Background: Continuous prophylaxis for patients with hemophilia B requires frequent injections that are burdensome and that may lead to suboptimal adherence and outcomes. Hence, therapies requiring less-frequent injections are needed. In the absence of head-to-head comparisons, this study compared the first extended-half-life-recombinant factor IX (rFIX) product-recombinant factor IX Fc fusion protein (rFIXFc)-with conventional rFIX products based on annualized bleed rates (ABRs) and factor consumption reported in studies of continuous prophylaxis.

Methods: This study compared ABRs and weekly factor consumption rates in clinical studies of continuous prophylaxis treatment with rFIXFc and conventional rFIX products (identified by systematic literature review) in previously-treated adolescents and adults with moderate-to-severe hemophilia B. Meta-analysis was used to pool ABRs reported for conventional rFIX products for comparison. Comparisons of weekly factor consumption were based on the mean, reported or estimated from the mean dose per injection.

Results: Five conventional rFIX studies (injections 1 to >3 times/week) met the criteria for comparison with once-weekly rFIXFc reported by the B-LONG study. The pooled mean ABR for conventional rFIX was slightly higher than but comparable to rFIXFc (difference=0.71; p = 0.210). Weekly factor consumption was significantly lower with rFIXFc than in conventional rFIX studies (difference in means = 42.8-74.5 IU/kg/week [93-161%], p < 0.001).

Conclusion: Comparisons of clinical study results suggest weekly injections with rFIXFc result in similar bleeding rates and significantly lower weekly factor consumption compared with more-frequently-injected conventional rFIX products. The real-world effectiveness of rFIXFc may be higher based on results from a model of the impact of simulated differences in adherence.

Download full-text PDF

Source
http://dx.doi.org/10.1080/13696998.2016.1265973DOI Listing

Publication Analysis

Top Keywords

conventional rfix
24
factor consumption
20
weekly factor
16
continuous prophylaxis
12
rfix products
12
factor
9
recombinant factor
8
factor fusion
8
fusion protein
8
study compared
8

Similar Publications

Background: Few have assessed physical activity (PA) and annual bleed rates (ABRs) among people with hemophilia on extended half-life (EHL) factors (recombinant factor VIII Fc [rFVIIIFc]/recombinant factor IX Fc [rFIXFc]) and conventional factors (recombinant factor VIII [rFVIII]/recombinant factor IX [rFIX]).

Objective: To assess changes in PA and ABR at consecutive annual visits in individuals with severe hemophilia A and B (HA/HB) on prophylactic treatment with rFVIIIFc/rFIXFc versus rFVIII/rFIX.

Patients/methods: We conducted a retrospective chart review of 344 people with severe HA/HB (ages 6-35) receiving prophylaxis with rFVIIIFc/rFIXFc (EHL factors) or rFVIII/rFIX (conventional factors) for ≥6 months in 2014-2015.

View Article and Find Full Text PDF

Background: Nonacog beta pegol (N9-GP, Refixia, Rebinyn) is a human recombinant coagulation factor IX (rFIX) conjugated to a 40-kDa polyethylene glycol (PEG) moiety. PEGylation significantly prolongs the circulation half-life compared with conventional FIX replacement treatments, resulting in higher FIX levels. Although there is extensive clinical experience with PEGylated molecules, the potential for abnormal and/or indefinite PEG accumulation during long-term treatment and the hypothetical impact on long-term safety is still under discussion.

View Article and Find Full Text PDF

Albutrepenonacog alfa (Idelvion), a fusion protein that genetically fuses recombinant factor IX (rFIX) with recombinant human albumin (rAlbumin), is indicated in the treatment of haemophilia B. This narrative review discusses the pharmacological properties and clinical data related to the use of this novel fusion protein, hereafter referred to as rIX-FP. The fusion of rFIX to rAlbumin prolongs the elimination half-life of rIX-FP in the circulation, allowing routine prophylaxis to be administered once every 7-14 days.

View Article and Find Full Text PDF

Background: Continuous prophylaxis for patients with hemophilia B requires frequent injections that are burdensome and that may lead to suboptimal adherence and outcomes. Hence, therapies requiring less-frequent injections are needed. In the absence of head-to-head comparisons, this study compared the first extended-half-life-recombinant factor IX (rFIX) product-recombinant factor IX Fc fusion protein (rFIXFc)-with conventional rFIX products based on annualized bleed rates (ABRs) and factor consumption reported in studies of continuous prophylaxis.

View Article and Find Full Text PDF

Purpose: The aim is to develop a pharmacokinetic model for factor IX activity (FIX) after BeneFIX (nonacog alfa, rFIX) administration and assess potential covariates using all available clinical data collected during development.

Methods: The data set for model development combined observations from eight studies. Postdose FIX observations were adjusted by subtracting predose FIX if these were above the lower limit of quantification (BLQ) and all BLQ observations were removed.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!