Aridis Pharmaceuticals Inc. has taken a few knocks in the past year but its new agreement with the U.S. FDA is giving it an opportunity to move forward. The company’s stock (NASDAQ:ARDS) rose 115% on May 31 to close at 39 cents per share as the company and agency agreed on the design of a single confirmatory phase III superiority study of AR-301 (tosatoxumab), an adjunctive therapy for treating pneumonia caused by gram-positive bacteria Staphylococcus aureus in mechanically ventilated hospitalized patients.