Is oxaliplatin a good partner for EGFR monoclonal antibodies as first-line treatment in KRAS wild-type metastatic colorectal cancer? A meta-analysis.

e14645 Background: This meta-analysis was performed to determine whether the addition of monoclonal antibodies (mAbs) of epidermal growth factor receptor (EGFR) to oxaliplatin-based chemotherapy treatment improves efficacy in KRAS wild-type metastatic colorectal cancer (mCRC), and whether infusional 5-fluorouracil (5-FU) and oxaliplatin is a preferred combination for EGFR mAbs. Methods: Oxaliplatin (including treatment), EGFR mAbs, first-line treatment, KRAS wild-type, and mCRC were used as key words. The PRIME, OPUS, COIN, and NORDIC VII trials were identified by two independent authors. Time-to-event outcomes of overall survival (OS) and progression-free survival (PFS) were analyzed using HRs (Hazard Ratios) with fixed effect, and response rate (RR) using odd ratios (OR) with fixed effect. Results: A total of 1,767 patients who were KRAS wild-type were included in this meta-analysis, with 866 patients in the mAbs and chemotherapy combination group and 901 patients in the chemotherapy alone group. The addition of mAbs to oxaliplatin-based chemotherapy in patients with KRAS wild-type mCRC as first-line treatment resulted in significant improvements in PFS (HR=0.88; 95% confidence interval (CI), 0.79 to 0.99; P=0.03) and response rate (RR) (OR = 1.38; 95% CI, 1.14 to 1.66; P = 0.009) compared with chemotherapy alone, but the difference in OS was not significant (HR=0.96; 95% CI, 0.85 to 1.08; P=0.48). However, the differences neither in OS nor in PFS were not significant when mAbs were added to bolus 5-FU or capecitabine-based regimens compared with chemotherapy alone, whereas PFS improved with an infusional 5-FU and oxaliplatin combination (P=0.06; PFS, HR=0.76; 95% CI, 0.65 to 0.86; P=0.0002), and even OS was marginally significant. Conclusions: Oxaliplatin and infusional 5-FU regimen tends to be a better backbone combination with EGFR mAbs as first-line treatment in KRAS wild-type mCRC.