The U.S. Food and Drug Administration has rejected a new drug application for a treatment of schizophrenia from Solvay Pharmaceuticals and Wyeth Pharmaceuticals.

Solvay, which is based in Marietta, said in a statement issued Friday that the companies plan to meet with the FDA to discuss the decision.

The drug, an antipsychotic, is designed as what the companies call an “acute treatment” of schizophrenia as well as maintenance of “stable adult patients.” Solvay and Wyeth have worked together on the drug since 2004.

“The FDA stated in the letter that bifeprunox demonstrated effectiveness in the long-term maintenance study and indicated that a second positive maintenance study could be sufficient to support a maintenance claim for bifeprunox,” Solvay and Wyeth said.

“The Companies will meet with the FDA to discuss the study design and to assess how this additional study combined with ongoing and planned studies can support a maintenance indication,” they added. “… the Agency concluded that the efficacy data, when compared to reference drugs, were not sufficient for approval.”

Solvay said it is committed to winning approval.

"We believe that bifeprunox is a promising drug for the treatment of schizophrenia, and that there is a need for new treatment options to help people with schizophrenia manage their disease," said Laurence Downey, Solvay’s chief executive."We will work with the FDA to address its comments and pursue the approval of bifeprunox as soon as possible."

The drug is designed to normalize chemical activity in the brain and has been studied in some 2,650 patients with schizophrenia at more than 200 clinical trial sites.