The U.S. Food and Drug Administration (FDA) has granted accelerated approval to Etcamah (camizestrant) for the treatment of adult patients with advanced breast cancer. The approval was granted to AstraZeneca and is contingent upon the detection of an estrogen receptor-1 (ESR1) mutation during aromatase inhibitor and CDK4/6 inhibitor therapy.
The treatment is indicated for adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer. The FDA authorized the Guardant360 CDx assay as a companion diagnostic device to identify patients with breast cancer who have ESR1 mutations.
Efficacy for the approval was evaluated in a clinical trial comparing Etcamah in combination with a CDK4/6 inhibitor versus continuing an aromatase inhibitor in combination with a CDK4/6 inhibitor. The trial reported an estimated median progression-free survival of 16 months in the Etcamah and CDK4/6 inhibitor arm, compared to 9.2 months in the aromatase inhibitor and CDK4/6 inhibitor arm.
The FDA emphasized that this approval is based on how long patients lived without their disease worsening, measured from the point when the resistance mutation was first detected in the blood. The agency has required confirmatory studies to verify and describe clinical benefit, as it is not yet confirmed whether intervening at this point translates into a clinically meaningful benefit.
The prescribing information for Etcamah includes a boxed warning for the risk of irregular heart rhythm when the drug is taken together with certain other medications, as well as warnings and precautions for an abnormally slow heart rate and potential harm to an unborn baby.
