Abiraterone acetate is registered for the treatment of metastatic castration-sensitive and resistant prostate cancer (mCRPC). Treatment outcome is associated with plasma trough concentrations (C ) of abiraterone. Patients with a plasma C below the target of 8.4 ng/mL may benefit from treatment optimization by dose increase or concomitant intake with food. This study aims to investigate the cost-effectiveness of monitoring abiraterone C in patients with mCRPC.
A Markov model was built with health states progression-free survival, progressed disease, and death. The benefits of monitoring abiraterone C followed by a dose increase or food intervention were modeled via a difference in the percentage of patients achieving adequate C taking a healthcare payer perspective. Deterministic and probabilistic sensitivity analyses were performed to assess uncertainties and their impac to the incremental cost-effectiveness ratio (ICER).
Monitoring abiraterone followed by a dose increase resulted in 0.149 incremental quality-adjusted life-years (QALYs) with €22 145 incremental costs and an ICER of €177 821/QALY. The food intervention assumed equal effects and estimated incremental costs of €7599, resulting in an ICER of €61 019/QALY. The likelihoods of therapeutic drug monitoring (TDM) with a dose increase or food intervention being cost-effective were 8.04%and 81.9%, respectively.
Monitoring abiraterone followed by a dose increase is not cost-effective in patients with mCRPC from a healthcare payer perspective. Monitoring in combination with a food intervention is likely to be cost-effective. This cost-effectiveness assessment may assist decision making in future integration of abiraterone TDM followed by a food intervention into standard abiraterone acetate treatment practices of mCRPC patients.