Analysis of real world patient compliance to everolimus-based therapy among post-menopausal women with hormone receptor positive and human epidermal growth factor receptor 2 negative (HR+/HER2-) metastatic breast cancer (mBC).

Abstract

e12546 Background: Patient compliance, typically not captured in clinical trials, may have profound effects on treatment effectiveness. As there has been limited real-world data, the objective of this analysis was to examine compliance among HR+/HER2- mBC patients treated with everolimus as a second or later line of therapy in the US across age groups. Methods: In this retrospective cohort study, the MarketScan Commercial and Medicare Supplemental claims databases were used to select post-menopausal HR+/HER2- mBC women who initiated an everolimus-based line of therapy during 1/1/2013- 7/31/2016 study period. The first secondary malignancy diagnosis was the index date. Patients had 6 months of continuous enrollment in their health plans pre- and post- index, and were followed until the earliest of disenrollment, inpatient death, or end of study. Compliance was measured using medication possession ratio (MPR) during a second (2L), third (3L) and fourth (4L) line of therapy. MPR was defined as total days of supply of everolimus during the line of therapy divided by total duration of the line. Results: Of 645 eligible mBC patients treated with everolimus during follow-up, there were 239, 142, and 80 with a 2L, 3L, and 4L of therapy respectively. Mean age overall was 61.1 + 11.7 years and average duration of follow-up was 718.3 + 304.1 days. Across all patients the median MPR ranged during each line from 0.90-0.92 and the majority (93.8%-97.5%) were highly compliant to therapy (defined as MPR>80%). These results were consistent for patients aged <65 and 65+ years across a 2L, 3L, and 4L of therapy (Table). Conclusions: This study shows high compliance for everolimus-based therapy within a 2L, 3L, and 4L of therapy and this is consistent across ages. This real world data suggests good drug manageability and may provide valuable information for clinicians in selecting treatment for mBC. [Table: see text]