Generics firm Par Pharmaceuticals has agreed to pay Salix Pharmaceuticals $100 million to settle a patent infringement lawsuit over its version of Salix’s heartburn drug Zegerid.

The settlement covers Salix, its subsidiary Santarus and curators of the University of Missouri, Par said in a recent SEC filing. Santarus was the original NDA holder but Salix acquired the company Jan. 2. 

The deal ends the long-running suit that started Sept. 13, 2007, when Santarus sued Par for patent infringement based on its proposed generic version of Zegerid (omeprazole/sodium bicarbonate). 

The Delaware federal court initially ruled Zegerid’s patents invalid on obviousness grounds, and Par launched its generic version July 1, 2010, based on that decision. However, a federal appellate court on Sept. 4, 2012, reversed the invalidity finding and sent the lawsuit back to the district level. Par stopped distributing its generic version after the appellate ruling. As recently as the end of August, Par had been scheduled to go to court Nov. 3 to counter Santarus’ appeal.

As part of the settlement, Par said it would not distribute its version of Zegerid until the drug’s patents expire, which happens in July of 2016. — Bryan Koenig

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.