Alnylam Announces Top-Line Results of Phase IIb Clinical Trial of ALN-RSV01, an Inhaled RNAi Therapeutic for the Treatment of Respiratory Syncytial Virus Infection

Alnylam Pharmaceuticals, Inc.

announced today top-line results from a 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 to discuss the results of this study with U.S. and European regulatory authorities later this year and, thereafter, determine appropriate next steps, if any, on our ALN-RSV program,” said Akshay K. Vaishnaw, M.D., Ph.D., Senior Vice President and Chief Medical Officer of Alnylam. “In the meanwhile, we continue to execute on our ‘Alnylam 5x15' product strategy with a focus on our transthyretin-mediated amyloidosis and hemophilia programs.”