 Japanese subjects will be assigned to Cohort J1 at a dose of 75 mg, Cohort J2 105 mg, Cohort J3 150 mg, or Cohort J4 450 mg in a randomized, double-blind, placebo-controlled manner, while Caucasian subjects to Cohort C1 at a dose of 75 mg or Cohort C2 150 mg in an open-label manner. 