Vaccine Info

Ensitrelvir COVID-19 Antiviral

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Last reviewed
July 26, 2022
Fact checked by
Robert Carlson, MD

Ensitrelvir COVID-19 Antiviral Description

S-217622 is a therapeutic drug for COVID-19, a 3CL protease inhibitor created through joint research between Hokkaido University and Shionogi.

SARS-CoV-2 has an enzyme called 3CL protease, which is essential for virus replication.

S-217622 suppresses the replication of SARS-CoV-2 by selectively inhibiting 3CL protease. 

Ensitrelvir Indication

Ensitrelvir is an antiviral candidate to treat SARS-COV-2 infections.

Ensitrelvir Clinical Trials

July 26, 2021 - Shionogi initiated a Japanese Phase 1 clinical trial of the therapeutic agent S-217622 as an orally administered antiviral drug for COVID-19, caused by the novel coronavirus (SARS-CoV-2) infection, and the first dose was administered successfully on July 22. No safety concerns have been identified after the first dose.

September 28, 2021 - Shionogi initiated a Japanese Phase 2/3 clinical trial. The Phase 2/3 clinical trial will evaluate the efficacy and safety of oral administration of this drug once daily for 5 days in patients with mild COVID-19 or asymptomatic SARS-CoV-2 infection compared with placebo. 

January 31, 2022 - Shionogi presented results up to day 6 of Phase 2a part of a Phase 2/3 clinical trial of S-217622. The Phase 2b/3 part of a Phase 2/3 clinical trial is currently underway in mild, moderate, or asymptomatic COVID-19 patients.

Clinical Trials

No clinical trials found