FDA Approves Amantadine Extended Release for Parkinson, Movement Disorders

The US Food and Drug Administration (FDA) has approved an amantadine extended release tablet (OSMOLEX ER) for the treatment of Parkinson’s disease (PD) and drug-induced extrapyramidal reactions in adult patients.

The tablet, manufactured by Osmotica Pharmaceutical, is a drug formulation of both immediate and extended release amantadine that utilizes the company’s patented Osmodex technology to provide once-daily therapy for adult patients with PD and drug-induced involuntary movement disorders, such as tardive dyskinesia (TD).

Three dosage options of the extended-release amantadine therapy — 129mg, 193mg, 258mg — will be available to patients, with a maximum daily dose regulated at 322mg. Because the once-daily therapy is administered in the morning, patients will have the flexibility to set their regimen among the 3 set dose options.

Amantadine has been previously approved by the FDA for antiviral and antiparkinsonian treatment. Just last year, the treatment made news for its benefit in treating both dyskinesia and motor symptoms in patients with PD. An oral 274mg amantadine treatment was analyzed in a randomized, controlled trial versus placebo in a population of 126 patients with PD who developed levodopa-induced dyskinesia (LID).

LID is observed in more than half of patients with PD to have received levodopa treatment — a fairly common therapy — for at least 4 years. Patients were administered either amantadine or placebo at bedtime for 25 weeks, while researchers measured improvement by change in their Unified Dyskinesia Rating Scale (UDRS) total score from baseline to week 12.

Researchers also tested for an efficacy against lapse of time in which treatment is not controlling motor symptoms in patients with PD or, Parkinson’s “off time.”

At week 12, patients to have received amantadine reported a mean UDRS score decrease of 15.9 from baseline, a nearly-twice as great decrease than the placebo patients (8-point decrease). Amantadine patients’ “off time” had also decreased, by 0.6 hours per day by week 12. Placebo patients’ “off time” had actually increased by 0.3 hours in that same span of time.

Common adverse reactions to OSMOLEX ER in clinical settings included nausea, dizziness and lightheadedness, and insomnia. Reactions were reported in at least 5% of patients provided recommended dosage.

Plans to commercialize the product are currently being finalized, Osmotica Chief Executive Officer Brian Markinson said in a statement. He expressed eagerness to make another therapy available to adult patients with PD or movement disorders.

“We believe that the approved indications and compelling value proposition will be important factors in physician adoption and marketing of OSMOLEX ER,” Markinson said.

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