Alprolix Could Be Viable Treatment Option for Hemophilia B Patients

Low bleeding rates found with intervals of up to 2 weeks between infusions.

Hemophilia patients received positive news this week after the release of clinical data that supports the long-term safety and efficacy of Alprolix in people with severe hemophilia B treated for up to 2 years. Data from the interim analysis revealed that participants involved in the phase 3, open-label extension study, B-YOND, maintained low bleeding rates with 1 to 2 week prophylaxis regimens.

Eligible patients for the B-YOND study had to have completed either the B-LONG or kids B-LONG studies. B-YOND is a multi-year study for people with severe hemophilia B.

The average time on Alprolix during B-YOND was 27.6 months for adults and adolescents and 47.7 weeks for children under age 12.The study’s primary endpoint was inhibitor development; no inhibitors have been detected to date.

In the B-YOND trial, patients had the option of weekly, individualized, and modified prophylaxis dosing. 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, MD, 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. With prophylactic infusions every 1 to 2 weeks, adults and adolescents demonstrated protection against bleeding episodes.

The participants had overall average annualized bleeding rates (ABR) of 2.28 for weekly prophylaxis, 2.25 for individualized prophylaxis and 2.42 for modified prophylaxis. In contrast, those receiving on-demand or “as needed” therapy had an average ABR of 11.27.

The average overall ABR for children under 6 years of age who received weekly prophylaxis was zero. For children between the ages of 6 to 12 years, average overall ABR was 2.65, 2.37, and 3.12 for weekly, individualized and modified prophylaxis, respectively.

Safety results of the trial were typical of the hemophilia B populations studied. Adverse events associated with Alprolix included headache, common cold and vomiting for adults and adolescents. Falls, common cold, and seasonal allergy were the most common adverse effects in children under age 12.

With mild side effects and long-term safety and efficacy reported in the study, Alprolix will surely become a staple treatment in patients with severe hemophilia B. Hemophilia B affects about 4000 people in the United States and 28,000 people worldwide. With the advent of Alprolix, patients can now seek better treatment options for the pain and joint damage associated with the disease.