Achieving and maintaining an optimal trough level for prophylaxis in haemophilia: the past, the present and the future.

Recurrent joint bleeding, leading to the development of joint disease and arthropathy, are the hallmarks of haemophilia. Prevention of bleeding through prophylaxis, rather than the on-demand treatment of bleeding events when they occur, is considered the gold standard of treatment for severe haemophilia. The original aim of prophylaxis was to avoid arthropathy by changing the bleeding phenotype from a severe to moderate form. While the use of prophylaxis has undoubtedly improved patients’ outcome and quality of life (QoL) by preventing bleeding and joint disease progression, challenges remain, and there is a growing awareness that prophylaxis may also benefit vulnerable patients with mild/moderate haemophilia. The ultimate treatment goal for haemophilia is the absence of joint bleeds, and ensuing joint disease and arthropathy, for all. Members of the Zurich Haemophilia Forum convened for their tenth meeting in November 2012 to discuss current and future treatments for haemophilia and the aims to mitigate disease severity and prevent arthropathy. In particular, discussions regarding the concept of an optimal trough level - what this should be and how to achieve it (now and in the future) for haemophilia patients without inhibitors - are summarised in this report.