Outpatient Treatment With Anti-Coronavirus Immunoglobulin

The primary objective will be addressed by testing two hypotheses aimed at assessing whether hIVIG + standard of care (SOC) is superior to placebo + SOC for the primary ordinal endpoint at Day 7. These hypotheses will be tested for the following two groups: a) among all randomized participants (stratum 1 and 2), and b) among only participants enrolled in stratum 1. For the primary analysis, overall type 1 error will be controlled at 5% by using a 2-sided significance level of 0.035 for each hypothesis. This significance level was obtained using the correlation between the test statistics for the proportional log odds ratio for all randomized participants and for this log odds ratio for those in stratum 1. This correlation was determined to be 0.895. With this approach hIVIG will be considered superior to placebo if either of the two hypotheses is rejected. Participants will be randomized to a single infusion of an hIVIG product or placebo in a 1:1 allocation. Randomization will be stratified by study site pharmacy and the two SOC strata.