Real-world adherence and treatment discontinuation with trifluridine/tipiracil (FTD-TPI) compared with regorafenib (REG) for the treatment of metastatic colorectal cancer (mCRC).

Abstract

e15000 Background: FTD-TPI and REG both prolong survival in refractory mCRC. Both agents have the benefit of oral administration but with distinct side effect profiles. This study aims to compare real-world treatment patterns following initiation of FTD-TPI or REG for mCRC in a large, nationally representative US claims database. Methods: Retrospective data from 10/2014 to 7/2016 from the US Symphony Health Solutions’ Integrated Dataverse (IDV®) database were analyzed for patients (pts) receiving FTD-TPI or REG. The index date was the date of first FTD-TPI or REG prescription. Pts were included if: 1) age ≥18 years old, 2) ≥1 CRC diagnosis, 3) no diagnosis of gastric cancer or gastrointestinal stromal tumor, and 4) continuous clinical activity for ≥3 months before and after index date. The observation period spanned from index date to end of data, end of continuous clinical activity, or switch to another mCRC treatment. Medication adherence was assessed by medication possession ratio (MPR), with MPR ≥80% as the defined threshold for adherence, as well as by proportion of days covered (PDC) at 3 months. Between treatment groups, binary endpoints were compared using Chi-square tests and mean and median time to treatment discontinuation (TTD) were compared using t-test and Wilcoxon test, respectively. Results: The study population consisted of 1,630 FTD-TPI pts and 1,425 REG pts. Mean ± standard deviation (SD) age of FTD-TPI pts was 61 ± 11 and REG pts was 63 ± 11 (p < 0.01). Mean ± SD length of observation period in days was 161 ± 59 for FTD-TPI pts and REG pts was 212 ± 113 (p < 0.01). 84% of FTD-TPI and 74% of REG pts reached MPR ≥80% (p < 0.01). FTD-TPI pts had higher mean PDC (71% vs 59%, p < 0.01) than REG pts. Mean and median TTD were significantly longer for FTD-TPI than REG pts (mean: 101 vs. 88 days, p < 0.01; median: 97 vs. 69 days, p < 0.01). Conclusions: In this analysis of real-world medication utilization for mCRC pts, those pts started on FTD-TPI had significantly higher medication adherence and longer TTD than those on REG.