New Data Supports Safety & Efficacy Claims of ALPROLIX

Note: This is an edited form of a press release from Biogen. To read the original release in its entirety, click here. 

New clinical data support the long-term safety and efficacy of ALPROLIX® [Coagulation Factor IX (Recombinant), Fc Fusion Protein] in people with severe hemophilia B treated for up to two years, Biogen announced on Monday, August 17, 2015. Participants in the Phase 3, open-label extension study, B-YOND, maintained low bleeding rates with one to two week prophylaxis regimens, according to data from an interim analysis. Investigators presented these interim results for the first time at the 67th Annual Meeting for the National Hemophilia Foundation (NHF) in Dallas.
B-YOND is a multi-year study for people with severe hemophilia B who completed the Phase 3 pivotal B-LONG or Kids B-LONG studies. In this interim analysis, the median time on ALPROLIX during B-YOND was 27.6 months for adults and adolescents (n=93), and 47.7 weeks for children under age 12 (n=23). The study’s primary endpoint is inhibitor development, and no inhibitors have been reported to-date. There were three prophylactic dosing options for adult, adolescent, and pediatric participants in the B-YOND trial – weekly, individualized, and modified prophylaxis. An episodic treatment arm was also available for adult and adolescent patients.
“We believe B-YOND will play an important role in helping us understand this therapy’s clinical profile over the long term,” said Amy Shapiro, M.D., co-founder and medical director of the Indiana Hemophilia and Thrombosis Center. “Study participants receiving prophylactic treatment with intervals of one to two weeks between infusions continue to experience low bleeding rates during this ongoing extension study.”
ALPROLIX is a recombinant clotting factor IX therapy designed to have prolonged circulation in the body. According to the interim analysis, adults and adolescents treated prophylactically maintained protection against bleeding episodes with infusions every one to two weeks. These participants had overall median annualized bleeding rates (ABR) of 2.28 for weekly prophylaxis (20-100 IU/kg of ALPROLIX every seven days), 2.25 for individualized prophylaxis (100 IU/Kg of ALPROLIX every 8 to 16 days, or twice-monthly) and 2.42 for modified prophylaxis (personalized dosing if optimal prophylaxis could not otherwise be achieved). In contrast, people receiving on-demand therapy, or treatment when a bleeding episode occurred, had a median ABR of 11.27.
The median overall ABR was zero for children under age six who received weekly prophylaxis (n=9). For children between six to 12 years old, median overall ABRs were 2.65 (n=10), 2.37 (n=5) and 3.13 (n=1) in weekly, individualized and modified prophylaxis regimens, respectively. In each age group, the median average weekly dose for participants previously on prophylaxis was similar for individuals in the weekly and individualized treatment arms.
Safety results were typical of the hemophilia B populations studied. The most common adverse events (incidence of greater than or equal to five percent) included headache, common cold and vomiting for adults and adolescents. For children under age 12, falls, common cold and seasonal allergy were the most common adverse events.

Growing Body of Evidence Further Validates the Prolonged Half Life of ALPROLIX

In B-YOND, participants can change between treatment groups at enrollment, and at any time during the study. Most adult and adolescent participants remained in the same treatment group during B-YOND that they had participated in during B-LONG. The majority of children under age 12 stayed on once-weekly treatment (78 percent). Adults and adolescents were able to achieve a median dosing interval of 6.9 days in the modified prophylaxis arm, and 13.7 days in the individualized prophylaxis arm, while maintaining low ABRs.
From the beginning of B-LONG or Kids-B-LONG until the B-YOND interim data analysis, the cumulative median time on ALPROLIX was 171.6 weeks for adults and adolescents, and 95.3 weeks for children under age 12.
“The safety and efficacy of ALPROLIX with extended-interval prophylaxis dosing has been established across a robust clinical development program, where we consistently have observed low overall bleed rates, as well as low rates of spontaneous and joint bleeds,” said Kate Dawson, vice president, U.S. Medical Affairs at Biogen. “These results of the B-YOND study provide additional insights supporting the efficacy and safety profile of ALPROLIX in adults and children with hemophilia B.”
B-YOND enrolled 116 males, including 93 participants (81 percent) who completed B-LONG, and 23 (100 percent) of those who completed Kids B-LONG. Secondary endpoints of the B-YOND study include ABRs (including spontaneous joint bleeding rates) per participant and treatment exposure days per participant. Additional outcomes are incidence of adverse events and serious adverse events, and evaluation of treatment of a bleeding episode (number of infusions, dose per infusion).