is reaffirming its belief that Pristiq, its experimental drug for menopause symptoms, is safe and effective.
The company also said it thinks the Food and Drug Administration's request last week for another clinical trial won't affect the agency's review of Pristiq as a treatment for depression.
Greg Norden, Wyeth's chief financial officer, said Tuesday that he expects the agency to rule favorably on the depression application during the first quarter of 2008. The depression application is being reviewed by a different unit in the FDA than the menopause application.
reaffirmed its 2007 earnings guidance of $3.48 to $3.56 a share, excluding one-time items, that was issued July 19.
Last week, the FDA granted the menopause application conditional approval, saying
another clinical trial would be required to assess possible liver and cardiovascular side effects.
At the time, Wyeth executives said the trial would take 12 months or more, and now they say it could take about 18 months. Wyeth is still discussing the trial's guidelines with the FDA.
"We strongly believe Pristiq does not present" cardiovascular side effects for women experiencing menopausal symptoms, said Dr. Gary Stiles, chief medical officer for Wyeth's prescription drug business. "The benefit-risk ratio is positive."
In a conference call with analysts, Stiles said three of four clinical trials submitted in the menopause application didn't show cardiovascular side effects for Pristiq patients. In the other study, five Pristiq recipients had these side effects while no placebo-recipients had problems, he said. However, the fourth test included 612 women receiving Pristiq, while only 77 received a placebo.
Wyeth views Pristiq as a multifaceted drug that would help it bolster its women's health business and provide a successor to the antidepressant Effexor XR, its best-selling drug.
Effexor XR's U.S. patent expires in June 2010 and foreign sales will be hit by generics in late 2008. The faster Wyeth gets FDA approval for Pristiq as an antidepressant, the faster it can start trying to convince patients to switch from Effexor XR.
The announcement came after the market had closed. In regular trading, the stock was off 4 cents, closing at $48.52.