07 Dec, 2015 Positive Data with Monthly Dosing Cohorts from Ongoing Phase 1 Trial with Fitusiran (ALN-AT3) for the Treatment of Hemophilia and Rare Bleeding Disorders
We reported new data from our Phase 1 study with the newly named fitusiran (ALN-AT3), an investigational RNAi therapeutic targeting antithrombin (AT) for the treatment of hemophilia and rare bleeding disorders. Interim results – presented at the American Society of Hematology (ASH) 2015 Annual Meeting, held December 5 – 8, 2015 – showed that monthly, subcutaneous administration of fitusiran achieved potent and dose-dependent lowering of AT of up to 88% in patients with hemophilia. This AT lowering was associated with statistically significant increases in thrombin generation and an 85% reduction in estimated median annualized bleeding rates (ABR) in all evaluable cohorts. The observed bleeding rates are comparable to those reported for prophylactic intravenous infusions of replacement factors in patients with hemophilia. Fitusiran was found to be generally well tolerated to date, including no thromboembolic events or clinically significant increases in D-dimer, a biomarker of excessive clot formation.
Also at the ASH conference, we and collaborators presented pre-clinical data demonstrating that AT lowering in vitro led to increased thrombin generation in plasma from patients with hemophilia who have developed inhibitory antibodies to replacement factor therapy.
We believe that fitusiran is an innovative investigational medicine with a novel mechanism of action. We look forward to the continued advancement of fitusiran as we work to provide patients with hemophilia with improved therapeutic options.