For most of medical history, treating disease meant casting a wide net. Chemotherapy attacked every fast-dividing cell it could find, healthy or cancerous. Broad-spectrum drugs treated symptoms without ever asking why a particular patient's biology behaved the way it did. That era is ending. Targeted therapeutics, treatments engineered to lock onto the specific genes, proteins, or signaling pathways that drive a disease, have moved from experimental promise to clinical mainstay in barely two decades. Monoclonal antibodies like rituximab and trastuzumab rewired treatment for lymphoma and HER2-positive breast cancer. Oral kinase inhibitors now push response rates above ...
