Outcomes, challenges and prospects of emicizumab prophylaxis in Sub-Saharan Africa – Insights from the Tanzanian experience

Abstract

Abstract Background Prophylaxis is the global standard of care for haemophilia A (HA), and its adoption has been accelerated by wide use of emicizumab prophylaxis globally. Reports on the prophylaxis in people with haemophilia living in Africa are limited. Objectives We evaluated adherence trends, bleeding outcomes and safety profile of emicizumab prophylaxis in haemophilia A patients managed at the Muhimbili National Hospital (MNH), Tanzania. Methodology This was a cross-sectional analysis which included HA patients of all ages on emicizumab prophylaxis. After obtaining informed and institutional approvals, we collected data on adherence patterns, self-reported adverse events and bleeding outcomes. We assessed factors associated with breakthrough bleeding using a robust Poisson method. Results From January to March 2024, 55 people with HA (PwHA) were included in the study. The median age (IQR) was 8 (4,14) years with the majority having severe haemophilia. The median (IQR) ABR for spontaneous bleeds was 8 (5,16), which became zero following a year of emicizumab prophylaxis. Most participants (78%) were adherent. Bleeding occurred in 63.6% of the participants, the majority being traumatic (62.9%). Spontaneous bleeding occurred in 17%, while 20% experienced both spontaneous and traumatic bleeds. In the 19 participants with target joints, the target joint resolution was 79% (15/19). Age was the sole predictor of breakthrough bleeding, which occurred predominantly in those over 18 years of age. The adverse event rate was low (9.1%), with injection site reactions being the most frequent. Conclusions In this real-world experience with emicizumab prophylaxis from Africa, the majority of the patients’ adherence was good and emicizumab prophylaxis was effective in preventing spontaneous bleeding. The safety profile of emicizumab was acceptable and consistent with other global real-world experiences.