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Ljung R, Matino D, Shapiro AD. Recombinant factor IX Fc for the treatment of hemophilia B. Eur J Haematol 2024; 112:678-691. [PMID: 38369860 DOI: 10.1111/ejh.14176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 02/20/2024]
Abstract
Current hemophilia B treatment guidelines recommend routine prophylaxis with factor IX (FIX) replacement products, tailored to maintain plasma activity at levels that will prevent bleeds. However, plasma FIX activity may not be the primary determinant or best indicator of hemostatic efficacy due to its extravascular distribution. FIX replacement therapy has evolved to include extended half-life (EHL) products that provide effective bleed protection when administered at intervals of 7 days or longer. rFIXFc is a recombinant fusion protein with an extended circulation time. rFIXFc has a biodistribution profile consistent with distribution into extravascular space, where it may support hemostasis at sites of vessel injury independent of circulating plasma activity levels. The safety and efficacy of rFIXFc prophylaxis is well established in adults, adolescents and children including previously untreated patients with hemophilia B, with substantial evidence from clinical trials and real-world clinical practice. This review describes the pharmacokinetic characteristics of rFIXFc, summarizes available safety and efficacy data, and evaluates the use of rFIXFc in special populations. Current hemophilia B treatment challenges, including target FIX plasma levels, perioperative use, and management of patients with comorbidities, are discussed together with the potential role of EHL products in the future treatment landscape of hemophilia B.
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Affiliation(s)
- Rolf Ljung
- Department of Clinical Sciences-Pediatrics, Lund University, Lund, Sweden
| | - Davide Matino
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Amy D Shapiro
- Indiana Hemophilia & Thrombosis Center, Inc, Indianapolis, Indiana, USA
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Shapiro AD, Kulkarni R, Ragni MV, Chambost H, Mahlangu J, Oldenburg J, Nolan B, Ozelo MC, Foster MC, Willemze A, Barnowski C, Jain N, Winding B, Dumont J, Lethagen S, Barnes C, Pasi KJ. Post hoc longitudinal assessment of the efficacy and safety of recombinant factor IX Fc fusion protein in hemophilia B. Blood Adv 2023; 7:3049-3057. [PMID: 36848635 PMCID: PMC10331408 DOI: 10.1182/bloodadvances.2022009230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 03/01/2023] Open
Abstract
Long-term efficacy and safety of the extended half-life recombinant factor IX Fc fusion protein (rFIXFc) has been established among previously treated patients with severe hemophilia B in 2 phase 3 trials (B-LONG [#NCT01027364] and Kids B-LONG [#NCT01440946]) and a long-term extension study (B-YOND [#NCT01425723]). In this study, we report post hoc analyses of pooled longitudinal data for up to 6.5 years for rFIXFc prophylaxis. In the B-LONG study, subjects ≥12 years received weekly dose-adjusted prophylaxis (WP; starting dose, 50 IU/kg), individualized interval-adjusted prophylaxis (IP; initially, 100 IU/kg every 10 days), or on-demand dosing. In the Kids B-LONG study, subjects <12 years received 50 to 60 IU/kg every 7 days, adjusted as needed. In the B-YOND study, subjects received WP (20-100 IU/kg every 7 days), IP (100 IU/kg every 8-16 days), modified prophylaxis, or on-demand dosing; switching between treatment groups was permitted. A total of 123 subjects from B-LONG and 30 from Kids B-LONG study were included, of whom 93 and 27, respectively, enrolled in the B-YOND study. The median cumulative duration of treatment was 3.63 years (range, 0.003-6.48 years) in B-LONG/B-YOND and 2.88 years (range, 0.30-4.80 years) in Kids B-LONG/B-YOND group. Annualized bleed rates (ABRs) remained low, annualized factor consumption remained stable, and adherence remained high throughout treatment. Low ABRs were also maintained in subjects with dosing intervals ≥14 days or with target joints at baseline. Complete resolution of evaluable target joints and no recurrence in 90.2% of baseline target joints during follow-up were observed. rFIXFc prophylaxis was associated with sustained clinical benefits, including long-term bleed prevention and target joint resolution, for severe hemophilia B.
