Investigators at Wake Forest Baptist Medical Center have concluded research on a new postmenopausal hormone therapy that shows promise as an effective treatment for menopausal symptoms and the prevention of osteoporosis without increasing the risk for heart disease or breast cancer.
Traditional forms of hormone therapy (HT) provide the benefits of symptom relief, prevention of osteoporosis and prevention of atherosclerosis, but increase the risk of uterine cancer (with estrogens alone) or breast cancer (with combined estrogens and progestins). Thus, the risk-benefit ratio of traditional HT is not ideal. Less potent plant-derived estrogens are relatively safe, but less effective. Selective estrogen receptor modulators (SERMs) provide both beneficial effects and adverse effects, but the ideal treatment has proven elusive, said J. Mark Cline, D.V.M., Ph.D., one of the co-authors.
The Wake Forest Baptist team worked in partnership with the pharmaceutical company Pfizer to explore a new strategy, termed a Tissue Selective Estrogen Combination (TSEC). Using this strategy, a conventional estrogen (CEE) was combined with a bone-protective SERM-like drug, bazedoxifene acetate (BZA), to produce a complementary pattern of tissue effects that maximize the benefits of HT while avoiding the risk. The study involved a 20-month randomized, parallel-arm trial - which has a comparison group and at least one new or active therapy group - in postmenopausal nonhuman primates, designed to determine the effect of TSEC treatment on the breast, uterus and cardiovascular system.
The TSEC strategy has been evaluated in the Selective estrogens, Menopause, And Response to Therapy (SMART) phase 3 trials involving more than 6,000 women. Cline said the Wake Forest Baptist nonhuman primate trials are important because they can address tissue responses directly, whereas studies in women use clinical outcomes that may require many years to provide conclusive results.