Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of BIA 5-1058

Each cohort will follow the same study design. Subjects will be screened for inclusion in the study between 28 and 3 days before the first dose. Eligible subjects will be admitted 2 days before dosing (Day -2) for all regimens, and will remain resident in the clinic until 72 h after the last dose (Day 13). On Day -1, blood samples will be taken in all cohorts for PD assessments at pre-defined time points. These time points will be time matched to Day 1 PK and PD time points. Subjects in Cohorts 2, 4, 6, 8, 10 and 11 (fed cohorts) will also undergo continuous cardiac monitoring via 24 h Holter recordings on Day -1. Subjects in Cohorts 1, 3, 5, 7 and 9 will receive oral doses of BIA 5-1058 or matching placebo once daily from Day 1 to Day 10, administered in the morning of each day after a minimum of 8 h fast and will remain fasted until 4 h post-dose. Subjects in Cohorts 2, 4, 6, 8, 10 and 11 will receive oral doses of BIA 5-1058 or matching placebo once daily from Day 1 to Day 10, administered in the morning of each day, 30 minutes after the start of a moderate breakfast containing approximately 550 kcal with fat contributing approximately 150 kcal.