Shionogi says Phase III ensitrelvir study misses goal in COVID-19

The Phase III study (SCORPIO-HR) with ensitrelvir did not meet its primary endpoint of a statistically-significant reduction in time to sustained resolution (symptoms completely absent for at least two days) of 15 common COVID-19 related symptoms, said Japanese drugmaker Shionogi (TYO: 4507) today.

Despite the disappointing results, Shionogi’s shares closed the day up 1.9% at 7,629 yen.

A pre-defined supportive analysis of resolution (symptoms completely absent for at least one day) of six symptoms using a statistical method similar to that used in the SCORPIO-SR Study (Phase III part of the Phase II/III study of ensitrelvir conducted in Asia) yielded a significant difference (p<0.05) in the time to resolution of symptoms. Ensitrelvir demonstrated a potent antiviral effect, leading to a substantial reduction from baseline in viral RNA levels and viral culture positivity compared to placebo. Symptomatic viral rebound did not occur in this study, which is consistent with previous findings from SCORPIO-SR.