Use of the Synthetic Hormone CDB-2914 in Treating Symptoms of Menopause

Doctors recommend hormone replacement therapy to postmenopausal women as treatment for symptoms of estrogen-deficiency. However, many women do not take hormone replacement therapy because of side effects. In women with an intact uterus, estrogen must be given with progesterone to prevent overgrowth of the lining of the uterus. Side effects from progesterone may cause women to discontinue hormone replacement therapy. Compounds that are similar to naturally occurring hormones have been synthesized and studied for their ability to block or simulate the action of sex steroids such as estrogen and progesterone. The development of this class of compounds, called selective hormone receptor modulators, may provide new treatments that are targeted to specific organs or tissues. One example is the selective estrogen receptor modulator raloxifene, which blocks estrogen action at the uterus, and acts like estrogen at the bone. Raloxifene has been approved for use in post-menopausal women as a form of hormone replacement therapy and a treatment for osteoporosis. It provides many of estrogen's benefits without stimulating the uterine lining and thus may be taken without a progestin. This study evaluates the selective progesterone receptor modulator CDB-2914, a man-made hormone. Other progesterone receptor modulators have been shown to block estrogen's stimulating effect on the uterus in monkeys. If CDB-2914 has this effect in menopausal women, it may provide a new approach to hormone replacement therapy. In women studied at the NIH, single doses of CDB-2914 slowed uterine development or induced menses, depending on when it was given during the menstrual cycle. Like raloxifene, CDB-2914 has the potential for use in hormone replacement therapy, but to date the effects of its chronic administration have not been studied. This study aims to evaluate the safety and the physiologic and endocrine effects of chronic oral administration of CDB-2914 in postmenopausal women. All study subjects will receive daily oral estrogen and either CDB-2914, progesterone or a placebo to evaluate whether CDB-2914 blocks or enhances the usual effects of hormone replacement therapy on the uterine lining, lipid levels, clotting factors, bone turnover, hot flashes and quality of life. Weekly blood measurements, quality of life questionnaires, pre- and post-treatment ultrasound examinations of the uterus and a single biopsy of the uterine lining will be performed on all study subjects to assess these endpoints.