The study is one of four ongoing or planned trials in the ACTIV program and is receiving support through Operation Warp Speed. The trial will begin by studying the investigational antibody Ly-CoV555 discovered by Abcellera Biologics in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID) and subsequently developed and manufactured by Eli Lilly in partnership with Abcellera.

ACTIV-3 aims to initially enroll 300 volunteers who have been hospitalized with COVID-19 who will be given either intravenous infusion of Ly-CoV555 or a saline placebo infusion. Patients' symptoms will be accessed after five days and will be followed for 90 days. If successful, the study will enroll an additional 700 participants.

The trial will take place in select hospitals within an existing clinical trial network, including the International Network of Strategic Initiatives in Global HIV Trials, the Prevention and Early Treatment of Acute Lung Injury network, and Cardiothoracic Surgical Trials Network.

Ly-CoV555 is currently also being tested in ACTIV-2, a safety and efficacy study in people with mild to moderate symptoms of COVID-19 who have not been hospitalized.

ACTIV-3 will use an adaptive two-stage phase III protocol design, where the trial can be modified to test additional experimental therapeutics and allow novel therapeutics to enter at either stage.