On September 28, Shionogi announced that the Phase III portion of a Phase II/III clinical trial in Asia involving its 3CL protein inhibitor Ensitrelvir Fumaric Acid (S-217622) met its primary endpoint.
The results showed that, for the first time, ensitrelvir was shown to significantly reduce the time to remission of five typical Omicron symptoms compared with placebo. At the same time, ensitrelvir also showed a significant reduction in viral RNA load on day 4 (after the third dose).
It is the second 3CL drug after Pfizer's paxlovid. The difference is that paxlovid needs to be used in combination with ritonavir. ensitrelvir alone is effective.
