Evaluation of Safety and Efficacy of Emicizumab Prophylaxis in Egyptian Pediatric Patients with Hemophilia A

Objective: Hemophilia A (HA) is a hereditary X-linked bleeding disorder secondary to deficiency of the clotting factor VIII (FVIII). Emicizumab is a monoclonal antibody that replaces the function of the activated FVIII and prevents bleeding in HA patients. Emicizumab is expected to ameliorate bleeding risk in those patients together with subsequent complications. However, there is a scarcity of data about its safety and efficacy in patients with HA. We aimed to evaluate the safety and efficacy of emicizumab prophylaxis in Egyptian pediatric patients with HA. Materials and Methods: A prospective cohort study was carried out with 88 HA patients who received emicizumab prophylaxis. Breakthrough bleeding episodes and the annualized bleeding rate (ABR) were reported for all patients before and after emicizumab prophylaxis. Also, all adverse events during prophylaxis were documented to evaluate the safety of emicizumab. Results: Joint bleeds occurred in 94% of the patients. Among those patients, 58% had one target joint, 36.4% had more than one target joint, and 5.6% had no target joints. Furthermore, 17% of patients were positive for FVIII inhibitors. The median annualized joint bleeding rate was reduced remarkably after emicizumab prophylaxis (36 before versus 0 after emicizumab). The median ABR was 48 before emicizumab versus 0 after emicizumab. Eight patients experienced mild breakthrough bleeding episodes. The most common adverse events were local reactions at injection sites, headache, arthralgia, fever, and diarrhea. Conclusion: Prophylaxis using emicizumab was associated with a significantly lower bleeding rate in HA patients with and without inhibitors. The majority of patients had zero bleeds with emicizumab prophylaxis.