Ensitrelvir Fumaric Acid: First Approval

Ensitrelvir fumaric acid (Xocova^®) is an oral SARS-CoV-2 main protease inhibitor developed by Shionogi for the treatment of SARS-CoV-2 infection. It is the first single-entity, nonpeptidic, noncovalent, small molecule antiviral of its kind. Following emergency regulatory approval in Japan in November 2022, ensitrelvir received standard approval in Japan on 5 March 2024 for the treatment of SARS-CoV-2 infection. This article summarizes the milestones in the development of ensitrelvir leading to this first standard approval for SARS-CoV-2 infection.