2023 World Conference on Lung Cancer (Posters)-EP12.01. Updated First-line Osimertinib in Asian patients with Advanced EGFR-mutated Lung Cancer

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A study was conducted to evaluate the efficacy and outcomes of first-line osimertinib treatment in Asian patients with advanced EGFR-mutated non-small cell lung cancer (NSCLC). A total of 161 Asian patients were included in the study, and their clinical data, including patient characteristics, concomitant mutations, baseline brain metastases, time-to-treatment failure, and survival outcomes, were analyzed.<br /><br />The majority of the patients were female (65.8%), never-smokers (80.7%), and had adenocarcinoma histology (97.5%). The most common EGFR mutations were sensitizing exon 19 deletions (55.9%) and exon 21 mutations (36.6%). Baseline brain metastases were present in 52.2% of patients, and some patients received radiotherapy to the brain metastases before starting osimertinib. The overall response rate to osimertinib was 78.9%, and the rate of CNS disease progression was 21.2%.<br /><br />After a median follow-up of 40.2 months, the median overall survival was 33.9 months, the median progression-free survival was 17.7 months, and the median time-to-treatment failure was 23.6 months. Patients with exon 19 mutations had a longer median overall survival compared to patients with exon 21 mutations. Factors associated with shorter overall survival included a positive smoking history, poor ECOG performance status, and exon 21 mutation.<br /><br />Resistance mechanisms to osimertinib included histologic transformation, cMET amplification, C797S mutation, and ALK rearrangement. Repeat tissue biopsy was performed in 36.9% of patients who had disease progression on osimertinib.<br /><br />In conclusion, first-line osimertinib treatment in Asian patients with advanced EGFR-mutated NSCLC showed durable overall survival, progression-free survival, and time-to-treatment failure. Smoking history, ECOG performance status, and exon 21 mutation were identified as negative prognostic factors. The common resistance mechanisms to osimertinib included cMET amplification, C797S mutation, and histologic transformation.

Asset Subtitle

Wan Ling Tan

Meta Tag

Speaker Wan Ling Tan

Topic Metastatic NSCLC: Targeted Therapy - EGFR/HER2

Keywords

osimertinib

Asian patients

EGFR-mutated

non-small cell lung cancer

clinical data

baseline brain metastases

overall survival

progression-free survival

time-to-treatment failure

resistance mechanisms