Aridis Pharmaceuticals Inc. announced positive clinical results from its Phase 1/2a study of AR-301, its fully human monoclonal antibody against Staphylococcus aureus alpha-toxin being evaluated as an adjunctive therapy in combination with standard of care antibiotics for hospital-acquired pneumonia and ventilator-associated pneumonia ("HAP" and "VAP"). The double-blind, placebo-controlled study met its primary endpoint of safety. Aridis will move forward with plans for late-stage clinical studies of AR-301 in 2017. AR-301 (or Salvecin) is a fully human monoclonal IgG1 antibody that specifically targets S. aureus alpha-toxin and protects host cells from destruction. It was discovered by applying Aridis' MabIgX® technology to screen human B-cells of convalescent pneumonia patients. S. aureus is a gram-positive bacterium and is among the leading causative agents of bacterial pneumonia in intensive care units (ICU) and other hospital-acquired infections. S. aureus is also a common pathogen in other infections including the skin and soft tissues infection, post-surgery infection, endocarditis, bacteremia, sepsis, and toxic shock syndrome. AR-301's mode of action is independent of the antibiotic resistance profile of S. aureus, hence it is active against drug-resistant strains, including MRSA (methicillin-resistant S. aureus). In animal studies, AR-301 reduced bacterial load and significantly improved survival following localized and systemic S. aureus infections.