Bevacizumab + FOLFOXIRI (VEGF blockade + triplet chemo) misses PFS bar vs bevacizumab doublets in right-sided mCRC

Bevacizumab (anti-VEGF antibody) plus FOLFOXIRI (5-FU/leucovorin, oxaliplatin, irinotecan) was tested against bevacizumab plus investigator’s choice FOLFOX/FOLFIRI as first-line therapy in the randomized, open-label Phase II KCSG CO19-18 trial in unresectable metastatic right-sided colon cancer (cecum to splenic flexure; n=61; NCT03641976). The primary endpoint was negative: 6-month PFS rate 100% vs 87.1% (HR 1.05, 95% CI 0.53–1.71; p=0.87), with similar median PFS (14.7 vs 16.6 months) despite a numerically higher ORR with triplet (82.8% vs 64.6%; p=0.245). Grade ≥3 neutropenia was more frequent with FOLFOXIRI, while neuropathy/GI toxicity/hypertension were comparable or slightly higher with the doublet arm; efficacy here looks directionally in-line with historical bevacizumab+doublet first-line benchmarks (mPFS often ~10–11 months), and does not clearly recapitulate the broader all-comers TRIBE signal where FOLFOXIRI+bevacizumab improved OS vs FOLFIRI+bevacizumab (29.8 vs 25.8 months).