anastrozole + palbociclib + pertuzumab + trastuzumab

This is a four-drug combination therapy being investigated for hormone receptor-positive (HR+), HER2-positive metastatic breast cancer. The combination represents a novel, chemotherapy-free approach that targets multiple pathways simultaneously. Anastrozole is an aromatase inhibitor that reduces estrogen production. Palbociclib is a CDK4/6 inhibitor that blocks cell cycle progression. Trastuzumab and pertuzumab are both HER2-targeted monoclonal antibodies that bind to different domains of HER2, preventing dimerization and downstream signaling. This combination aims to provide effective treatment while reducing the toxic effects typically associated with chemotherapy regimens.