The first attempt in humans to correct the muscle defect that is at the heart of muscular dystrophy was a success, researchers reported Saturday.
The therapy involves transplanting healthy muscle cells from another person into the muscle of a patient with muscular dystrophy. The healthy cells began making the protein that is lacking in patients with the disease.The work does not mean a treatment is imminent for muscular dystrophy, a genetic disease that causes progressive and irreversible muscle deterioration that almost always leads to death by age 30.
Among other things, scientists must determine whether the transplants will work on large muscle groups and whether patients will reject the transplanted tissue.
Nevertheless, experts who cited the new results and previous work in animals said the finding held out a real ray of hope, not only for muscular dystrophy but also for other degenerative muscle diseases.
The results were announced Saturday by Dr. Peter Law, a professor of neurology at the University of Tennessee in Memphis, at a meeting of the Muscular Dystrophy Association in Tucson, Ariz.
Law's finding involved just a single patient, Sam Looper of Pickens, S.C., a 9-year-old boy with Duchenne muscular dystrophy, the most common form of the disease.
To avoid possible damage to important muscles, the researchers tested the treatment in one of his big toes.
At least seven other patients in this country are undergoing the experimental treatment, Law said Saturday, but those results are not yet available.
Dr. Leon Charash, chairman of the national medical advisory board of the Muscular Dystrophy Association, said he believed another group of researchers, at the Montreal Neurological Institute, had replicated the feat.
Charash said he expected the group, which like Law is being financed by the association, to announce its findings Monday.
Two other groups also are pursuing the treatment, and are supported in part by the Muscular Dystrophy Association, which encouraged the concurrent studies to have a "horse race," Charash said.
Charash added that the finding is promising enough that the researchers will now be moving quickly to try the muscle cell injections in larger muscles of the leg that help control balance.
In addition, Law said, the method could be applied to other forms of muscular dystrophy or to any disase of muscular degeneration, whether or not the exact genetic defect causing the degeneration is known.
"I think it is of great importance," Charash said. "This represents the first time a treatment has been offered. It is a moment of great scientific significance."
If the finding is confirmed, said Dr. W. French Anderson, a branch chief at the National Institutes of Health who has devoted his entire 22-year scientific career to designing human gene therapies, "this would be a landmark."
But investigators also sounded a note of caution.
Dr. Francis Collins, a gene-therapy researcher at the University of Michigan in Ann Arbor, said "it is encouraging to see that there are some real possiblities here, but there are a lot of hurdles ahead," before there can be an effective treatment.
Collins said the research "is a promising lead, but we ought to have our eyes open. Patients with muscular dystrophy are in a desparate situation and I think we should be very careful not to give them false hope."