Real-World Utilisation and Bleed Rates in Patients with Haemophilia B Who Switched to Recombinant Factor IX Fusion Protein (rIX-FP): A Retrospective International Analysis

Abstract

Introduction: Despite the well-documented benefits of prophylaxis, treatment burden is still a barrier to adherence in patients with haemophilia. An extended half-life fusion protein linking recombinant FIX (rFIX) with human albumin (rIX-FP) has been developed for the treatment of patients with haemophilia B and is indicated for dosing up to every 14 days. This analysis evaluated real-world outcomes in patients switching to rIX-FP from the previous FIX product in Italy, Belgium and the UK. Methods: Anonymised chart data were collected from the pre-existing medical records of patients with haemophilia B between May and September 2018. Patients were included in the analysis if they had been treated with rIX-FP for C 8 weeks. Data were compared between rIX-FP and the patient's prior FIX product. Results: Twenty-three HTCs from Italy (n = 13), Belgium (n = 3) and the UK (n = 7) provided data for 84 male patients, 92.8% of which had severe haemophilia B. The majority of patients were previously on prophylactic regimens with their prior FIX product (Italy, 44/49; Belgium, 7/10; UK, 22/25). The switch to prophylaxis with rIX-FP led to reductions in mean annualised bleeding rate of 94.3% in Italy, 93.9% in Belgium and 67.7% in the UK compared with prior FIX prophylaxis. Overall, 41% of patients experienced zero spontaneous bleeds prior to switching, compared with 88% following the switch to rIX-FP. The majority of patients had a reduction in dosing frequency following the switch, with 98.6% of patients dosing once weekly or less frequently compared with 9.6% of patients dosing at this frequency with their prior FIX. Mean weekly FIX consumption was reduced compared with prior FIX prophylaxis. Conclusion: This retrospective review of realworld evidence demonstrated that switching to rIX-FP from prior FIX was associated with Digital Features To view digital features for this article go to

IDELVION: A Comprehensive Review of Clinical Trial and Real-World Data

“…In addition to data from PROLONG-9FP studies, real-world clinical data has been collated and analyzed to determine the effectiveness, safety, and clinical response of rIX-FP in routine clinical practice. Two post-marketing studies have used retrospective patient chart data to compare bleeding rates, FIX product consumption, and dosing regimens in adult/adolescent and pediatric patients with hemophilia B who switched from prior FIX prophylaxis to rIX-FP prophylaxis [30,31].…”

“…The second post-marketing study identified 73 patients treated in 23 centers in Italy (n = 13), Belgium (n = 3) and the UK (n = 7) who switched to rIX-FP prophylaxis from prior FIX therapy [31]. Overall, 92.8% of patients had severe hemophilia B (Italy: 98%; Belgium: 70%; UK: 92%).…”

Expert opinion paper on the treatment of hemophilia B with albutrepenonacog alfa

“…The administration of rIX-FP increased the proportion of patients experiencing zero spontaneous bleeds from 41% to 88%. Dosing and frequency of administration were also reduced after the switch [31].…”

“…A recent real world study found that the cost per success (defined as patients experiencing no spontaneous bleeding) in patients switching from nonacog alfa to rIX-FP was reduced by 29% in Italy, 55% in Belgium, and 50% in the United Kingdom. The reduction continued to be true even when the price of nonacog alfa or when the efficacy of rIX-FP were reduced by 20% [31]. Patients with complications, such as arthropathies, severe muscle hematomas, and life-threatening hemorrhages, or those who are to undergo surgery, are also good candidates for prophylaxis with rIX-FP (Figure 1).…”

Prospects for the use of prolonged concentrates of blood clotting factor IX in the treatment of hemophilia B

“…Кроме того, по результатам проведенного анализа, было показано снижение общего количества использованного препарата для проведения профилактического лечения -в среднем на 40 % [13], а по некоторым данным -на 54-58 % [19], чем при применении О б з о р ы л и т е р а т у р ы || L i t e r a t u r e r e v i e w s ранее использовавшихся факторов свертывания. Использование препаратов с удлиненным периодом полувыведения позволит повысить эффективность проводимого лечения в условиях ограниченного количества концентратов [1,20,21] .…”