Cost-effectiveness analysis of ribociclib versus palbociclib as a first line theraphy in HR+/HER2- advanced breast cancer: evidence from the Chilean public health system

BACKGROUND: Ribociclib plus letrozole significantly improves survival in HR+/HER2- advanced-stage or metastatic postmenopausal breast cancer (BC) patients. AIM: To evaluate the cost-effectiveness of first-line ribociclib plus letrozole versus palbociclib plus letrozole for HR+/HER2- advanced BC in the Chilean public healthcare system. METHODS: A partitioned survival model with a 1-month cycle and 40-year horizon was utilized. Data were drawn from PALOMA-2 and MONALEESA-2 trials. Utility values were sourced from trial data and literature. Costs included drug acquisition, disease monitoring, subsequent therapies, and adverse events. Deterministic sensitivity analysis (DSA), probabilistic sensitivity analysis (PSA), and scenario analyses with varying clinical efficacy estimates were conducted to address uncertainty. RESULTS: Ribociclib plus letrozole consistently dominated palbociclib plus letrozole, showing better effectiveness at lower costs. In the base case, ribociclib saved $5,724 with an additional 0.506 QALYs. Scenario 1 showed savings of $4,942 and 0.398 QALYs, while Scenario 2 indicated $9,830 saved with 1.282 QALYs gained. PSA confirmed a 100% probability of ribociclib being cost-effective at a willingness-to-pay threshold of 1 GDP per capita. CONCLUSION: Ribociclib plus letrozole is cost-saving and cost-effective compared to palbociclib plus letrozole for the first-line treatment of postmenopausal women with HR+/HER2- advanced BC in Chile.