First Duchenne Patient Dosed in Pfizer's Mini-Dystrophin Study

Pfizer Inc announced this morning that it has begun a Phase 1b clinical trial for PF-06939926, its mini-dystrophin gene therapy candidate, intended for boys with Duchenne muscular dystrophy (DMD).

The initial dosing came on March 22^nd, when the first boy received an infusion of the gene, which was administered under the supervision of Edward Smith, MD, Associate Professor of Pediatrics and Neurology at Duke University Medical Center, who is serving as the study’s principal investigator.

Screening and enrollment of patients are expected to continue at up to 4 clinical research sites in the US, and early data from the trial are expected once all the patients have been evaluated for one full year post-treatment, likely in the first half of 2019.

With this study, Pfizer’s team of researchers and doctors aim to assess the safety of this approach to gene therapy in DMD. It is believed that it could provide valuable data as it is exhibiting its potential impact to slow down or stop the progression of the condition.

Approximately 12 ambulatory boys aged 5 to 12 years with DMD will be enrolled into the multi-center, open-label, non-randomized, ascending dose study of a single intravenous infusion of PF-06939926. The trial will evaluate measurements of dystrophin expression and distribution as well as assessments of muscle strength, quality, and function.

“Investment in this trial represents the culmination of years of research on behalf of patients by scientists at Pfizer and academic medical centers, along with the support of the DMD patient advocacy community, in the important quest to advance a program that could potentially change the trajectory of this debilitating disease,” said Greg LaRosa, PhD, Senior Vice President and Chief Scientific Officer of Pfizer’s Rare Disease Research Unit in a press release.

“We’ve listened to the patient community and we know there is a dire need for treatment options; with this in mind, we have built on important scientific advances to design a therapy with the potential to deliver the mini-dystrophin gene to the body and address the underlying cause of DMD, regardless of mutation.”

All potential candidates for treatment 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 as part of the screening process.

“On behalf of the community of individuals and families living with Duchenne muscular dystrophy, we applaud the important step Pfizer has taken to advance a potentially transformational treatment option for boys stricken with this terrible disease,” said Debra Miller, CEO and Founder of Cure Duchenne. “The momentum we are seeing in the field of gene therapy emphasizes the maturing opportunity to advance the science. Today, there are very limited treatment options for our boys. Through collaboration and ongoing dialogue with companies like Pfizer, we hope to succeed in finding therapies that could dramatically change the outcomes for those with DMD.”

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