Abbott files Depakote patent suit against Zydus Cadila

MUMBAI, India Abbott Laboratories has filed a lawsuit in the New Jersey District Court against Zydus Cadila to prevent the company from selling a generic version of its best-selling drug, Depakote, according to the Economic Times. The drug, indicated for the treatment of bipolar disorder, epilepsy and migraine headaches, recorded sales of $540 million in the U.S. in 2006.

Abbott's suit states that Zydus Cadila’s drug would infringe four patents for the controlled release version of Depakote that expire on Dec. 18, 2018.

This lawsuit, however, comes months after Zydus Cadila approached the Food and Drug Administration seeking marketing approval to sell a generic version of Depakote. The company had submitted an application to market the extended release version of Depakote in July 2006. However, Abbott did not sue the company within the 45 days prescribed by the Hatch-Waxman Act.

While it remains unclear why Abbott is now suing the company, legal experts say that this may be a new strategy by the big pharma companies to keep generic versions off the market. Abbott’s main patent on Depakote will expire on Jan. 29, 2008. This means that even if a court ruled in favor of the generic company, it would have been able to start selling the extended release version of Depakote next month.

While Zydus Cadila may shortly receive approval from the FDA to market the extended release version of Abbott’s drug, it may need to launch its product at risk of damages claim from the innovator, as it may take months for the court to rule on this case, a legal expert said. If the court rules in favor of Abbott after Zydus has started selling generic version in the market, Abbott may ask for triple the damages. In this case, the innovator company can claim more than $100 million in damages.