Cost-effectiveness of enzalutamide versus apalutamide versus androgen deprivation therapy alone for the treatment of metastatic castration-sensitive prostate cancer in Canada

AIMS: There are no direct comparisons of the relative cost-effectiveness of second-generation anti-androgens (enzalutamide and apalutamide) used in managing metastatic castration-sensitive prostate cancer (mCSPC) in Canada. This study compared the cost-effectiveness of enzalutamide versus apalutamide versus androgen deprivation therapy (ADT) alone (standard of care) in patients with mCSPC from the Canadian public payer perspective using a Markov model with a 15-year time horizon. MATERIALS AND METHODS: Efficacy data for enzalutamide and ADT alone were informed by the ARCHES and ENZAMET clinical trials, while a Bayesian network meta-analysis enabled comparison with apalutamide and ADT alone. RESULTS: Over the 15-year period, enzalutamide achieved the highest number of life-years (LY, 7.6) and quality-adjusted life-years (QALY, 5.62) compared with apalutamide (LY, 6.1; QALY, 4.59) and ADTs (LY, 4.9; QALY, 3.61). Enzalutamide incurred the most costs ($349,345) compared with apalutamide ($294,349) and ADT ($162,550). Sequential analysis showed that enzalutamide lies on the cost-effectiveness frontier with ADT alone (incremental cost-effectiveness ratio: $92,868/QALY), with apalutamide extendedly dominated through enzalutamide and ADT alone. LIMITATIONS: Limitations include the heterogeneity of the studies included in the network meta-analysis and the validations for the treatment sequencing assumptions in the modeling. CONCLUSIONS: Enzalutamide was the most effective treatment option for mCSPC in the Canadian market, with the greatest LYs and QALYs, and incurred the most costs.