On Apr. 15, 2021, The National Institute of Allergy and Infectious Diseases (NIAID) announced that the fourth iteration of the Adaptive COVID-19 Treatment Trial (ACTT-4) has closed to enrollment because the study met pre-defined futility criteria indicating that neither treatment regimen studied is likely significantly better than the other.

The NIAID-sponsored trial aimed to determine which of two drug combinationsﾗbaricitinib plus remdesivir or dexamethasone plus remdesivir ﾗ was more effective at preventing adults hospitalized with COVID-19 on supplemental oxygen from progressing to requiring mechanical ventilation or death, among other outcomes.