Papers of the Week

The presence and growth of endometrial tissue outside the uterine cavity in endometriosis patients is 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 anti-inflammatory and anti-nociceptive 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 SAR 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 DMPK properties. Notably, treatment with BAY 1316957 can be expected to lead to prominent and rapid pain relief and significant improvement of the patients` quality of life.