Enrollment complete in Alnylam's ALN-RSV01 Phase IIb study for RSV infection

Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), a leading RNAi therapeutics company, announced today that it has completed patient enrollment in its Phase IIb study with ALN-RSV01, an RNAi therapeutic for the treatment of respiratory syncytial virus (RSV) infection. The Phase IIb trial was designed as a multi-center, randomized, double-blind, placebo-controlled study in RSV-infected lung transplant patients. The global study is being conducted at 33 lung transplant centers in six countries around the world. Results are expected to be reported mid-2012.

“In the meanwhile, Alnylam remains focused on its core '5x15' strategy advancing RNAi therapeutics for the treatment of genetically defined targets and diseases, exemplified by our recent positive results in our ALN-TTR01 clinical study.”

"ALN-RSV01 represents Alnylam's most advanced partner-based program and is aimed at the treatment of RSV infection in high-risk adult populations. In an earlier small Phase IIa study, we showed promising clinical activity in RSV-infected lung transplant patients that we have aimed to reproduce in this current Phase IIb study. We look forward to reporting on data from this trial in mid-2012, and then evaluating next steps for this program together with our partners Cubist and Kyowa Hakko Kirin," said Akshay K. Vaishnaw, M.D., Ph.D., Senior Vice President and Chief Medical Officer of Alnylam. "In the meanwhile, Alnylam remains focused on its core '5x15' strategy advancing RNAi therapeutics for the treatment of genetically defined targets and diseases, exemplified by our recent positive results in our ALN-TTR01 clinical study."

The Phase IIb study was designed to repeat and extend findings from a previous small Phase IIa study of ALN-RSV01 in RSV-infected lung transplant patients (Zamora et al., Am. J. Respir. Crit. Care Med., Feb 2011, Vol 183, No 4: pp 531-538), where the drug was shown to significantly decrease the incidence of bronchiolitis obliterans syndrome (BOS), a life-threatening complication of RSV infection, at 90 days in ALN-RSV01 recipients compared to placebo (6.3% vs.50%; ALN-RSV01).

The RSV program is partnered with Cubist Pharmaceuticals in North America and the rest of the world outside of Asia, where the program is partnered with Kyowa Hakko Kirin Co., Ltd. These partners maintain opt-in rights for the development of ALN-RSV01.