Biochem/physiol Actions

XL388 is a potent, selective, orally bioavailable ATP-competitive inhibitor of mammalian target of rapamycin (mTOR) with an IC₅₀ of 9.9 nM for mTOR, 8 nM for mTORC1, 166 nM for mTORC2, and 1000-fold selectivity for mTOR over the closely related PI3K kinases and a panel of 141 protein kinases tested. XL388 blocked mTORC1 phosphorylation of p70S6K (T389) with an IC₅₀ value of 94 nM and blocked mTORC2 phosphorylationof AKT (S473) with an IC₅₀ value of 350 nM. XL388 showed complete tumor growth inhibition in mice bearing MCF-7 xenograft tumors.

Packaging

5, 25 mg in glass bottle