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Getting the latest healthcare news for you
Getting the latest healthcare news for you
The FDA has granted accelerated approval to camizestrant (Etcamah) combined with a CDK4/6 inhibitor for hormone receptor-positive, HER2-negative advanced breast cancer patients who develop an ESR1 mutation during treatment. In a landmark first, the approval allows clinicians to switch therapy based on a blood-based ctDNA test — not imaging evidence of disease progression. The move could redefine how oncologists monitor and respond to treatment resistance in real time.
The FDA has granted accelerated approval to camizestrant (Etcamah, AstraZeneca), an oral selective estrogen receptor degrader, in combination with a CDK4/6 inhibitor (abemaciclib, palbociclib, or ribociclib) for adults with hormone receptor-positive, HER2-negative locally advanced or metastatic breast cancer who develop an ESR1 mutation during aromatase inhibitor (AI) and CDK4/6 inhibitor therapy. About 30% of patients on frontline AI-based regimens develop ESR1 mutations, which drive resistance — and this approval lets clinicians act on that resistance earlier than ever before.
What makes this approval especially groundbreaking: it's the first time the FDA has authorized a cancer treatment switch based on circulating tumor DNA (ctDNA) testing rather than radiographic evidence of disease progression. The FDA simultaneously approved the Guardant360 CDx liquid biopsy assay to detect the mutation, cementing ctDNA's role in real-time treatment decisions. Confirmatory studies are still required to verify long-term survival benefit.
By the Numbers
Why it matters: This approval signals a shift toward proactive, biomarker-driven treatment adjustments in breast cancer — acting on molecular signals before tumors visibly progress. Experts are already calling ctDNA-guided switching a potential new standard of care in hormone receptor-positive breast cancer management.
