GlaxoSmithKline announced that federal Judge Gregory Sleet of the United States District Court in Wilmington, Delaware, has ruled in GSK's favour in patent litigation with Teva Pharmaceuticals Inc over the company's product, Zofran (ondansetron).

Zofran is a selective 5-HT3 receptor antagonist used for the management of chemotherapy and radiation therapy-induced emesis, and for the prevention and treatment of post-operative nausea and vomiting. The judge upheld the validity of GSK's method of use patents (U.S. Patent No. 5,578,628 and 4,753,789).

The company is awaiting closing arguments in a second trial considering similar challenges to the Zofran patents. The latest of the two methods of use patents is set to expire in December 2006, taking into account the six-month paediatric exclusivity which the company expects to obtain, company said in release.