September 25, 2008

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 , 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.

Data Highlights

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.

About TSEC

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.

About Menopause

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.

About Wyeth Pharmaceuticals

Wyeth Pharmaceuticals, a division of Wyeth, has leading products in the areas of women's health care, infectious disease, gastrointestinal health, central nervous system, inflammation, transplantation, hemophilia, oncology, vaccines and nutritional products.

Wyeth is one of the world's largest research-driven pharmaceutical and health care products companies. It is a leader in the discovery, development, manufacturing and marketing of pharmaceuticals, vaccines, biotechnology products, nutritionals and non-prescription medicines that improve the quality of life for people worldwide. The Company's major divisions include Wyeth Pharmaceuticals, Wyeth Consumer Healthcare and Fort Dodge Animal Health. For additional information about the company, please visit

The statements in this press release that are not historical facts are forward-looking statements that are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. In particular, clinical trial data are subject to differing interpretations, and the views of regulatory agencies, medical and scientific experts and others may differ from ours. In addition, there can be no assurance that bazedoxifene/conjugated estrogens or bazedoxifene will ever receive regulatory approval or be successfully developed and commercialized. Other risks and uncertainties that could cause actual results to differ materially from those expressed or implied by forward-looking statements include, without limitation, the inherent uncertainty of the timing and success of, and expense associated with, research, development, regulatory approval and commercialization of our products and pipeline products; government cost-containment initiatives; restrictions on third-party payments for our products; substantial competition in our industry, including from branded and generic products; emerging data on our products and pipeline products; the importance of strong performance from our principal products and our anticipated new product introductions; the highly regulated nature of our business; product liability, intellectual property and other litigation risks and environmental liabilities; uncertainty regarding our intellectual property rights and those of others; difficulties associated with, and regulatory compliance with respect to, manufacturing of our products; risks associated with our strategic relationships; economic conditions including interest and currency exchange rate fluctuations; changes in generally accepted accounting principles; trade buying patterns; the impact of legislation and regulatory compliance; risks and uncertainties associated with global operations and sales; and other risks and uncertainties, including those detailed from time to time in our periodic reports filed with the Securities and Exchange Commission, including our current reports on Form 8-K, quarterly reports on Form 10-Q and annual report on Form 10-K, particularly the discussion under the caption "Item 1A, Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2007, which was filed with the Securities and Exchange Commission on February 29, 2008. The forward-looking statements in this press release are qualified by these risk factors. We assume no obligation to publicly update any forward-looking statements, whether as a result of new information, future developments or otherwise.

Wyeth Pharmaceuticals

CONTACT: Media: Gwen Fisher of Wyeth Pharmaceuticals, +1-484-865-5160,or Douglas Petkus of Wyeth, +1-973-660-5218; or Investors: Justin Victoria ofWyeth, +1-973-660-5340

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