Motavizumab was shown to reduce hospitalizations in Native American infants due to respiratory syncytial virus (RSV) by 83% as compared to placebo, according to Phase 3 study results announced by MedImmune Inc. In addition, the trial showed a 71% reduction in the incidence of RSV-specific lower respiratory infections (LRIs) requiring outpatient management.

Motavizumab is an investigational monoclonal antibody (MAb) being evaluated for its potential to prevent serious disease caused by RSV in high-risk pediatric patients. This Phase 3 trial involved 1,410 full-term infants less than six months of age in two Native American populations. In previous medical studies these populations were shown to have high rates of hospitalization due to RSV.

The randomized (2:1), double-blind study was designed to compare monthly intramuscular injections of motavizumab against placebo. After an interim analysis conducted by an independent data safety monitoring committee, the study was unblinded early due to statistical evidence demonstrating that motavizumab reduced RSV hospitalizations and LRIs requiring outpatient medical management within this population.