Alnylam Pharmaceuticals announced that it has presented new pre-clinical data with ALN-AT3, a subcutaneously administered RNAi therapeutic targeting antithrombin for the treatment of hemophilia and rare bleeding disorders. In these new studies, repeat administration of ALN-AT3 was found to be well tolerated in Hemophilia A mice, with no adverse findings up to dose levels 200 times greater than levels required to achieve 50% AT knockdown. Further, the new studies demonstrate that ALN-AT3 administration achieves complete correction of the activated Partial Thromboplastin Time, an ex vivo measure of blood coagulation that is significantly prolonged in hemophilia, in HA mice. ALN-AT3 is a program in the company’s “Alnylam 5x15” product strategy, which is aimed at advancing five RNAi therapeutic programs directed toward genetically validated disease targets into clinical development, including programs in advanced stages, by the end of 2015. Alnylam remains on track to begin a Phase I trial with ALN-AT3 early in 2014, and Alnylam announced that it has received CTA approval from the MHRA for the initiation of the Phase I clinical study. The study will be conducted in the U.K. as a single- and multi-dose, dose-escalation study consisting of two parts.