On May 26, 2020, Merck and and and Ridgeback Biotherapeutics announced a collaboration agreement to develop EIDD-2801, an orally available antiviral candidate currently in early clinical development for the treatment of patients with COVID-19.

Merck, through a subsidiary, will gain exclusive worldwide rights to develop and commercialize EIDD-2801 and related molecules. Ridgeback Bio will receive an undisclosed upfront payment, specified milestones and a share of the net proceeds of EIDD-2801 and related molecules, if approved. Merck will be responsible for clinical development, regulatory filings and manufacturing.