Drug-drug Interaction Study of GSK1278863 With Pioglitazone, Rosuvastatin and Trimethoprim in Healthy Adult Volunteers

This study will be a two-part with an open-label, single oral dose, two-way crossover study design. Part A and Part B of the study are independent and may be conducted in parallel. The Part A of the study will assess the effect of an oral dose of GSK1278863 on the pharmacokinetics of a CYP2C8 (pioglitazone) and OATP1B1 (rosuvastatin) probe substrate in order to determine the potential for clinically-significant drug interactions with CYP2C8 and OATP1B1 substrates. The Part B of the study will assess the effect of a weak CYP2C8 inhibitor (trimethoprim) on the pharmacokinetics of GSK1278863 and its six predominant metabolites. Part A will be conducted in approximately 30 healthy subjects, having a randomized study design. There will be approximate 7-day washout period between each dosing period. Part B will be conducted in approximately 20 healthy subjects, having single sequence study design. Follow up will be conducted within 7 to 10 days after the last dose in both Part A and B. The total duration of a subject\'s involvement in the part A of the study will be approximately 8 weeks (Screening to Follow-up) and in part B will be approximately 7 weeks (Screening to Follow-up).