427P - The efficacy of a reduced dose (40mg) of Osimertinib with T790M-positive advanced non-small-cell lung cancer (427P)

Date 18 November 2017
Event ESMO Asia 2017 Congress
Session Poster lunch
Topics Anticancer Agents
Thoracic Malignancies
Non-Small Cell Lung Cancer
Translational Research
Basic Principles in the Management and Treatment (of cancer)
Biological Therapy
Presenter Shoko Sonobe
Citation Annals of Oncology (2017) 28 (suppl_10): x124-x143. 10.1093/annonc/mdx671
Authors S. Sonobe1, Y. Taniguchi1, N. Saijo1, Y. Naoki1, A. Tamiya1, N. Omachi1, K. Okishio2, S. Atagi3
  • 1Internal Medicine, Kinki-Chuo Chest Medical Center, 591-8555 - Sakai/JP
  • 2Clinical Research Center, Kinki-Chuo Chest Medical Center, 591-8555 - Sakai/JP
  • 3Clinical Research Center, Kinki-Chuo Chest Medical Center, Sakai/JP



The third-generation EGFR tyrosine kinase inhibitor (TKI) osimertinib is now the standard therapy for patients with T790M-positive advanced non-small-cell lung cancer (NSCLC). Although a regular dose (80mg) of osimertinib is effective, the efficacy of a reduced dose (40mg) is unclear. We conducted the retrospective analysis about the efficacy of a regular dose and reduced dose for adverse events of osimertinib.


Twenty-nine consecutive patients (Pts) with histologically proven NSCLC and harboring the T790M EGFR mutation treated with osimertinib between 4th April 2016 and 4th April 2017 at Kinki-Chuo Chest Medical center were retrospectively reviewed. We collected clinical date including age, gender, smoking status, pathological type, previous treatment, EGFR mutation status and EGFR T790M detection methods in rebiopsy at the time of starting osimertinb. We evaluated the efficacy including median progression free survival (PFS). The date cut off was on 30th June 2017.


Pts (female, 20; male, 9) had a median age of 70 years (range: 41-87 years), 16 Pts didn’t have smoking history and all had been diagnosed with lung adenocarcinoma with exon 19 deletion (n = 16) or exon 21 L858R mutation (n = 13). Rebiopsy from the primary lung cancer (n = 12), lung metastasis (n = 8), pleural effusion (n = 5), plasma (n = 3) and lymph node (n = 2) was performed. All Pts had been previously treated with EGFR TKIs, with twenty-two (75.8%) having been treated with cytotoxic chemotherapy. The median number of regiments having been previously treated with all chemotherapy were 3 (range: 1-7). Thirteen out of twenty-nine Pts took a reduced dose of osimertinib for adverse events. The response rate (RR) and median PFS were 62.5% (10/16 Pts) and 3.46months in the regular dose group, 76.9% (10/13 Pts) and 5.4months (p = 0.56) in the reduced dose group.


Dose reduction of osimertinib for adverse events was frequently needed. However, the efficacy of osimertinib was maintained after dose reduction.

Clinical trial identification

Legal entity responsible for the study

Shinji Atagi




Y. Taniguchi: Grant: Ono Pharmaceutical, Bristol-Myers Squibb Personal fee: Ono Pharmaceutical, Bristol-Myers Squibb, Chugai Pharmaceutical, Boehringer Ingelheim, A. Tamiya: Grants: Ono Pharmaceutical, Bristol-Myers Squibb, personal fees: Ono Pharmaceutical, Bristol-Myers Squibb, Chugai Pharmaceutical, AstraZeneka, Eli Lilly, Boehringer Ingelheim, K. Okishio: Personal fees: Ono Pharmaceutical, S. Atagi: Honoraria : Chugai, Astrazeneca, Taiho, Bristol-Myers Squibb, Eli Lilly, Ono, Borhringer Ingelheim Research funding: Pfizer, Merck Serono, Taiho, Yakult, Eli Lilly, Ono, Borhringer Ingelheim, Chugai, AstraZeneca

All other authors have declared no conflicts of interest.