Abstract Number: PB0504
Meeting: ISTH 2021 Congress
Theme: Hemophilia and Rare Bleeding Disorders » Hemophilia - Clinical
Background: Emicizumab is a bispecific humanised antibody, approved for treatment of patients with haemophilia A (HA). Data from paediatric patients were limited at the time of marketing authorization. Moreover, a different coagulation system in very young infants may contribute to unexpected side effects.
Aims: To evaluate safety and efficacy of Emicizumab prophylaxis in children.
Methods: The PedNet Registry includes all children with haemophilia born since January 1st 2000 (NCT02979119), diagnosed and treated in one of the 33 participating centres in Europe, Canada and Israel. For this analysis, data were collected from the moment children switched to Emicizumab until 1 January 2021, on total number of bleeds, additional treatment for bleeds, trauma and surgery as well as adverse events (AE).
Results: A total of 141 patients with HA (134 severe, 6 moderate and 1 mild) were included, of whom 79 (56%) had inhibitors. Twenty-eight children were below 2 years of age. The median treatment period in months (IQR) was 17,9 (7,9 – 28,1) for children with inhibitors and 3,8 (2,3-9,0) months for those without. A total of 82 patients (58%) reported zero bleeds. Details on bleeds are described in the table and figure. Major bleeds were more frequent in inhibitor patients; this might be due to longer follow-up for inhibitor patients. Three adverse events were reported: one patient had a local skin reaction, one patient developed antibodies against Emicizumab, and one child died from unrelated problems.
| Inhibitor | Non-inhibitor | All patients | |
| Number (N) of patients | 79 | 61 | 141^ |
| Median age at start emicizumab, months (IQR) | 80,5 (26,1-138,0) |
71,5 (33,9-128,2) |
75,5 (27,6-135,5) |
| N start emicizumab before 2 years of age | 17 | 11 | 28 |
| median treatment duration, months (IQR) | 17,9 (7,9-28,1) | 3,8 (2,3-9,0) | 9,8 (3,6-19,8) |
| N patients with bleeds | 42 | 16 | 58 |
| N reported major* joint & soft tissue bleeds | 28 | 11 | 39 |
| N reported major & minor joint bleeds | 44 | 5 | 49 |
| N reported minor** soft tissue bleeds | 134 | 15 | 149 |
Inhibitor and non-inhibitor patients from start emicizumab to January 2021
* major bleed: pain, swelling, limitation of motion and failure to respond within 24 hours of treatment
** minor bleed: mild pain, minimal swelling, minimal restriction of motion, resolving within 24 hours
^ 1 patient with unknown inhibitor status.
Total bleeds per category and inhibitor status
Conclusions: Emicizumab prophylaxis provided excellent bleed control. Follow up for non-inhibitor patients is still short. One patient developed anti-drug antibodies.
To cite this abstract in AMA style:
Kenet G, Nolan B, Oldenburg J, Motwani J, D' Oiron R, Male C, Chambost H, Fischer K, Van Geet C, van den Berg HM, PedNet Study Group . Emicizumab Treatment in Pediatric Haemophilia A Patients: >1 Year Safety Based on Real-world Data from the PedNet Cohorts [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/emicizumab-treatment-in-pediatric-haemophilia-a-patients-1-year-safety-based-on-real-world-data-from-the-pednet-cohorts/. Accessed November 29, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/emicizumab-treatment-in-pediatric-haemophilia-a-patients-1-year-safety-based-on-real-world-data-from-the-pednet-cohorts/