mTOR inhibitor-3

mTOR inhibitor-3 is a remarkably selective mTOR inhibitor with a K_i of 1.5 nM. mTOR inhibitor-3 suppresses mTORC1 and mTORC2 in cellular and in vivo pharmacokinetic (PK)/pharmacodynamic (PD) experiments. IC50 & Target: Ki: 1.5 nM (mTOR)^[1]
mTORC1, mTORC2^[1] In Vitro: mTOR inhibitor-3 (Compound 12i) inhibits mTOR with a K_i of 1.5 nM, 500-fold selectivity over closely related PI3 kinases. mTOR inhibitor-3 inhibits NCI-PC3 and MCF7neo/Her2 cells proliferation with IC₅₀s of 150 nM and 57 nM, respectively^[2]. In Vivo: mTOR inhibitor-3 (Compound 8h) has high free plasma clearance in both mice (1818 mL/min/kg) and rats (1538 mL/min/kg in rat) ^[1]. mTOR inhibitor-3 (Compounds 12i) is selected for this study due to its potency, selectivity, and favorable mouse PK profile. Plasma levels of mTOR inhibitor-3 6 h following oral administration in PC3 tumor-bearing mice along with the fold decreases of phosphorylated mTORC1 and -2 substrates relative to time-matched vehicle controls. mTOR inhibitor-3 has moderate terminal elimination half-life (t_1/2=1.7 h for mouse(1 mg/kg, iv)). mTOR inhibitor-3 achieves tumor stasis at the highest 200 mg/kg/day dose examined, which appears to also be approaching the limit of tolerability for this molecule^[2].