Double blind, placebo controlled, ascending single and multiple intravenous dose, sequential group study. This will be a study in two parts. In the first part, up to twenty four subjects will complete the study in up to 3 cohorts (Groups A to C), each group consisting of 8 subjects, six of whom will receive active compound and two will receive placebo for eight days. Each subject 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 13 (120 hours post the last dose).