PB1139 - Annualized Bleeding Rates in Severe Hemophilia on Prophylaxis in a Real-World Setting

Tuesday, July 12, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Daniel Kraemmer, MD

PhD Student
Department of Medicine I, Clinical Division of Haematology and Haemostaseology; Medical University of Vienna, Vienna, Austria
Vienna, Wien, Austria

Co-Author(s)

BB

Benedikt Bauer

Data Management Assistant
Department of Medicine I, Clinical Division of Haematology and Haemostaseology, Medical University of Vienna
Vienna, Wien, Austria
Cihan Ay, MD

Professor, Head of the Thrombosis and Haemostasis Research Group
Clinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
Vienna, Wien, Austria
Ingrid Pabinger, MD

Co-Head of the Thrombosis and Haemostasis Research Group
Clinical Division of Hematology and Hemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
Vienna, Wien, Austria

Background: Therapeutic options for hemophilia have expanded considerably with the introduction of extended half-life products (EHL).

Aims: We investigated prophylaxis with standard (SHL) and EHL in a real-world setting.

Methods: In our center, patient diaries used to self-document infusions and bleeding episodes are collected within the framework of the Austrian Haemophilia Registry. We included all recorded infusions of adult patients with hemophilia A (HA) or B (HB) receiving prophylaxis with SHL or EHL (albutrepenonacog-alfa, damoctocog-alfa-pegol, efmoroctocog-alfa, eftrenonacog-alfa, lonoctocog-alfa, nonacog-beta-pegol, rurioctocog-alfa-pegol) for ≥6 months between 2018-01-01 and 2020-12-31. Since switching between products could occur, we analyzed the data using mixed-effects models allowing for random intercepts and adjusting for age and hemophilia type.

Results: Fifty HA (median age 35 years; interquartile range 25-41) and 7 HB patients (42 years; 29-59) recorded a total of 31.3 million IU over 13,820 infusions for a median of 730 days (range 190-1,095). Median annualized bleeding rate (ABR) and joint ABR of the whole cohort was 4.74 (0.67-14.15) and 3.01 (0-8.36), respectively. Twenty-five patients were treated with EHL, eight of which documented a switch during the observation period. Summary statistics of ABR, joint ABR, infusion frequency, and factor consumption are presented in Table 1. Prophylaxis with EHL was associated with an incidence total and joint ABR ratio of 0.55 (95%CI 0.42, 0.73) and 0.73 (95%CI 0.53, 1.01), respectively; and a difference in weekly factor usage of 386.6 IU (95%CI -480.9, 1,254.1). Weekly infusions were lower on EHL (-0.43; 95%CI -0.76, -0.08).

Conclusion(s): ABR and joint ABR during prophylaxis with EHL, albeit lower when compared to SHL, were still high overall, which might partly be explained by preferential switching of patients with more complicated bleeding phenotypes. Patients with high bleeding rates despite prophylaxis require an individualized approach such as an increase in their infusion frequency, a switch to non-factor treatments, or gene therapy.