Abstract
INTRODUCTION: Evidence is lacking on second-line and later treatments for patients with RAS wild-type colorectal cancer (CRC) who receive first-line anti-epidermal growth factor receptor (EGFR) antibody therapy. In this study, we explored the real-world treatment sequences, treatment duration, and factors associated with treatment sequences and durations in Japanese patients with CRC. METHODS: This retrospective observational cohort study used a Japanese administrative claims database (April 2008 to July 2021). Patients with confirmed CRC (presumed RAS wild-type) who received first-line FOLFOX (leucovorin + 5-fluorouracil + oxaliplatin) plus anti-EGFR therapy in or after May 2016, followed by second-line irinotecan-based chemotherapy plus an antiangiogenic drug, were included. Treatment durations were estimated by the Kaplan-Meier method. Cox regression analysis was used to identify factors associated with treatment duration. RESULTS: Analysis populations consisted of 1163 (first-line and second-line) and 645 (third-line) patients. At the start of first-line therapy, 67.8% of patients were male, the mean age was 64 years, 83.4% had left-sided CRC, and 84.3% were prescribed FOLFOX plus panitumumab. For second-line therapy, patients were prescribed bevacizumab (63%), ramucirumab (27%), or aflibercept beta (10%). Median (95% CI) treatment durations from the start of second-line therapy to the end of antitumor drug therapies were similar for bevacizumab (12.5 months [11.2, 14.0]), ramucirumab (12.5 months [11.2, 14.8]), and aflibercept beta (14.0 months [10.4, 17.0]). Treatment duration from second-line was positively associated with first-line treatment duration of 6 months or more, CRC surgery before starting first-line therapy, and liver surgery during first-line therapy, and was negatively associated with use of nonsteroidal anti-inflammatory drugs before second-line therapy. CONCLUSION: Real-world data revealed that all three antiangiogenic drugs were used as second-line therapy after first-line anti-EGFR antibodies and showed similar treatment durations.