Variant of Parkinson's Drug Tested In ALS

Investigators at the University of Virginia in Charlottesville are testing a compound known as R(+) pramipexole in people with amyotrophic lateral sclerosis (ALS) to see whether it alters their decline in function or changes biochemical markers of the cell-damaging process known as oxidative stress.

James Bennett, a professor of neurology at the University of Virginia School of Medicine, became interested in testing R(+) pramipexole in ALS a few years ago, after S(-) pramipexole, whose structure is a mirror image of the R form, was found effective in Parkinson’s disease.

S(-) pramipexole was developed into the drug Mirapex, which mimics the brain chemical dopamine and acts as an antioxidant, combatting oxidative stress. It enters the nervous system and the mitochondria, the sites of energy generation inside cells.

Bennett, a physician who has a doctoral degree in pharmacology, recently found that 15 ALS patients tolerated 30 milligrams a day of R(+) pramipexole, which does everything the S(-) form does except mimic dopamine, which isn’t a goal in ALS treatment.

Thirty milligrams is about five times the tolerable dose of the S form, says Bennett, who’s now testing one ALS patient at a time to see how high he can boost the dose of the R form.

The investigators aren’t seeking new trial participants at this time, but they may be in the future.

“So far the results are encouraging for slowing disease progression,” Bennett says, “but there aren’t enough data yet to draw any firm conclusions.”

For more information, see R(+) Pramipexole in Early ALS.