A U.S. FDA oncology advisory panel voted against a “new paradigm” for AstraZeneca’s oral SERD camizestrant, declining to find a clinically meaningful benefit in the proposed setting. The panel’s 6-3 vote centered on evidence limitations for switching patients based on ctDNA-informed strategies. The backdrop includes FDA review scrutiny of whether camizestrant can support earlier treatment changes when used to direct therapy decisions around ESR1 mutations, rather than waiting for radiographic progression. The advisory outcome increases the probability that AstraZeneca must refine its evidence package or trial approach for any label strategy built on the proposed paradigm. For oncology drug developers, today’s decision signals how strongly ODAC may weigh consistency between study design, clinical meaningfulness, and practical implementation of biomarker-driven switching. Investors and trial strategists will now focus on what additional data could address panel concerns and whether subsequent analyses can bridge the gap between sponsor claims and regulator-advised standards.