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H.-. Tu
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P3.01 - Advanced NSCLC (ID 621)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Advanced NSCLC
- Presentations: 1
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.01-051 - Dramatic Response to Afatinib in EGFR-Mutant Lung Adenocarcinomas After Resistance to First-Generation EGFR Inhibitors: A Brief Report (ID 9706)
09:30 - 09:30 | Author(s): H.-. Tu
- Abstract
Background:
T790M inhibitor, a third-generation epithelial growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), was significantly superior to chemotherapy for EGFR-mutant patients with advanced non-small-cell lung cancer (NSCLC) harboring T790M mutation after resistance to the first-generation EGFR-TKIs. However, for those without acquired T790M mutations or MET amplification, few data showed whether the second-generation EGFR-TKI could overcome resistance to the first-generation EGFR-TKIs.
Method:
EGFR mutation was detected by amplification refractory mutation system (ARMS) technology. Overexpression of MET was determined by immunohistochemistry (IHC), and MET amplification was detected by FISH. Next generation sequencing (NGS) was used to test tumor tissues before and after resistance to TKIs.
Result:
Patient 1 was a 53-year-old Asian male, who underwent surgery followed by adjuvant chemoradiotherapy with an 11 months of disease-free survival. A biopsy was performed and revealed an activating deletion mutation in exon 19 of the EGFR. He started gefitinib 250mg once daily and achieved an initially good partial response (PR) followed by continuously stable disease for a progression-free-survival (PFS) about 29 months. A rebiopsy showed that exon 19 deletion mutation still existed without an acquired T790M mutation or MET amplification. He refused to receive chemotherapy so we prescribed afatinib 40mg daily. He then achieved a dramatic PR 23 days later which was confirmed 1.5 months after that. We sent tumor tissue of the patient before and after TKI therapy for NGS, the result showed a decreasing abundance of EGFR exon 19 deletion without T790M mutation, MET amplification and Her2 mutation/amplification. Patient 2 was a 63-year-old Asian female harboring EGFR exon 20 insertion (A763-Y764 ins), who received first and second lines of chemotherapy with short PFSs. He was enrolled in the trial of allitinib (AST-1306) as the third line therapy with the best response of stable disease(SD) and the PFS of 7 months. A later rebiopsy showed the strong overexpression of MET, but the forth-line therapy crizotinib failed. He then received chemotherapy as the-fifth line therapy, 4 cycles later he progressed. So he started afatinib 40mg daily. His symptoms were relieved significantly 5 days later, and PR was confirmed 1.5 months later.
Conclusion:
Afatinib might overcome resistance to the first-generation EGFR-TKIs for EGFR-mutant patients with advanced NSCLC without acquired T790M mutation or MET amplification. Further investigations are warranted.
