Would you start fulvestrant plus CDK4/6 inhibitors in a patient with ESR1 mutation with metastatic breast cancer on liquid biopsy in a first-line setting?

Since the presence of ESR1 mutation is associated with a lack of benefit from aromatase inhibitors, I tend to start patients who have evidence of this mutation on fulvestrant in combination with a CDK 4/6 inhibitor (typically ribociclib). ESR1 mutation found on circulating tumor DNA suggests that a ...

Yes. If a patient’s tumor has an ESR1mut in the first-line setting (presumably due to progressive disease while on an AI for early stage breast cancer), I would absolutely pursue fulvestrant with a CDK4/6 inhibitor. Several trials (including PADA-1 above) have demonstrated the efficacy of fulvestran...

For patients with HR+/HER2- breast cancer who develop metastatic progression on (or shortly after receiving) aromatase inhibitor therapy, fulvestrant with a CDK4/6 inhibitor (CDK4/6i) is a widely utilized therapeutic option. Several new medications have recently been approved for patients with metas...