A COVID-19 antiviral therapy authorized in Japan, ensitrelvir, shortened the duration of symptoms from five days to four days in a phase 3 study.
Among 1,030 patients with mild to moderate COVID-19 cases, researchers tested the efficacy of 125 milligram and 250 milligram solutions of ensitrelvir compared to a placebo. All of the study participants received treatments within the first three days of symptom onset.
The biggest finding was the 125 milligram dose, which cut symptom duration by 24.3 hours compared to the placebo. The results from the study, which was conducted in 2022, were published Feb. 9 in JAMA.
The FDA is still reviewing ensitrelvir as a possible COVID-19 treatment.