A single centre retrospective study of low dose prophylaxis with extended half-life factor IX for severe haemophilia B

Alexandros Rampotas; Michael J R Desborough; Sayma Raza-Burton; Stephanie Taylor; Alice Wilkinson; Georgina W Hall; Susan Shapiro; Nicola Curry

doi:10.1111/hae.13936

A single centre retrospective study of low dose prophylaxis with extended half-life factor IX for severe haemophilia B

Haemophilia. 2020 Mar;26(2):278-281. doi: 10.1111/hae.13936. Epub 2020 Feb 21.

Authors

Alexandros Rampotas¹, Michael J R Desborough^{2

3

4}, Sayma Raza-Burton^{5

6}, Stephanie Taylor^{5

6}, Alice Wilkinson⁷, Georgina W Hall⁷, Susan Shapiro^{5

6}, Nicola Curry^{5

6}

Affiliations

¹ NIHR Academic Clinic Fellow in Haematology, Haematology Department, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
² Oxford Biomedical Research Centre, Oxford Haemophilia and Thrombosis Centre, Oxford, UK.
³ Nuffield Division of Clinical Laboratory Sciences, Oxford Clinical Research in Transfusion Medicine, University of Oxford, Oxford, UK.
⁴ Haemophilia and Thrombosis Centre, St Thomas' Hospital, London, UK.
⁵ Oxford Haemophilia and Thrombosis Centre, Churchill Hospital, Oxford, UK.
⁶ NIHR BRC Blood Theme, Oxford Centre for Haematology, Oxford University, Oxford, UK.
⁷ Paediatric Haemophilia centre, Children's Hospital, John Radcliffe hospital, Headington, UK.

PMID: 32083769
DOI: 10.1111/hae.13936

Abstract

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.

Keywords: annual bleeding rate; bleeding disorders; extended half-life factors; factor IX; haemophilia.

MeSH terms

Adolescent
Adult
Factor IX / pharmacology
Factor IX / therapeutic use*
Female
Half-Life
Hemophilia B / drug therapy*
Humans
Male
Middle Aged
Quality of Life / psychology*
Retrospective Studies
Young Adult

Substances

Factor IX