Ensartinib as first-line treatment for SMARCA4-deficient and EML4-ALK non-small cell lung cancer: a case report

Quanfang Chen^1*Yanqing Pan²玲欣 严¹Shaoxi Wang¹Huiling Li³

• ¹First Affiliated Hospital, Guangxi Medical University, Nanning, China
• ²The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
• ³Guangxi Medical University, Nanning, Guangxi Zhuang Region, China

SMARC4 is the catalytic subunit of the SWI/SNF chromatin remodeling complex and is one of the most common altered chromatin remodeling ATPases in cancer. Studies indicate that SMARCA4 loss is associated with highly aggressive tumors, independently predicting shorter overall and disease-specific survival. SMARCA4-deficient non-small cell lung cancer (NSCLC) primarily affects males, especially smokers, and is characterized by large, aggressive tumors.Cases of SMARCA4 deletion combined with actionable driver gene mutations (e.g., ALK) are rarely reported. In this report, we describe a male non-smoker diagnosed with SMARCA4-deficient, EML4-ALK non-small cell lung cancer, who has been undergoing ensartinib targeted therapy for 3 months, resulting in a significant partial response. We also propose that, from a signaling perspective, the presence of SMARCA4 deficiency may influence the sensitivity of EML4-ALK NSCLC to targeted therapy, highlighting the need for further investigation into the underlying mechanisms and the exploration of novel therapeutic approaches.