The US FDA has disapproved Schering-Plough’s drug for schizophrenia. The agency wants more data on the research drug known asenapine by the chemical name. The Kenilworth-based company revealed in a statement that it won't have to do additional studies to provide additional data.

Schering-Plough had expected an approval so that it could start selling drug in June 2009. According to a statement the company would give a reply to FDA’s request after March.

The drug by the brand name of Saphris was considered by Schering-Plough as one of five "stars" of its research pipeline. The company had forecast that Saphris sales could exceed $1 billion a year.

However, it has also been demonstrated that Asenapine worked no better than a placebo in half its schizophrenia studies. Rather it had more side effects in patients with bipolar disorder. Schizophrenia, is a psychological disorder which usually affects people in their teens to late 20s. Schizophrenics often hear voices, feel frightened and hallucinate.

"We are pleased with the progress on the Saphris filing and look forward to working with the agency to address its request, finalize the product labeling and gain approval," Thomas Koestler, president of the Schering-Plough Research Institute, said in a statement.