In patients hospitalized with COVID-19 without end-organ failure, findings demonstrated absence of efficacy of SARS-CoV-2 hyperimmune intravenous immunoglobulin (hIVIG) when given with standard of care including remdesivir. Based on the presence of endogenous neutralizing antibodies at entry, variations might be seen in the safety of hIVIG.

• This is an international randomized, double-blind, placebo-controlled trial of 593 hospitalized patients with COVID-19 without acute end-organ failure who were randomized (1:1) to receive either hIVIG (n=301) or an equivalent volume of saline as placebo (n=292), in addition to remdesivir, when not contraindicated, and other standard clinical care.

• At day 7, the primary outcome was assessed by a seven-category ordinal endpoint that considered pulmonary status and extrapulmonary complications and ranged from no limiting symptoms to death; composite safety outcomes (deaths and adverse events) were assessed at days 7 and 28.

• No significantly greater odds of a more favorable outcome at day 7 were obtained in the hIVIG group, vs placebo; adjusted OR was 1·06.

• Despite good tolerability of infusions, infusion reactions were more common in the hIVIG group (18·6% vs 9·5% for placebo).

• For both groups, the percentage with the composite safety outcome at day 7 was similar (25%; OR 0·98).

• In subgroups, no variation was observed in ORs for the day 7 ordinal outcome, but there was evidence of heterogeneity of the treatment effect for the day 7 composite safety outcome: hIVIG was associated with a greater risk than placebo for those who were antibody positive (OR 2·21); for those who were antibody negative, the OR was 0·51.