This study will be conducted in three parts (Part 1, Part 2 and Part 3). Part 1 of this study will evaluate the relative bioavailability of a single dose of GSK2140944 tablet formulation compared to the reference capsule formulation under fasted conditions. The effect of food on the pharmacokinetics (PK) of a single dose of the tablet formulation will also be assessed. Part 2 will evaluate the effect of repeat doses of itraconazole on the pharmacokinetics of GSK2140944 following a single dose. A decision will be made whether to use the current capsule formulation or the new tablet formulation in Part 2 based upon the safety and PK data obtained from Part 1. Part 3 is conditionally based upon progression of the tablet formulation from Part 1 and will evaluate the effect of food on the safety, tolerability, and pharmacokinetics of the tablet formulation following multiple doses in elderly healthy subjects.