Alnylam Reports Positive ALN-TTR02 Clinical Data, with Robust Knockdown of Serum Transthyretin (TTR) of up to 94% After Single Dose

– Results of Clinical Study Demonstrate Rapid, Dose-Dependent, Durable, and Specific Knockdown of TTR, the Disease-Causing Protein in TTR-Mediated Amyloidosis (ATTR) – Alnylam Pharmaceuticals, Inc.

announced today the achievement of positive clinical results from its Phase I trial with ALN-TTR02, an RNAi therapeutic targeting the transthyretin (TTR) gene for the treatment of TTR-mediated amyloidosis (ATTR). The data were presented today in a seminar by Alnylam scientists at Boston University School of Medicine. Results from this study show that administration of ALN-TTR02 leads to robust knockdown of serum TTR protein levels of up to 94%; the overall results were highly significant (p<0.00001 by ANOVA). Suppression of TTR, the disease-causing protein in ATTR, was found to be rapid, dose dependent, durable, and specific after just a single dose. Alnylam recently reported that it has initiated a Phase II study of ALN-TTR02 in patients with ATTR and has guided that its goal is to start a pivotal trial in 2013. “We are very excited with these new ALN-TTR02 results, where we have achieved very robust effects, including up to 94% reduction of serum TTR and a nearly 80% level of suppression sustained at one month with just a single dose. These results document an unprecedented level of clinical activity for RNAi therapeutics and strongly support advancement of this innovative program to meet the needs of ATTR patients,” said Akshay Vaishnaw, M.D., Ph.D., Executive Vice President and Chief Medical Officer of Alnylam. “Knockdown of circulating TTR is a validated endpoint in ATTR based on data from patients receiving liver transplants. Further, evidence from other systemic amyloidotic diseases shows that as little as a 50 percent reduction of the disease-causing protein can result in disease improvement or stabilization. Accordingly, these data with ALN-TTR02 provide key human proof of concept with associated clinical relevance as we advance this medicine to patients for the treatment of ATTR, a debilitating orphan genetic disease. We look forward to continuing to share clinical data from our ALN-TTR02 program, and, assuming positive results in the current Phase II study, we plan to advance to a pivotal trial in 2013.”