The patent is currently due to expire in May 2013 and the decision by the US court could prevent the onset of generic versions of Aciphex.
However, the trial has not yet concluded and the court has reserved ruling on the enforceability arguments until after trial. The generic manufacturers are still to provide their arguments at the trial and are expected to maintain that there were flaws in Eisai's patent procedure.
Eisai commented that it is looking forward to the trial and will vigorously defend its Aciphex patent in order to protect the company's interests.
Aciphex has been shown to have a rapid onset of action and a reliable inhibitory effect on acid secretion related to duodenal ulcers and gastroesophageal reflux disease, which are confirmed in clinical studies.
Aciphex was launched in the US in 1999 and is currently marketed worldwide.