Evaluation of Safety and Efficacy of Emicizumab Prophylaxis in Egyptian Pediatric Patients with Hemophilia A: Single Center Cross Sectional Study.

Purpose: Hemophilia A (HA) is an X-linked hereditary bleeding disorder caused by deficiency of coagulation factor VIII activity. Emicizumab is a bispecific monoclonal antibody that replaces the function of activated FVIII and prevents bleeds in patients with hemophilia A. Emicizumab is expected to reduce the risk of severe bleeds in those patients with their subsequent complications. However, data about its safety and efficacy in patients with hemophilia A is limited. We aimed to evaluate safety and efficacy of Emicizumab prophylaxis in Egyptian pediatric patients with HA.

Methods: A prospective cohort study was conducted on 88 HA patient who received prophylaxis with Emicizumab. Breakthrough bleeding episodes as well as annualized bleeding rate(ABR) were reported for all patients before and after Emicizumab prophylaxis. All adverse events during prophylaxis were reported to evaluate the safety of Emicizumab.

Results: Joint bleeds were present in 94 % of the patients. 58% of them had one target joint, 36.4% had more than one target joint while 5.6% had no target joints. 17% of patients were positive for FVIII inhibitors. The median annualized joint bleeding rate (AJBR) was reduced remarkably after Emicizumab prophylaxis (36 before versus zero after Emicizumab. Also, the median ABR was 48 before Emicizumab versus zero after Emicizumab. Eight patients developed mild breakthrough bleeding episodes. The most common adverse events were local reaction at the injection sites, headache, arthralgia, fever and diarrhea.

Conclusion: Emicizumab prophylaxis was associated with significantly lower rate of bleeding events in patients with HA with and without inhibitors. The majority of patients had zero bleeds with Emicizumab prophylaxis.