On Dec. 17, 2020, NIAID announced that two randomized, controlled Phase 3 clinical trials had begun evaluating investigational monoclonal antibodies for their safety and efficacy in treating people hospitalized with moderate COVID-19.

The trials were part of the ACTIV-3 master protocol, which has an adaptive design allowing investigators to add new sub-studies of additional investigational agents. ACTIV-3 is sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.