An FDA oncology advisory panel voted 6–3 against switching patients to AstraZeneca’s oral SERD camizestrant based on ESR1 mutations detected in circulating tumor DNA. The vote reflected panel concerns that the evidence did not support the proposed change in treatment paradigm. The discussion centered on whether waiting for radiographic progression versus switching earlier at ctDNA ESR1 detection is clinically justified. Separate reports indicate the panel did not accept the “new paradigm” approach supported by the trial strategy. The outcome adds uncertainty to label-expansion plans that depend on ctDNA-based decisioning and will influence next regulatory conversations around biomarker-triggered switching.