Author of

• 11692

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  P2.10 - Poster Session 2 - Chemotherapy (ID 207)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11718

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    P2.10-026 - Final results of EGFR mutation reanalysis and KRAS mutation screening by Scorpion ARMS method: Phase II Study of Erlotinib for EGFR wild type Non-small cell Lung Cancer Patients. Central Japan Lung Study Group (CJLSG) 0903 trial. (ID 1529)

    09:30 - 09:30  |  Author(s): K. Ogawa
    • Abstract

    Background
    Erlotinib might benefit non-small cell lung cancer (NSCLC) patients with EGFR wild-type (WT) genotype based on the subgroup analysis of the BR21 trial and SATURN trial. However, the sensitivity of methods for detection of EGFR mutation can influence the evaluation of erlotinib efficacy. We conducted CJLSG0903 trial, a phase II study of erlotinib for previously treated EGFR WT NSCLC patients screened by peptide nucleic acid-locked nucleic acid (PNA-LNA) PCR clamp method. The efficacy and safety results of CJLSG0903 were previously reported at the ESMO meeting 2012. Here we present the final results of EGFR mutation reanalysis and KRAS mutation screening by S-ARMS method.

    Methods
    Stage IIIB or IV NSCLC patients were eligible. EGFR mutation status was screened by PNA-LNA PCR clamp method, which is known to be a highly sensitive. Primary endpoint was objective response rate (ORR). Oral erlotinib 150 mg was given daily until progression or unacceptable toxicity.

    Results
    From February 2010 and April 2012, 53 evaluable patients were enrolled. ORR was 11.3% (95% confidence interval: 4.3–23.0%). We performed preplanned reanalysis of EGFR mutation status and KRAS mutation by Scorpion ARMS (S-ARMS) methods if remaining samples from participants were available. Samples from 26 patients (49%) were available for EGFR mutation reanalysis. Only one patient who achieved partial response (PR) was EGFR mutation positive (exon 19 deletion). In 25 patients, EGFR WT genotype was reconfirmed by S-ARMS method. Two of them achieved PR. ORR was 8.0 % in patient with EGFR WT genotype confirmed by both PNA-LNA PCR clamp and S-ARMS methods. Samples from 42 patients (79%) were available for KRAS mutation screening. KRAS mutations were detected in 4 of 42 patients, and progressive disease (PD) was observed in all of KRAS mutation positive patients.

    Conclusion
    Erlotinib still shows activity in patients with EGFR WT genotype confirmed by two different highly sensitive methods. Activating KRAS mutation might be negative predictive factor for erlotinib efficacy in patients with EGFR WT genotype. (UMIN Clinical Trials Registry: UMIN000002692)