Double blind, placebo controlled, ascending multiple (10) oral dose, sequential group study. Twenty-four subjects will complete the study in 3 cohorts (Groups A to C), each group consisting of 8 subjects. Each cohort will consist of 4 male and 4 female subjects. Each subject will be dosed for 10 days and will be on study for approximately 7 weeks. Each subject will participate in one treatment cohort only, residing at the Clinical Research Unit (CRU) from Day -1 (the day before dosing) to Day 15 (120 hours post the last dose). The dose will range between 2 and 10 mg/kg daily, given as either a single daily dose or as two doses divided over the 24-hour dosing period.