Response to erlotinib and bevacizumab combination therapy after acquired resistance to osimertinib in patients with non-small cell lung cancer

Abstract

Osimertinib is the most reliable epidermal growth factor receptor-tyrosine kinase (EGFR-TKI) and is recommended as the first-line EGFR-TKI. Therefore, developing acquired resistance to this TKI might be problematic because no appropriate treatment with TKIs has been established after acquired resistance to osimertinib. For patients with osimertinib resistance, antitumor drugs having different mechanism from that of EGFR-TKI are usually prescribed. However, these treatments do not include the effective utilization of several EGFR-TKIs for these patients. We herein report two cases of response to erlotinib and bevacizumab combination therapy after acquired resistance to osimertinib in patients with non-small cell lung cancer. Although the precise biological mechanism is unknown, this combination therapy may be an option for some patients who suffer from acquired resistance to osimertinib.