Abstract
BACKGROUND: EGFR and Src are frequently activated in non-small cell lung cancer (NSCLC). In preclinical models, combining EGFR and Src inhibition has additive synergistic effects. We conducted a phase I/II trial of the combination of Src inhibitor dasatinib with EGFR inhibitor erlotinib to determine the maximum tolerated dose (MTD), pharmacokinetic drug interactions, biomarkers, and efficacy in NSCLC. METHODS: The phase I 3+3 dose-escalation study enrolled patients with solid tumors to determine the MTD. The phase II trial enrolled patients with advanced NSCLC who had undergone no previous treatments to determine progression-free survival (PFS) and response. Pharmacokinetic and tissue biomarker analyses were performed. RESULTS: MTD was 150 mg of erlotinib and 70 mg of dasatinib daily based on 12 patients treated in the phase I portion. No responses were observed in phase I. The 35 NSCLC patients treated in phase II had an overall disease control rate of 59% at 6 weeks. Five patients (15%) had partial responses; all had activating EGFR mutations. Median PFS was 3.3 months. Epithelial-mesenchymal transition markers did not correlate with outcomes. CONCLUSION: The combination of erlotinib and dasatinib is safe and feasible in NSCLC. The results of this study do not support use of this combination in molecularly unselected NSCLC.