AstraZeneca Sues Novartis Over Generic Seroquel

AstraZeneca is suing Novartis subsidiary Sandoz to block it from marketing generic Seroquel, documents filed in U.S. federal court last week revealed.

According to the complaint, filed in the U.S. District Court for the District of New Jersey, Sandoz is seeking to market 25-mg doses of Seroquel (quetiapine). AstraZeneca markets the antipsychotic in 25-, 50-, 100-, 200-, 300- and 400-mg formulations.

A March 22 letter notified AstraZeneca that Sandoz filed a Paragraph IV certification to distribute the product prior to the expiration of patent '288, which is the only patent for Seroquel listed in the FDA's Orange Book and expires in September 2011. The '288 patent covers the use of the product for the treatment of bipolar mania and schizophrenia, the Orange Book states. In court documents, Sandoz claims that patent '288 is invalid.

"Sandoz alleged that claim four of the '288 patent will not be infringed [on by its abbreviated new drug application]," AstraZeneca wrote. Sandoz also alleged that claims six and eight of the '288 patent "will not be infringed on by the intended uses of that product." However, AstraZeneca noted that the generic firm failed to file for a lack of infringement for other claims the patent covers.

According to the FDA's website, a Paragraph IV certification for quetiapine 25 mg was filed in August 2005, and certifications for the 100-, 200- and 300-mg dosages were filed in February 2006.

Seroquel is AstraZeneca's second-best-selling medication in the U.S., reaching $2.49 billion in 2006. The FDA approved the antipsychotic in October 2006 for a second indication for the treatment of major depressive episodes associated with bipolar disorder.