PB0508 - Long-term follow-up of adult hemophilia A patients with FVIII inhibitors treated with emicizumab: real world efficacy and safety data

Monday, June 24, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

JW

Jerzy Windyga

Head Department of Hemostasis Disporders and Internal Medicine
Institute of Hematology and Transfusion Medicine
Warsaw, Mazowieckie, Poland

Co-Author(s)

AB

Anna Buczma

Department of Hemostasis Disorders and Internal Medicine
Institute of Hematology and Transfusion Medicine
Warsaw, Mazowieckie, Poland
ES

Ewa Stefanska-Windyga

Head Outpatient Clinic for Persons with Disorders of Hemostasis
Institute of Hematology and Transfusion Medicine
Warsaw, Mazowieckie, Poland
EC

Ewa Chmielewska

Department of Hematology
Pomeranian Medical University
Szczecin, Zachodniopomorskie, Poland
KC

Krzysztof Chojnowski

Department of Haemostasis and Haemostatic Disorders
Medical University of Lodz, Poland
Łódź, Lodzkie, Poland
MG

Magdalena Gorska-Kosicka

Department of Hemostasis Disorders and Internal Medicine
Institute of Hematology and Transfusion Medicine
Warsaw, Mazowieckie, Poland
MJ

Michal Jamrozik

Department of Hematology and Bone Marrow Transplantation
Medical University of Silesia
Katowice, Slaskie, Poland
AK

Aleksandra Kostyra

Department of Hematology
Multidisciplinary Hospital in Torun
Toruń, Kujawsko-Pomorskie, Poland
JK

Justyna Kozińska

Department and Clinic of Hematolooncology and Bone Marrow Transplantation
Medical University of Lublin
Lublin, Lubelskie, Poland
HK

Halyna Krainiak

Department and Clinic of Hematology, Oncology and Radiotherapy
University of Zielona Góra
Gorzów Wielkopolski, Lubuskie, Poland
JO

Jolanta Oleksiuk

Department of Hematology, Internal Diseases and Angiology
University Białystok
Białystok, Podlaskie, Poland
JR

Joanna Rupa-Matysek

Department of Hematology and Bone Marrow Transplantation
Poznan University of Medical Sciences
Poznań, Wielkopolskie, Poland
JT

Jacek Treliński

Department of Haemostasis Disorders
Medical University of Lodz
Łódź, Lodzkie, Poland
EZ

Ewa Zarzycka

Department of Hematology and Transplantology
Medical University of Gdańsk
Gdańsk, Pomorskie, Poland
JZ

Joanna Zdziarska

Department of Hematology
Jagiellonian University Medical College
Kraków, Malopolskie, Poland

Background: Since 2020, under the National Hemophilia Treatment Program (NHTP) (outside of clinical trials), emicizumab has been used to manage Polish patients with hemophilia A complicated by factor VIII (FVIII) inhibitors (PWHAinh).

Aims: To evaluate the efficacy and safety of emicizumab in adult PWHAinh.

Methods: We calculated annualized bleeding rates requiring hemostatic therapy (ABR-HT) during emicizumab prophylaxis and compared these with ABR-HT in the 6-moth pre-emicizumab period. These and other clinical data were entered from patients’ medical records into a specifically designed electronic case report form.

Results: Forty-six PWHAinh, aged 18-70 (median:44) years were included. The mean maximum inhibitor titer was 628±1299 (median:123, range:1-5940) BU/mL. 32/46(69.6%) patients received long-term prophylaxis in the 6 month pre-emicizumab period, most of them (30/32, 93.7%) – activated prothrombin complex concentrate (aPCC). The mean duration of emicizumab treatment for all patients was 2.8±2.2 (range:1-7) (median:2) years. 10/46(21.7%) had started emicizumab in clinical trials and continued treatment in the NHTP. The mean and median ABR-HT was 17.3±20 and 14 respectively, in the pre-emicizumab period, and 0.3±0.9 and 0 respectively, while on emicizumab (p < 0.0001). During emicizumab treatment, 8/46(17.4%) patients experienced 39 breakthrough bleeds (27 traumatic and 12 spontaneous, including 10 spontaneous hemarthroses) requiring hemostatic therapy (as compared with 37/46(80.4%) patients in the pre-emicizumab period). 9/46(19.6%) patients on emicizumab underwent 19 invasive interventions, including one total knee replacement, 6 tooth extractions, and 12 other small diagnostic/therapeutic invasive procedures under hemostatic cover of rFVIIa, FVIII concentrate or tranexamic acid. All procedures went uneventfully. No emicizumab-related adverse events were observed during whole follow-up.

Conclusion(s): This study demonstrates that according to the most recent Polish data [Windyga J et al. Res Pract Thromb Haemost. 2023; 7(suupl.2):571], clinical outcomes in adult PWHAinh receiving emicizumab are superior to these in people with severe hemophilia A without inhibitors receiving long-term prophylaxis with FVIII concentrates.