Camizestrant (Etcamah) received FDA approval for ESR1-mutated HR+/HER2– advanced breast cancer, with accompanying emphasis on ctDNA monitoring and earlier switching once ESR1 mutations surface. The interview coverage highlights SERENA-6 data suggesting an early switch to camizestrant plus a CDK4/6 inhibitor improved progression-free survival and delayed quality-of-life deterioration versus continuing aromatase inhibitor therapy. The approval is positioned as enabling clinicians to intervene at molecular progression rather than waiting for clinical deterioration, potentially shifting future trial designs toward ctDNA-triggered decision points. For developers, the approval also strengthens the regulatory and clinical trajectory for ctDNA as a practical tool to manage resistance evolution in endocrine-responsive tumors.