New Muscular Dystrophy Treatment Offers Hope
Study Shows Patients With Duchenne's Muscular Dystrophy Are Walking Better With PRO051 Treatment
In their study, van Deutekom and colleagues enrolled 12 DMD patients at an average age of 9 years. In the first phase of the study, they gave increasing doses of the drug to sets of three patients. There were no serious safety issues, and patients given higher doses showed evidence of making functional dystrophin.
This led to a second phase in which all 12 patients received weekly abdominal injections of PRO051 at the highest dose tested.
"We noticed a modest improvement, which is quite remarkable for patients with this disease, in the distance they can walk in six minutes," van Deutekom says. "The dystrophin probably accumulated over time in their muscles and led to the observed improvement."
Three of the patients improved their walking distance by 213 feet or more. That may not seem like much. But in just the six to 15 months between the first and second phases of the study, these patients' six-minute walking ability had declined by 121 feet.
"This is exciting, but it is not going to be for everyone with DMD," Kula says. "But the exciting thing is, if the technology works out, you can generate drugs for different DMD mutations. That is the wave of the future."
Indeed, van Deutekom says that is exactly what her company is doing. PRO051 should work for patients with DMD mutations on or very near exon 51. Now in the works are similar drugs targeting exons 44, 45, 52, 53, and 55.
PRO051 is not the only drug candidate in clinical trials. A U.S. company, AVI BioPharma, is testing a similar exon-51-skipping antisense oligonucleotide called AVI-4658. Promising findings -- but not clinical improvement -- was reported last October from early clinical trials of AVI-4658.
Van Deutekom and colleagues report their findings in an early online release of the New England Journal of Medicine.