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Published on: September 30, 2021
A single centre retrospective study of low dose prophylaxis with extended half-life factor IX for severe haemophilia
Alexandros Rampotas1, Michael J R Desborough2,3,4, Sayma Raza-Burton5,6
1NIHR Academic Clinic Fellow in Haematology, Haematology Department, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
Introduction:
Extended half-life factor IX concentrates (EHL-FIX) can be administered weekly to prevent bleeding for persons with severe haemophilia B. We report the experience of a large UK haemophilia comprehensive care centre using low dose EHL-FIX for persons with severe haemophilia B.
Aim:
The low doses used in real world are approximately half of the doses used in clinical trials. We aim to assess the efficacy and safety of low dose EHL-FIX.
Methods:
Data from a cohort of 13 patients who were switched from standard half-life factor IX (SHL-FIX) to Alprolix® (mean dose 31.5 IU/kg) and seven patients who switched from standard half-life factor IX to Idelvion® (mean dose 20.2 IU/kg) were included.
Results:
The median annualized bleeding rate was similar for SHL-FIX (median 3, interquartile range [IQR] 1-5) and EHL-FIX (median 3, IQR 1-5.25). Quality of life scores, measured using the European Quality of Life 5 Dimensions assessment were similar for SHL-FIX (median 0.76, IQR: 0.63-0.84) and EHL-FIX (median 0.79, IQR: 0.58-0.88).
Conclusion:
This study shows that EHL-FIX given at low doses can be effective for prevention of bleeding for persons with severe haemophilia B.
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