How did trastuzumab begin the era of targeted therapy for HER2-positive breast cancer?

The approval of trastuzumab (Herceptin) by the U.S. Food and Drug Administration in 1998 is widely recognized as the pivotal moment that ushered in the era of targeted therapy for cancer.12

This milestone was rooted in the 1987 discovery that the HER2 gene is overexpressed in an aggressive form of breast cancer. Trastuzumab, a monoclonal antibody, was specifically engineered to bind to the HER2 protein on the surface of these cancer cells, effectively blocking the signals that drive their rapid growth and survival.13

Trastuzumab’s development was a landmark in translational medicine because it necessitated the use of a diagnostic test to identify patients whose tumors were HER2-positive. This requirement for molecular diagnostic testing to determine treatment eligibility established the paradigm for precision medicine, ensuring that therapy is tailored to the specific biological characteristics of an individual's tumor while minimizing damage to healthy cells.12