Background: Axitinib is an oral, potent, small molecule tyrosine kinase inhibitor with selective inhibition of VEGFR 1,2, 3, as well as inhibition of potential downstream effectors of the EGFR pathway. Given the upregulation of EGFR and VEGFR in head and neck squamous cell carcinoma, treatment with axitinib holds promise as a rational targeted therapy.
Patients and methods: Patients with unresectable, recurrent or metastatic head and neck squamous cell carcinoma were included in this open label, single arm, phase II trial. Primary endpoint was 6 month progression free survival. All patients received single agent axitinib with planned dose escalation based on tolerability. A planned interim efficacy analysis was performed after enrollment of 30 patients.
Results: Forty-two patients were registered, 30 were evaluable. While treatment was well-tolerated with no severe bleeding events, only 19 patients were able to achieve full planned dose. The best overall response rate was 6.7% (two partial responses) with a disease control rate of 76.7%. Median progression free survival was 3.7 months (95% Confidence Interval (CI): 3.5-5.7) and overall survival was 10.9 months (95% CI: 6.4-17.8). Exploratory analysis demonstrated that patients with a smaller sum of diameter of target lesions experienced improved response rates, and better progression-free and overall survival.
Conclusion: Treatment with single agent axitinib should be considered due to acceptable toxicity profile and favorable median overall survival compared to standard therapies.
Keywords: Axitinib; Head and neck cancer; Squamous cell carcinoma; Tyrosine kinase inhibitor; Vascular endothelial growth factor receptor.