Duchenne Muscular Dystrophy (DMD or Duchenne) is a fatal genetic disorder that affects 1 in every 3,500 boys born globally. Duchenne results in progressive muscle weakness due to a mutation in a gene encoding for dystrophin on the X-chromosome. It first affects boys around age four and by age twelve, most people with Duchenne cannot walk. By age 21, most people cannot move below the waist. Few people with Duchenne live past thirty, due to the serious medical complications that include issues with the heart and lung functioning.
Researchers at the Cedars-Sinai Heart Institute offered hope last week to families of kids with Duchenne, when they released the results of the aptly-named “HOPE Duchenne” trial, a joint Stage I/II-A trial that used cellular therapy to treat Duchenne. In the trial, children with Duchenne were given cardiac progenitor cell infusions through a catheter placed in their three main arteries. Cardiac progenitor cells, are a certain type of stem cell that when signaled, develop into new heart tissue.
This is important for children with Duchenne, as heart tissue is, after all, muscle tissue, and Duchenne can lead to the wasting away of heart tissue just as it leads to the weakening of arms or legs. Later in life, cardiomyopathy is a grave concern for people with Duchenne. “Generally, the primary cause of death in [patients with Duchenne] is heart failure,” said Eduardo Marban, MD, PhD, the lead researcher of the study. “If we can slow or reverse heart failure in Duchenne patients, it will be a step forward.” But research to this point has not addressed this need.
“The need is great because there is no current treatment to address heart failure in these patients,” said Dr. Marban. Dr. Marban has been at the forefront of this area of research, developing the process to make the type of cell that the children were treated with, “cardiosphere-derived cells,” or CDCs. Cardiosphere-derived cells are harvested from donor hearts, so they carry none of the moral ambiguity of embryonic stem cells, and can easily be made available.
In the study, twenty-five children with Duchenne were treated. Twelve were treated with the experimental cellular therapy, while the other thirteen received the standard therapy for a child with Duchenne. The results were striking. The patients treated with cellular therapy had a 7% reduction in scarring from cardiomyopathy compared to when the patients started the therapy. For the children receiving the standard therapy, their scarring continued to worsen.
Muscular regeneration was not confined to the heart; the people that received the treatment had stronger arms, as well. One year after treatment, eight out of nine of the patients that had advanced impairment of the muscles in their arms showed improvements in their arm strength. In contrast, none of the patients receiving the standard course of treatment saw improvements and all continued to get weaker.
This study shows the promise of cellular therapy in helping people with Duchenne to live longer, happier lives. If studies like this can develop methods of treatment that can reverse, rather than just slow, the effects of Duchenne, that can lead to real advances in both length and quality of life.
Dr. Marban and his team are not done. Phase II trials for the CDC-based treatment of Duchenne are scheduled to start in early 2018. Dr. Ronald G. Victor, another primary researcher at Cedars-Sinai, says that in this trial, “instead of a one-time infusion during a cath lab procedure, the patients will receive the CDCs in an intravenous drip.” This would make the treatment even less invasive than in the stage I/II trial, and therefore more accessible to patients. Also, patients “will receive multiple treatments spaced out over several months,” according to Dr. Victor.
For parents of children with Duchenne, both now and in the future, this study offers hope that perhaps a cure is possible. Sometimes, hope makes all the difference in the world.