Gene Therapy May Help Muscular Dystrophy Patients
Research May Lead to Future Treatments for Duchenne Muscular Dystrophy
First Human Tests continued...
The nucleotides were matched to the exact kind of genetic defect that was shared by all the patients, and they were given by weekly intravenous infusion.
Researchers tested samples of muscle tissue before and after the treatments to check dystrophin levels.
Seven patients, nearly all of them on the two highest doses of the drug given in the study, saw their dystrophin protein levels increase on the treatment.
Two of the best responders saw their levels climb from 0.9% to 17% and from 2% to 18%.
"There really is reason to be excited," says Richard Moxley III, MD, a pediatric neurologist at the University of Rochester. Moxley treats patients with muscular dystrophy and helped pioneer the use of corticosteroids in the disease. He was not involved in the current research.
He says there are other approaches to treatment in development. "Among the different things that are out there, for me, this is the most straightforward, the least plagued with toxic reactions, and the most immediately promising."
None of the patients appeared to see any clinically significant benefits from the study medication. But study researcher Franceso Muntoni, a pediatric neurologist and professor of medicine in the Institute of Child Health at University College London, says some patients noticed that they had better stamina.
"However, it is important to be aware of the placebo effect in short studies like this," he says.
And he says that because of how the protein works, patients wouldn't necessarily see immediate benefits.
"Dystrophin is a protein that does not make muscle stronger. It protects muscles from further breakdown, as would a shock absorber in our cars," Muntoni tells WebMD.
There were three serious adverse events reported in the study. Two, a case of vomiting after anesthesia and a broken ankle, were judged to be unrelated to the treatment. The third, a serious heart problem, was possibly related to treatment, but may also have developed as part of the underlying disease.
Muntoni says they are already working on putting together a larger study that would follow patients for a longer period of time.
He says it's the first time they've been able to try to correct the specific, underlying genetic defect in human patients. "This is remarkable and, until a few years ago, completely unforeseen."