Identification of a Benzimidazolecarboxylic Acid Derivative (BAY 1316957) as a Potent and Selective Human Prostaglandin E2 Receptor Subtype 4 (hEP4-R) Antagonist for the Treatment of Endometriosis

The presence and growth of endometrial tissue outside the uterine cavity in endometriosis patients are primarily driven by hormone-dependent and inflammatory processes-the latter being frequently associated with severe, acute, and chronic pelvic pain. The EP4 subtype of prostaglandin E2 (PGE2) receptors (EP4-R) is a particularly promising antiinflammatory and antinociceptive target as both this receptor subtype and the pathways forming PGE2 are highly expressed in endometriotic lesions. High-throughput screening resulted in the identification of benzimidazole derivatives as novel hEP4-R antagonists. Careful structure-activity relationship investigation guided by rational design identified a methyl substitution adjacent to the carboxylic acid as an appropriate means to accomplish favorable pharmacokinetic properties by reduction of glucuronidation. Further optimization led to the identification of benzimidazolecarboxylic acid BAY 1316957, a highly potent, specific, and selective hEP4-R antagonist with excellent drug metabolism and pharmacokinetics properties. Notably, treatment with BAY 1316957 can be expected to lead to prominent and rapid pain relief and significant improvement of the patient's quality of life.