everolimus + exemestane + xentuzumab

This is a combination therapy consisting of three agents: everolimus, exemestane, and xentuzumab. Everolimus is an oral mTOR inhibitor that blocks the mTOR pathway, which is involved in cell growth and proliferation. Exemestane is an oral steroidal aromatase inhibitor that reduces estrogen production by inhibiting the aromatase enzyme, thereby decreasing hormone-driven tumor growth in hormone receptor-positive breast cancer. Xentuzumab is a humanized monoclonal antibody targeting insulin-like growth factors IGF-1 and IGF-2; it neutralizes their proliferative activity and helps restore inhibition of AKT signaling by everolimus. This triple combination has been studied primarily in post-menopausal women with hormone receptor-positive (HR+), HER2-negative advanced or metastatic breast cancer with non-visceral disease who have progressed on prior endocrine therapy[1][2][3]. The rationale for this regimen is to intensify inhibition of tumor growth by blocking both estrogen signaling (exemestane), mTOR pathway (everolimus), and compensatory IGF-mediated survival pathways (xentuzumab)[1][3].