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Case Report: Short-term disease control with subsequent icotinib therapy in EGFR L858R/C797S, T790M-negative lung
Shihang Song1,2, Di Yao1,2, Jinlong Liu1,2
1Graduate School, Hebei North University, Zhangjiakou, China.
Abstract:
Osimertinib resistance, particularly EGFR C797S without T790M, lacks established treatment strategies. We report a 71-year-old woman with stage IVB lung adenocarcinoma harboring EGFR L858R (T790M-negative) who received first-line osimertinib for 29 months until progression. Post-progression ctDNA revealed L858R/C797S (T790M-negative) who received first-line osimertinib for 29 months until progression. Post-progression ctDNA revealed L858R/C797S (T790M-negative). She was subsequently treated with icotinib 125 mg tid, achieving stable disease for 6 months. This case suggests that first-generation EGFR-TKI subsequent therapy may provide short-term disease control in this rare molecular context.
Insights
Treatment options for osimertinib resistance due to EGFR C797S mutations (without T790M) are limited. This case study shows icotinib may offer temporary disease control in this specific EGFR-mutated lung cancer scenario.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Osimertinib is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) used for non-small cell lung cancer (NSCLC).
- Acquired resistance to osimertinib, particularly the EGFR C797S mutation in the absence of T790M, presents a significant clinical challenge with few established treatment options.
- The patient presented with stage IVB lung adenocarcinoma and an EGFR L858R mutation, initially responsive to first-line osimertinib.
