On Apr. 15, 2020, Humanigen announced that U.S. Food and Drug Administration (FDA) had given permission to commence a Phase III study of lenzilumab in patients with COVID-19.

Humanigen planned to enroll patients in a multicenter, randomized, placebo-controlled, double-blinded clinical trial with lenzilumab for the prevention of respiratory failure and/or death in hospitalized patients with pneumonia associated with SARS-CoV-2 infection in COVID-19 patients.