Real-world data on the use of emicizumab in patients with haemophilia A with and without inhibitors in Singapore

Abstract

Introduction: Emicizumab is a bispecific monoclonal antibody that mimics the function of factor VIII by bi ndi ng to factor IXa and factor X to achi eve haemostasis in haemophilia A. The long half-life and subcutaneous mode of administration makes emicizumab a compelling treatment option for bleeding prophylaxis. There is still limited real-world data on its use and management considerations, especially during surgical procedures. The objective of the study is to describe the real-world experience of emicizumab in a cohort of adult and paediatric haemophilia A patients in Singapore, including its use in the periprocedural setting. Method: This was an observational study conducted at the 2 main haemophilia treatment centres in Si ngapore. Al l haemophi l i a A pat i ent s who commenced treatment with emicizumab before 1 July 2022 were recruited. Results: A total of 18 patients with haemophilia A were included in this study. Ten (55.6%) patients had active inhibitors. The median annual bleeding rate for all patients before emicizumab use was 4.5 events (interquartile range [IQR] 2.8–8.3) compared with 0 events (IQR 0–0) after emici zumab was commenced (P=0). There were no adverse events of venous or ar t er i al t hrombosi s, t hrombot i c microangiopathy, or death. A total of 6 procedures in 5 patients were performed during the study period with no major bleeding complications. Conclusion: Emicizumab effectively protects against bleeding in haemophilia A patients with and without inhibitors, including in children less than 12 years old. More studies are required to address clinical nuances, such as periprocedural management and the rol e of i mmune tol erance i n pati ents wi th inhibitors on emicizumab.