This is a double-blind, placebo-controlled study in healthy adult volunteers that will be conducted to evaluate the safety, tolerability, and pharmacokinetics of ascending single doses of SKI-O-703. A total of 48 subjects are planned to participate in 6 cohorts (8 subjects each). In each cohort, 6 subjects will be randomly assigned to receive SKI-O-703 and 2 subjects will be randomly assigned to matching placebo. Dosing will be initiated in the 50 mg dose cohort and sequentially escalated to the 100 mg, 200 mg, 400 mg, 600 mg, and 800 mg cohorts.