# Triple-Dose Furmonertinib for Leptomeningeal Metastases in Advanced Epidermal Growth Factor Receptor (EGFR) L858R-Mutated Lung Adenocarcinoma: A Case Report

## TL;DR

A 73-year-old woman with advanced lung cancer achieved long-term survival using high-dose furmonertinib after other treatments failed.

## Contribution

Demonstrates the potential of triple-dose furmonertinib as a salvage therapy for leptomeningeal metastases in EGFR L858R-mutated lung cancer.

## Key findings

- High-dose furmonertinib combined with bevacizumab provided symptom relief and extended survival in a patient with LM.
- The patient's overall survival exceeded six years from initial diagnosis, highlighting the effectiveness of the treatment strategy.
- Sequential and multimodal management is crucial for advanced EGFR-mutant NSCLC with CNS involvement.

## Abstract

Leptomeningeal metastases (LM) represent a severe and life-threatening manifestation of advanced non-small cell lung cancer (NSCLC). Despite advances in epidermal growth factor receptor (EGFR)-targeted therapies, central nervous system involvement continues to present major therapeutic challenges. We report a 73-year-old woman with EGFR L858R-mutated NSCLC who developed LM after multiple lines of therapy, including gefitinib, osimertinib, chemotherapy, anti-angiogenic therapy, and radiotherapy. Treatment with high-dose furmonertinib (240 mg daily) combined with bevacizumab resulted in symptom relief and additional survival. Remarkably, her overall survival exceeded six years from initial diagnosis. This case highlights the potential role of dose-escalated furmonertinib as salvage therapy in LM after osimertinib resistance and underscores the importance of sequential and multimodal management in advanced EGFR-mutant NSCLC.