Dataset from A Randomized Double-blind (Sponsor Unblind) Placebo Controlled Study in Healthy Subjects to Evaluate: Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of the Repeat Doses of GSK2881078, the Selective Androgen Receptor Modulator With an Open Label Dosing Arm to Evaluate the Effect of CYP3A4 Inhibition on Pharmacokinetics of GSK2881078

GSK2881078 is a selective androgen receptor modulator (SARM) that is being evaluated for effects on muscle growth and strength in subjects with muscle wasting to improve their physical function. Part A of this study will evaluate the safety, efficacy and pharmacokinetics of GSK2881078 in healthy, older men and post-menopausal women who will take daily dosing for 28 days and be followed for a total of 70 days. Part B of this study will characterize the effect of Cytochrome P450 3A4 (CYP3A4) inhibition on the GSK2881078 pharmacokinetics. Part B will only be conducted if safe and efficacious dose is identified in Part A. Part A will include healthy older males and post-menopausal females; and randomize approximately 60 subjects (about 15 per cohort [4 cohorts]) to complete approximately 48 (about 12 per cohort). Part B will enroll one cohort of approximately 15 healthy male subjects to complete approximately 12. The study duration will be approximately 115 days for Part A and 122 days for Part B.