Endometriosis is a serious and chronic medical condition where endometrial connective tissue (stroma) and glands that are normally present in the uterine cavity are found in other parts of the body. This misplaced tissue develops into growths or lesions that can be found anywhere in the pelvic cavity: on the ovaries, the fallopian tubes, on the pelvic sidewall. These endometrial growths may also be found on other sites in the body including the bladder, bowel, vagina, cervix, vulva, and in abdominal surgical scars. Less commonly, these lesions can be found in the lung, arm, thigh and other locations. The cause of endometriosis is unknown. One leading hypothesis, the basis for MPI-676’s product concept, links endometriosis to the overexpression of aromatase in endometriotic tissue ex utero.
Endometriosis lesions respond to the menstrual cycle in the same way that the tissue of the uterine lining does each month. However, unlike normal menstruation whereby the menstrual blood flows from the uterus and out of the body through the vagina, the blood and tissue shed from endometrial growths have no way of leaving the body. This results in internal bleeding, breakdown of the blood and tissue from the lesions, and inflammation.
The most common symptom of endometriosis is pelvic pain. The pain often correlates to the menstrual cycle, but a woman with endometriosis may also experience pain that doesn’t correlate to her cycle. Chronic pelvic pain, painful periods (dysmenorrheal), fatigue, infertility, painful urination and painful intercourse (dyspareunia) are common symptoms of endometriosis. For many women, the pain of endometriosis is so severe and debilitating that it impacts their daily lives in significant ways.
According to the Endometriosis Association, endometriosis affects at least 6.3 million women and girls in the U.S. It is estimated that seven to 10 percent of all women are affected by endometriosis, including 70 to 87 percent of women with chronic pelvic pain and 30 to 40 percent of all infertile women.
There are several medical treatment options, including danazol, GnRH agonists and progestins, each of which have limitations associated with patient response, tolerability, side-effect profile and duration of treatment.