Comparison of the Efficacy of EGFR Tyrosine Kinase Inhibitors Erlotinib and Low-dose Osimertinib on a PC-9-GFP EGFR Mutant Non-small-cell Lung Cancer Growing in the Brain of Nude Mice

Abstract

Background/aim: Brain metastases are found in approximately 30% of patients with epidermal-growth-factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC). We compared the efficacy of two EGFR-tyrosine kinase inhibitors (TKIs), erlotinib and osimertinib on a PC-9-GFP EGFR mutant NSCLC growing in the brain of nude mice.

Materials and methods: The brain metastasis models were randomized into five groups and treated for 15 days: Control; 5 mg/kg erlotinib; 50 mg/kg erlotinib; 0.5 mg/kg osimertinib; 5 mg/kg osimertinib. Tumor volume was evaluated by non-invasive fluorescence imaging.

Results: Only 5 mg/kg osimertinib, a low-dose compared to the clinically-equivalent dose, showed significant tumor regression compared to the control.

Conclusion: This study strongly supports the high activity of osimertinib for intracranial lesions of EGFR-mutant NSCLC.

Keywords: Erlotinib; PC-9-GFP; non-small cell lung cancer; nude mice; osimertinib.