Background: In this multicenter, open-label, randomized phase 2 trial, the authors evaluated the vascular endothelial growth factor receptor inhibitor axitinib, bevacizumab, or both in combination with chemotherapy as first-line treatment of metastatic colorectal cancer (mCRC).
Methods: Patients with previously untreated mCRC were randomized 1:1:1 to receive continuous axitinib 5 mg twice daily, bevacizumab 5 mg/kg every 2 weeks, or axitinib 5 mg twice daily plus bevacizumab 2 mg/kg every 2 weeks, each in combination with modified 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX-6). The primary endpoint was the objective response rate (ORR).
Results: In all, 126 patients were enrolled from August 2007 to September 2008. The ORR was numerically inferior in the axitinib arm (n = 42) versus the bevacizumab arm (n = 43; 28.6% vs 48.8%; 1-sided P = .97). Progression-free survival (PFS) (11.0 months vs 15.9 months; 1-sided P = .57) and overall survival (OS) (18.1 months vs 21.6 months; 1-sided P = .69) also were numerically inferior in the axitinib arm. Similarly, efficacy endpoints for the axitinib/bevacizumab arm (n = 41) were numerically inferior (ORR, 39%; PFS, 12.5 months; OS, 19.7 months). The patients who received axitinib had fewer treatment cycles compared with other arms. Common all-grade adverse events across all 3 treatment arms were fatigue, diarrhea, and nausea (all ≥49%). Hypertension and headache were more frequent in the patients who received axitinib. Patients in the bevacizumab arm had the longest treatment exposures and the highest rates of peripheral neuropathy.
Conclusions: Neither the addition of continuous axitinib nor the axitinib/bevacizumab combination to FOLFOX-6 improved ORR, PFS, or OS compared with bevacizumab as first-line treatment of mCRC.
Trial registration: ClinicalTrials.gov NCT00460603.
Keywords: FOLFOX; axitinib; bevacizumab; colorectal cancer.
© 2013 American Cancer Society.