Evolution of joint health and physical activity in people with haemophilia A without factor VIII inhibitors switching to emicizumab prophylaxis: 12-month interim analysis of the BEYOND ABR study

Introduction Advances in haemophilia A (HA) treatment have led to lower bleeding rates, shifting focus towards functional endpoints. BEYOND ABR (NCT05181618) aims to evaluate joint health and physical activity in people with HA (PwHA) switching from factor (F)VIII prophylaxis to emicizumab. This interim analysis reports 12 months of follow-up. Method BEYOND ABR is a Phase IV, multicentre, open-label study in PwHA aged 13–69 years with moderate/severe HA without FVIII inhibitors. Joint health is evaluated in joints without prior surgery/procedures using the Hemophilia Joint Health Score (HJHS) 2.1. Changes in problem joint counts (defined as per Chowdary, et al. [ 1 ]) are captured. Physical activity is measured with the International Physical Activity Questionnaire (IPAQ). The number of participants with zero treated bleeds is reported. The Emicizumab Preference Survey was carried out following 6 months of treatment. Results Overall, 136 male PwHA were enrolled. At the participant level, mean (standard deviation [SD]) HJHS sum of joints (excluding Global Gait Score; maximum score: 120=6 joints×20 points each) was 10.1 (13.2) at baseline and improved by−2.0 (6.4) at Month 6 and−2.8 (7.9) at Month 12. In total, 23/88 (26.1%) participants had a≥4-point improvement in HJHS sum of joints from baseline to Month 12; 5/88 (5.7%) reported a worsening of≥4 points at Month 12. Similar outcomes were observed at the single joint level. At Month 12, the number of participant-reported problem joints decreased from baseline in 35/117 (29.9%) participants, whereas 16/117 (13.7%) participants reported an increase in problem joints. The proportion of participants engaged in low physical activity decreased from 30.8% (32/104) at baseline to 22.3% (23/103) at Month 3, and remained stable at Month 12 (23.4% [22/94]); proportions of participants engaged in high physical activity increased from 44.2% (46/104) to 52.4% (54/103) at Month 3, and was 50.0% (47/94) at Month 12. Zero treated bleeds were reported by 110/136 (80.9%) participants between Weeks 1 and 24, and 105/134 (78.4%) between Weeks 25 and 48. At Month 6, 125/130 (96.2%) participants preferred emicizumab to their previous FVIII prophylaxis. Conclusion After switching to emicizumab, participants had low bleeding rates associated with numerical improvements in joint health. Physical activity levels were stable or shifted towards higher activity. Most participants preferred emicizumab over their previous treatment. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany