Author of

• 11745

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  P2.11 - Poster Session 2 - NSCLC Novel Therapies (ID 209)

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

  • 11754

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    P2.11-009 - Erlotinib in metastatic pulmonary adenocarcinomas harbouring EGFR activating mutations, in Sao Paulo - Brazil. (ID 1025)

    09:30 - 09:30  |  Author(s): C.S. Mesquita
    • Abstract

    Background
    Background: EGFR-activating mutations are predictive of high response rates and overall survival gains in patients (pts) with pulmonary adenocarcinomas, treated with EGFR- tyrosine-kinase inhibitors (EGFR-TKIs), as erlotinib. Our objectives in this study were to analyze the efficacy and safety of erlotinib as first-line therapy or later in pts with adenocarcinomas harbouring EGFR-activating mutations.

    Methods
    Methods: It is a prospective, observational study on all consecutively pts whose tumors were genotyped for EGFR-activating mutations. All studied pts were treated in a single institution (ICESP) with erlotinib 150 mg PO daily. Tumor samples were formalin-fixed and paraffin-embedded. Tumor areas were selected and macrodissected, followed by whole DNA extraction and amplification by PCR. EGFR genotyping was performed through DNA sequencing (exons 18, 19, 20 and 21) by Sanger´s methodology.

    Results
    Results: 49 pts were treated with erlotinib from Nov/2010 to May/2013, as first-line (11 pts, 22%), second-line (31 pts, 63%) or third-line therapy (7 pts, 14%). Erlotinib was administered during a median time of 4 mo. (0.2-23.6 mo.). Among these 49 pts, 38 (78%) were diagnosed with adenocarcinomas harbouring EGFR-activating mutations: 26 with exon 19 deletions, 10 with L858R mutation in exon 21 and one presented a rare mutation in exon 18 (G719S). As expected, erlotinib was well tolerated, and acneiform rash and diarrhea were the most commonly observed toxicities. No treatment-related deaths were seen. Tumor response assessment was done in 42 pts: progressive disease was observed in 15 pts (36%) and 27 pts (64%) presented either partial response or disease stabilization. In a mean follow-up of 14 mo., 13 pts were dead. Median overall survival was not reached for the 38 pts with EGFR-mutated adenocarcinomas, and 1-year overall survival rate was 94% in these pts. In those pts with wild-type EGFR tumors, median overall survival was 15.6 mo (HR 0.17; 95% CI 0.02-0.33, p=0.0004). No difference in overall survival was observed between pts with EGFR-mutated adenocarcinomas if treated with erlotinib either as first-line therapy or later (HR 1.11; 95% CI 0.20-6.15, p=0.895). No difference in overall survival was observed between pts with EGFR-mutated adenocarcinomas according to the type of mutations (exon 19 deletions or others, p=0.147).

    Conclusion
    Conclusions: High rate of disease control (64%) and an impressive 1-year overall survival rate (94%) were observed among pts with metastatic pulmonary adenocarcinomas harbouring EGFR-activating mutations, as expected, with a favorable toxicity profile. These results do reinforce the importance of the correct identification of this subgroup of pts with EGFR-activating mutations and their treatment with an EGFR-TKI as a targeted therapy.