Erlotinib or Gifitinib resistance is mainly due to the following reasons
1, 50% of tumors are T790M mutations
2, 22% MET amplification
3. 14% of small cell carcinomas are transformed
Development of TKIs to overcome T790M mutation afatinib-BIBW2992, PF00299804
Mechanism of action of Afatinib Ji Youxin, Department of Oncology, Qingdao Central Hospital
Irreversible binding to epidermal growth factor receptor
Orally administered small molecule tyrosine kinase inhibitor (TKI) that irreversibly binds to the ATP binding site.
Treatment.
Re-biopsy, sample genetic testing
1. susceptibility mutation (exon 19 or 21) + T790M mutation
— Continue EGFR or EGFR + chemotherapy
or Afatinib + cetuximab
2. Epidermal growth factor receptor alteration wild type
— Chemotherapy
3.EGFR wild type + T790M mutation
— Afatinib + cetuximab
4.MET or PI3K
—specific antagonist
5.Transformation of SCLC
— Chemotherapy