
2.7. Rationale for the primary endpoint
CORONAVIRUS DISEASE 2019, PROLIFERATION, PATHOPHYSIOLOGY, CORONAVIRUS, SEVERE ACUTE RESPIRATORY SYNDROME
The phase 2aIn the phase 2a and 2b studies,Patient demographics and clinical characteristics (ITTThis population comprises all patients randomly assigned to the study intervention with SARS-CoV-2 viral titer detected at baseline. The detection of SARS-CoV-2 viral titer was confirmed by viral titer assessment based on nasopharyngeal swab samples. Patients were analyzed according to the assigned study intervention.This table was presented as a poster at OPTIONS-XI(26-29 Sep 2022): Post-Hoc Analyses of Ensitrelvir Phase 2b part in Phase 2/3 Study (SCORPIO-SR): Exploratory Clinical Endpoints in Patients with Mild to Moderate COVID-19 Symptoms (P-535).Hiroshi Yotsuyanagi, Norio Ohmagari, Yohei Doi, Hiroki Sakaguchi, Takuhiro Sonoyama, Genki Ichihashi, Yuko Tsuge, Takeki Uehara, Hiroshi Mukae.ITT = intention-to-treat, SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2.The main pathophysiology of COVID-19 is due to viral proliferation for several days after onset followed by inflammatory reaction by the host immune system starting around 7 days after onset,In the post hoc analysis of the phase 2b study, the median time to resolution of the 5 COVID-19 symptoms in patients randomized to the study intervention <72 hours from the COVID-19 onset was shorter both in ensitrelvir 125 mg and 250 mg arms compared with the placebo arm (placebo, 10.4 days; ensitrelvir 125 mg, 6.9 days; ensitrelvir 250 mg, 6.3 days; Fig. Kaplan–Meier plot of the time to resolution of the 5 COVID-19 symptoms in the patient group with <72 h from the onset to randomization in the phase 2b study (ITT* population). *This population comprises all patients randomly assigned to the study intervention with SARS-CoV-2 viral titer detected at baseline. The detection of SARS-CoV-2 viral titer was confirmed by viral titer assessment based on nasopharyngeal swab samples. Patients were analyzed according to the assigned study intervention. COVID-19 = coronavirus disease 2019, ITT = intention-to-treat, SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2.The primary endpoint was finalized after consultations with experts and regulatory authorities.