655 - The Efficacy and Safety of Bevacizumab Beyond First Progression in Japanese Patients Treated with First-Line Mfolfox6 Followed By Second-Line Folfiri in Advanced Colorectal Cancer: a Multicenter, Single-Arm Phase Ii Trial (CCOG-0801); Final Report

Abstract

ABSTRACT Purpose The aim of this study was to evaluate the efficacy and safety of the planned continuation of bevacizumab beyond first progression in Japanese patients with metastatic colorectal cancer (mCRC). Methods Previously untreated patients with assessable disease were treated with mFOLFOX6 plus bevacizumab until tumor progression, followed by FOLFIRI plus bevacizumab. The primary endpoint of the study was the second progression-free survival (2nd PFS), defined as duration from enrollment until progression after second-line therapy. Secondary endpoints of the study were overall survival (OS), survival beyond first progression (SBP), progression free survival (PFS), response rate (RR), disease control rate (DCR) and safety. Results In the first-line setting, 47 patients treated with mFOLFOX6 plus bevacizumab achieved RR of 61.7%, DCR of 89.4% and median PFS of 13.1 months (95% CI, 8.7 to 17.5 months). Thirty one patients went on to receive second-line therapy with FOLFIRI plus bevacizumab and achieved RR of 27.6%, DCR of 62.1% and median PFS of 7.5 months (95% CI, 5.5 to 9.5 months). Median 2nd PFS, the primary endpoint, was 18.0 months (95% CI, 13.7 to 22.3 months). The median OS was 30.8 months (95% CI, 27.7 to 33.9 months), and median SBP was 19.6 months (95% CI, 14.3 to 24.9 months), after median follow up period of 35.9 months. No critical events associated with bevacizumab were observed during the second-line therapy. Concluson The planned continuation of bevacizumab during second-line treatment is feasible for Japanese mCRC patients. A prospective randomized control study to confirm efficacy is warranted. Disclosure All authors have declared no conflicts of interest.