Etcamah wins US approval to switch breast cancer treatment when resistance emerges
AstraZeneca’s Etcamah received accelerated US approval for certain advanced breast cancer patients when an ESR1 mutation emerges during ongoing treatment. The decision permits a switch before scans show disease progression. The medicine will be used with a CDK4/6 inhibitor, with Guardant360 CDx helping identify eligible patients. FDA required further studies to confirm the clinical benefit of switching this early and included warnings about heart rhythm risks.
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Approval covers emerging ESR1 mutations
The US Food and Drug Administration granted accelerated approval to AstraZeneca’s Etcamah for a defined group of adults with advanced breast cancer. The indication covers hormone receptor-positive, HER2-negative disease that is locally advanced or metastatic. Eligibility requires an ESR1 mutation detected by an FDA-authorized test during ongoing treatment with an aromatase inhibitor and a CDK4/6 inhibitor. The active ingredient in Etcamah is camizestrant.[1], [2]
A blood test will guide the switch
The resistance-associated ESR1 mutation can be detected in circulating tumour DNA, genetic material from the tumour found in blood. FDA’s decision permits a treatment switch before imaging shows that the disease is progressing. The agency also approved Guardant360 CDx as a companion diagnostic to identify eligible patients. Etcamah can be used with the CDK4/6 inhibitors abemaciclib, palbociclib or ribociclib; the approval is for combination treatment.[1], [2]
FDA requires further studies and rhythm warnings
FDA required further studies to verify the clinical benefit of switching treatment this early. Continued approval may depend on that confirmation. Etcamah’s prescribing information carries a boxed warning about the risk of irregular heart rhythm when it is taken with certain other medicines. Warnings also cover an abnormally slow heart rate and potential harm to an unborn baby.[1], [2]
