In clinical trial results presented today at the Movement Disorders Society meeting in Sydney, Australia, Adamas Pharmaceuticals, Inc., announced that its investigational extended-release amantadine formula helped Parkinson’s patients with dyskinesia.
The Phase 2/3 clinical trial was conducted in 83 volunteers with Parkinson’s disease. Volunteers were separated into four different treatment groups and placebo, with each treatment group receiving a different dose. Two of the tested doses resulted in a statistically significant reduction in dyskinesia and all doses resulted in increased “on” time without dyskinesia.
“Though it doesn’t work for everyone, amantadine is one of the only medications we’ve got for treating dyskinesia,” said Irene Hegeman Richard, MD, Professor of Neurology and Psychiatry at the University of Rochester and a member of MJFF’s scientific advisory board. “The Adamas study suggests that the company’s formulation of amantadine is effective in reducing motor fluctuations and appears to have a similar side effect profile to the currently available form of amantadine. It does not, however, tell us how this formulation compares to the already available form of amantadine.”
Though amantadine has been used to treat Parkinson’s for decades, its benefit in Parkinson’s was discovered more or less by accident in the 1960s, and there have been few well-designed, controlled clinical studies of its use in PD. The Adamas trial joins a previous study sponsored by The Michael J. Fox Foundation in providing clinicians with new evidence-based guidance on factors that play an important role in prescribing — including dosage, administration of the drug, and safety issues and side effects. (Known side effects of amantadine include constipation, dizziness, dry mouth, headache and nausea.)
Adamas’ formulation is extended-release, designed to be taken at bedtime and slowly release into the bloodstream overnight, so that peak amounts of the drug are present when it’s time to wake up.
The company plans additional studies in Parkinson’s patients with dyskinesia.