FDA Clears First Drug for Parkinson's Dyskinesia

Megan Brooks


August 25, 2017

The US Food and Drug Administration (FDA) has approved amantadine extended-release capsules (Gocovri, Adamas Pharmaceuticals Inc) for treatment of dyskinesia in patients with Parkinson's disease receiving levodopa-based therapy, with or without concomitant dopaminergic medications, the company announced today.

"Gocovri's approval is an important advancement for the treatment of Parkinson's disease, as it is the first FDA-approved medicine for the treatment of dyskinesia in Parkinson's disease patients," Rajesh Pahwa, MD, professor of neurology at the Kansas Medical Center and director of the Parkinson's Disease Center of Excellence at the University of Kansas Health System, Kansas City, said in a company news release.

"Notably, Gocovri is the first Parkinson's disease medicine proven in controlled trials to reduce both dyskinesia and OFF time in Parkinson's disease patients receiving levodopa. Treatment of dyskinesia and OFF time continues to be an unmet need in the medical management of Parkinson's disease and the approval of Gocovri is a major step in that direction," added Dr Pahwa.

Dr Pahwa led a phase 3 placebo-controlled trial of amantadine extended-release (ER), published online June 12 in JAMA Neurology and reported by Medscape Medical News.

The amantadine ER capsules, administered at bedtime, are specifically formulated so that the plasma concentration increases slowly during sleep, with peak concentration in the morning and sustained concentrations throughout the day.

The efficacy and safety of amantadine ER for Parkinson's dyskinesia were demonstrated in two phase 3 controlled trials. In study 1, patients receiving the drug showed statistically significant and clinically relevant reductions in dyskinesia, with a 37% reduction in Unified Dyskinesia Rating Scale (UDysRS) total score, compared with 12% for placebo at week 12. These results were confirmed in study 2, in which amantadine ER achieved a 46% reduction in UDysRS compared with 16% for placebo.

Secondary data from Parkinson's disease patient-reported diaries in study 1 and study 2 showed that amantadine ER–treated patients experienced, respectively, a 3.6- and 4.0-hour increase in functional time daily (defined as "on" time without troublesome dyskinesia) vs a 0.8- and 2.1-hour increase for placebo-treated patients at week 12. The increases in functional time were achieved by decreases in both "on" time with troublesome dyskinesia and "off" time. The placebo-adjusted reduction in "off" time in both studies was about 1 hour per day.

The most commonly observed adverse reactions (>10% and greater than with placebo) with amantadine ER were hallucinations, dizziness, dry mouth, peripheral edema, constipation, falls, and orthostatic hypotension.

The company expects amantadine ER to be available in the fourth quarter.

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