A, A schema for the concurrent treatment schedule. B and C, PC-9 xenografts in nude mice (6 mice/group) were treated with vehicle, osimertinib (15 mg/kg, og, once/day), trametinib (1 mg/kg, og, once/two days) or the combination of osimertinib and trametinib. Tumor sizes and mouse body weights were measured every three days and presented as means ± SEMs.