Cardiovascular Adverse Events and Associated Costs of CDK4/6 Inhibitors in Patients With Breast Cancer.

Abstract

Background: Cardiotoxicity and cardiovascular (CV) adverse events associated with CDK4/6 inhibitors have raised concerns in the treatment of advanced breast cancer, impacting patient safety and increasing health care costs. This study compares the incidence of hypertension and major adverse cardiovascular events (MACE) in patients with breast cancer receiving CDK4/6 inhibitors and estimates the incremental health care costs associated with these conditions.

Methods: This retrospective cohort study utilized the 2017-2021 Merative MarketScan Research Database. Women with breast cancer who initiated CDK4/6 inhibitors (palbociclib, ribociclib, or abemaciclib) were included in 2 cohorts. The hypertension cohort comprised patients with no prior hypertension in the 12 months before initiating CDK4/6 inhibitors, whereas the MACE cohort included those with no prior hypertension or MACE during the same period. The primary outcomes were the incidence of hypertension and MACE, with secondary outcomes being the incremental health care costs associated with these conditions.

Results: A total of 2,780 patients were included in the hypertension cohort and 2,043 in the MACE cohort. Compared with ribociclib, neither abemaciclib (hazard ratio [HR], 0.791; 95% CI, 0.507-1.232) nor palbociclib (HR, 0.723; 95% CI, 0.493-1.060) showed a statistically significant difference in hypertension risk. For MACE, palbociclib was associated with a statistically significant lower risk (HR, 0.636; 95% CI, 0.454-0.892), whereas abemaciclib was not (HR, 0.795; 95% CI, 0.540-1.169). Patients who developed hypertension and MACE incurred higher health care costs, averaging $2,964 and $4,010 per patient per month, respectively.

Conclusions: Palbociclib was associated with a significantly lower risk of MACE compared with ribociclib in patients with breast cancer. Patients who developed hypertension or MACE incurred substantially higher health care costs. These findings underscore the importance of minimizing CV adverse events in patients with breast cancer treated with CDK4/6 inhibitors.