Humanigen, Inc. announced that target enrollment in the Phase 2/3 ACTIV-5/BET-B study has been achieved. The study, sponsored by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, enrolled over 400 patients in the primary analysis population at approximately 55 recruiting clinical sites including international sites. The ACTIV-5/BET-B study was designed to align with the Company's Phase 3 study of its lead investigational product candidate, lenzilumab, in hospitalized patients with COVID-19 (“LIVE-AIR”), results of which recently were published in Lancet Respiratory Medicine.

The Lancet publication concluded that lenzilumab treatment of hospitalized patients with COVID-19 can improve the likelihood of survival without the need for mechanical ventilation, with a safety profile similar to that of placebo. Hospitalized COVID-19 patients enrolled in ACTIV-5/BET-B were randomized to receive either lenzilumab and remdesivir or placebo and remdesivir. Patients in both arms also received current standard of care for hospitalized COVID-19 patients, including corticosteroids.

The primary analysis population in ACTIV-5/BET-B comprises all randomized patients with a baseline C-reactive protein (“CRP”) less than 150 mg/L, age < 85, and do not require mechanical ventilation at the time of enrollment. The primary endpoint of ACTIV-5/BET-B is the incidence of invasive mechanical ventilation or death through day 29. Analysis of the LIVE-AIR results demonstrated that patients with baseline CRP levels below 150 mg/L had even greater response to lenzilumab therapy, with a 62% relative reduction in the incidence of invasive mechanical ventilation or death (OR:0.38, 95%CI, 0.19-0.75, p = 0.005).