FDA Updates Label of Bioverativ’s Alprolix Upon Review of Positive Interim B-YOND Trial Data

The U.S. Food and Drug Administration (FDA) has approved an update to the label of Alprolix, based on long-term efficacy and safety data from two Phase 3 studies, the B-YOND extension trial and the Kids B-LONG pediatric study, manufacturer Bioverativ announced.

This label extension, which adds pediatric data, further supports the efficacy of Alprolix to treat adults and children with hemophilia B.

Bioverativ markets Alprolix (recombinant coagulation factor IX fusion protein) to treat hemophilia B patients in the United States, Japan, Canada, Australia, New Zealand, Brazil and other countries. The drug is also available in Europe, where is marketed by Sobi for patients with hemophilia B who have received prior therapy.

“Alprolix has the most clinical trial experience of any hemophilia B extended half-life therapy on the market, and in the three years since approval, we have continued to observe low overall bleed rates, as well as low spontaneous and joint bleeds with extended prophylactic dosing across all populations,” Dr. Rogerio Vivaldi, executive vice president and chief global therapeutics operations officer at Bioverativ, said in a press release.

“The addition of the pediatric annual bleed rates, and adult and adolescent joint bleed data, to the label reflects a growing body of evidence highlighting the clinical benefit of Alprolix and our commitment to improving patient outcomes through extended half-life protection,” he added.

Alprolix is the only recombinant clotting factor IX engineered based on fusion protein technology. Its particular structure improves its ability to circulate in the body, making it more stable for longer periods of time.

Its clinical development program has included more than 150 patients with hemophilia B, and over 17,000 exposure days. The new label reveals additional clinical trial collected from 93 patients who received Alprolix prophylactically for more than 104 weeks.

The extension B-YOND study (NCT01425723) included 93 patients older than 12 with severe hemophilia who completed Alprolix treatment during the B-LONG trial (NCT01027364), and 23 patients under 12 who completed the Kids B-LONG (NCT01440946) trial.

During these trials, patients received weekly prophylactic treatment with Alprolix. Interim results show that the drug significantly reduced bleeding rates. Indeed, children presented a median spontaneous annualized bleeding rate and a median joint annualized bleeding rate of zero, whereas adults averaged 1.04 and adolescents 1.11.

Based on this data, the FDA added obstructure uropathy, the inability to drain urine, to the label as a common adverse reaction, which was reported to be resolved with hydration. Other adverse reactions linked to Alprolix include headache and abnormal sensation in the mouth.