The potential of gene therapy to transform treatment for patients with haemophilia is entering clinical practice. The literature in adeno-associated viral (AAV) vector-mediated gene therapy demonstrates improvement in endogenous factor levels over sustained periods, significant reduction in annualised bleed rates, lower exogenous factor usage and thus far a positive safety profile. Gene therapy is also associated improvements in the burden of illness for haemophilia patients as measured by HRQoL and economic analysis.

Real World Evidence (RWE) including the CHESS studies, has been instrumental in establishing the evidence base to support patient access by establishing and reporting the patient perspective. HCD Economics, in partnership with the University of Chester and the international Haemophilia community continues to advocate the importance of studies that are designed to address patient and public involvement and engagement in the treatment of haemophilia.


As treatment is transforming the therapy and consequently the patient experience of the disease, previously accepted concepts such as the assessment of severity into mild, moderate and severe categories are challenged by patient reported, burden of illness research. As more RWE becomes available, the Haemophilia community, including patients, families and physicians will be able to continue to question the current status quo by utilising RWE to transform treatment of all patients by addressing the needs of all patients, whether assessed as mild, moderate or severe. Effectively this implies a treatment paradigm that seeks to achieve a transition from severe to moderate and moderate to mild.


The pan-European burden of illness haemophilia study CHESS was published in 2017. Further extensions of the study have also been undertaken in the US and in the paediatric population. In recognition of the importance of building RWE from a patient perspective, CHESS II is now recruiting patients.


For more information on the expected dates when results will be available to study partners and the projected timing of academic dissemination of results - contact Tom Burke -