Successful therapy of a critically ill non-small cell lung cancer patient with compound mutations in EGFR G719X and S768I genes using furmonertinib: A case report

Background: Somatic mutations in epidermal growth factor receptor (EGFR) genes, such as G719X and S768I, and tyrosine kinase inhibitors (TKIs) have been confirmed to be promising for developing new targeted therapies against advanced non-small-cell lung cancer (NSCLC). The G719X and S768I mutations are uncommon and often occur in the form of compound mutations. However, the efficacy of furmonertinib in patients with these uncommon compound mutations has not yet been elucidated. Case presentation: In this study, the G719X/S768I compound mutations were detected in a critically ill NSCLC patient. This patient received furmonertinib for 14 months and successfully responded to the treatment. The present case report highlights the ideal clinical response, with ongoing follow-up. Conclusion: We report the successful treatment of a critically ill NSCLC patient carrying rare compound EGFR G719X and S768I mutations using furmonertinib. To the best of our knowledge, this is the first reported case of a successful furmonertinib treatment of compound EGFR G719X and S768I mutations. Furmonertinib, a third-generation EGFR-TKI, may be effective in controlling the EGFR G719X and S768I compound mutations in NSCLC.