OBJECTIVES: For the treatment of advanced prostate cancer, the Food and Drug Administration approved relugolix as an oral form of a gonadotropin-releasing hormone receptor antagonist with no evident superiority over leuprolide. With its substantial cost implications, it is imperative that an economic evaluation study on relugolix be conducted. Therefore, the goal of this study is to assess the cost-effectiveness of 120mg of relugolix compared to 7.5mg of leuprolide subcutaneous injection for the treatment of advanced prostate cancer.

METHODS: A Markov model was used to assess and compare the costs of APC treatment from a healthcare payer’s perspective and the effectiveness of androgen deprivation therapy with relugolix and leuprolide at the three lines of APC treatment among modified intent-to-treat (mITT) patients. Relative progression-free and overall survival rates were estimated, while outcomes measured in the analyses included costs of therapies, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios (ICERs), cost-effectiveness acceptability curves, and Markov probability curves.

RESULTS: The cost-effectiveness analysis showed the ICER for hormonal therapy with relugolix to be US $49571.1/QALY. At the ICER, the probabilistic sensitivity analyses indicated that ADT with leuprolide was dominant in 100% of the simulations. The acceptability of ADT with relugolix was 100% when a willingness-to-pay threshold was set at $100,000/QALY. At 5-years, the relative progression-free and overall survival rates for relugolix at the first line of therapy were 72.7% and 86.0%, respectively, compared to 61.0% and 85.90% for leuprolide.

CONCLUSIONS: Though the influence of adverse events was not considered in the analysis, ADT with relugolix was not a cost-effective choice for the treatment of APC when compared to ADT with leuprolide. While the analysis revealed that patients had a slight chance of sustaining testosterone suppression with relugolix in terms of PFS, ADT with relugolix provided no overall survival advantages over ADT with leuprolide.