by: Parent Project Muscular Dystrophy
We are deeply disappointed to learn that Pfizer is terminating two ongoing clinical studies evaluating domagrozumab (PF-06252616) for the treatment of Duchenne: a Phase 2 safety and efficacy study (B5161002) and an open-label extension study (B5161004).
The Phase 2 study (B5161002), did not meet its primary efficacy endpoint, which was to demonstrate a difference in the mean change from baseline in 4 Stair Climb (in seconds) following one year of treatment with domagrozumab as compared to placebo in patients with Duchenne. Further evaluation of the totality of evidence including secondary endpoints did not support a significant treatment effect. The decision comes after a thorough review of data available at the time of the primary analysis, which evaluated all study participants after one year of treatment, as well as those participants who were in the trial beyond one year.
It is important to note that the studies were not terminated for safety reasons. Pfizer has ensured our community that they will continue to advance research and clinical development efforts focused on Duchenne, including their investigational mini-dystrophin gene therapy program. In addition, they will remain involved in efforts focused on optimizing drug development for Duchenne and data from the phase 2 clinical study of domagrozumab will be shared with the Duchenne community in order to contribute to the body of scientific knowledge which may enable the development of new therapies for patients.
We are so grateful to the families who have participated in these trials and the sacrifices they have made so that momentum in fight to end Duchenne can continue. We appreciate Pfizer’s continued commitment to our community and hope to learn more about what led to this decision so that future research can learn from this study.
Pfizer’s Press Release:
Pfizer Terminates Domagrozumab (PF-06252616) Clinical Studies for the Treatment of Duchenne Muscular Dystrophy
NEW YORK, NY, August 30, 2018 – Pfizer Inc. (NYSE: PFE) announced today that it is terminating two ongoing clinical studies evaluating domagrozumab (PF-06252616) for the treatment of Duchenne muscular dystrophy (DMD): a Phase 2 safety and efficacy study (B5161002) and an open-label extension study (B5161004). The Phase 2 study (B5161002), did not meet its primary efficacy endpoint, which was to demonstrate a difference in the mean change from baseline in 4 Stair Climb (in seconds) following one year of treatment with domagrozumab as compared to placebo in patients with DMD. Further evaluation of the totality of evidence including secondary endpoints did not support a significant treatment effect. The decision comes after a thorough review of data available at the time of the primary analysis, which evaluated all study participants after one year of treatment, as well as those participants who were in the trial beyond one year. The studies were not terminated for safety reasons. Pfizer will continue to review the data to better understand any insights they may provide, and will share results with the scientific and patient community.
“We are disappointed by these results and while we are not progressing with the studies, the data will contribute to a greater understanding of this disease and we will evaluate the total data set to see if there is a place for this medicine in muscular diseases,” said Seng Cheng, PhD, Senior Vice President and Chief Scientific Officer, Pfizer Rare Disease Research Unit. “We are extremely grateful to all those involved with this trial, especially the boys who participated, and their families.”
Pfizer is continuing research in DMD and rare neuromuscular diseases, with the goal of bringing therapies to patients with unmet needs. The company’s continued partnership with advocacy associations and the community is critical to finding innovative therapies for these diseases. Pfizer has one ongoing clinical trial in DMD with a gene therapy, PF-06939926, which is an investigational, recombinant AAV9 capsid carrying a truncated or shortened version of the human dystrophin gene (mini-dystrophin) under the control of a human muscle specific promotor.1
About the Domagrozumab Clinical Studies[i]
The Phase 2 double-blind, placebo-controlled, multicenter clinical trial investigated the efficacy and safety of domagrozumab, administered in monthly IV doses, in 121 boys aged 6 to 15 with DMD, regardless of underlying mutation. It was designed as a two-year, placebo-controlled study (with the primary analysis after one year); all subjects used background corticosteroid therapy. The open-label extension study was designed to evaluate long-term safety and efficacy of domagrozumab.
[i] Data on file. Pfizer Inc. New York, NY.
