MCH-R1 antagonists: what is keeping most research programs away from the clinic?

Despite the high number of drug-discovery programs dedicated to finding small-molecule MCH-R1 antagonists for the treatment of obesity and/or mood disorders, a very limited number of these have progressed into the clinic. Beyond the common challenges in drug design related to ADME and safety profiles, cardiovascular risk involving hERG binding and the potential for subsequent drug-induced QTc prolongation has been a major hurdle for a significant number of MCH-R1 research programs. Many of these programs have evolved, and effectively designed MCH antagonists having decreased hERG-binding affinity have emerged. Currently, however, only a selected few candidates have progressed to clinical development. Drug-design strategies, in vivo efficacy, ADME, and cardiovascular safety profiles for a selection of MCH-R1 antagonist research programs are discussed ahead.