Response to Afatinib in a Patient with NSCLC Harboring Novel EGFR Exon 20 Insertion Mutations

Abstract

Ling Lin1 ,* Xiaomai Wu1 ,* Shuangquan Yan,1 Yefei Zhu,1 Zhengqing Yan,2 Dongqing Lv,1 Hongfei Ge3 1Department of Respiratory Medicine, Taizhou Hospital of Wenzhou Medical University, Taizhou, People’s Republic of China; 2The Medical Department, 3D Medicines Inc., Shanghai, People’s Republic of China; 3Department of Thoracic Surgery, Taizhou Hospital of Wenzhou Medical University, Taizhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Dongqing Lv; Hongfei Ge Email [email protected]; [email protected]: Most epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations are resistant to tyrosine kinase inhibitors (TKIs). While some non-small cell lung cancer (NSCLC) patients harboring special subtypes of EGFR ex20ins still achieved clinical response after TKIs treatment, identifying special subtypes of EGFR ex20ins is helpful to find out NSCLC patients who can respond to TKIs.Case Presentation: A 71-year-old non-smoker Chinese female was diagnosed with advanced lung adenocarcinoma harboring EGFR ex20ins (N771delinsKG). The patient received first-line afatinib (40 mg/day) therapy and a significant and substantial reduction in tumor size was observed subsequently. According to RESIST 1.1, a radiological partial response was achieved. The final progression-free survival was 10 months.Conclusion: This is the first published case report of EGFR N771delinsKG lung adenocarcinoma, which highlighted the heterogeneity of clinical response to TKIs for EGFR ex20ins-mutant NSCLC. Such results need to be further investigated in prospective studies.Keywords: afatinib, lung adenocarcinoma, EGFR exon 20 insertions, next generation sequencing

Keywords

• afatinib
• lung adenocarcinoma
• egfr exon 20 insertions
• next generation sequencing