sirolimus (albumin-bound) + fulvestrant

This is a combination of **sirolimus (albumin-bound)**—a nanoparticle, albumin-bound formulation of the mTOR inhibitor sirolimus—and **fulvestrant**, an estrogen receptor antagonist. - **Sirolimus (albumin-bound)** is designed to improve intravenous delivery and tumor penetration of sirolimus via albumin-mediated endocytosis[1][3][4]. It acts primarily by binding FKBP-12, forming a complex that inhibits mTOR, thereby blocking downstream PI3K/AKT signaling, reducing cell proliferation and angiogenesis[3][4][6]. - **Fulvestrant** is a selective estrogen receptor downregulator (SERD) that binds, blocks, and accelerates estrogen receptor degradation, used mainly in hormone receptor-positive advanced breast cancer. - The combination targets both the **mTOR pathway** (involved in growth/proliferation) and **estrogen receptor signaling** (stimulating tumor growth in hormone-sensitive cancers).[3][4] - **Developers:** (as Fyarro: sirolimus (albumin-bound))—Aadi Bioscience[5][7][9]. Fulvestrant was developed by AstraZeneca. - **Primary indications (as combination):** There is preclinical and investigational clinical interest in combining mTOR inhibitors like sirolimus with estrogen pathway blockade (fulvestrant) for hormone receptor-positive cancers, especially breast cancer. As a combination, regulatory approval status is investigational or clinical trial only.

Brand names

fyarro + fulvestrant

Other names

sirolimus protein-bound particles + fulvestrantsirolimus nab + fulvestrantsirolimus albumin-bound nanoparticles + fulvestrant