An Open Label Study to Examine the Effects of a High-Fat Meal and Particle Size on the Pharmacokinetics of Orally Administered GSK2118436 in Subjects With BRAF Mutation Positive Tumor

GSK2118436 is an orally administered, potent and selective small molecule BRAF inhibitor that is currently being developed for the treatment of BRAF mutation-positive tumors. This study is designed to evaluate the effects of particle size on the relative bioavailability of GSK2118436 (Cohort 1) and to evaluate the effects of a high-fat meal on the pharmacokinetics of GSK2118436 (Cohort 2). Subjects will randomly receive two of four possible regimens over two periods. Subjects enrolled in Cohort 1 will receive a single 150 mg dose of GSK2118436 as micronized particles fasted (gelatin capsule formulation) and a single 150 mg dose of GSK2118436 as non-micronized particles fasted (larger particle size). Subjects enrolled in Cohort 2 will receive a single 150 mg dose of GSK2118436 (HydroxyPropyl Methyl Cellulose (HPMC) capsule formulation) fasted and with a high-fat breakfast. GSK2118436 will be administered as the mesylate salt (equivalent to 150 mg free base). Safety and tolerability will also be evaluated. The study will be conducted at a sufficient number of centers to complete approximately 28 adult subjects (14 subjects per cohort) with BRAF mutation-positive tumors. Following completion of this study, subjects may continue dosing with GSK2118436 in the roll-over study, Protocol BRF114144.