Generic Seroquel Held Off by US Appeals Court

The U.S. Court of Appeals for the Federal Circuit has rejected attempts by generic drug makers to invalidate AstraZeneca’s patent on the atypical antipsychotic drug Seroquel, meaning that generic versions of the drug will not be available until the patent expires in September 2011, with pediatric exclusivity extending through March 2012.

AstraZeneca’s patent was found to be valid and enforceable, affirming the decision of a federal trial judge in New Jersey. The challenge was brought by Teva Pharmaceuticals Industries Ltd. and Novartis AG’s subsidiary, Sandoz, who want to create their own generic Seroquel.

The court found that AstraZeneca did not deceive or misrepresent Seroquel to the U.S. Patent and Trademark office when it applied for its patent.

Seroquel (quetiapine fumarate) is an atypical-antipsychotic that is a top selling drug for AstraZeneca, generating nearly $5 billion a year in sales. Approved by the FDA in 1997 for the treatment of schizophrenia, it is also commonly used off-label for treatment of anxiety, obsessive dementia, compulsive disorders and autism. Seroquel has been used by more than 19 million people worldwide.

AstraZeneca currently faces nearly 20,000 Seroquel lawsuits filed by plaintiffs who claim that the drug maker failed to adequately warn users about potential Seroquel side effects that may increase the risk of diabetes, weight gain, hyperglycemia, and a rare movement disorder known as tardive dyskinesia. Most of the cases have been consolidated in an MDL, or Multidistrict Litigation, that is centralized in the U.S. District Court for the Middle District of Florida.

Internal documents from AstraZeneca disclosed during the litigation, which were unsealed last week, suggested that the pharmaceutical giant was not telling doctors in the United States about the potenital Seroquel diabetes side effects, even though they had already admitted to doctors in Japan that there was likely a connection between the antipsychotic drug and an increased risk of diabetes.

Earlier this year, two of the first cases set for trial in the federal MDL were dismissed after the court determined that those plaintiffs could not establish that their diabetes was caused by Seroquel under Florida law. The first trial for a Seroquel lawsuit is now scheduled to occur in Missouri state court in October 2009.