Modified FOLFOX6 plus bevacizumab followed by FOLFIRI plus bevacizumab beyond first progression in advanced colorectal cancer: CCOG-0801 study.

Abstract

641 Background: Bevacizumab provides survival benefit as the first-line and second-line therapies in metastatic colorectal cancer (mCRC). A large observational study suggested use of bevacizumab beyond first progression (BBP) improved survival. This prompted us to conduct a multicenter phase II study of mFOLFOX6 plus bevacizumab followed by FOLFIRI plus bevacizimab in mCRC to further explore the strategy of BBP in Japanese patients. 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 the second-line therapy. If the patient failed to receive the second-line treatment due to medical reasons or refusal, the PFS during the first-line therapy was used for analysis. Secondary endpoints were PFS, overall survival (OS), response rate (RR), disease control rate (DCR) and safety. Results: In the first-line therapy, 47 patients treated with mFOLFOX6 plus bevacizumab achieved RR of 61.7%, DCR of 89.4% and median PFS of 11.7 months. Thirty patients went on to receive the second-line therapy with FOLFIRI plus bevacizumab and achieved RR of 27.6%, DCR of 62.1%, and median PFS of 6.0 months. Median 2nd PFS was 16.2 months. Median survival time did not reach the median follow-up time of 27.4 months. Severe adverse events associated with bevacizumab during the first-line therapy were a venous thromboembolic event in one case (2%), a grade 2 bleeding event in one case (2%) and GI perforation in one case (2%). However, no critical events associated with bevacizumab were reported during the second-line therapy. Conclusions: The planned continuation of bevacizumab during the second line treatment is feasible in Japanese mCRC patients. A prospective randomized control study to confirm the efficacy has to be conducted in the future.