 BURLINGAME, Calif.--BUSINESS WIRE--Humanigen, Inc. Nasdaq: HGEN Humanigen, a clinical-stage biopharmaceutical company focused on preventing and treating an immune hyper-response called cytokine storm, announced today the U.S. FDA has declined its request for emergency use authorization of lenzilumab to treat newly hospitalized COVID-19 patients. In its letter, FDA stated that it was unable to conclude that the known and potential benefits of lenzilumab outweigh the known and potential 