Structure and ligand-based design of mTOR and PI3-kinase inhibitors leading to the clinical candidates VS-5584 (SB2343) and SB2602.

Phosphoinositide 3-kinases (PI3Ks) and the mammalian target of rapamycin (mTOR) act as critical effectors in a commonly deregulated cell signaling pathway in human cancers. The abnormal activation of the PI3K/mTOR pathway has been shown to play a role in initiation, progression, and metastasis of human tumors. Being one of the most frequently activated pathways in cancer, much effort has been directed toward inhibition of the PI3K/mTOR pathway as a novel oncology therapy. Previous work by a number of groups has revealed several selective PI3K and dual mTOR/PI3K inhibitors. However, there are few reports of therapeutic agents with a pan-PI3K/mTOR inhibitory profile within a narrow concentration range. We therefore initiated a drug discovery project with the aim of discovering dual mTOR/PI3K inhibitors which would equipotently inhibit the 4 isoforms of PI3K, α, β, γ, and δ, and mTOR a compelling profile for powerful blockage of the PI3K/mTOR pathway. A pharmacophore model was generated and used for designin...