Baxter International Inc. (NYSE:BAX) today announced pivotal Phase I/III study results evaluating the safety and efficacy of BAX 326, an investigational recombinant factor IX (rFIX) protein, for the treatment and prophylaxis of bleeding episodes for patients with hemophilia B over 12 years of age. The data were presented at the 54 th Annual Meeting and Exposition of the American Society of Hematology (ASH) in Atlanta. BAX 326 was recently granted orphan-drug designation by the U.S. Food and Drug Administration (FDA), a special status given to a product that when approved, will address an unmet need for people with a rare disease or condition. Data supporting the prophylaxis indication, which is the basis for the orphan drug designation, was included in the biologics license application (BLA). ''With only one recombinant protein currently available to treat hemophilia B, it was important to focus research efforts on finding another option for patients with this debilitating disease,'' said lead investigator Jerzy Windyga, MD, PhD, Institute of Hematology and Blood Transfusion, Warsaw, Poland. ''In this study, more than 40 percent of patients using BAX 326 as a prophylactic treatment experienced no bleeds, an important finding given the potentially harmful impact of bleeding episodes for patients.'' The Phase I/III prospective, controlled, multicenter study investigated the pharmacokinetics, efficacy and safety of BAX 326 in 73 previously-treated patients with severe or moderately severe hemophilia B. Results from the study showed that twice-weekly prophylactic treatment with BAX 326 achieved a median annualized bleed rate of 1.99 with 43 percent of patients experiencing no bleeds. The impact of prophylaxis with BAX 326 also translated into statistically significant improvements in physical health-related quality of life (HRQoL), as measured by improvements in the Bodily Pain and Role-Physical domains in the Short Form Health Survey (SF-36v2) tool. Statistically significant changes were not seen in the other physical health-related domains or the mental health domains.