Idelvion controlled bleeds in small hemophilia B study
The replacement therapy was effective for five people in a real-world setting
That’s according to data reported in the study, “Benefits of rIX-FP prophylaxis in patients with Haemophilia B: real-world evidence from a Spanish reference centre,” published in the journal Hematology.
Hemophilia B is caused by mutations that disrupt the production or function of a clotting protein called factor IX (FIX). Replacement therapies that work to supply patients with a functional version of the clotting factor they are missing are considered the standard care treatment for hemophilia.
Idelvion is a replacement therapy that contains a version of the FIX protein that can be administered to people with hemophilia B to prevent or control bleeds.
The therapy specifically contains a version of FIX that’s modified though a process called albumin fusion, which entails fusing FIX to albumin — a protein naturally found in the blood that’s known to be highly stable, so it can remain in circulation for long periods of time.
This modification causes Idelvion to last longer in the body, thus allowing for less-frequent dosing compared with replacement therapies that use an unmodified version of FIX. It is marketed by CSL Behring, which was not involved in the present study.
Four scientists at a center in Spain reported on the outcomes of hemophilia B patients given prophylactic (preventive) treatment with Idelvion at their institution.
Scientists sought ‘real practice experience’
“It is important to have data about the real-world use of [Idelvion] in various settings and populations and this study reports real practice experience with [Idelvion] in Spain,” the researchers wrote.
The study included data on five patients treated with Idelvion, ranging in age from 1 to 60 years. Four of the patients switched to Idelvion after receiving prior treatment with other replacement therapies, while the fifth patient (a 1-year-old infant) started on Idelvion as a first treatment.
Idelvion initially was given once per week or every other week, but based on positive responses to treatment, most of the patients extended dosing to every other week or every three weeks.
Notably, patients switching from other treatments experienced a reduction in the number of infusions they received over the course of a year, as well as in FIX consumption. The annual infusion rate dropped by up to 84% (in two patients), while the annual FIX consumption rate dropped by a mean of 61%.
Results also showed that none of the five patients reported spontaneous or joint bleeds while on treatment with Idelvion, and all of them experienced fewer than two bleeds per year on average.
FIX levels maintained
Data also suggested that FIX levels were maintained at high enough levels to prevent bleeding episodes.
Bleeds that did occur were mostly due to injury resulting from physical activity. Researchers noted that, because Idelvion was generally very effective for controlling bleeds, many patients were able to be more physically active while on the treatment.
“While treatment efficacy should always remain the most important outcome when selecting a treatment regimen, the enhanced features of [Idelvion] are allowing patients with haemophilia the opportunity to live a healthier and less burdensome life,” the researchers wrote.