The FDA’s Oncologic Drugs Advisory Committee voted 3–6 on April 30 against the benefit-risk profile of AstraZeneca’s camizestrant combined with a CDK4/6 inhibitor for first-line use in HR-positive, HER2-negative advanced breast cancer with emergent ESR1 mutations, based on the SERENA-6 trial. The panel cited concerns over trial design, specifically whether switching patients early upon ctDNA-detected mutation improves long-term outcomes compared with waiting for radiographic progression. Although the agency granted Breakthrough Therapy Designation and accepted the NDA in 2025, it is not bound by the vote and remains under active review. Traders see limited realistic paths to near-term approval given these clinical and regulatory hurdles, though unexpected positive data or a surprise FDA decision could still shift outcomes.