Phase 1b/2a, Randomized, Double-Blind, Placebo Controlled, Multiple Ascending Dose Escalation Study of the Safety, Tolerability, and Efficacy of Intravenous AP-SAO2 as an Adjunct to Best Available Antibiotic Compared to Best Available Antibiotic Therapy Alone for the Treatment of Adults With Bacteremia Due to Staphylococcus aureus.