Managing Acquired Resistance to Third-Generation EGFR Tyrosine Kinase Inhibitors Through Co-Targeting MEK/ERK Signaling

Danlei Yu,^1,2,* Wen Zhao,^2,3,* Karin A Vallega,² Shi-Yong Sun<sup>2

1</sup>Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of China; ²Department of Hematology and Medical Oncology, Emory University School of Medicine and Winship Cancer Institute, Atlanta, GA, USA; ³Department of Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Shi-Yong Sun
Department of Hematology and Medical Oncology, Emory University School of Medicine and Winship Cancer Institute, 1365-C Clifton Road, C3088, Atlanta, GA, 30322, USA
Tel +1 (404) 778-2170
Fax +1 (404) 778-5520
Email ssun@emory.edu

Abstract: Although epidermal growth factor receptor (EGFR)-targeted therapy has improved clinical outcomes of patients with advanced non-small-cell lung cancer (NSCLC) carrying activating EGFR mutations, the development of acquired resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs), including the promising third-generation ones, results in disease progression and has become an unavoidable problem that limits patient long-term benefit. The third-generation EGFR-TKIs, osimertinib and almonertinib, are now approved for the treatment of advanced NSCLC patients harboring activating EGFR mutations (first-line) and/or the resistant T790M mutation (second-line). Clinically, appropriate management of acquired resistance to third-generation EGFR-TKIs will substantially improve their long-term efficacy against EGFR-mutant NSCLC. Recent preclinical and clinical studies suggest that activation of the Ras/Raf/MEK/ERK signaling pathway may be an important resistance mechanism and accordingly co-targeting this pathway effectively overcomes and abrogates acquired resistance to third-generation EGFR-TKIs. This review focuses on discussing the scientific rationale for and potential of co-targeting MEK/ERK signaling in delaying and overcoming acquired resistance to third-generation EGFR-TKIs, particularly osimertinib.

Keywords: acquired resistance, EGFR inhibitors, osimertinib, MEK/ERK, lung cancer