13 November, 1998: Zanamivir (Relenza) has been shown to cut the time to recover from influenza by up to one-third in otherwise healthy patients, and reduce complications from influenza by 71 per cent in high risk patients. These were the results of two Phase III clinical trials of zanamivir reported today at the 36th meeting of the Infectious Diseases Society of America (IDSA) in Denver, Colorado, USA (November 12-15, 1998).
The first study, conducted in Europe in the winter of 1997/8, recruited 356 patients, of whom 78 per cent (277) were confirmed to have influenza infection, and 32 (9 per cent) were classified as 'high risk'. Patients were given either placebo or orally inhaled zanamivir at 10 mg twice-daily (bd) for five days, in the double-blind, randomised trial. The primary endpoint of the trial was median time to alleviation of clinically significant symptoms of influenza, measured by the patient's own assessment as an absence of fever and a score of 'none' or 'mild' for headache, cough, sore throat and myalgia. Zanamivir reduced the severity of all these symptoms and loss of appetite as confirmed by the investigator's assessment. High risk and otherwise healthy zanamivir-treated patients experienced relief from symptoms two and a half days sooner than placebo treated patients, a highly significant difference in the otherwise healthy group (p<0.001).1
Dr. Douglas Fleming, Birmingham Research Unit, Royal College of General Practitioners, UK, and principal investigator of the study said: "The trial confirmed that zanamivir provided significant treatment benefits. We observed a significant reduction in the severity of symptoms reported by all patients, so zanamivir not only reduced the duration of illness, but also made it less debilitating. These results convincingly demonstrate the efficacy of zanamivir."
Compared with those receiving placebo, patients taking zanamivir experi