On Jul. 2, 2020, Regeneron and Sanofi announced that the U.S. Phase 3 trial of Kevzara (sarilumab) 400 mg in COVID-19 patients requiring mechanical ventilation did not meet its primary and key secondary endpoints when Kevzara was added to best supportive care compared to best supportive care alone (placebo).

In the primary analysis group, adverse events were experienced by 80% of Kevzara patients and 77% of placebo patients.