Medscape March 14, 2025
Oral ensitrelvir was significantly more effective than placebo for preventing COVID-19 infection in uninfected at-risk adults who had exposure to those infected, based on data from a phase 3 trial presented at the 2025 Conference on Retroviruses and Opportunistic Infections.
Ensitrelvir, an oral SARS-CoV-2 3CL protease inhibitor, is approved in Japan for the treatment of mild-to-moderate COVID-19, wrote Akimasa Fukushi, MD, of Shionogi & Co., Ltd, the drug’s Japanese manufacturer, in the study abstract.
The researchers randomized adults who were household contacts of confirmed COVID-19 patients but not yet infected themselves. The modified intent-to-treat population was confirmed negative for COVID-19 at baseline. Participants received ensitrelvir at doses of 375 mg on day 1 and 125 mg on days...