Oops, you're using an old version of your browser so some of the features on this page may not be displaying properly.

MINIMAL Requirements: Google Chrome 24+Mozilla Firefox 20+Internet Explorer 11Opera 15–18Apple Safari 7SeaMonkey 2.15-2.23

Mini Oral session I

157 - Potential resistance mechanisms using next generation sequencing from Chinese EGFR T790M+ non-small-cell lung cancer patients with primary resistance to osimertinib:A multicenter study


11 Apr 2019


Mini Oral session I


Youcai Zhu


Annals of Oncology (2019) 30 (suppl_2): ii38-ii68. 10.1093/annonc/mdz063


C. Xu1, W. Wang2, Y. Zhu3, Z. Yu4, H. Zhang5, H. Wang6, J. Zhang7, W. Zhuang8, T. Lv9, Y. Song9

Author affiliations

  • 1 Pathology, Fujian Cancer Hospital, 350014 - Fuzhou/CN
  • 2 Zhejiang Cancer Hospital, Zhenjiang/CN
  • 3 Zhejiang Rongjun Hospital, Zhenjiang/CN
  • 4 Fuzhou General Hospital, Nanjing Military Area, Fuzhou/CN
  • 5 Xijing Hospital, 4th Military Medical University, Xi'an/CN
  • 6 Affiliated Hospital of Academy of Military Medical Science, Beijing/CN
  • 7 The Military General Hospital of Beijing, Beijing/CN
  • 8 Fujian Cancer Hospital, Fuzhou/CN
  • 9 Jinling Hospital, Nanjing/CN


Login to access the resources on OncologyPRO.

If you do not have an ESMO account, please create one for free.

Abstract 157


Osimertinib (AZD9291) is a third generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that has demonstrated significant clinical benefits in patients with EGFR sensitizing mutations or T790M mutation. However, approximately 5% to 15% of patients with non-small-cell lung cancer (NSCLC) with EGFR T790M mutation has primary resistance to osimertinib treatment. The underlying mechanism is unknown.


A total of 117 patients with stage IIIb-IV EGFR-T790M NSCLC were undergoing tumor biopsies or blood withdrawing by the time of primary or acquiring to osimertinib, including FFPE samples, serum samples and serous effusions. We used targeted NGS to detect genes status of patients.


Among 117 patients treated with osimertinib, 82.91% (97/117) developed acquired resistance, and 7.69% (9/117) had primary resistance. Using the specimens at the baseline, there were 3 (33.33%) patients with MET amplification, 1 (11.11%) patient with BCL2L11 loss (BIM deletion polymorphism), 1 (11.11%) patient with ERBB2 amplification, 1 (11.11%) patient with PTEN mutation, 1 (11.11%) patient with EZH2 mutation, and 2 (22.22%) patients with unknown status.


The mechanisms of primary resistance to EGFR-T790M may be highly heterogeneous. BCL2L11 loss, MET amplification, ERBB2 amplification, PTEN mutations, EZH2 mutations might contribute to molecular mechanisms of primary resistance to osimertinib in EGFR-T790M NSCLC. Further investigations are warranted to overcome these primary resistances.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.


Has not received any funding.


All authors have declared no conflicts of interest.

This site uses cookies. Some of these cookies are essential, while others help us improve your experience by providing insights into how the site is being used.

For more detailed information on the cookies we use, please check our Privacy Policy.

Customise settings
  • Necessary cookies enable core functionality. The website cannot function properly without these cookies, and you can only disable them by changing your browser preferences.