The primary objectives of this study are: to evaluate the pharmacokinetic (PK) profiles of BIIB091 modified release (MR) formulations in healthy participants after single dose administration in the fasted state (Part 1); to evaluate the PK profile of the BIIB091 immediate release (IR) tablet formulation in healthy participants after single dose administration (Part 1B); to determine the relative bioavailability of single doses of the selected BIIB091 regimen in healthy participants taking a proton pump inhibitor (PPI) compared to healthy participants not taking a PPI, to determine the relative bioavailability of single doses of the selected BIIB091 regimen in healthy participants taking a cytochrome P450 (CYP)3A4 inhibitor compared to healthy participants not taking a CYP3A4 inhibitor (Part 2); to evaluate the PK of the selected BIIB091 regimen in healthy participants after multiple dose administration (Part 3). The secondary objectives of this study are: to determine the relative bioavailability of a single dose of the BIIB091 MR formulations compared to that of the IR drug in capsule (DiC) reference formulation in healthy participants in the fasted state, to ass...