Johnson & Johnson says it has only received an approvable letter from the US Food and Drug Administration regarding Risperdal as a treatment for schizophrenia in adolescents.

The company had submitted two supplemental New Drug Applications for Risperdal (risperidone) for the treatment of schizophrenia in adolescents aged 13-17 and for the short-term treatment of bipolar mania associated with bipolar I disorder in children aged 10 to17 years, respectively.

J&J was not specific about the information that the FDA has requested but noted that the agency had not asked for any additional studies to be carried out. The firm added that it is “currently reviewing the approvable letter and looks forward to finalising the label with the agency”.

Risperdal is approved in the USA for the treatment of schizophrenia and bipolar disorder in adults, and for the treatment of irritability associated with autistic disorder in children and adolescents between five and 16 years of age. Sales of the drug, which is expected to face generic competition next year, reached $4.2 billion in 2006 but getting this latest indication fully approved will push that total way up.