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Affiliation(s)
- Amy D. Shapiro
- Indiana Hemophilia & Thrombosis Center, Inc, Indianapolis, IN
| | - Roshni Kulkarni
- Department of Pediatrics and Human Development, Michigan State University, East Lansing, MI
| | - Margaret V. Ragni
- Department of Medicine, University of Pittsburgh, and Hemophilia Center of Western Pennsylvania, Pittsburgh, PA
| | - Hervé Chambost
- Assistance Publique–Hôpitaux de Marseille, Hemophilia Centre, Hospital La Timone, Marseille, France
- Aix Marseille Université, INSERM, INRA, C2VN, Marseille, France
| | - Johnny Mahlangu
- Haemophilia Comprehensive Care Center, Faculty of Health Sciences, University of Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa
| | - Johannes Oldenburg
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
| | - Beatrice Nolan
- Department of Paediatric Haematology, Children’s Health Ireland at Crumlin, Dublin, Ireland
| | | | | | | | | | | | | | | | | | - Chris Barnes
- Haematology Department, Royal Children’s Hospital, Melbourne, VIC, Australia
| | - K. John Pasi
- Royal London Haemophilia Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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Lamb YN, Hoy SM. Eftrenonacog Alfa: A Review in Haemophilia B. Drugs 2023:10.1007/s40265-023-01868-7. [PMID: 37081241 DOI: 10.1007/s40265-023-01868-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2023] [Indexed: 04/22/2023]
Abstract
Eftrenonacog alfa (Alprolix®) is an extended half-life recombinant factor IX (rFIX)-Fc fusion protein (hereafter referred to as rFIXFc). Administered as an intravenous bolus, it is approved for prophylactic use and the treatment of bleeding in patients with haemophilia B in various countries worldwide, including those of the EU, as well as the USA. In multinational, phase III trials, rFIXFc was effective for the prophylaxis, perioperative management or on-demand treatment of bleeding in male patients with severe haemophilia B regardless of age and irrespective of whether or not they had been previously treated with FIX replacement products. Prophylactic efficacy was maintained over the longer term (up to 5 years) in previously treated patients. rFIXFc effectiveness in the real-world setting is supported by results of prospective studies, as well as the outcomes of several retrospective trials. rFIXFc was well tolerated in clinical trials in previously treated and untreated children, adolescents and/or adults with severe haemophilia B. Thus, rFIXFc continues to represent a useful treatment option among the haemophilia B patient population.
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Affiliation(s)
- Yvette N Lamb
- Springer Nature, Private Bag 65901, Mairangi Bay, Auckland, 0754, New Zealand
| | - Sheridan M Hoy
- Springer Nature, Private Bag 65901, Mairangi Bay, Auckland, 0754, New Zealand.
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Abstract
Efmoroctocog alfa (Elocta®, Eloctate®, Eloctate™), an extended half-life (EHL) recombinant factor VIII (rFVIII)-Fc fusion protein, is approved for the treatment and prophylaxis of bleeding in patients with haemophilia A. The efficacy of efmoroctocog alfa in the prevention and treatment of bleeding in previously treated patients (PTPs) and previously untreated patients (PUPs) with severe haemophilia A has been demonstrated in phase III studies; this includes its use in the perioperative setting (in PTPs). Furthermore, the effectiveness of efmoroctocog alfa in clinical practice has been confirmed in numerous real-world studies; compared with conventional, standard half-life (SHL) FVIII products, prophylaxis with this EHL FVIII product achieved similar or reduced bleeding rates with fewer injections. Efmoroctocog alfa was generally well tolerated; inhibitors occurred in approximately one-third of PUPs in a phase III study. Efmoroctocog alfa is an established and effective EHL FVIII replacement therapy for the management of haemophilia A. Compared with SHL FVIII products, EHL FVIII products such as efmoroctocog alfa have the potential to optimise prophylactic outcomes by decreasing the burden of treatment or increasing the level of bleed protection.
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Affiliation(s)
- James E Frampton
- Springer Nature, Private Bag 65901, Mairangi Bay, Auckland, 0754, New Zealand.
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