Cost-effectiveness of the addition of CDK4/6 inhibitors to standard endocrine therapy in first-line treatment of women with advanced HR+/HER2− breast cancer in Mexico

Purpose To estimate the cost-effectiveness of adding a CDK4/6 inhibitor to standard endocrine therapy in the first-line setting for advanced HR+/HER2− breast cancer in postmenopausal and premenopausal women, from the perspective of the Mexican public healthcare system. Methods We used a partitioned survival model to simulate relevant health outcomes in a synthetic cohort of patients with breast cancer derived from the PALOMA-2, MONALEESA-2, MONARCH-3 trials for postmenopausal patients, and from the MONALEESA-7 study for premenopausal patients. Effectiveness was measured in life years gained. Cost-effectiveness is reported through incremental cost-effectiveness ratios (ICER). Results In postmenopausal patients, palbociclib led to an increase of 1.51 life years, ribociclib of 1.58 years, and abemaciclib of 1.75 years, compared to letrozole alone. The ICER was 36,648 USD, 32,422 USD, and 26,888 USD, respectively. In premenopausal patients, ribociclib led to an increase of 1.82 life years when added to goserelin and endocrine therapy, with an ICER of 44,579 USD. In the cost minimization analysis, for postmenopausal patients, ribociclib was the treatment with the highest costs due to follow-up requirements. Conclusion Palbociclib, ribociclib, and abemaciclib demonstrated a significant increase in effectiveness in postmenopausal patients, and ribociclib in premenopausal patients, when added to standard endocrine therapy for patients with advanced HR+/HER2− breast cancer. At the national stablished willingness to pay, only the addition of abemaciclib to standard endocrine therapy in postmenopausal women would be considered cost-effective. However, differences on results between therapies for postmenopausal patients were not statistically significant.