PMS47 - The Impact of Disease Modification on the Cost-Effectiveness of Pegloticase for the Treatment of Severe Debilitating Chronic Tophaceous Gout In Adult Patients

Abstract

To determine the cost-effectiveness of pegloticase (Krystexxa®) for patients with severe debilitating chronic tophaceous gout (SDCTG), from a UK health care perspective. Severe debilitating chronic tophaceous gout (SDCTG) is a debilitating disease, with high unmet medical need. Existing treatments mainly provide symptom relief and do not modify the disease course. Pegloticase has the potential to be a disease modifying agent. A decision analytical model was built to compare the use of pegloticase in patients with SDCTG with best supportive care (BSC) with a Markov model used to extrapolate outcomes to a 20 year time-horizon. In the basecase, the disease modifying properties of pegloticase were modelled. In scenario analyses only symptomatic relief of pegloticase on acute attacks and tophi was included. In the basecase, the cost-effectiveness of pegloticase compared to BSC was £31,027 per QALY gained. In this basecase, pegloticase dramatically reduced the uric acid burden in over 60% of patients who completed a six month course and were assumed could then be controlled on xanthine oxidase inhibitor maintenance treatment. In a pessimistic scenario whereby pegloticase was assumed to only provide symptomatic relief, the ICER was £48,672/QALY gained. In a further scenario whereby utility benefits were limited to only short-term reduction in acute flares and presence of tophi, the ICER was £54,345/QALY. Apart from these two drivers, the cost-effectiveness estimates were relatively stable across a range of sensitivity analyses. In the context of a highly severe and debilitating form of gout, with small patient numbers and a lack of alternative effective treatment options, pegloticase can be considered good value-for-money. Further clinical evidence is required to demonstrate the disease modifying properties of pegloticase. However, such data collection and hence the ability to perform robust economic evaluations for HTA purposes is difficult especially when the sponsoring company is small with limited funds.