PCN239 Cost-Utility of the CDK 4/6 Inhibitors for Postmenopausal Women with HR-Positive, HER2-Negative Advanced Breast Cancer in Brazil: A Dime Project

Several trials have demonstrated the benefit of CDK 4/6 inhibitors for postmenopausal women with HR-positive, HER2-negative advanced breast cancer. This research aims to compare the cost-utility of the CDK 4/6 inhibitors in patients who had no prior systemic therapy in the advanced setting. A systematic review was carried out to extract the efficacy and safety data from the pivotal trials selected. An indirect comparison was performed to identify the Hazard Ratio for CDK inhibitors versus letrozole. ROB2 and GRADE analyses evaluated the risk of bias and the confidence in the evidence. A Markov model was constructed to estimate the incremental cost in American dollars per quality-adjusted life years (QALY) of treatments from a Brazilian public healthcare system perspective over a lifetime horizon and with a 5% annual discount rate. Deterministic and probabilistic sensitivity analyses evaluated the robustness of the results. There is high-quality evidence that the CDK 4/6 inhibitors consistently increase close to 10 months in progression-free survival, with a tolerable safety profile. There are no head-to-head studies between the CDK 4/6 inhibitors, and the indirect comparison did not identify clinical superiority in any of them. The most cost-effective technology was ribociclib ($64,425/QALY), followed by Abemaciclib ($81,530/QALY) and Palbociclib ($85,321/QALY). The univariate analysis showed that the incremental cost-effectiveness ratio(ICER) was sensitive to the parameters of utility gains and the cost of the intervention. The one thousand-probabilist simulation showed that all ICER values were above a threshold of $35,000/QALY. In Brazil, even though there is no established willingness-to-pay threshold, the estimated ICER for the CDK 4/6 inhibitors will represent an obstacle to their incorporation into the Brazilian healthcare system.