AstraZeneca seeks summary judgment over Seroquel

LONDON Feb 8 (Reuters) - AstraZeneca Plc (AZN.L) is trying to head off the threat of generic competition to its blockbuster schizophrenia drug Seroquel by seeking a summary judgment in a U.S. court case, the Anglo-Swedish drugmaker said on Friday.

Lawyers for the company this week requested leave to file for a motion for summary judgment in the District Court of New Jersey in a patent dispute with Teva Pharmaceutical Industries Ltd (TEVA.O), a spokeswoman said.

Teva is challenging the patents protecting Seroquel and could launch a cheap generic copy of the medicine in the United States as early as the end of March, once a 30-month stay on approval is lifted.

Such an early launch would leave Teva exposed to paying damages if a court later backed AstraZeneca's patent position -- but generic companies are increasingly opting to pursue such "at risk" launches.

Seroquel, which is also used to treat bipolar disorder, generated worldwide sales of $4 billion last year and is one of AstraZeneca's most profitable medicines.

Losing it to generics would be a major blow, although most analysts think the patents protecting Seroquel are stronger than those covering Nexium, AstraZeneca's top-selling heartburn and ulcer pill, which also faces a patent challenge.

Initially, Teva would only be able to launch the 25 mg dose of Seroquel, accounting for around a quarter of U.S. prescriptions of the drug.

If is waits until August, it would be able to launch more doses.

Worries about the threat of generic competition to its top two medicines have hit AstraZeneca shares hard recently. The stock was down 1.2 percent at 19.55 pounds by 1010 GMT, after touching a fresh three-year low of 19.50.

Concerns about Nexium were fuelled on Thursday when India's Ranbaxy Laboratories Ltd (RANB.BO) won tentative U.S. approval to sell a generic form of the medicine.

Nexium is the second biggest prescription medicine globally, with sales of $5.2 billion in 2007. (Editing by Louise Ireland)