Wyeth’s pipeline suffered a pair of setbacks Friday as the FDA rejected Wyeth’s schizophrenia drug bifeprunox and safety concerns led the drugmaker to stop using a developmental hepatitis C drug in a patient study.
 
Wyeth said it could take one to two years for the drugmaker to address the FDA’s concerns over bifeprunox and refile for approval for the compound.

In another blow to Wyeth’s pipeline, Wyeth and partner Viropharma said Friday that safety concerns had caused them to stop treating patients in a mid-stage study with their developmental hepatitis C drug.

Wyeth said in a statement that both companies will work with the FDA to “determine the appropriate path forward.”

Friday’s pipeline problems follow July’s approvable letter for Pristiq for menopause symptoms. The FDA called for a yearlong study into safety concerns related to the drug’s heart and liver effects.

And in April, Wyeth received an approvable letter for osteoporosis drug Viviant. The drugmaker is expecting a ruling on that drug by the end of the year.

The wave of negative results sent Wyeth shares spiraling down by 7.5% as of Monday.

Even if Wyeth’s troubled drugs do make it to market, it seems unlikely they will replace the sales the drugmaker will lose as its blockbusters face generic competition, wrote Deutsche Bank pharmaceuticals analyst Barbara Ryan in a note to investors.

Ryan said Wyeth’s earnings per share growth may be essentially flat through 2011.