A total of 1355 patients were included in two Phase 3 multicenter, placebo-controlled trials in naturally acquired influenza conducted in the United States, Europe, etc. (Studies WV15670 & WV15671). Time to alleviation of symptoms, the primary efficacy endpoint, was significantly reduced by up to 30 hours in the patients received 75 mg of oseltamivir twice daily compared with placebo. Significant improvements in the secondary efficacy endpoints, such as the median total symptom score AUC and the time to return to an afebrile state, were also observed [5, 9].
The Phase 3 study conducted in Japan (Study JV15824) included 316 patients with influenza. As with the Phase 3 studies noted above, significant improvements in the time to alleviation of symptoms, the median total symptom score AUC and the time to return to an afebrile state were observed in Japanese patients [10].