TSUBASA Study: Evaluating Association of Physical Activity and Bleeding Events in People With Haemophilia A Without Factor VIII Inhibitors Receiving Emicizumab.

BACKGROUND

Emicizumab is approved for routine prophylaxis, but limited data exist investigating the relationship between bleeds and exercise in people with haemophilia A (PwHA) receiving emicizumab.

AIM: To evaluate the relationship between physical activity and bleeding outcomes in Japanese PwHA receiving emicizumab prophylaxis.

METHODS

This prospective, multicentre, observational study was conducted in Japanese PwHA initiating emicizumab between November 2019 and October 2021. Physical activity and bleeding events were reported using an electronic patient-reported outcomes application, while activity intensity was collected by a wearable activity tracker worn over five 8-day monitoring periods. Data on safety were recorded by investigators using electronic case report forms. Quality of life data were also collected and will be reported in a separate publication.

RESULTS

Overall, 129 participants enrolled. Median age was 32 years (range 0-73), and 83.7% of participants had severe HA. Overall, 73 participants performed 968 exercise events, with 18.8% and 6.0% of events classified as moderate and high risk, respectively. Two (0.2%) exercise events were associated with bleeding: one basketball (moderate risk) and one fishing (low risk). In total, 137 adverse events (AEs) were reported in 62 participants. No serious AEs were emicizumab-related. The mean annualised treated bleed rate was 1.9 and 51 (39.5%) participants experienced zero bleeds during the study period (97 weeks).

CONCLUSION

This study suggests that PwHA receiving emicizumab prophylaxis can participate in a wide range of physical activities with minimal bleeding risk, which supports their access to the health benefits of exercise. Emicizumab remains well tolerated.