Effectiveness of Everolimus Versus Endocrine Monotherapy or Chemotherapy Among HR+/HER2- mBC Patients With Multiple Metastatic Sites

Abstract

Purpose: This review compared the real-world effectiveness of everolimus-based therapy versus endocrine monotherapy or chemotherapy in postmenopausal hormone receptor positive (HR+)/ human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC) patients with multiple metastatic sites.

Methods: This retrospective chart review examined a nationwide sample of postmenopausal HR+/HER2- mBC women with ≥2 non-lymph-node metastatic sites. Patients must have initiated everolimus-based therapy (monotherapy or combination therapy including everolimus), endocrine monotherapy (any endocrine agent), or chemotherapy (monotherapy or combination with another chemotherapeutic or endocrine agent) for mBC between July 1, 2012 and August 15, 2013 after nonsteroidal aromatase inhibitor failure. Progression-free survival and time on treatment were compared using Kaplan-Meier analysis and Cox proportional hazard models, adjusting for line of therapy and baseline characteristics.

Findings: One hundred patients received everolimus-based therapy, 79 received endocrine monotherapy, and 86 received chemotherapy. Everolimus-based therapy was associated with significantly longer progression-free survival and time on treatment than endocrine monotherapy and chemotherapy.

Implications: Among HR+/HER2- mBC patients with multiple metastatic sites, everolimus-based therapy was associated with better real-world effectiveness than endocrine monotherapy or chemotherapy.

Keywords: HR+/HER2− metastatic breast cancer; chemotherapy; clinical outcome; endocrine therapy; everolimus.