Abstract
The DEBBRAH study showed promising results for patients with HER2-expressing (including HER2-low) metastatic breast cancer who received the antibody-drug conjugate (ADC) trastuzumab deruxtecan for leptomeningeal disease. ADCs represent a novel tool in the precision biomarker-based armamentarium, including in the tumor-agnostic setting, for targeting highly cytotoxic chemotherapy into cancer cells.