OBJECTIVES:

The purpose of this study was to evaluate the cost-effectiveness of avacopan in combination with cyclophosphamide (CYC) or rituximab (RTX) compared with glucocorticoids (GC) and cyclophosphamide or rituximab for patients with antineutrophil cytoplasm antibody–associated vasculitis (AAV) in Canada from the perspective of healthcare payer

METHODS:

A Markov model comprised of 9 health states was developed. The health states include an active disease state where patients start, three remission and three relapse states, end-stage renal disease (ESRD) and death. The disease progression was modeled over a lifetime horizon. The clinical efficacy for avacopan was based on the results of ADVOCATE, and included disease remission at 26, 52 and 60 weeks, change in estimated glomerular filtration rate and health-related quality of life. The transition probabilities to ESRD were sourced from literature. Cost data were obtained from published literature, including adverse events, and clinical management of AAV. The model uses utility values from EQ-5D-data from ADVOCATE stratified by health state. Benefits were expressed as quality-adjusted life years (QALYs). Costs were reported in 2022 Canadian dollars (CAD)

RESULTS:

Avacopan in combination with CYC or RTX was associated with higher costs, and with higher QALYs compared with GC and CYC or RTX. The incremental cost for avacopan with CYC or RTX was partially offset by the savings that resulted from delaying the progression to ESRD. At a willingness to pay threshold of CAD 50,000 and CAD 100,000 per QALY, the probabilistic analysis showed that a regimen including avacopan would be deemed cost-effective in approximately 65% and >90% of iterations, respectively. The results of the model were most sensitive to changes in utility values, time horizon, and the assumptions related to the progression to ESRD

CONCLUSIONS:

Avacopan in combination with cyclophosphamide or rituximab is a new, cost-effective option for AAV patients in Canada