Axitinib or bevacizumab plus FOLFIRI or modified FOLFOX-6 after failure of first-line therapy for metastatic colorectal cancer: a randomized phase II study.

OBJECTIVE: Axitinib, a potent and selective second-generation inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, shows activity in multiple tumor types, including those refractory to previous antiangiogenic therapy. This randomized, multicenter, parallel-group, open-label phase II trial compared axitinib with bevacizumab each in combination with 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX) or 5-fluorouracil/leucovorin/irinotecan (FOLFIRI) for second-line treatment of metastatic colorectal cancer.

METHODS: Patients were randomized 1:1 to axitinib 5 mg twice daily or bevacizumab 5 mg/kg every 2 weeks plus modified FOLFOX-6 (if previously treated with irinotecan) or FOLFIRI (if previously treated with oxaliplatin) and were stratified by performance status and prior bevacizumab therapy. Primary endpoint was progression-free survival.

RESULTS: In 171 patients, progression-free survival was 7.6 months with axitinib/FOLFOX vs. 6.4 months with bevacizumab/FOLFOX (hazard ratio [HR], 1.04; 95% confidence interval [CI], 0.55-1.96; 1-sided P = .55) and 5.7 months with axitinib/FOLFIRI vs. 6.9 months with bevacizumab/FOLFIRI (HR, 1.27; 95% CI, 0.77-2.11; 1-sided P = .83). Overall survival was 17.1 vs. 14.1 months with axitinib/FOLFOX and bevacizumab/FOLFOX (HR, 0.69; 95% CI, 0.37-1.27; 1-sided P = .12) and 12.9 vs. 15.7 months with axitinib/FOLFIRI and bevacizumab/FOLFIRI (HR, 1.36; 95% CI, 0.82-2.24; 1-sided P = .88). More grade ≥ 3 adverse events (eg, diarrhea, fatigue, decreased appetite) and treatment discontinuations due to adverse events occurred with axitinib.

CONCLUSIONS: Compared with bevacizumab, axitinib did not improve outcomes when added to second-line chemotherapy for metastatic colorectal cancer. With current dosing regimens, axitinib plus FOLFOX or FOLFIRI seems to be less well tolerated than bevacizumab-based regimens.