Recent clinical trials of mTOR-targeted cancer therapies.

The mammalian target of rapamycin (mTOR) is a central component within a complex intracellular signaling network that regulates various processes including cell growth, proliferation, metabolism, and angiogenesis. A hyperactive PI3k/Akt/mTOR signaling pathway is found in many human cancers and alterations in this pathway is associated with the development and progression of cancer. Drugs that target and inhibit mTOR activity are therefore expected to provide therapeutic value in a number of cancer types. Several classes of mTOR-targeted therapeutics are currently being evaluated in cancer clinical trials, including the rapamycins, dual PI3K-mTOR inhibitors, and ATP-competitive mTORC1/2 inhibitors. This review summarizes important findings from recently completed trials of mTOR inhibitors and also discusses preliminary data from ongoing trials.