A meta-analysis of efficacy and safety data from head-to-head first-line trials of epidermal growth factor receptor inhibitors versus bevacizumab in adult patients with RAS wild-type metastatic colorectal cancer by sidedness

The first-line treatment choice of EGFRIs plus doublet chemotherapy vs. bevacizumab plus doublet chemotherapy remains a topic of interest for patients with left-sided RAS WT mCRC. We conducted a systematic literature review and meta-analysis of clinical trial data published between 2015 and 2024. We evaluated the relative efficacy and safety of first-line EGFRIs plus doublet chemotherapy (FOLFIRI or FOLFOX) vs. bevacizumab plus doublet chemotherapy for patients with RAS WT left-sided mCRC, as well as in all- and right-sided tumors. We identified eight trials with 2624 patients. Five trials reported outcomes by tumor sidedness. In the left-sided population, overall survival (OS) (Hazard Ratio (HR) = 0.80, 95% Confidence Interval (CI): 0.71-0.90) and objective response rate (ORR) (Odds ratio [OR]=1.61, 95% CI: 1.30-1.99) favored EGFRI plus chemotherapy, while no statistically significant differences were observed for progression-free survival (PFS) (HR=0.93, 95% CI: 0.84-1.04) or resection rate (RR). Similar results were found in the all-sided population. In the right-sided population, PFS favored bevacizumab plus chemotherapy (HR=1.45, 95% CI: 1.19-1.78), while no statistically significant differences were observed for OS (HR=1.17, 95% CI: 0.95-1.44), ORR (OR=0.99, 95% CI: 0.69-1.41), and RR. Early tumor shrinkage in the all-sided population favored EGFRI plus chemotherapy (OR=1.72; 95% CI: 1.36-2.17); limited data precluded evaluation by sidedness. Safety was available in 6 trials for all-sided tumors and 1 trial for left-sided tumors, each demonstrating typical class-specific adverse events. This most comprehensive meta-analysis indicates a benefit for first-line EGFRI plus chemotherapy over bevacizumab plus chemotherapy in patients with left-sided RAS WT mCRC.