Fulvestrant versus everolimus plus exemestane for patients with metastatic breast cancer resistant to aromatase inhibitors: Clinical experience from real world.

Abstract

e12522 Background: To present treatment patterns and the outcome of pure endocrine therapy fulvestrant (FUL) versus Exemestane (EXE)and target therapy everolimus (EVE) combination among hormone receptor-positive (HR+)/human epidermal growth factor 2 (HER2)-negative metastatic breast cancer (MBC) after progression on aromatase inhibitor (AI) in the real-life setting. Methods: Patients with HR+/HER2- MBC after AI who received FUL or EVE-EXE between June 2013 and June 2016 were identified from electronic database. Outcome measures included progression free survival (PFS), overall survival (OS) and safety profile. Propensity score matching (PSM) was applied to minimize potential confounders. Results: Among the 168 patients included, 124 patients received FUL and 44 patients treated with EVE-EXE. Patients that received EVE-EXE were significantly younger, more likely to have visceral, liver, multiple sites of metastases and had received more prior chemotherapy than FUL group. There was no significant difference in PFS after adjusted for propensity score between two groups (HR,1.173; 95%CI, 0.797-1.727; p = 0.419). In subgroup analysis, treatment effects were consistent across predefined subgroups except for the subgroup of multiple metastatic sites which the median PFS was significantly longer in EVE-EXE group than in FUL group (6.1vs3.2months, respectively; HR = 0.508;95%CI,0.299-0.862; p = 0.012). The toxicity of FUL regimen was more manageable. More patients discontinued the treatment due to intolerable toxicity in EVE-EXE group than FUL group. Conclusions: We observed substantial changes in treatment patterns in patients received EVE-EXE and FUL. Treatment outcomes were comparable between two schedules after adjusted for confounding factors, while FUL has been better tolerated. Clinical trial information: NCT03695341.