Discovery of AZD8165 – a clinical candidate from a novel series of neutral thrombin inhibitors

A novel series of neutral thrombin inhibitors has been developed using a selection process based on docking experiments and property calculations and predictions.

New proline mimetics: synthesis of thrombin inhibitors incorporating cyclopentane- and cyclopentenedicarboxylic acid templates in the P2 position. Binding conformation investigated by X-ray crystallography

With the aim to prepare nonpeptidic thrombin inhibitors, the amino acids of the thrombin-inhibiting tripeptide chain D-Phe-Pro-Arg were replaced with isosteres. Arg was replaced with the more rigid P1 truncated p-amidinobenzylamine (Pab), Pro with either cyclopentane-1, 2-dicarboxylic acid or cyclopentene-1,5-dicarboxylic acid, and D-Phe with a series of readily available lipophilic amines. One of the most potent compounds (25, pIC(50) = 6.01) in these series was cocrystallized with thrombin where the X-ray crystal structure provide insight to the structure-activity relationship (SAR).