On Feb. 8, 2021, the NIH announced that an international randomized, controlled Phase 3 clinical trial had begun evaluating the safety and efficacy of an investigational long-acting antibody combination for treating people hospitalized with COVID-19.

The trial, part of a master protocol known as ACTIV-3, was an adaptive design allowing investigators to add new sub-studies of additional investigational agents. ACTIV-3 as sponsored by the National Institute of Allergy and Infectious Diseases.