This is a randomized, double-blinded, placebo-controlled study in which subjects will be assigned to receive treatment with one of the following oral dosages of VCH-759: 400 mg t.i.d., 600 mg t.i.d., and 800 mg t.i.d., or placebo; enrollment into the three cohorts will occur sequentially. Within each cohort, subjects will be randomized to a treatment: placebo ratio of 3:1 for a total of 12 subjects per cohort; subjects will be randomized in blocks of 4. The decision to continue dosing within a cohort will be determined by an independent review of all safety data up to and including Day 11 for the first 4 subjects within that dose cohort; this review will be conducted by a qualified medical specialist, in conjunction with the sponsor and medical monitor. The decision to proceed to the next cohort will be decided by an independent review of Day 11 safety data for all 12 subjects in the previous cohort. Eligible subjects will receive study medication three times daily for 10 days and will return to the study center for follow-up assessments on Day 11, Day 17, and Day 24.