Study results from two research papers have shown that use of the drug Ospemifene in combination with other anti-estrogens for vaginal atrophy reduces the incidence of
breast cancer. The study has been proved in mouse model and researchers are planning for a clinical trial.
DeGregorio and his colleagues at UC Davis compared the ability of ospemifene, tamoxifen and raloxifen to inhibit breast cancer in mice exposed to a carcinogen. Ospemifene and tamoxifen both inhibited breast cancer development. Results show that the mice in the ospemifene group were 95 percent less likely than mice in the control group to develop breast cancer and the study result is to be published in the Journal of Steroid Biochemistry and Molecular Biology.
The second study in which the first study author DeGregorio is also a co-author was led by Jeffrey P. Gregg, Associate professor of pathology and laboratory medicine at UC Davis, where they reported that Tamoxifen and Ospemifene both inhibited the growth and progression of pre-malignant breast lesions that closely resemble human ductal carcinomas in situ in mouse model.
Ospemifene is a Selective Estrogen Receptor Modulator (SERM), and is an effective anti-estrogen like tamoxifen and raloxifen which is used in the prevention and treatment of breast cancer which binds to estrogens. Ospemifene is now being developed by QuatRx Pharmaceuticals, an Ann Arbor, Mich.-based biopharmaceutical company that recently merged with Hormos Medical Corp. The drug is expected to enter Phase 3 clinical testing in the United States early next year for the treatment of vaginal atrophy, a common condition among postmenopausal women.
The advantage of Ospemifene over tamoxifen and raloxifen is due to its reduced side effects as raloxifen can cause hot flashes, insomnia and blood clots. Tamoxifen can cause endometrial cancer in patients undergoing tamoxifen therapy for breast cancer. But ospemifene have a unique estrogen-like effect on the vagina, yet a neutral effect on the endometrium, or lining of the uterus, and no aggravation or initiation of hot flashes.