Association of physical activity with bleeding events and safety in patients with haemophilia A starting emicizumab prophylaxis: an interim analysis of the TSUBASA study

Abstract

Introduction: Little information exists on the relationship between bleeding outcomes and physical activity in patients with haemophilia A (PwHA).

Aim: This interim analysis of the TSUBASA study (UMIN-CTR ID: UMIN000037448) evaluated the association of physical activity with bleeding and safety in PwHA starting emicizumab.

Methods: PwHA without factor VIII inhibitors were recruited. Physical activity and bleed data were obtained using an electronic patient-reported outcome application and wearable activity tracker. Adverse events (AEs) were documented.

Results: At data cut-off (31-May-2021), 107 PwHA were enrolled, with a median (range) age of 35 (0-73) years. Physical activity data were obtained for 74 participants. Of these, 47 (63.5%) recorded a total of 396 exercise events. The most common exercise events were walking (32.4%), cycling (14.9%), and football (5.4%). Two (0.5%) exercise events in the same individual were associated with bleeding (running, weight training). The safety analysis population consisted of 106 participants treated with emicizumab (median observation period: 241.5 days). Twenty-one (19.8%) participants experienced a total of 39 AEs. Five (4.7%) experienced a serious AE, none of which was emicizumab-related, and three (2.8%) experienced an adverse drug reaction.

Conclusions: PwHA receiving emicizumab in the TSUBASA study experienced minimal bleeding associated with physical activity.

Trial registration: Trial registration: UMIN-CTR ID: UMIN000037448.

Keywords: Emicizumab; Haemophilia A; Patient-reported outcome; Physical activity.