The FDA granted accelerated approval to AstraZeneca’s camizestrant (Etcamah) for certain patients with HR+/HER2– advanced breast cancer with ESR1 mutations after the company’s April advisory committee vote went against the drug. The approval is based on the Serena-6 Phase III program, which met progression-free survival, alongside Guardant Health’s Guardant360 companion diagnostic to identify ESR1 mutations. The FDA’s decision contrasts with the panel’s concerns that the randomized treatment switch was supported only by ESR1 detection at an earlier disease point. Analysts said the decision creates a defined, though not unlimited, opportunity for the SERD, while AstraZeneca gets a new line of clinical differentiation versus existing endocrine therapy strategies. For developers of targeted endocrine therapies, the approval reinforces how diagnostic-linked trial designs and endpoint tradeoffs continue to shape regulatory outcomes.