On Jun. 8, 2021, Merck announced it had entered into a procurement agreement with the U.S. government for molnupiravir (MK-4482). Molnupiravir was being evaluated in a Phase 3 clinical trial, the MOVe-OUT study, for the treatment of non-hospitalized patients with laboratory-confirmed COVID-19 and at least one risk factor associated with poor disease outcomes.

Merck was developing molnupiravir in collaboration with Ridgeback Biotherapeutics.