Antibody-drug conjugates (ADCs) offer a compelling promise: delivering a cytotoxic payload directly to a tumor cell while sparing the rest of the body from harm. Composed of a tumor-targeting antibody, a cytotoxic agent, and a chemical linker, ADCs combine the selectivity of monoclonal antibodies that bind to tumor-specific antigens with the cytotoxic potency of small-molecule drugs. These therape...