Gilead Sciences reported that Trodelvy failed to meet the primary endpoint in a Phase 3 trial for a subset of breast cancer patients, representing a significant setback for the antibody‑drug conjugate that has been a cornerstone of Gilead’s oncology portfolio. The miss raises questions about the drug’s positioning and long‑term commercial trajectory as the company reassesses the program and investors recalibrate expectations. Clarification: a Phase 3 failure on a primary endpoint typically requires sponsors to revisit trial design, subgroup analyses, or development strategy.