Comparison of safety and efficacy of fluorouracil + oxaliplatin + irinotecan (FOLFOXIRI) and modified FOLFOXIRI with bevacizumab for metastatic colorectal cancer: data from clinical practice.

Purpose The efficacy of fluorouracil + oxaliplatin + irinotecan with bevacizumab (FOLFOXIRI + BV) has been verified for metastatic colorectal cancer (mCRC). In clinical practice, the original (O-FOLFOXIRI + BV) and modified dose settings (M-FOLFOXIRI + BV) are adopted for Asian patients. We aimed to compare the real-world efficacy and safety of these two regimens. Methods This retrospective cohort study reviewed clinical data of all consecutive mCRC patients treated with FOLFOXIRI + BV at a cancer centre in Japan. One hundred patients were divided into two groups: one that received O-FOLFOXIRI + BV (group O, n = 30) and another that received M-FOLFOXIRI + BV (group M, n = 70). Progression-free survival (PFS) was set as the primary endpoint, with overall survival (OS), overall response rate (ORR), and safety as secondary endpoints. Results PFS was superior in group M (median PFS; 8.7 vs. 11.5 months, P = 0.098). The use of O-FOLFOXIRI + BV emerged as an independent risk factor of poor PFS (hazard ratio = 2.155, P = 0.012). Both ORR (43.3 vs. 65.7%, P = 0.047) and OS (median OS; 17.9 vs. 27.0 months, P = 0.127) were more favourable in group M. Grade ≥ 3 adverse events were more frequently observed in group O (90 vs. 74.3%, P = 0.108), whereas dose intensity was higher in group M because a shorter duration was required for cytotoxic drug administration (2.9 vs. 2.6 weeks/course, P = 0.051) in the induction term. Conclusion We found that M-FOLFOXIRI + BV had more favourable efficacy and safety than O-FOLFOXIRI + BV, which may be a better fit for Asian patients and can be potentially used as an alternative for upfront chemotherapy for mCRC.