The US Food and Drug Administration (FDA) has approved Impax Pharmaceuticals' Rytary, an extended-release oral capsule formulation of carbidopa-levodopa, for the treatment of Parkinson's disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication and / or manganese intoxication. Rytary is not for use in patients using nonselective monoamine oxidase inhibitors (MAO) inhibitors.
"The FDA approval of Rytary (pronounced rye-TAR-ee) is an important new development for the treatment of Parkinson's disease and provides an extended-release carbidopa-levodopa product that treats Parkinson's disease," said Fred Wilkinson, president and CEO, Impax Laboratories. "Rytary is designed to address one of the most significant unmet needs for patients living with Parkinson's disease, which is to reduce the amount of time during the day when their symptoms are not adequately controlled."
"There are approximately one million Americans living with this chronic disease and we are pleased to offer this new therapy as a treatment option for those patients," added Wilkinson. "Today's approval of Rytary is also a significant milestone for Impax because it is our first branded drug internally developed and approved for commercialisation."
Rytary contains immediate release and extended-release beads, with a specific amount of carbidopa and levodopa in a 1:4 ratio, and provides both initial and extended levodopa plasma concentrations after a single dose. Rytary may be swallowed whole or, for patients who have trouble swallowing, the capsule may be opened and the beads sprinkled on applesauce and consumed immediately.
Impax expects the four strengths of Rytary, 23.75mg/95mg, 36.25mg/145mg, 48.75mg/195mg, and 61.25mg/245mg (carbidopa/levodopa) to be available for commercial distribution in February 2015.
The Rytary clinical program studied patients with early (levodopa-naive) to advanced Parkinson's disease in the US and in Europe. In APEX-PD (Study 1), a trial that enrolled and randomised 381 levodopa-naive patients, the study met its primary efficacy endpoint of mean change from baseline in the sum of Unified Parkinson's Disease Rating Scale (UPDRS) Part II (activities of daily living) score and UPDRS Part III (motor skills) score for Rytary versus placebo at Week 30 (or early termination).
In ADVANCE-PD (Study 2), a trial of 393 randomised patients with advanced Parkinson's disease having "off" time, the results showed treatment with Rytary reduced the percentage of "off" time (36.9 per cent to 23.8 per cent) from baseline versus immediate-release carbidopa-levodopa (36.0 per cent to 29.8 per cent) during waking hours to end of study. Rytary also increased "on" time without troublesome dyskinesia during waking hours versus baseline to end of study by 1.8 hours. Less "off" time was primary related to more "on" time without troublesome dyskinesia.
The most common adverse reactions with Rytary in the APEX-PD trial (in at least 5 per cent of patients and more frequently than in placebo) were nausea, dizziness, headache, insomnia, abnormal dreams, dry mouth, dyskinesia, anxiety, constipation, vomiting, and orthostatic hypotension. The most common adverse reactions with Rytary in the ADVANCE-PD trial (in at least 5 per cent of patients and more frequently than an oral immediate-release carbidopa-levodopa) were nausea and headache.
Parkinson's disease is a chronic neurodegenerative movement disorder affecting approximately one million people in the US, with 50,000-60,000 new cases diagnosed each year in the US alone. There is currently no known cure for Parkinson's.