Industry Partner News: Pfizer’s Letter to the Duchenne Community Regarding Initiation of Gene Therapy Trial


April 12, 2018

Pfizer is pleased to provide the following update regarding the Phase 1b, Multicenter, Open-label, Single Ascending Dose Study to Evaluate the Safety and Tolerability of PF-06939926 in Ambulatory Boys with Duchenne Muscular Dystrophy (DMD). The first boy received an infusion of the mini-dystrophin gene on March 22nd, administered under the supervision of the principal investigator at the study site.  This first participant continues to be monitored.

The study will enroll approximately 12 ambulatory boys aged 5 to 12 years with DMD.  In addition to evaluating safety and tolerability, the study will evaluate measurements of dystrophin expression and distribution, as well as assessments of muscle strength, quality, and function. As part of the screening process, potential candidates invited by the study principal investigator will be tested to confirm a negative result for antibodies against the adeno-associated virus, serotype 9 (AAV9) capsid and for a T-cell (immune) response to dystrophin. Screening and enrollment of patients is expected to continue at up to four clinical research sites in the United States.   Early data from this trial are expected in the first half of 2019, once the first patient completes one full year post-treatment. More information about the trial and participating sites may be found at (NCT03362502).

We recognize the commitment that the DMD community has shown for this study and for Pfizer’s research and development efforts related thereto. We further recognize the potential impact innovative therapies, like gene therapy, may have in transforming the lives of individuals and families affected by DMD and we share with you that hope and vision. It is with heartfelt gratitude that we extend our sincerest ‘thank you’ to all the boys and families who continue to express interest in and who participate in clinical research.  We are furthermore indebted to the advocacy associations and advocates who provide the tools and support needed for families to engage in clinical research, who continue to care for the Duchenne community and who lend their expertise in the research and development process.

Additional public-facing information about this milestone achievement can be found at:

Kind regards,
Katherine Beaverson
Patient Advocacy Lead