Retrospective Analysis of Phase 3 Data Suggest Wyeth's Investigational Compound Bazedoxifene/Conjugated Estrogens Comparable to Placebo on Incidence of Abnormal Mammograms
COLLEGEVILLE, Pa., Sept. 25 /PRNewswire/ -- A retrospective analysis of Phase 3 two-year data presented at the annual meeting of the North American Menopause Society (NAMS) suggest that postmenopausal women treated with bazedoxifene/conjugated estrogens (BZA/CE) may experience incidence of breast tenderness and abnormal mammograms no greater than those treated with placebo. BZA/CE is an investigational compound being studied by Wyeth Pharmaceuticals, a division of Wyeth (NYSE: WYE), for the treatment of moderate-to-severe menopausal vasomotor symptoms such as hot flashes and night sweats, and for the prevention of postmenopausal osteoporosis. Wyeth describes this compound as a tissue selective estrogen complex (TSEC).
In a retrospective analysis of data from another phase 3 study, treatment with Wyeth's investigational compound bazedoxifene (BZA) alone did not appear to increase mammographic breast density in postmenopausal women with osteoporosis compared to raloxifene (the active comparator) or placebo over two years. BZA is an investigational selective estrogen receptor modulator (SERM) under development for the treatment and prevention of postmenopausal osteoporosis.
NAMS Poster Titled: Breast Effects of Bazedoxifene/Conjugated Estrogens in a Randomized, Controlled Trial of Postmenopausal Women
In the phase 3 study involving 3,397 postmenopausal women, primarily designed to evaluate the effects of BZA/CE on the endometrium and bone mineral density, mammograms were taken at baseline, and again at years one and two as part of the safety evaluation. Breast tenderness was reported in daily diaries. A retrospective analysis suggested no significant differences in the incidence of breast tenderness or abnormal mammograms between the BZA/CE groups at any of the doses studied and placebo or raloxifene.
In this study, the incidence of treatment-emergent adverse events, serious adverse events, and withdrawals due to adverse events were similar among the active treatment groups and placebo.
NAMS Poster Titled: Effects of Bazedoxifene on Mammographic Breast Density in Postmenopausal Women with Osteoporosis
A retrospective study examined mammograms in a subset representing 726 postmenopausal women from a primary phase 3 fracture reduction study of BZA, raloxifene, and placebo. The objective was to evaluate the quantitative changes in mammographic breast density after 24 months of treatment. This study indicated treatment with BZA over 24 months did not affect mammographic breast density in postmenopausal women with osteoporosis. Changes in breast density with BZA were similar to those with raloxifene and placebo.
Also presented at the NAMS meeting were data on the effects of BZA/CE on sleep and overall menopausal symptoms.
Wyeth describes the pairing of a selective estrogen receptor modulator (SERM) and one or more estrogens as a TSEC. The TSEC concept is based on the blended tissue-selective activity of the components, which is hypothesized to yield different clinical results than those provided by either the SERM or estrogen(s) alone.
According to the U.S. Census Bureau, in 2006, there were approximately 20 million women of menopausal age (45-54 years) in the United States. As many as 50 percent to 90 percent of women going through menopause experience vasomotor symptoms, such as hot flashes, which can greatly impact a woman's life. Furthermore, between 10 percent and 40 percent of postmenopausal women experience symptoms of vulvar and vaginal atrophy, which typically do not subside without treatment.
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