Wyeth's Pristiq helps menopause hot flashes-trials

By Deena Beasley

SAN DIEGO, May 8 (Reuters) - Wyeth's (WYE.N: Quote, Profile, Research, Stock Buzz) experimental drug Pristiq alleviates symptoms of menopause such as hot flashes without a significant impact on sexual function, researchers said on Tuesday, but the degree of relief falls short of that seen with estrogen therapy.

Pristiq, an altered form of Wyeth's top-selling anti-depressant Effexor, is awaiting U.S. Food and Drug Administration approval as a treatment for both hot flashes associated with menopause and depression in adults.

Trial results unveiled here at a meeting of the American College of Obstetricians and Gynecologists also showed that Pristiq helped with mood disturbances and sleep.

Wyeth expects to launch Pristiq as a treatment for hot flashes in the third quarter of this year. The new drug is expected to help fill the void in Wyeth's sales that would emerge when Effexor loses its patent protection by 2010 and faces competition from cheaper generics.

A six-month trial involving 541 women suffering from moderate-to-severe hot flashes found that a 100 mg dose of Pristiq resulted in about a 60 percent reduction in symptoms after 12 weeks, compared with a drop of about 50 percent for women given a sugar pill. A 150 mg dose cut symptoms by 66 percent.

"You can get a 90 percent, or more, reduction in hot flashes with estrogens," said Dr. Isaac Schiff, chief of obstetrics and gynecology at Massachusetts General Hospital in Boston. He was not involved in the Pristiq trials.

Wyeth is the maker of once-blockbuster hormone replacement therapy Premarin, sales of which have plummeted after hormone drugs were linked to a higher risk of breast cancer.