Biopharmaceutical company Neurocrine Biosciences Inc (NASDAQ:NBIX) said on Wednesday that it has successfully filed its New Drug Application (NDA) with the US Food and Drug Administration (FDA) for opicapone as an adjunctive treatment to levodopa/carbidopa in patients with Parkinson's disease experiencing OFF episodes.

The FDA has set a standard 12-month review process with a Prescription Drug User Fee Act (PDUFA) target action date of 26 April 2020.

Parkinson's disease is a chronic, progressive and debilitating neurodegenerative disorder that affects approximately one million people in the US.

Opicapone is a novel, once-daily, selective catechol-O-methyltransferase (COMT) inhibitor. Opicapone works by prolonging the clinical effect of levodopa through decreasing its conversion rate into 3-O-methyldopa to allow for greater availability in the brain, the company explained.

The NDA for opicapone is supported by data from Neurocrine Biosciences' 38 clinical studies, including two Phase III studies (BIPARK-1 and BIPARK-2), with more than 1,000 Parkinson's disease patients treated with opicapone. The primary endpoint in both studies was the change from baseline in absolute time in the OFF state, as assessed by patient diaries.

BIPARK-1 was a Phase III, randomised, double-blind placebo- and active-controlled study of opicapone as an adjunct to levodopa therapy in which 600 patients with Parkinson's disease and motor fluctuations received once-daily opicapone (5 mg, 25 mg, or 50 mg), placebo, or 200 mg doses of the COMT inhibitor entacapone for 14 to 15 weeks. BIPARK-2 was a Phase III, randomised, double-blind placebo-controlled study of opicapone as an adjunct to levodopa therapy in which 400 patients with Parkinson's disease and motor fluctuations received once-daily opicapone (25 mg or 50 mg) or placebo for 14 to 15 weeks.