Discovery Of 2-Chloro-N-(4-Methoxyphenyl)-N-Methylquinazolin-4-Amine (Ep128265, Mpi-0441138) As A Potent Inducer Of Apoptosis With High In Vivo Activity

Using a live cell, high-throughput caspase-3 activator assay, we have identified a novel series of 4-anilinoquinazolines as inducers of apoptosis. In this report, we discuss the discovery of 2-chloro-N-(4-methoxyphenyl)-N-methylquinazolin-4-amine, compound 2b (EP128265, MPI-0441138) as a highly active inducer of apoptosis (EC(50) for caspase activation of 2 nM) and as a potent inhibitor of cell proliferation (GI(50) of 2 nM) in T47D cells. Compound 2b inhibited tubulin polymerization, was effective in cells overexpressing ABC transporter Pgp-1, and was efficacious in the MX-1 human breast and PC-3 prostate cancer mouse models. In contrast to the SAR of 4-anilinoquinazolines as EGFR kinase inhibitors, the methyl group on the nitrogen linker was essential for the apoptosis-inducing activity of 4-anilinoquinazolines and substitution in the 6- and 7-positions of the quinazoline core structure decreased potency.