Durable response of leptomeningeal disease with osimertinib and pemetrexed in EGFR mutated metastatic non-small cell lung cancer: a case report

Abstract Optimal management of epidermal growth factor (EGFR) mutated non-small cell lung cancer (NSCLC) with leptomeningeal (LM) disease progression through EGFR tyrosine kinase inhibitor (TKI) remains unclear. We present a 39 year old male with EGFR mutated NSCLC and LM disease progression through osimertinib 80 mg daily, with subsequent durable radiographic and symptomatic response to systemic pemetrexed in combination with osimertinib. This builds on the limited data evaluating LM disease response to systemic pemetrexed and lends further support to consideration of this treatment strategy.