PB0247 - Clinical report of five young patients (3-26 months of age) with moderate or severe hemophilia A receiving emicizumab

Sunday, July 10, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Ivonne Wieland, MD

Oberärztin
Päd. Hämatologie und Onkologie, Medizinische Hochschule Hannover
Hannover, Niedersachsen, Germany

Co-Author(s)

LH

Laura Hinze

Resident
Medizinische Hochschule Hannover
Hannover, Niedersachsen, Germany
KL

Katharina-Antonia Lambeck

Resident
Hanover Medical University
Hannover, Niedersachsen, Germany

Background: Emicizumab is the first approved non replacement therapy for bleeding prophylaxis in hemophilia A (HA) patients. Although emicizumab was approved for all age groups, data is limited for young children ( < 2 years).

Aims: Experience in young children

Methods: Here, we present the clinical course of 5 patients with HA treated with emicizumab.

Results: Four patients with a severe HA started with emicizumab treatment in an age range of 3 to 12 months. Three of them were minimal treated patients with 2 to 7 factor VIII (FVIII) exposure days (EDs) prior start of emicizumab. One patient switched to emicizumab after having previously received 29 EDs of FVIII during prophylaxis. The follow up time of our patients was 1 to 23 months. No spontaneous bleedings occurred during this time. For bleeding prevention due to head injuries, or for factor VIII immune tolerance purposes, these patients received additional single doses of FVIII (9-16 EDs). Of note, the patients did not develop an inhibitor after 2 to 53 doses of FVIII.
By contrast, the fifth patient was a 28 months old boy with moderate HA (FVIII 2-4%) and reduced von Willebrand parameters (39-50%). Due to several traumatic bleeding requiring treatment with 15 FVIII substitutions within 16 months, we first decided to start a standard prophylaxis. Due to a complicated venous access, a prophylaxis with this regimen was not possible. We thus requested an off-label use of emicizumab, and received the approval for treatment. After start of emicizumab, no additional FVIII substitutions were necessary.

Conclusion(s): To conclude, in four patients with severe HA and one patient with moderate HA, emicizumab was well tolerated and safe. There was no occurrence of spontaneous bleedings. All FVIII substitutions were performed following head injuries as single doses, or were given for FVIII immune tolerance. The parents’ satisfaction upon emicizumab treatment was high.