This review summarizes drug discovery efforts on mGluR2 positive allosteric modulators (PAMs) from 2000 to 2013. Medicinal chemistry programs and the identified 21 chemotypes are analyzed and compared in terms of their biological activity and ligand efficiency. Comparative analysis of ligand efficiency metrics including ligand efficiency and lipophilic ligand efficiency allowed us to identify the most promising chemotypes. The perspective of their clinical development was evaluated in the light of recent human data.
Keywords: Clinical development, ligand efficiency, medicinal chemistry, mGluR2 receptors, positive allosteric modulators.