Cost-effectiveness of lifelong eculizumab versus disease monitoring of aHUS

Atypical haemolytic uraemic syndrome (aHUS) is a rare but severe condition caused by complement dysregulation. Eculizumab prophylaxis prevents recurrence and improves survival, yet the benefits of lifelong treatment for patients are uncertain and the long-term costs for health services are substantial. This economic evaluation applied the results from the Stopping Eculizumab Treatment Safely in aHUS (SETS aHUS) trial and assessed the cost-effectiveness of replacing lifelong eculizumab with a disease monitoring strategy over the long term. A Markov model was used to estimate cost and quality adjusted life years (QALYs) for a treatment withdrawal and disease monitoring strategy over the long term. Results from the SETS aHUS trial informed the risk of relapse diagnosis or progression, utility values, and additional health care use. Time to relapse diagnosis was extrapolated using parametric survival functions. The treatment withdrawal and disease monitoring strategy increased average patient QALYs by 0.08 (95% CrI: -0.33 to 0.53), and reduced patient costs by £4 234 196 (95% CrI: -£684 495 to -£6 403 694) compared with the lifelong delivery of eculizumab. The impact on survival estimates was low, withdrawal patients had an average reduction of 0.0005 patient Life Years (LYs) (95% CrI: -0.0029 to 0) over an 80-year time horizon. Withdrawal and monitoring had a 64% likelihood of being more effective and less costly than lifelong treatment. Results remained robust across multiple scenarios exploring uncertainties. Treatment withdrawal and disease monitoring was cost-effective compared with lifelong eculizumab therapy. Its adoption is expected to substantially reduce costs per patient and may improve average patient quality of life.