Science notes: Experimental drug may help fragile X syndrome
- September 22, 2012 - 4:10 PM
An experimental drug can improve sociability in patients with fragile X syndrome and may be helpful as a treatment for autism, a new study said.
Fragile X is a genetic disorder that affects about 1 in 4,000 boys and 1 in 8,000 girls, said the National Institutes of Health. It usually results in mental retardation and -- in about half of cases -- some form of autism. In fragile X, which accounts for 2 percent of autism cases, a mutation in a gene on the X chromosome turns off production of a regulatory protein known as FMRP. That leads to out-of-control activation of the brain chemical glutamate, which plays a key role in learning and memory, potentially explaining social anxiety and other symptoms.
Researchers tested a drug known as STX209 in genetically engineered mice and found that it helped correct the biochemical abnormalities, reducing seizures and repetitive behaviors.
In a related study also in the journal Science Translational Medicine, 46 children and 17 adults with fragile X were assigned to take the drug for four weeks and a placebo for four weeks. Patients made bigger improvements on a "social avoidance" scale while they were taking the drug compared with when they were taking the placebo.
"This study nails a core feature in autism," said Dr. Randi Hagerman, an expert in neurodevelopmental disorders at the University of California, Davis, MIND Institute and co-author of the human study. "We think this is a great drug."
But scientists who were not involved in the study said the improvements were modest at best and that their applicability to autism -- a highly variable disorder that may have many distinct causes -- was unclear. "The data have to be viewed with extreme caution," said Dr. Christopher McDougle, a psychiatrist at Harvard University. "They're interesting. That's about all you can say."
LOS ANGELES TIMES
MULTIPLE SCLEROSIS PILL SHOWS PROMISE
A new oral medication to treat patients in the early stages of multiple sclerosis has shown promise in two clinical trials, researchers said.
The medication is on track to become just the third oral drug available to MS patients, and potentially the safest and most effective, experts said. The second oral drug, called Aubagio, was approved earlier this month.
MS was virtually untreatable only two decades ago, but today nine "disease-modifying" drugs are available for early-stage patients; a half-dozen more are in the late stages of development. Most patients in the early stage of the disease, a form called relapsing-remitting MS, take drugs by injection.
The two new studies, published online in the New England Journal of Medicine, found that the drug BG-12, developed by Biogen Idec, reduced relapse rates in patients with relapsing MS by about 50 percent. The drug also significantly reduced the frequency of new brain lesions often associated with these attacks, and slowed the progression of disease compared with a placebo.
The studies were Phase 3 trials, a last step on the road to drug approval. The Food and Drug Administration is required to make a decision about the drug before year's end.
NEW YORK TIMES
CHRONIC FATIGUE NOT LINKED TO RETROVIRUS
Chronic fatigue syndrome is not caused by a mouse retrovirus, said a study initiated by the National Institutes of Health to settle the contentious scientific question.
The long-awaited results, posted online in the journal mBio, found no link between the illness, called myalgic encephalomyelitis, and mouse leukemia retroviruses, including one called XMRV. Two earlier studies had identified higher levels of the viruses in patients with chronic fatigue syndrome. Later research did not confirm the finding, and scientists blamed laboratory contamination for the earlier results.
The NIH asked Dr. Ian Lipkin, a virologist at Columbia, to investigate. Lipkin recruited scientists who initially reported the link to mouse retroviruses, and they serve as authors on the new paper. In the study, none of the researchers reported finding mouse leukemia viruses in any of 293 blood samples, half from people with chronic fatigue syndrome and half without it.
NEW YORK TIMES
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