Duchenne's Muscular Dystrophy Advance
Drug May Partially Correct Deadly Form of Muscular Dystrophy
Dec. 27, 2007 -- An "antisense" compound may partially correct the
genetic defect that causes deadly Duchenne's muscular dystrophy.
Researchers are not calling the finding a breakthrough, but they are
cautiously optimistic that the approach may one day lead to a treatment that
extends the lives of people afflicted with the always-fatal disease.
Duchenne's muscular dystrophy is a genetic disease seen in one in 3,500 baby
boys. The boy's muscles get weaker and weaker, landing them in wheelchairs by
their twelfth birthday. Their hearts and lungs also weaken, and the brain may
Most of these boys die in early childhood; with steroid treatment and
breathing aids, their life span can be as long as 25 to 35 years. Nothing,
however, prevents eventual death.
Now there's a small glimmer of hope. Scientists now know the specific
genetic mutation that causes Duchenne's muscular dystrophy. That mutation
causes a "misreading" of the gene that encodes dystrophin, a substance
crucial for muscle cell survival.
In the test tube, a compound called an antisense oligonucleotide partially
corrects this genetic misreading. It seems to work in animals. Might it work in
Judith C. van Deutekom, PhD, of Netherlands' Leiden University, and
colleagues tested the treatment, called PRO051, in four 10- to 13-year-old boys
with Duchenne's muscular dystrophy. They'd all been confined to wheelchairs
since ages 7 to 11.
Each boy got a single treatment -- four injections -- in a leg muscle.
The idea wasn't to cure the boys, but to make sure nothing bad happened and to
see whether the genetic correction works in humans.
The answer: Nobody got hurt by the treatment. And at the site of the
injections, there were signs of dystrophin production.
On the downside, there was evidence that the disease in these young boys may
have already advanced too far for an eventual treatment to be much help. Future
clinical trials may require even younger patients.
The treatment, van Deutekom and colleagues cautiously conclude, "may be
a potential approach to restoring dystrophin synthesis in the muscles of
patients with Duchenne's muscular dystrophy."
The researchers report their findings in the Dec. 27 issue of TheNew England Journal of Medicine.