ACTIV-5 / Big Effect Trial (BET-C) for the Treatment of COVID-19

This is a platform trial to conduct a series of randomized, double-blind, placebo-controlled trials using common assessments and endpoints in hospitalized adults diagnosed with COVID-19. BET is a proof-of-concept study with the intent of identifying promising treatments to enter a more definitive study. The study will be conducted in up to 70 domestic sites and 5 international sites. The study will compare different investigational therapeutic agents to a common control arm and determine which have relatively large effects. In order to maintain the double blind, each intervention will have a matched placebo. However, the control arm will be shared between interventions and may include participants receiving the matched placebo for a different intervention. The goal is not to determine clear statistical significance for an intervention, but rather to determine which products have clinical data suggestive of efficacy and should be moved quickly into larger studies. Estimates produced from BET will provide an improved basis for designing the larger trial, in terms of sample size and endpoint selection. Products with little indication of efficacy will be dropped on the basis of interim evaluations. In addition, some interventions may be discontinued on the basis of interim futility or efficacy analyses. One or more interventions may be started at any time. The number of interventions enrolling are programmatic decisions and will be based on the number of sites and the pace of enrollment. At the time of enrollment, subjects will be randomized to receive any one of the active arms they are eligible for or placebo. Approximately 200 (100 treatment and 100 shared placebo) subjects will be assigned to each arm entering the platform and a given site will generally have no more than 3 interventions at once. The BET-C stage will evaluate the combination of remdesivir with danicopan vs remdesivir with a placebo. Subjects will be assessed daily while hospitalized. Once subject