Osimertinib in combination with other telomerase inhibitors synergistically decreases the survival of osimertinib-resistant cell lines. The indicated cell lines were treated with varied concentrations of osimertinib alone, the tested telomerase inhibitor alone, or their respective combinations for 3 days. Cell numbers were determined with the SRB assay. The data are means ± SDs of four replicate determinations. The numbers in the graph by the red lines are CIs.