giredestrant + inavolisib + ribociclib

A combination therapy of **giredestrant**, **inavolisib**, and **ribociclib** designed for the treatment of hormone receptor-positive, HER2-negative breast cancer. - **Giredestrant** is an oral *selective estrogen receptor degrader* (SERD) that antagonizes and degrades the estrogen receptor (ER), blocking estrogen signaling and downregulating ER expression. - **Inavolisib** is a *phosphatidylinositol 3-kinase alpha (PI3Kα) inhibitor* targeting tumors with activating PIK3CA mutations to inhibit the PI3K signaling pathway, a driver of cell growth and survival. - **Ribociclib** is a *cyclin-dependent kinase 4/6 (CDK4/6) inhibitor* that blocks CDK4/6-mediated cell cycle progression, impairing tumor cell proliferation. This triple-combination aims to maximize anti-tumor activity by simultaneously inhibiting ER function, PI3K pathway activation, and cell cycle progression, addressing resistance mechanisms in advanced or endocrine-resistant breast cancer. This regimen is studied in ongoing clinical trials for advanced and metastatic hormone receptor-positive, HER2-negative breast cancer, particularly in patients with PIK3CA mutations[5][1].