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M. D. Anderson Opens First Clinical Trial to Examine Mifepristone in Treatment of Endometrial Cancer

M. D. Anderson Opens First Clinical Trial to Examine Mifepristone in Treatment of Endometrial Cancer
M. D. Anderson News Release 01/16/02

The University of Texas M. D. Anderson Cancer Center has opened the first clinical trial to study Mifepristone, formerly known as RU 486, as a treatment for specific types of endometrial cancers.

Mifepristone was approved by the U. S. Food and Drug Administration (FDA) on September 28, 2000 for use in the termination of early-stage pregnancy. This will be the first study since its approval by the FDA - and only the second ever conducted in the United States - to examine the hormone therapy's ability as an anti-cancer drug. 

pullquoteLed by Dr. Lois M. Ramondetta, assistant professor in M. D. Anderson's Department of Gynecologic Oncology, the Phase II clinical trial is recruiting 37 women whose tumors are progesterone-receptor positive with recurrent and/or advanced endometriod carcinomas or low-grade endometrial stromal sarcoma (LGESS).

"Recurrent and advanced endometrial cancer is very difficult to treat and even more difficult to cure," says Dr. Ramondetta. "With this trial of Mifepristone, we are offering patients with very few treatment options a new hormonal therapy with potential."

Endometrial cancer is the most common type of cancer of the gynecological tract. According to the American Cancer Society, 36,000 news cases were reported in the United States in 2000 and 6,500 women died from the disease.

According to Dr. Ramondetta, the presence of estrogen and progesterone receptors in endometrial tumors has been shown to correlate directly to a patient's survival and response to hormonal therapy. Fifty to 60 percent of primary endometrial cancers and the majority of LGESS are estrogen-receptor and progesterone-receptor positive.

Current hormonal therapy treatments - Megace, Depo-Provera and Provera -- are not always effective, said Dr. Ramondetta.

"The current response rate to hormonal therapy for women with progesterone-receptor positive advanced or recurrent endometrial carcinoma is 18 - 25 percent. Another 20 - 50 percent show stabilization of disease," says Dr. Ramondetta. "Similarly, patients with LGESS tumors respond to current hormonal therapy options at a rate of 33 - 45 percent.

"By binding the progesterone receptors more powerfully than progesterone, we believe that Mifepristone shows promise for treating these specific types of endometrial tumors," Dr. Ramondetta continued. "Should Mifepristone prove successful on this trial, there is potential for further studies in endometrial cancer, as well as other hormone-associated cancers, such as ovarian, prostate and breast."

Prior to the drug gaining FDA approval in September 2000, very few studies had been conducted with Mifepristone for alternative medical applications. Still, says Dr. Ramondetta, the hormone therapy's potential is impressive. Mifepristone has shown promise shrinking uterine fibroids and treating endometriosis. Small, limited trials have studied Mifepristone as a cancer therapy. A trial with Mifepristone and ovarian cancer was conducted in Camden, New Jersey. Three studies outside of the United States examined the drug in patients with metastatic breast cancer. All studies showed measurable response.

"Not only will this be the first time since its approval by the FDA that Mifepristone will be studied as a cancer therapy, but it will also be the first time that the drug is administered in volume at lower doses to patients, rather than one pill at a time," said Dr. Ramondetta.

M. D. Anderson's non-randomized study will involve participants taking one pill a day (200 milligrams) of Mifepristone. (To terminate early-term pregnancies, Mifepristone is administered in a single dose of 600 milligrams.) Throughout the trial, participants will receive physical exams and CAT scans at specific intervals to evaluate the size of the endometrial tumors. To further evaluate Mifepristone's effect on tumors, patients may elect to undergo a biopsy two to three months after beginning treatment.

Few side effects are associated with Mifepristone, the most serious being a dermatological rash. Other side-effects of the hormone therapy, including mild nausea, hot flashes, fatigue and thinning of hair, are uncommon and do not occur in a majority of patients, said Dr. Ramondetta.

Mifepristone is manufactured by Danco Laboratories. Drug cost to participants is $500 per month. (Follow-up tests involved, including blood-work and x-rays are considered standard and should be covered by insurance.) Prospective participants and/or referring physicians who would like to learn more about the study, as well as additional inclusion requirements, should call (713) 794-1422 or The M. D. Anderson Information Line at (800) 392-1611. For more information about the trial, visit M. D. Anderson's Mifepristone Trial webpage.


© 2015 The University of Texas MD Anderson Cancer Center