Treatment patterns, adverse events, and direct and indirect economic burden in a privately insured population of patients with HR+/HER2– metastatic breast cancer in the United States

Abstract

ABSTRACT Background Real-world evidence specific to HR+/HER2– metastatic breast cancer (MBC) prior to introduction of CDK4/6 inhibitors is limited. In an effort to provide context for the introduction of new treatments, we assessed treatment patterns, adverse events, productivity loss, and direct/indirect economic burden in a privately insured population of patients with HR+/HER2– MBC. Research design and methods Using a retrospective cohort design, patients aged 18–64 years, selected from MarketScan databases (2007–2014), were analyzed using descriptive and multivariable methods. Results Among 5,563 eligible patients, endocrine therapy was the most common first-line (1L) therapy; its utilization trended downward from 63% (1L) to 23% (4L), with a simultaneous increase in chemotherapy use, 25% (1L) to 50% (4L). Two hundred and seventy-eight unique treatment regimens were used in the 1L setting. The average per patient monthly all-cause costs were $14,424. The 12-month indirect costs for short-term disability were substantially higher in MBC patients ($10,397) than in matched noncancer patients ($394). Conclusion The increasing use of chemotherapy as patients progressed to second and later lines and the substantial direct/indirect economic burden underscore an unmet need. The high number of 1L regimens highlights significant heterogeneity and a lack of consensus related to the management of HR+/HER2– MBC in routine practice.