Contact: Joe Landi/Rosemarie Yancosek [Landmark Communications] (201) 567-4242 or Kristin Fayer [Searle] (847) 470-6728
NOVEMBER 6, 1996 Boston, MA The first head-to-head study comparing GnRH agonists, the most recent class of endometriosis treatments, indicates that Synarel® (nafarelin acetate) Nasal Solution relieves the symptoms of endometriosis with significantly less reduction in bone mineral density (BMD) of the spine than treatment with Lupron Depot®* (leuprolide acetate). Investigators presenting today at the 52nd annual meeting of the American Society for Reproductive Medicine say the study opens new research avenues for exploring longer-term drug treatment strategies as alternatives to hysterectomy and other surgical interventions.
"Currently, women with endometriosis do not have attractive alternatives for long-term relief. Concerns about BMD loss have limited effective drug therapies to short-term application only," said Sanjay Agarwal, M.D., interim director of reproductive medicine at Cedars-Sinai Medical Center, Los Angeles, and lead investigator of the study. "Evidence that nafarelin impacts spinal BMD less than leuprolide invites further study to confirm these results and to see what the cumulative effect of this trend would be in a chronic-care model."
Endometriosis is a disease that affects an estimated 5 million American women in their reproductive years. It involves abnormal growth of the endometrium, the tissue that lines the inside of the uterus that builds up and sheds each month as part of the menstrual cycle. In endometriosis, endometrial-like tissue grows outside of the uterus -- for example, on the ovaries, fallopian tubes and bladder. Common symptoms include dysmenorrhea (pain before and during menstruation), dyspareunia (pain during and after sexual activity), infertility, and heavy or irregular bleeding. Left untreated, endometriosis can permanently damage the reproductive organs.
The multicenter study evaluated more than 200 women who had a diagnosis of endometriosis confirmed by laparoscopy: 105 were given Synarel® (200 mcg. of nafarelin acetate in an intranasal spray twice daily) and 103 were administered Lupron Depot® (3.75 mg. of leuprolide acetate in an intramuscular injection once monthly). Both products are gonadotropin-releasing hormone (GnRH) agonists that inhibit estrogen production. By reducing estrogen, GnRH agonists improve the clinical signs and symptoms of endometriosisfor example, healing endometrial lesions and alleviating pain.
After a single, six-month course of therapy, results indicated that a standard dose of nafarelin was as effective as a standard dose of leuprolide in alleviating symptoms associated with endometriosis. However, overall loss of BMD was 40 percent less in the nafarelin group. Patients in the leuprolide group experienced a five percent decrease in BMD over the course of one treatment compared to only a three percent decrease in the nafarelin group. Investigators attribute the difference to a higher level of estrogen in nafarelin-treated patients than in the leuprolide group. In addition to its many reproductive and regulatory functions, estrogen is a known protector of bone. At six months post-treatment, both patient groups experienced some regrowth of bone and the mean loss of BMD was 50 percent less in the nafarelin group compared to the leuprolide group.
"To effectively manage the symptoms of endometriosis, we need to find the proper balance of estrogen. Levels must be low enough to interfere with endometrial growth but high enough to protect bone," said Dr. Agarwal. "Our data suggest that leuprolide virtually shuts down estrogen production. In contrast, nafarelin reduces estrogen levels enough to control endometriosis symptoms, while causing fewer hypoestrogenic side effects including less BMD loss."
A similar trend was found when investigators examined the incidence of hot flashes in the two patient groups. The median percentage of days that women reported experiencing hot flashes was 66 percent in the nafarelin group and 91 percent in the leuprolide group.
"The difference in incidence of hot flashes among both groups underscores the likelihood that, unlike nafarelin, leuprolide suppresses estrogen levels more than required to provide effective relief of endometriosis symptoms," said Agarwal.
Synarel® is a product of Searle, a Skokie, IL-based developer, manufacturer and marketer of pharmaceuticals and other healthcare solutions worldwide. Searle is a wholly owned subsidiary of Monsanto Company. For more information about Searle and its products, please visit Searle healthNet on the World Wide Web at www.searlehealthnet.com.
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*Lupron Depot is a registered trademark of Takeda-Abbott Pharmaceuticals.
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