Cost-Utility of the CDK 4/6 Inhibitors for Postmenopausal Women With Luminal Advanced Breast Cancer in Brazil

Objectives: Several trials have demonstrated the benefit of the CDK 4/6 inhibitors for postmenopausal women with luminal advanced breast cancer. This research aims to compare the cost-utility of the CDK 4/6 inhibitors in patients with no history of resistance to endocrine therapy.

Methods: A Markov model was constructed to estimate the incremental cost per quality-adjusted life-years (QALYs) of treatments from the Brazilian public health system perspective over a lifetime horizon (30 years) with 5% annual discount rate for both benefits and costs. Efficacy parameters were extracted from the pivotal studies. Costs were based on open data from the Brazilian Ministry of Health. The utilities were calculated according to the overall population preferences from a British study. Deterministic and probabilistic sensitivity analyses evaluated the robustness of the results.

Results: The most cost-effective drug was ribociclib (US$50 748/QALY), followed by abemaciclib (US$64 052/QALY) and palbociclib (US$65 289/QALY). The univariate analysis showed that the incremental cost-utility ratio (ICUR) was mainly sensitive to the overall survival hazard ratio. The one thousand-probabilistic simulation showed that all ICUR values were above classical thresholds such as 1 to 3 gross domestic product (GDP) per capita per QALY.

Conclusions: Even though there is no established willingness to pay threshold in Brazil, the estimated ICUR for CDK 4/6 inhibitors is >6 times the Brazilian GDP per capita (GDP per capita = US$5694.73), which might be a barrier to their inclusion in the Brazilian public health system.