvovec program as dosing has been completed in those studies.
The safety and well-being of the patients in our clinical trials remains our top priority, and we are committed to sharing more information with the medical and patient community as soon as we can. We are also aware that many in the patient community are hopeful about the potential benefit of fordadistrogene movaparvovec for the treatment of DMD, and we will continue to collect data from our trials to evaluate its ability to address this disease.
As always, if you have questions please do not hesitate to reach out.
Sincerely,
The Pfizer DMD gene therapy team










