A tragic incident occurred in a trial for Pfizer’s experimental gene therapy for Duchenne muscular dystrophy, where a young boy lost his life. The boy, who was part of the Daylight trial aimed at studying the treatment in boys aged 2 or 3, had received the therapy in the previous year. Pfizer conveyed the heartbreaking news of the boy’s death due to cardiac arrest to patient advocates via a note shared online by Parent Project Muscular Dystrophy.

Despite attributing the cause of death to cardiac arrest, Pfizer mentioned that they were still in the process of investigating the incident to determine the exact circumstances surrounding the tragedy.