Selective progesterone receptor modulators (SPRMs): a novel therapeutic concept in endometriosis.

Endometriosis, the presence of endometrial tissue outside the uterus, is a progressive, estrogen-dependent disease and occurs nearly exclusively in menstruating women of reproductive age. Pain syndrome, however, represents the major clinical problem of this disease, manifested as dysmenorrhea, pelvic pain, lower abdominal pain, and dyspareunia. The manifestation of the disease, that is, the pain syndrome, rather than the disease itself currently represents the major indication for both the medical and surgical therapies of endometriosis. The major drawbacks of current medical therapies of endometriosis are sometimes severe side effects. In this review, selective progesterone receptor modulators (SPRMs, mesoprogestins) as a potential therapeutic concept in endometriosis are discussed. Due to endometrial selectivity and favorable pharmacological profile, SPRMs may have advantages over the current medical treatments of this disease. Other emerging therapeutic approaches for this disease are also mentioned.