Part A This will be a randomised, double blind, placebo controlled, parallel group titration of up to seven single dose levels of ATX2417. In each cohort, six subjects will receive active compound and two will receive placebo in a randomised fashion. At each dose level, 2 subjects (1 subject will receive ATX2417 and 1 subject will receive placebo) will be dosed on Day 1 and the remaining 6 subjects will be dosed at least 24 hours later. Safety and pharmacokinetic observations will be made. There will be a minimum of two weeks between the first dosing day at each dose level. Safety and ATX2417 pharmacokinetic data will be reviewed prior to each dose escalation and, based on pharmacokinetic data, it is also possible to decrease the dose if the pharmacokinetic profile so indicates. This part will also include an assessment of the effect of a high fat breakfast on the absorption and pharmacokinetic profile of ATX 2417, performed at a dose predicted to be associated with therapeutic plasma concentrations.