Comparison between the three oxaliplatin-based regimens with bevacizumab in patients with metastatic colorectal cancer.
687 Background: XELOX (capecitabine/L-OHP) therapy that includes orally administered fluoropyrimidine instead of infusional fluorouracil (5-FU) was approved for metastatic colorectal cancer (mCRC) in Sep 2009 in Japan. A pivotal trial (NO16966 study) demonstrated the non-inferiority of XELOX to FOLFOX (5-FU/L-OHP/LV) and the superiority of those L-OHP-based regimens plus bevacizumab (BV) to those without in the first-line treatment of mCRC. We evaluated the safety and efficacy of XELO+BV compared with FOLFOX4 or mFOLFOX6 plus BV in the first-line treatment for mCRC patients at a single institute. Methods: Between Jun 2007 and Nov 2008, 85 patients received FOLFOX4+BV (FF4 arm), between Dec 2008 and Sep 2009, 40 patients received mFOLFOX6+BV (FF6 arm), and between Oct 2009 and Sep 2010, 60 patients received XELOX+BV (XELOX arm). The best overall responses were evaluated using RECIST 1.0 during chemotherapeutic treatment, and adverse events were graded according to CTCAE ver.3.0. Progression-free survival (PFS) was estimated by Kaplan-Meier methods. Results: Characteristics of patients of FF4 arm, FF6 arm, and XELOX arm were below: median age, 60 yr vs. 62 yr vs. 60.5 yr; gender (male), 48.2 % vs. 62.5 % vs. 58.3%. The overall response rates (CR+PR) were 61.1 %, 72.5 %, and 75 % (95% CI; 50.6-71.8%, 58.0-87.0%, and 63.7-86.3%). Median PFS were 17.0 months, 15.5 months, and 14.4 months, respectively (cut-off: Aug 31, 2011). There were no statistical significances not only between FF4 arm and FF6 arm (log-rank; p=0.641), but also between XELOX arm and FF4+FF6 (FOLFOX) arm (log-rank; p=0.138). FOLFOX arm was associated with higher incidence of grade 3/4 neutropenia than XELOX arm. Grade3 diarrhea and hand-foot syndrome (HFS) were more frequent in XELOX arm. Conclusions: This study suggests that XELOX arm was equal to FOLFOX arm, regardless of regimen, in tumor response and PFS. Further follow-up is necessary to confirm the benefit on survival.