Abiraterone vs. docetaxel for metastatic hormone-sensitive prostate cancer: A microsimulation model

Abstract

Introduction: Our aim was to determine whether androgen-deprivation therapy (ADT) with abiraterone acetate (AA) or ADT with docetaxel chemotherapy (DC) resulted in improved quality-adjusted life years (QALYs) among men with de novo metastatic castration-sensitive prostate cancer (mCSPC) and the cost-effectiveness of the preferred strategy using decision analytic techniques.
 Methods: A microsimulation model with a lifetime time horizon was constructed. Our primary outcome was QALYs. Secondary outcomes included cost, incremental cost-effectiveness ratio (ICER), unadjusted overall survival (OS), rates of second- and third-line therapy, and adverse events. A systematic literature review was used to generate probabilities and utilities to populate the model. The base case was a 65-year-old patient with de novo mCSPC.
 Results: A total of 100 000 microsimulations were generated. Initial AA resulted in a gain of 0.45 QALYs compared to DC (3.36 vs. 2.91 QALYs) with an ICER of $276 251.84 per QALY gained with initial AA therapy. Median crude OS was 51 months with AA and 48 months with DC. Overall, 46.6% and 42.6% of patients received second-line therapy and 8.7% and 7.9% patients received third-line therapy in the AA and DC groups, respectively. Grade 3/4 adverse events were experienced in 17.6% of patients receiving initial AA and 22.3% of patients receiving initial DC.
 Conclusions: Although ADT with AA results in a gain in QALYs and crude OS compared to DC, AA therapy is not a cost-effective treatment strategy to apply uniformly to all patients. The availability of AA as a generic medication may help to close this gap. The ultimate choice should be based on patient and tumor factors.

Population-Based Study of Docetaxel or Abiraterone Effectiveness and Predictive Markers of Progression Free Survival in Metastatic Castration-Sensitive Prostate Cancer

“…While an opportunistic comparison of men recruited simultaneously for the ADT + ABI and ADT + DOC arms of the STAMPEDE trial (arms G and C, respectively) suggests a similar OS benefit, ARSIs appear to be the preferred treatment option in meta-analyses compared to DOC when applying surface under the cumulative ranking analysis (17)(18)(19). On the other hand, it is worth noting that DOC is more costeffective than ABI (20)(21)(22). Secondly, there are no validated predictive (bio)markers of response to ARSIs or DOC (23).…”

Abiraterone Acetate for Metastatic Castration-Sensitive Prostate Cancer

“…The economic evaluation 21 was a cost-effectiveness analysis published in 2020. It had a lifetime horizon and was from the health care payer perspective.…”

“…The base case of the economic evaluation 21 was a 65-year-old patient with newly diagnosed mCSPC and a candidate for either intervention (docetaxel or abiraterone acetate). The modelled patients were a cohort with ECOG status of 0 to 2 and radiographic evidence of metastasis.…”

“…The research question, rationale for the selection of the intervention, the outcomes of interest, and the economic importance were clearly stated in the economic evaluation. 21 Details of the study design, including the viewpoint of the analysis, the time horizon, the source of effectiveness estimates, the analytic method, and model details, were provided. Incremental and sensitivity analyses were conducted.…”

“…The average cost of treatment for mCSPC with initial abiraterone acetate was estimated to be $188,815.07 compared with $64,501.75 for initial docetaxel. Hird et al (2020) 21 estimated an incremental cost-effectiveness ratio (ICER) of $276,251.82 per QALY gained, which is outside traditionally accepted willingness-to-pay thresholds. With the recent approval of a generic abiraterone product, the authors produced a modified ICER using pharmacy costing data for the generic product.…”