A Study of the Pharmacokinetics, Pharmacodynamics, and Safety of Opicapone in Subjects With Parkinson's Disease Taking Levodopa.

Inclusion criteria

• Have a clinical diagnosis of idiopathic Parkinson's Disease (PD) for at least 3 years with clear improvement with levodopa treatment
• Be at a stable dose of maintenance medication(s) for PD, including stable doses of CD/LD
• Subjects of childbearing potential who do not practice total abstinence must agree to use hormonal or two forms of nonhormonal contraception (dual contraception) consistently during the screening, treatment and follow-up periods of the study
• Have a body mass index (BMI) of 18 to 40 kg/m2
• Have a modified Hoehn and Yahr stage of ≤4 in the OFF state
• Be able to tolerate an overnight period of 12 hours without CD/LD
• Be in good general health and expected to complete the clinical study as designed

Exclusion criteria

• Are currently pregnant or breastfeeding
• More than 2 alcoholic beverages daily or more than 14 alcoholic beverages weekly within 7 days of Day -1 or consume any alcohol within 48 hours of Day -1.
• Have motor fluctuations during the day (ie, effect of levodopa "wearing off" or having unpredictable "off" periods), or severe or intolerable levodopa-induced dyskinesia
• Have had previous exposure to opicapone, or have an allergy, hypersensitivity, or intolerance to opicapone or other COMT inhibitor.
• Have a history of a medical condition or surgical procedure that might interfere with absorption or metabolism.
• Have a known history of neuroleptic malignant syndrome
• Have an unstable medical condition or chronic disease
• Have taken certain prohibited medications within 28 days of Day -1.
• Have a known or suspected diagnosis of AIDS, or have tested seropositive for HIV
• Have hepatitis A or B
• Have a significant risk of suicidal or violent behavior