Discovery of Novel 3,3-Disubstituted Piperidines as Orally Bioavailable, Potent, and Efficacious HDM2-p53 Inhibitors

A new subseries of substituted piperidines as p53-HDM2 inhibitors exemplified by <b>21</b> has been developed from the initial lead <b>1</b>. Research focused on optimization of a crucial HDM2 Trp23–ligand interaction led to the identification of 2-(trifluoromethyl)­thiophene as the preferred moiety. Further investigation of the Leu26 pocket resulted in potent, novel substituted piperidine inhibitors of the HDM2-p53 interaction that demonstrated tumor regression in several human cancer xenograft models in mice. The structure of HDM2 in complex with inhibitors <b>3</b>, <b>10</b>, and <b>21</b> is described

MK-8353: Discovery of an Orally Bioavailable Dual Mechanism ERK Inhibitor for Oncology

The emergence and evolution of new immunological cancer therapies has sparked a rapidly growing interest in discovering novel pathways to treat cancer. Toward this aim, a novel series of pyrrolidine derivatives (compound <b>5</b>) were identified as potent inhibitors of ERK1/2 with excellent kinase selectivity and dual mechanism of action but suffered from poor pharmacokinetics (PK). The challenge of PK was overcome by the discovery of a novel 3­(<i>S</i>)-thiomethyl pyrrolidine analog <b>7</b>. Lead optimization through focused structure–activity relationship led to the discovery of a clinical candidate <b>MK-8353</b> suitable for twice daily oral dosing as a potential new cancer therapeutic