7160 Background: The HER1/EGFR inhibitor erlotinib significantly prolongs survival of patients with previously-treated advanced NSCLC. Methods for selecting patients most likely to derive clinical benefit from erlotinib are not established. Increased HER1/EGFR gene copy number has been suggested as a potential predictive biomarker of clinical benefit, and was investigated in this phase II study. Methods: Advanced NSCLC patients who failed first line chemotherapy were treated with erlotinib monotherapy, 150 mg/d p.o. Each patient underwent tumor biopsy before start of treatment. Tumor HER1/EGFR gene amplification status was assessed using FISH, and classified as positive (amplification, polysomy, high polysomy) or negative (disomy, trisomy). Results: 83 patients were included: median age 56 (range 35–78); sex: male 72%, female 28%; histology: adenocarcinoma 43%, large cell 31%, squamous cell 19%, others 7%; smoking status: 44 current smokers, 28 former smokers, 11 never smokers. Of 73 evaluable patients, 7 (10%) achieved partial response (PR), 28 (38%) had stable disease (SD) and 38 (52%) had disease progression. PRs were observed in 4 males / 3 females; in 5 adenocarcinomas / 1 large cell/ 1 squamous cell; in 2 current / 3 former / 2 never smokers. Erlotinib was well tolerated and no unexpected toxicities were seen. HER1/EGFR gene copy number was evaluated in 53 patients. 15 patients were FISH +, 10 of whom achieved clinical benefit (PR, or SD for ≥12 weeks). Only 5 of 38 FISH - patients had clinical benefit. FISH + patients achieved a longer median time to progression (137 vs 43 days; p = 0.00011; HR 0.35) as well as overall survival (226 vs 115 days; p = 0.3221, HR 0.722). Conclusion: In this study, increased HER1/EGFR gene copy number was associated with a better outcome on erlotinib therapy. [Table: see text] [Table: see text]
Immunotherapy plus chemotherapy showed superior clinical benefit to chemotherapy alone in advanced
NSCLC
patients after progression on osimertinib