Abstract 4036: The efficacy of immune checkpoint inhibitors in patients with EGFR mutated non small cell lung cancer in retrospective analysis

Abstract

Abstract Background The treatment with EGFR-TKIs leads to initial response in most patients with EGFR mutated non-small cell lung cancer (NSCLC). In contrast, little is known the subpopulation of NSCLC patients with EGFR mutations who had clinical outcomes to treat for immune checkpoint inhibitors (ICIs). Therefore, to seek for the eligible cases to treat with ICIs, we retrospectively analyzed the correlation between clinical feature and the efficacy of ICIs in patients with EGFR mutations. Methods/Materials and methods We analyzed a retrospective study of patients with advanced NSCLC harboring with EGFR mutations who were treated with ICIs after the resistance to EGFR-TKIs between February 2016 and April 2018 at six institutions in Japan. The association between clinical outcome and the efficacy or ICIs was investigated. Results We enrolled 27 patients who have EGFR activating mutation. The objective response and disease control rates were higher in patients with uncommon EGFR mutations than in those with common EGFR mutations (71% versus 35.7%, and 57% versus 7%, p= 0.14 and p < 0.01, respectively). Patients with uncommon EGFR mutations or without T790M mutations was associated with a significantly longer median progression-free survival than those with common EGFR mutations or with T790M mutations (p = 0.003, 0.03, respectively). Conclusions Patients with uncommon EGFR mutations and without T790M mutations are associated with best outcomes for the treatment with immunotherapy among EGFR mutated NSCLC in the retrospective analysis. Further research is needed to validate for the clinical biomarkers involved in ICI responders with EGFR mutation. Citation Format: Tadaaki Yamada, Soichi Hirai, Akihiro Yoshimura, Satoshi Watanabe, Junji Uchino, Koichi Takayama. The efficacy of immune checkpoint inhibitors in patients with EGFR mutated non small cell lung cancer in retrospective analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4036.