Belgian healthcare group UCB S.A. and Sepracor has filed a legal action against Synthon for allegedly infringing the following Orange book patent on its antihistamine drug levocetirizine (Xyzal) in the federal court of Delaware.
US5698558 (Expiry: September 24, 2012)- This patent covers a method of treating the symptoms of seasonal and perennial allergic rhinitis in a human which comprises administering to a human in need of such symptomatic relief therapy an amount of (-) cetirizine, or a pharmaceutically acceptable salt thereof, substantially free of its (+) stereoisomer, said amount being sufficient to alleviate or palliate said allergic rhinitis.
Sepracor said the company has filed a lawsuit in the U.S., together with UCB, claiming Synthon used the levocetirizine in the treatment of allergic rhinitis.UCB said the move is a response to Synthon's statement at the end of March that it believes itself to be the only first Para IV filer' of an ANDA for the Xyzal drug product.As a result (of the filing) Synthon expects to be eligible for 180 days exclusivity upon the first commercial marketing of the generic drug product.Xyzal is the successor to blockbuster drug Zyrtec, whose patent has expired.
