The Food and Drug Administration wants more data from Wyeth on how its proposed drug to treat hot flashes and other symptoms of menopause affects the heart and liver, the company said Tuesday.
The FDA is seeking a one-year study of how the drug Pristiq affects those organs, said Wyeth's chief medical officer, Dr. Gary Stiles.
Shares of the pharmaceutical company dropped more than 7% Tuesday on the news.
The FDA on Monday stopped short of approving Pristiq for menopause symptoms, sending Wyeth a so-called approvable letter, according to agency spokeswoman Rita Chappelle. That indicates the company's application is acceptable in many respects, but that staff scientists want more information about the treatment before approving it.
The decision was a blow to Madison-based Wyeth, which hopes to market the drug as the first non-hormonal treatment for menopausal symptoms.
"Wyeth remains committed to the development of Pristiq as a potential treatment for moderate-to-severe vasomotor symptoms associated with menopause," Stiles told reporters in a teleconference. "We will work with the agency, and we have not yet met with them, to satisfy its requests for additional data and move this medicine forward in the FDA review process."
He said Wyeth is confident the drug is safe and that it will be able to address the FDA's concerns. The process would take more than a year, since a study has yet to be designed, he said.
The FDA letter said that before it could approve Pristiq, Wyeth must provide additional data regarding the potential for serious adverse cardiovascular and hepatic effects, the company said.
The FDA requested that such data come from a randomized, placebo-controlled clinical trial of a duration of one year or more conducted in postmenopausal women, Wyeth said.
Stiles said that elevated liver enzymes were found in three of 2,000 women taking Pristiq in a trial. Each was taken off the drug and their enzymes returned to normal, he said.
Stiles said that cardiovascular events were seen in just one of four studies conducted with the drug. The effects were seen in women with high risk factors for such events, he said.