Rose DiMarco, PharmD, BCPS, BCOP

Panelists discuss how antibody-drug conjugates (ADCs) combine monoclonal antibodies with cytotoxic payloads, enabling precise targeting of breast cancer (BC) cells through specific antigen recognition. Upon binding, the ADC-antigen complex is internalized, releasing the toxic payload inside cancer cells while largely sparing healthy tissue. This targeted approach offers improved efficacy and reduces systemic toxicity compared with traditional chemotherapy's broad cytotoxic effects.

Panelists discuss how the National Comprehensive Cancer Network (NCCN) and American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines for HER2-negative breast cancer (BC) have evolved to recognize HER2-low (IHC 1+  or 2+/ISH-negative) and HER2-ultra low (IHC 0) as distinct categories. These classifications, particularly HER2-low, guide eligibility for targeted therapies such as trastuzumab deruxtecan, expanding treatment options beyond traditional chemotherapy for previously categorized HER2-negative patients.