This study will be conducted in a randomised, placebo-controlled dose-escalation design with OZ439 OD administered with full fat milk for three days to healthy male and female subjects between 18 to 55 years of age, using features of an adaptive study design. The study is expected to have three cohorts with a total of 36 healthy male and female subjects. An additional two cohorts may be used if required. The results of this study will inform the maximum tolerated exposure of OZ439 following OD dosing for three days in subjects who are not fasted.