BARR CHALLENGES PATENTS ON RISPERDAL TABLETS

Barr Laboratories is challenging the patents protecting Janssen Pharmaceutica's antipsychotic Risperdal M-Tab (risperidone orally disintegrating tablets) in 0.5-, 1- and 2-mg dosage strengths.

Barr filed an abbreviated new drug application (ANDA) with a Paragraph IV certification for risperidone orally disintegrating tablets in March, and received notification that the FDA accepted the application in August. On Oct. 3, Janssen, a Johnson & Johnson subsidiary, filed suit in the U.S. District Court for the District of New Jersey to prevent Barr from proceeding with the commercialization of its product. This action formally initiates the patent challenge process under the Hatch-Waxman Act.

Risperdal M-Tab is indicated for the treatment of schizophrenia and the short-term treatment of acute manic or mixed episodes associated with bipolar I disorder. The drug had annual sales of approximately $67 million for the twelve months ended August 2005, according to IMS Health data.