FDA approvals advance treatment for ESR1-mutated breast cancer

Recent FDA approvals have highlighted the ESR1 mutation as a critical therapeutic biomarker for hormone-sensitive metastatic breast cancer. The latest approval involves the combination of imlunestrant and abemaciclib, providing a new treatment option for patients with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer following disease progression after previous endocrine therapy.

Medical experts from the Therapeutic Clinic of the Medical School of the National and Kapodistrian University of Athens, including Dr. Maria Kaparelou and Professor Thanos Dimopoulos, noted that this development follows the accelerated approval of camizestrant in combination with a CDK4/6 inhibitor. These two approvals represent different ways in which the molecular evolution of cancer can now guide treatment.

ESR1 mutations, which affect the gene encoding the estrogen receptor, are a primary mechanism of acquired resistance to endocrine therapy. These mutations often emerge during the course of metastatic disease under the selective pressure of aromatase inhibitors. Imlunestrant is a next-generation, orally selective estrogen receptor degrader (SERD) that binds to the receptor, inhibits its function, and promotes its degradation.