Cost-effectiveness of enzalutamide with androgen-deprivation therapy (ADT) versus ADT alone for the treatment of high-risk biochemically recurrent non-metastatic castration-sensitive prostate cancer in Canada

The EMBARK (NCT02319837) trial demonstrated that enzalutamide with androgen-deprivation therapy (ADT; enzalutamide combination) or without ADT (enzalutamide monotherapy) significantly improved metastasis-free survival compared with ADT alone in high-risk biochemically recurrent (BCR) non-metastatic castration-sensitive prostate cancer (nmCSPC; also known as non-metastatic hormone-sensitive prostate cancer [nmHSPC]). No new safety signals were observed during the trial. The findings of EMBARK led to Health Canada’s approval of enzalutamide for this patient population. The aim of this analysis was to assess the cost-effectiveness of enzalutamide combination versus ADT alone in patients with high-risk BCR nmCSPC from the Canadian payer’s perspective. A semi-Markov model was created to represent the treatment and disease progression of patients with high-risk BCR nmCSPC over a 30-year horizon. Costs and outcomes were discounted at 1.5% annually. Treatment effects for high-risk BCR nmCSPC were informed by data from the EMBARK trial. Life-years (LYs), quality-adjusted life-years (QALYs), lifetime costs and incremental cost-effectiveness ratio (ICER) were estimated for enzalutamide combination and ADT alone. A one-way sensitivity analysis (OWSA) and scenario analyses were conducted to assess the robustness of results. In the base-case deterministic analysis over the modeled time horizon, enzalutamide combination accumulated 11.85 LYs and 8.96 QALYs versus 8.75 LYs and 6.24 QALYs for ADT alone. The total cost for enzalutamide combination was Canadian dollars (CAD) 166,199, compared with CAD 95,146 for ADT alone. When combining cost and clinical outcome data, enzalutamide combination was associated with an ICER of CAD 26,129 per QALY gained. The OWSA and scenario analysis results were consistent with the base-case results. The study findings suggest that enzalutamide combination was associated with an ICER of CAD 26,129 per QALY gained, which is within the standard Canadian thresholds for willingness-to-pay (i.e. This study explored the benefits of two types of cancer treatment, enzalutamide and androgen-deprivation therapy (ADT), which are effective against certain types of prostate cancer. Recent data from a clinical trial, called EMBARK, led to the approval of enzalutamide for use in patients with high-risk biochemically recurrent non-metastatic castration-sensitive prostate cancer (BCR nmCSPC). The financial and health benefits were compared from the Canadian perspective for patients treated with enzalutamide in combination with ADT versus those using ADT alone. To determine the cost-effectiveness, we created a model that simulated the treatment, patient quality of life, disease progression, survival, and costs over 30 years. We found that enzalutamide plus ADT improved the quantity (life years; LY) and quality of life (quality-adjusted life years; QALYs) compared to ADT alone. Specifically, enzalutamide plus ADT provided 11.85 LYs and 8.96 QALYs, while ADT alone provided 8.75 LYs and 6.24 QALYs. The total cost for enzalutamide plus ADT was higher at Canadian dollar (CAD) 166,199 compared to CAD 95,146 for ADT alone. However, when considering the additional health benefits, enzalutamide plus ADT was found to be cost-effective compared to ADT alone, with an incremental cost-effectiveness ratio (ICER) of CAD 26,129 per QALY gained. ICER is used to compare the additional cost of one treatment option relative to another, in terms of the extra health benefits gained. These results suggest that enzalutamide plus ADT is a preferred treatment option for patients with high-risk BCR nmCSPC in Canada, due to its cost-effectiveness and improved health outcomes alongside a well-established safety profile, over ADT alone.