The purpose of this study is to investigate the effect of food on the catechol-O-Methyltransferase (COMT) activity after repeated doses of opicapone (OPC, development code BIA 9-1067) in healthy subjects and to characterize the effects of food on the pharmacokinetics (PK) and tolerability of OPC after repeated doses.

Single-centre, open-label, single-arm study in 28 healthy subjects. Subjects received a single-dose of 50 mg OPC once-daily (QD) in the evening for 12 days. On Day 1 (D1), 50 mg OPC was orally administered in the evening (reference hour for all other administrations) after a minimum of 6 hours fast. From D2 to D8 subjects were in ambulatory and received 50 mg OPC once-daily (evening administration after 2 hours fast). On D9, 50 mg OPC was orally administered in the evening after a minimum of 6 hours fast. On D10, 50 mg OPC was orally administered in the evening, thirty minutes after the start of a moderate meal (with a previous 6 hours fast). On D11 and D12 subjects received the last doses of 50 mg OPC (evening administration after 2 hours fast).

Inclusion Criteria:

• Able and willing to give written informed consent and to comply with the study restrictions.
• Male or female subjects aged between 18 and 45 years, inclusive.
• Body mass index (BMI) between 19 and 30 kg/m2, inclusive.
• Healthy as determined by pre-study medical history, physical examination, vital signs, complete neurological examination and 12-lead ECG.
• Negative tests for HBsAg, anti-HCV Ab and HIV-1 and HIV-2 Ab at screening.
• Clinical laboratory test results clinically acceptable at screening and admission.
• Negative screen for alcohol and drugs of abuse at screening and admission.
• Non-smokers or ex-smokers for at least 3 months.
• If female:
• Not of childbearing potential by reason of surgery or, if of childbearing potential, she uses an effective non-hormonal method of contraception (intrauterine device or intrauterine system; condom or occlusive cap [diaphragm or cervical or vault caps] with spermicidal foam or gel or film or cream or suppository; true abstinence; or vasectomized male partner, provided that he is the sole partner of that subject) for all the duration of the study.
• Negative serum pregnancy test at screening and a negative urine pregnancy test on admission.

Exclusion Criteria:

• Clinically relevant history or presence of respiratory, gastrointestinal, renal, hepatic, haematological, lymphatic, neurological, cardiovascular, psychiatric, musculoskeletal, genitourinary, immunological, dermatological, endocrine, connective tissue diseases or disorders.
• Clinically relevant surgical history.
• Clinically relevant abnormality in the coagulation tests.
• Clinically relevant abnormality in the liver function tests.
• History of relevant atopy or drug hypersensitivity, particularly to any COMT inhibitor.
• History of alcoholism or drug abuse.
• Consume more than 14 units of alcohol a week.
• Significant infection or known inflammatory process at screening or admission.
• Acute gastrointestinal symptoms (e.g., nausea, vomiting, diarrhoea, heartburn) at the time of screening or admission.
• Used medicines within 2 weeks of admission that may affect the safety or other study assessments, in the investigator's opinion.
• Previously received OPC.
• Used any investigational drug or participated in any clinical trial within 90 days prior to screening.
• Participated in more than 2 clinical trials within the 12 months prior to screening.
• Donated or received any blood or blood products within the 3 months prior to screening.
• Vegetarians, vegans or have medical dietary restrictions.
• Cannot communicate reliably with the investigator.
• Unlikely to co-operate with the requirements of the study.
• If female:
• Pregnant or breast-feeding.
• Of childbearing potential and not used an approved effective contraceptive method or she uses oral contraceptives.