What would be your next line of therapy for a postmenopausal metastatic ER+/Her 2- BC, s/p anastrazole and palbociclib/fulvestrant who has progressive disease and ESR1 mutation on ctDNA?

Patients with metastatic, hormone receptor positive, HER2 negative breast cancer who develop disease progression after aromatase inhibitor followed by fulvestrant and CDK4/6 inhibitor and have tumors with ESR1 mutation represent a therapeutic challenge. In patients whose cancer cells harbor PIK3CA m...

The only other chemotherapy-free alternative I would consider in this scenario would be continuing fulvestrant but adding everolimus. This combination has shown efficacy in patients who progressed on AI by doubling median PFS from 5.1 to 10.3 months based on PrE0102 Phase II study. However, we don't...