On Jun. 17, 2020, Aclaris Therapeutics announced that the FDA had allowed an investigational new drug application to evaluate ATI-450, its oral investigational MK2 inhibitor compound, in hospitalized patients with COVID-19.

Aclaris suppored an investigator-initiated trial of ATI-450 for cytokine release syndrome (CRS) in 36 hospitalized patients with COVID-19, and provided funding and clinical drug supply to the University of Kansas Medical Center, the sponsor of the trial. The primary endpoint was the proportion of subjects who were free from respiratory failure by day 14.