eGFRt790M是公认的最早对非小细胞肺癌靶向治疗产生耐药性的突变之一。尽管第一代和第二代tki（erlotinib、gefitinib、neratinib）成功扩增了egfr，但治疗前治疗携带这种突变的患者的疗效却显著降低。与野生型egfr或其他类型egfr突变患者相比，这种疗效的缺乏可能是导致这种突变患者预后较差的原因。大约一半获得性抗tki抑制的egfr突变肿瘤被证明含有这种突变，这意味着它是获得性治疗抵抗的机制。第三代TKI（Osimertinib）已被批准用于治疗EGFR T790M突变型NSCLC。血浆试验中T790M阳性的患者与肿瘤活检试验结果相似。
EGFR T790M was one of the very first mutations recognized to confer resistance to targeted therapies in non-small cell lung cancer. While successful in amplified EGFR, the efficacy of the first and second generation TKI's (erlotinib, gefitinib, neratinib) in treating patients harboring this mutation before treatment is notably lower. This lack of efficacy can likely be to blame for the poorer prognosis for patients with this mutation as compared to patients with wildtype EGFR or other types of EGFR mutations. Approximately half of EGFR mutant tumors with acquired resistance to TKI inhibition have been shown to harbor this mutation, implicating it as a mechanism of acquired therapy resistence. A third generation TKI (osimertinib) has been approved for the treatment of EGFR T790M mutant NSCLC. Patients positive for T790M in a plasma-based test have similar outcomes like those with tumor biopsy testing.