MEDIMMUNE'S NUMAX NONINFERIOR TO SYNAGIS IN RSV

MedImmune has announced preliminary results from a Phase III pivotal study showing that Numax met its primary endpoint of noninferiority by reducing the incidence of hospitalizations caused by respiratory syncytial virus (RSV) in infants at high risk for serious RSV disease by 26 percent when compared with Synagis (palivizumab). The data also indicate that Numax showed superiority over Synagis in a secondary endpoint by reducing the incidence of RSV-specific, medically attended outpatient lower respiratory infections (LRI) by approximately 52 percent.

The trial was a randomized, double-blind study involving approximately 6,600 high-risk infants at more than 300 centers in 24 countries conducted over two years during multiple RSV seasons. Study participants consisted of premature infants born at 35 weeks gestational age or less who were six months of age or younger at randomization, as well as children with chronic lung disease related to prematurity requiring medical management within the six months prior to study entry who were 24 months of age or less at randomization. The study was designed to compare the safety and efficacy of Numax with that of Synagis in infants at high risk for serious RSV disease for the reduction of serious RSV disease in the inpatient and outpatient settings. The primary endpoint was to assess the noninferiority of Numax compared with Synagis in the incidence of hospitalizations caused by RSV.

In this preliminary assessment, the number and type of adverse events and serious adverse events were balanced between the study groups. The overall mortality rates were comparable between the two groups (0.1 percent for Synagis and 0.2 percent for Numax). Study drug was discontinued due to related adverse events in a small number of children in each group (0.1 percent for Synagis and 0.3 percent for Numax). Immunogenicity in the Numax arm was low, less than 1 percent, and comparable to the historical Synagis rate.