Lazertinib‐Induced Rhabdomyolysis in a Patient With Non‐Small Cell Lung Cancer: A Case Report

Lazertinib is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor effective in patients with non-small cell lung cancer. Although generally well tolerated, this case report presents a rare occurrence of common terminology criteria for adverse events grade 3 rhabdomyolysis in a 69-year-old Korean woman after taking lazertinib. The patient exhibited general weakness and tea-coloured urine with elevated levels of creatine phosphokinase (CPK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), serum myoglobin and hyperkalemia. Lazertinib was temporarily discontinued, and urine alkalization was initiated. After the patient's condition improved, lazertinib was restarted at a reduced dose (80 mg) without any adverse effects. This case highlights the importance of assessing CPK and LDH levels in patients undergoing treatment with lazertinib, particularly in those with myalgia and elevated AST levels. Further studies are required to clarify the mechanisms underlying lazertinib-induced rhabdomyolysis.