FDA seeks further testing of Wyeth depression drug, deems drug for schizophrenia not approvable.

FDA's demand for further testing of Pristiq, a non-hormonal drug for menopause symptoms, should not delay approval of the same drug as a depression treatment, Wyeth said July 31, according to the Associated Press (AP).

In a conference call to address concerns triggered by the agency's decision to require a new study of the drug, officials at Wyeth said they will work closely with FDA to speed the drug's approval as the first non-hormonal treatment for menopause symptoms.

FDA said on July 16 that it wants more data on Pristiq's effects on the heart and liver, because a very small number of women in studies of the drug for menopause symptoms had serious heart or liver complications.

In one of Wyeth's four studies in postmenopausal women, two women in the group taking Pristiq had heart attacks and three needed procedures to repair clogged arteries, compared with none in the group taking dummy pills, Wyeth executives told analysts during a conference call July 31.

In that study, however, there were eight times as many women taking Pristiq as taking dummy pills. Eight additional factors were listed in Pristiq's defense, including that the five women with heart complications had long-standing heart disease.

Still, FDA requested that Wyeth conduct a randomized, placebo-controlled clinical trial of one year or longer, a huge blow to Wyeth.

While Pristiq was tested on a total of 2,158 post-menopausal women, only 318 took it for a year or more, with another 604 taking it for six months, apparently leading FDA to ask for more long-term data.

The request means Wyeth likely won't be able to re-apply for approval of Pristiq as a menopause drug for about 18 months, and the agency will then have about six months to review the new data and reach a decision, the AP reported.

About 85% of menopausal women are bothered by symptoms such as mood swings, hot flashes and trouble sleeping--often for several years. Many were scared off hormone drugs when a 2002 federal study linked them to serious risks.

FDA officials have reassured the company the additional safety data required to get approval as a menopause symptom treatment will not hold up approval of Pristiq as a depression treatment.

However, the news from FDA about a schizophrenia drug developed by Wyeth and two other drugmakers is not reassuring.

In addition, Wyeth announced Aug. 10 that FDA has issued a non-approvable letter for bifeprunox, after the agency concluded that effectiveness data for the drug were not sufficient for approval when compared with other drugs, according to a report from Reuters.

FDA had requested further information on the human metabolism of bifeprunox and the case of a patient who died while participating in one of the clinical trials of the drug, according to the company.

Studies have found bifeprunox to be less effective than other schizophrenia drugs but with fewer side effects, according to Wyeth and its partners. Older schizophrenia drugs have been linked to problems such as weight gain and elevated blood sugar.

Wyeth said the FDA action suggested the company could still gain approval for bifeprunox for the long-term maintenance of patients with schizophrenia. Company officials plan to meet with FDA to determine how other studies might support eventual approval.

During a conference call with analysts, Wyeth officials said the product's approval would be delayed for one to two years while the company gathered clinical data to satisfy regulators.

The officials said the patient death occurred during a trial examining bifeprunox for acute treatment of schizophrenia. They said it was a complex case and the patient was on bifeprunox.

Bifeprunox is part of a family of drugs called atypical anti-psychotics. It would compete with Johnson & Johnson's Risperdal, Lilly's Zyprexa and other medicines.

In another blow to Wyeth, its partner on an experimental hepatitis C drug, ViroPharma, said that the companies were stopping a clinical trial of the medicine due to safety concerns. ViroPharma said some patients taking the drug, HCV-796, developed elevated liver enzymes, a warning signal for liver damage. Wyeth and ViroPharma said they would analyze the data before deciding whether to continue development of the drug.