Wyeth drug has cross over potential

Estimated read time: 3-4 minutes

This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.

WASHINGTON (AFX) - Wyeth Pharmaceuticals Inc. is expected to receive initial approval next week for an antidepressant and analysts say the drug's greatest market potential could be among menopausal women seeking an alternative to hormone replacement therapy.

A spokesperson for Wyeth said the company expects the Food and Drug Administration to tentatively approve Pristiq as a treatment for major depression, though the company will likely need to submit additional information to get the final OK.

Pristiq is superior to other antidepressants already on the market because it helps balance two key hormones that affect a patient's mood and are particularly important in depressed women going through menopause, Wyeth says. The most commonly prescribed medications only address the hormone serotonin; Pristiq also acts on norepinephrine.

Pristiq's active ingredient is essentially a derivative of the ingredient in the company's blockbuster drug Effexor, which loses patent protection in 2010. Drug companies routinely patent slightly adjusted versions of old ingredients as a way to extend the shelf life of their drugs.

Effexor was the No. 1 depression medication worldwide in 2005 with sales of $3.46 billion, nearly twenty percent of Wyeth's total revenue.

Sales of Pfizer Inc.'s Zoloft, the top-selling antidepressant in the U.S. in 2005, plunged more than 40 percent in the third quarter of 2006 after the company lost its patent. Other leading antidepressants include Eli Lilly & Co.'s Cymbalta and GlaxoSmithKline Plc's Paxil.

Pristiq is unlikely to expand Wyeth's depression franchise, but it "will be used to capture Effexor patients before the latter's patent expires," Sanford C. Bernstein & Co. analyst Richard Evans said in a research note.

But even if Wyeth can successfully transfer patients from Effexor to Pristiq, the drug will enter an antidepressant market that seems to have passed its peak. Spending on antidepressants fell 4 percent last year amid concerns that the drugs increase risk of suicidal behavior in children.

With the market for antidepressants saturated, Wyeth is looking to steer Pristiq toward an alternative use that shows more financial promise: treating menopausal symptoms.

FDA is scheduled to issue a decision on Pristiq for menopause in April. While regulatory approval is never a certainty, Leerink Swann analyst Seamus Fernandez writes last month that the agency will likely see Pristiq for menopause as "a compelling indication given that there is a significant unmet need."

Roughly 40 million U.S. women experience hot flashes and night sweats as a result of lower estrogen levels that come with menopause.

Harvard University professor JoAnn Manson said studies have shown that antidepressants can be somewhat effective for treating menopausal symptoms, and some doctors have already begun prescribing them off-label. A drug is used off-label when it is prescribed for a use other than the one authorized by government regulators.

"I would say there is a strong need for non-hormonal options because we know one in five women going through menopause have severe hot flashes that impair their quality of life," Manson said. "They are looking for a therapy that doesn't pose the risks of hormone replacement."