Top-line Results of our Phase IIb Study of ALN-RSV01

We reported top-line results from our Phase IIb trial with ALN-RSV01 for the treatment of respiratory syncytial virus (RSV) infection in lung transplant patients.  The primary endpoint of the study was the incidence of new or progressive bronchiolitis obliterans syndrome (BOS) at 180 days after RSV infection.

The study missed the primary endpoint of reduced BOS in an “intent-to-treat” (ITTc) analysis of confirmed RSV infected patients (p=0.058), but achieved statistically significant reductions  in prospectively defined analyses of ITTc patients with their “last observation carried forward” (LOCF) with a p-value of 0.028, and of ITTc patients treated “per protocol” (PP) with a p-value of 0.025.  In all analyses, ALN-RSV01 treatment was associated with a clinically meaningful treatment effect, with a reduction of over 50% in the incidence of day 180 BOS as compared with placebo.

We believe that these data provide important evidence that ALN-RSV01 reduces the incidence of new or progressive BOS in RSV-infected lung transplant patients, replicating the findings from our Phase IIa study of this agent in the same clinical setting.  We plan on presenting additional study results in the fall of this year at the European Respiratory Society Annual ( September 1-5, 2012 in Vienna).