Author of

• 10801

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  P1.11 - Poster Session 1 - NSCLC Novel Therapies (ID 208)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10817

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    P1.11-016 - A Prospective, Multi-center Phase II Trial on the Efficacy and Safety of Low-dose Erlotinib Monotherapy for Patients with EGFR Mutation-positive, Previously Treated Non-small Cell Lung Cancer: Results of Thoracic Oncology Research Group (TORG) Trial 0911. (ID 1385)

    09:30 - 09:30  |  Author(s): Y. Komase
    • Abstract

    Background
    Several studies of erlotinib and gefitinib have shown similar benefit in terms of response and progression-free survival (PFS) for EGFR mutation-positive (EGFRm+) non-small cell lung cancer (NSCLC). However, the steady-state plasma trough concentration of erlotinib was approximately 3.5 times higher than that of gefitinib when administered at the respective approved dose. Hence, low-dose treatment of erlotinib may be as effective as gefitinib or erlotinib given at full dose, with reduced toxicity and treatment cost.

    Methods
    Eligible patients were adults (over 20 years), with advanced or recurrent EGFRm+ NSCLC who had received one to three prior chemotherapy regimens, ECOG PS of 0-2, measurable lesion, and adequate organ function. Erlotinib 50 mg was administered daily until disease progression or unacceptable toxicities. Dose was escalated to 150 mg/day in case of not achieving CR or PR classified by RECIST criteria (i.e., not responded, NR) at the first 4 weeks. The primary endpoint was objective response rate (ORR); SWOG two-stage design with an early stopping rule based on response rate was used. Response was initially judged by the investigators and confirmed by the independent review committee (IRC). Finally, 26 or more responses among 40 eligible patients were to be considered as evidence of sufficient efficacy of this treatment.

    Results
    Thirty-four patients were enrolled between April 2010 and November 2012: males/females 20/14; median age 67 (range 31-81); PS 0/1/2 16/18/0; Ad/Sq 33/1. EGFR mutation types were: exon 18 and 19/19/21/other 1/21/11/1. One patient was excluded for evaluation because of not having a measurable lesion, therefore, efficacy and safety were evaluated among 33 patients. The study was closed early according to the protocol definition at the time that NR was confirmed in 15 of 33 patients, because it was determined impossible to meet the primary endpoint even if the study was continued. The IRC-judged best responses to the 50 mg/day erlotinib were: PR 18 (54.5%), SD 10 (30.3%) and PD 5 (15.2%). ORR and disease control rate were 54.5% (95%CI: 36.4-71.9%) and 84.8 % (95%CI 68.1-94.9%), respectively. In addition, 4 out of the 10 patients with SD to the initial dose yielded PR after dose escalation to 150 mg/day. At data cut-off (April, 2013), median PFS was 8.6 months (95%CI: 6.7-15.0 months). Toxicities were generally mild, with a few grade 3 or more toxicities. The only grade 3 toxicities were 2 cases with neutropenia and 1 with AST/ALT elevation. No grade 4 toxicity or treatment-related death was observed. There was no treatment-related interstitial lung disease.

    Conclusion
    Although low-dose erlotinib appeared to have a certain efficacy in this population, this study could not meet the primary endpoint. Because of its relatively lower toxicity and cost, it may be worth further evaluation for elderly or frail patients.