Treatment patterns and factors associated with the use of everolimus among post-menopausal women with HR+/HER2- metastatic breast cancer: a retrospective US claims study.

Objective: To assess the real-world use of everolimus in the treatment of hormone-receptor-positive/human-epidermal-growth-factor-receptor-2-negative (HR+/HER2-) metastatic-breast-cancer (mBC). Methods: Postmenopausal women with HR+/HER2-mBC who initiated a new therapy for mBC between 20 July 2012 and 31 March 2014 after a non-steroidal-aromatase-inhibitor were identified from two commercial claims databases. Multivariate logistic regressions were used to identify factors associated with everolimus use versus endocrine-monotherapy or chemotherapy. Dosing patterns and adherence to everolimus were summarized. Results: A total of 940 everolimus, 6,134 endocrine-monotherapy, and 3,410 chemotherapy regimens were included across patients' first four lines of therapy. Patients with bone and visceral metastases were more likely to use everolimus versus endocrine-monotherapy. Patients with more comorbidities, visceral or central-nervous-system metastases, and prior chemotherapy use for mBC were less likely to use everolimus versus chemotherapy. Approximately 80% of patients initiated everolimus at labelrecommended-dose of 10 mg daily; 60-70% of patients had a medical possession ratio >0.8 to everolimus, and consistently high adherence was observed across lines of therapy. Conclusions: For HR+/HER2-mBC, patients treated with everolimus had more severe disease than patients treated with endocrine-monotherapy but less severe disease than patients treated with chemotherapy. Most patients used everolimus according to label-recommended dose and adherence was high across lines of therapy.