Traditional chemotherapy indiscriminately kills cancer cells and healthy cells alike, which leads to side effects. But what if antibodies could deliver a chemo payload directly to tumors, thereby sparing normal cells?

That’s the idea behind antibody-drug conjugates (ADCs), which use monoclonal antibodies to carry lethal drugs to tumors. “These conjugates combine the ability of monoclonal antibodies to target specific receptors on cancer cells and then deliver a drug to the cancer cell,” says Richard Pazdur, MD, director of the Food and Drug Administration (FDA) Oncology Center of Excellence.

The FDA approved three new ADCs last year. Polivy (polatuzumab vedotin) targets cancerous B cells in people with lymphoma. Padcev (enfortumab vedotin) targets nectin-4, a protein found on bladder cancer cells. The newest ADC, Enhertu (fam-trastuzumab deruxtecan), joins Kadcyla (ado-trastuzumab emtansine) as an option for people with HER2-positive breast cancer. A study presented at the San Antonio Breast Cancer Symposium showed that 61% of women treated with Enhertu had complete or partial tumor shrinkage.