Virtual Library

Start Your Search

H. Kim



Author of

  • +

    MA 11 - Emerging Diagnostic/Biomarkers in NSCLC (ID 668)

    • Event: WCLC 2017
    • Type: Mini Oral
    • Track: Advanced NSCLC
    • Presentations: 1
    • +

      MA 11.09 - Real World Data of Rebiopsy, Mutation Status, and Its Association with Plasma Genotyping after EGFR TKI Failure in NSCLC (ID 8234)

      11:00 - 12:30  |  Author(s): H. Kim

      • Abstract
      • Presentation
      • Slides

      Background:
      After the introduction of third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) in non-small cell lung cancer (NSCLC), the second tumor biopsy and EGFR mutation test to confirm T790M status is an established standard practice. But second biopsy is invasive, cost and time-consuming and occasionally impossible. We aimed to investigate the success rate of tissue rebiopsy and incidence of T790M mutation in tissue and plasma at the time of progression with earlier-generation EGFR TKIs in real world setting. Also, we studied the association between the efficacy of osimertinib and the status of tissue and/or plasma T790M mutation.

      Method:
      We analyzed patients who were screened and enrolled into ASTRIS trial in Yonsei Cancer Center (NCT02474355). Key inclusions were advanced/metastatic NSCLC with tissue and/or plasma T790M mutation and prior EGFR-TKI therapy. Tissue and plasma EGFR mutation tests were performed using PNAClamp[TM] and PANAMutyper[TM], respectively.

      Result:
      We screened 193 patients with NSCLC harboring EGFR-activating mutation who experienced disease progression upon earlier-generation EGFR TKIs during study period. The second biopsy including tissue and/or cytology was performed only in 60.1% of the patients (116/193) and the success rate was 86.2% (100/116). The reasons for not trying a biopsy were as follow: inaccessibility (n=25), poor PS (n=8), previously reported plasma T790M+ (n=8), and patients’ refusal (n=4). The parenchymal lung tissue (n=61) was most commonly targeted lesion and bronchoscopy was the most frequently used method (n=35). Six patients underwent video-assisted thoracoscopic surgery. Tumor T790M mutation was reported in only 25.9% of patients (50/193). Of 193 patients, 88 patients were enrolled into ASTRIS trial and 43 patients were registered based on the plasma test only. With a median follow-up of 25.1 weeks, the objective response rate (ORR), median progression-free survival (PFS), and duration of the response (DoR) were 44.3%, 32.7 weeks, and 27.0 weeks, respectively. Median overall survival (OS) was not reached. The ORR, median PFS and DoR of tumor T790M+ (n=45) vs. plasma T790M+ (n=54) were 57.8% vs. 35.2%, 45.0 vs. 20.4 weeks, and 26.3 vs. 25.9 weeks, respectively.

      Conclusion:
      With the increasing importance of tissue rebiopsy after EGFR-TKI failure, there is a growing interest to overcome the challenge of subsequent biopsy. Even though relatively lower ORR and shorter PFS in patients with plasma T790M+ compared with tissue T790M+, the plasma EGFR genotyping may be good alternative to the tissue biopsy in consideration of long DoR when treated with osimertinib and low yield rate of tissue T790M testing.

      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.