On the basis of these results, we administered afatinib, a second-generation TKI, and bevacizumab, a vascular endothelial growth factor inhibitor, as the second-line treatment. The patient's symptoms improved, and this treatment was continued for 12 months. This report suggests that afatinib plus bevacizumab can effectively treat osimertinib-refractory lung tumors with an exon 18 mutation.