FDA Approves New Combination Therapy for ESR1-Mutant Breast Cancer

The FDA has granted accelerated approval to camizestrant in combination with a CDK4/6 inhibitor for adult patients with HR-positive, HER2-negative, locally advanced or metastatic breast cancer who develop an ESR1-mutation during aromatase inhibitor and CDK4/6 inhibitor therapy. This marks the first FDA approval of a cancer therapy guided by the detection of a resistance mutation in circulating tumor DNA before imaging tests show disease progression. The Guardant360 CDx assay was also approved as a companion diagnostic.