This study is the first administration of GSK2881078 to humans. The intention of this study is to provide sufficient confidence in the safety of the molecule to inform progression to further repeat dose and proof of concept studies. This study will include approximately 52 subjects and consist of 2 parts. Part A will consist of two cohorts of 8 subjects to assess the safety, tolerability, and pharmacokinetic (PK) of ascending single oral doses of GSK2881078. Cohorts 1 and 2 will include healthy male subjects. Part B (Cohorts 3, 4 and 5) will include three cohorts of 12 healthy male subjects to examine the safety, tolerability, PK, and pharmacodynamic (PD) of repeated doses of GSK2881078 over 14 days. The total duration of the study including screening and follow-up, is not expected to exceed 70 days.