Value contribution of etranacogene dezaparvovec gene therapy in moderately severe and severe haemophilia B through multi-criteria decision analysis

Introduction: The value of gene therapies for haemophilia needs to be assessed holistically.

Aim: To determine the value of etranacogene dezaparvovec (ED) compared to current extended half-life (EHL) recombinant factors (rFIX), using multi-criteria decision analysis (MCDA).

Method: MCDA EVIDEM methodology adapted to orphan drugs was used, with nine quantitative criteria and four contextual criteria. The MCDA framework was rated by 28 multidisciplinary experts. Descriptive statistics were performed for quantitative and qualitative criteria.

Results: Haemophilia B (HB) was considered a severe disease (mean ± SD: 4.3 ± 0.7) with some unmet needs (mean ± SD 3.3 ± 0.9). Experts found ED more effective (mean ± SD 2.0 ± 2.3) and provide better quality of life (QoL) (mean ± SD: 1.8 ± 1.5) than the comparative HB treatments but with safety uncertainties (mean ± SD -1.2 ± 1.8). ED could lead to medical cost and non-medical cost savings over time (mean ± SD: 1.6 ± 2.0 and 2.0 ± 1.5, respectively). The quality of the evidence was high (mean ± SD: 3.9 ± 0.9). ED was considered aligned with the priorities of the National Health System (NHS) and the specific interests of patients. ED's value contribution was 0.45 (+1 = highest value).

Conclusions: ED brings added value in the treatment of moderately severe and severe HB (sHB) compared to current EHL rFIX, addressing the severity of the disease and increasing efficacy and patients' QoL especially related to the single dose and low bleeding rate. Concerns about long-term safety need to be addressed.