GAITHERSBURG, Md. - Although the FDA's Antiviral Drugs Advisory Committee voted 14-4 last week against recommending approval of Glaxo Wellcome's Relenza (zanamivir) for treatment of influenza, the panel's discussions left open the possibility that the company could persuade the panel to support the drug based on results from on-going studies. The discussions also highlighted changes in the way the committee and FDA view therapies for influenza and the types of end points that will be considered clinically significant.

The committee was most troubled by the discordance between two smaller Phase III studies, which demonstrated statistically significant reductions in time to alleviation of symptoms in patients who received Relenza compared to those on placebo, and a larger Phase III study that failed to show a statistically significant difference (see BioCentury Extra, Feb. 25).