OBJECTIVES:

Prostate cancer is the second leading cause of death and second most common cancer among American men. Metastatic castration-sensitive prostate cancer (mCSPC) has largely been treated with androgen deprivation therapy (ADT) alone or ADT plus docetaxel for the past few decades. The emergence of antiandrogen therapies like abiraterone acetate, apalutamide, and enzalutamide in the last decade has transformed the treatment landscape of mCSPC. We aimed to compare the cost-effectiveness of abiraterone, enzalutamide, and apalutamide in addition to ADT in treating mCSPC from the US payer perspective.

METHODS:

A partitioned-survival model was developed to compare the lifetime costs and outcomes of these three treatment options for mCSPC using data from phase 3 trials and their extensions for each. Drug costs were obtained from the Redbook database and Medicaid. Health outcomes were measured in life-years and quality adjusted life years (QALYs). Survival data was extrapolated from progression-free and overall survival curves from trials. Utility values were derived from published data, including the pivotal trials. One-way and probabilistic sensitivity analyses were conducted to test the uncertainty of our model results.

RESULTS:

Compared to abiraterone, apalutamide provided a 0.88 QALY and $867,785 gain with an ICER of US$990,307 per QALY. Enzalutamide provided a 0.41 QALY and $55,363 gain against apalutamide with an ICER of $135,983 per QALY. Apalutamide was dominated by abiraterone when using the low input value of pre-progression utility for abiraterone in our one-way sensitivity analyses. When comparing enzalutamide to apalutamide, apalutamide was dominated when using the low and high input values of cost for enzalutamide and apalutamide, respectively. Enzalutamide was dominated when using the low and high input values of pre-progression utility for enzalutamide and apalutamide, respectively.

CONCLUSIONS:

Abiraterone plus ADT is the preferred treatment compared to either enzalutamide or apalutamide plus ADT at a willingness to pay threshold of US$100,000 per QALY.