Unexpected Cardiotoxicity in Patients With -Mutant NSCLC Treated With Trastuzumab Deruxtecan: A Case Report.

Antibody-drug conjugates targeting receptor tyrosine-protein kinase erbB-2 () have emerged as promising targeted options for -mutant NSCLC. Among antibody-drug conjugates targeting HER2, trastuzumab deruxtecan was found to have the most impressive efficacy and is a potential new standard of care. Drug-related interstitial lung disease remains a serious unpredictable identified risk for patients treated with trastuzumab deruxtecan, requiring careful monitoring and multidisciplinary management. We report the first two cases of drug-related cardiotoxicity with acute myocarditis that developed after the first trastuzumab deruxtecan cycle. Routine cardiovascular risk screening is advisable, with close collaboration between cardiology specialists and oncologists.