Two Phase I studies (P1A114070 & P1A114347) have been conducted in healthy volunteers using GSK2018682 in capsule formulation. These capsules were produced from a single batch of compound (second drug substance campaign, termed CD2) with a particle size of 15 µm (D90). In order to support further clinical development of GSK2018682, a new batch (CD3) of compound has been synthesized that has a slightly larger particle size (29 µm, D90). In addition, it is intended that longer term studies (Proof of Concept and beyond) will be conducted with a tablet form of the drug. There is also a possibility that obtaining a smaller particle size through micronisation of the CD3 batch (to produce particles with diameters of approximately 3.8 µm, D90) may improve bioavailability; so a tablet made from micronized CD3 GSK2018682 is also being developed. In order to ensure appropriate dose selection for future studies, there is a need to investigate the pharmacokinetic profiles of both new tablet forms of GSK2018682 (manufactured from CD3 campaign) and compare these to the original (CD2) capsule formulation. Therefore, this study will evaluate the relative bioavailability of single doses of each of the 3 different formulations (CD2 capsule, CD3 tablet and CD3 micronized tablet) of GSK2018682 in a cross over, randomized, 4 period, open label design. The fourth treatment arm will be added to examine the effect of food on relative bioavailability of the CD3 tablet formulation. The study will also measure the effects of each dose form of GSK2018682 on total lymphocyte counts.