PB1184 - A survey of clinical practice of laboratory monitoring and management of bleeding in children on emicizumab prophylaxis in the PedNet centers

Tuesday, June 25, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

JM

Jayashree Motwani, MBBS,FRCPATH

Haematology consultant
Birmingham Children's Hospital
Birmingham, England, United Kingdom

Co-Author(s)

SR

Susanna Ranta

Dr.
Astrid Lindgren's Children's Hospital, Karolinska University Hospital, and Department of Women's and Children's Health, Karolinska Institutet, both in Stockholm, Sweden
Stockholm, Stockholms Lan, Sweden
NA

Nadine Gretenkort Andersson

Senior consultant
Department of Clinical Sciences, Lund University, Lund; Department of Pediatrics and Malmö Centre for Thrombosis and Haemostasis, Skåne University Hospital, Malmö, Sweden
Malmo, Skane Lan, Sweden
Kathelijn Fischer

Pediatric Hematologist
Centre for Benign Haematology, Thrombosis and Haemostasis, Van Creveldkliniek, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
Utrecht, Utrecht, Netherlands
GK

Gili Kenet

CONSULTANT PAEDIATRIC HAEMATOLOGIST
National Hemophilia Center Sheba Medical center, Tel Hashomer & Amalia Biron Research Institute of Thrombosis & Hemostasis, Tel Aviv University, Israel,
Tel Aviv, Tel Aviv, Israel
CK

Christoph Königs

MD, PhD
University Hospital Frankfurt, Goethe University, Department of Pediatrics and Adolescent Medicine, Clinical and Molecular Hemostasis, Frankfurt, Germany
Frankfurt, Hessen, Germany
Md

Marloes de Kovel

statistician
PedNet Haemophilia Research Foundation, Baarn, The Netherlands
Barn, Utrecht, Netherlands
Martin Olivieri

Head of Pediatric Thrombosis and Hemostasis Unit, Pediatric Hemophilia Center
Paediatric Thrombosis and Haemostasis Unit, Dr. von Hauner Children's Hospital LMU Munich, Germany
munich, Bayern, Germany
Veerle Labarque

Professor
Department of Pediatric Hematology and Oncology, University Hospital Leuven Gasthuisberg, Leuven
ฺฺBrussels, Brussels Hoofdstedelijk Gewest, Belgium

Background: Emicizumab is used as prophylaxis in children with hemophilia A, with & without inhibitors. Guidelines on laboratory monitoring, management of bleeding episodes and new inhibitors are lacking.

Aims: Assess how children on emicizumab prophylaxis are treated in PedNet centers.

Methods: Electronic survey on approach to past & current inhibitors, laboratory monitoring, management of bleeding in children on emicizumab prophylaxis sent to all 32 PedNet centres in autumn 2023.

Results: 30/32 centers responded, 25 had used emicizumab > 4 , 2 centers 3-4 ,3 centers 2-3 years. Emicizumab concentrations are monitored by19/30 (63%) centers: 9 every 3-6 months, 4 annually, 1 “sometimes”, 3 more in the beginning, 8 -if clinical concerns.
FVIII inhibitor testing is available in all centers. 29 monitor for FVIII inhibitors in patients with no active inhibitors & < 50 exposure days: 16 after exposure to FVIII, 15 every 3-6 months, 3 annually, 3 every visit and 9 with clinical concerns. 25 centers monitor >50 exposure days too. If a child developed a new high-titer inhibitor, 9 centers would initially “watch and wait” & 17 offer ITI.
23 offer emicizumab to children with previous inhibitors, now tolerised, of which 7 offered concomitant FVIII.
29/30 centers monitor for inhibitors to FVIII in children with known inhibitor . In children with previous inhibitors on emicizumab and major bleed 12 treat with Novoseven, 11 with FVIII concentrate and 6 based on clinical situation.
With low emicizumab levels, 15 centers would test for antidrug antibody (ADA). 14 would increase the dose , 2 the frequency of injections, 9 would continue the same regimen.

Conclusion(s): Evidence-based guidelines for laboratory monitoring and management of bleeding are sparse. Majority monitor for inhibitors & emicizumab levels. ADA considered by majority. This survey highlights the need for real life data collection to address these questions.