New Drug Stalls Parkinson's Progress
Rasagiline buys time for people with early stages of disease
MONDAY, Dec. 16, 2002 (HealthDayNews) -- An experimental drug for Parkinson's disease may buy time for people whose condition isn't severe enough to demand more serious treatment, a new study has found.
The drug, rasagiline mesylate, can improve mood, motor control and overall daily functioning in people in the early stages of the degenerative condition. It frees up the production of dopamine, a key signaling molecule that dwindles in Parkinson's patients.
People who took rasagiline for six weeks showed significant improvement in their scores on standard neurological tests compared with those who took sugar pills. However, a double dose of the drug proved no more effective than a single, one milligram pill per day.
Between 700,000 and 1 million Americans have Parkinson's. The disorder results from the gradual deterioration of brain cells that respond to dopamine, which is linked to a sweeping range of functions including motor control and cognition. Parkinson's patients typically develop stiff movement, tremors and weakness, and they can also become profoundly confused about even the most trivial tasks.
The typical Parkinson's patient goes about a year after diagnosis before needing treatment for symptoms of the disease. Until then, experts say, simply stalling progression of the disorder would be a significant step. A report on the findings appears in the December issue of the Archives of Neurology.
Rasagiline is made by Teva Pharmaceutical Industries, an Israeli company that paid for the study, which was done in the United States and Canada. The drug, which has not yet been approved for use in the United States, inhibits a brain enzyme called monoamine oxidase type B (MAO-B), leading to an increase in dopamine.
A previous study showed patients seem to tolerate the drug. In the new study, researchers gave one or two milligrams a day of rasagiline for 26 weeks to 266 men and women recently diagnosed with Parkinson's. Another 138 received placebo tablets.
At the beginning of the study, patients in all three groups had an average score of roughly 25 on the Unified Parkinson's Disease Rating scale. This test gauges a person's ability to perform daily tasks such as dressing and walking, as well as their emotional state.
By the end of the study, the untreated group scored about four points worse than those on either one or two milligrams of the drug.
"A four-point difference over six months is definitely a good improvement," says study co-author Dr. Raj Pahwa, director of the Parkinson's Disease Clinical and Research Center at the University of Kansas. "It's not a cure, and it's not the biggest invention yet for Parkinson's. But it's another small step in trying to slow the disease progression."
People taking the drug were more likely than those on sugar pills to report dizziness and nausea. However, Pahwa says those side effects are mild and wouldn't deter him from prescribing rasagiline if it were approved by the U.S. Food and Drug Administration.
A Teva spokesman says the company hasn't submitted a new drug application for rasagiline and doesn't have a concrete timetable for when it would do so.
Robin Elliott, executive director of the Parkinson's Disease Foundation, in New York City, said his group was "not terribly excited about" the latest study.
Rasagiline is a "mildly good product" that "really doesn't advance things so far," he added.
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