Epelsiban

Epelsiban (INN, USAN, code name GSK-557,296-B) is an orally bioavailable drug which acts as oxytocin receptor antagonist. It is being developed by GlaxoSmithKline for the treatment of premature ejaculation in men and as an agent to enhance embryo or blastocyst implantation in women undergoing embryo or blastocyst transfer associated with in vitro fertilization (IVF). Epelsiban has high affinity for the oxytocin receptor (K_i = 0.13 nM) with >31,000-fold selectivity over the related vasopressin receptors.