Salix files another patent lawsuit against Par

Salix Pharmaceuticals reported Tuesday that it has filed a patent infringement lawsuit against Par Pharmaceuticals.

The suit comes just four months after Raleigh-based Salix reached a $100 million settlement with Par over patent litigation filed by the University of Missouri and Santarus, the San Diego-based specialty drug company that Salix acquired last year.

In the latest suit, Santarus and Cosmo Technologies Limited allege that Par has infringed on six patents listed with the Food and Drug Administration for the drug Uceris, a rectal foam used to treat ulcerative colitis. The lawsuit was filed after Par filed a new drug application with the FDA to manufacture and sell budesonide extended release tablets.

Salix’s earlier settlement with Par involved the heartburn treatment Zegerid.

Under that agreement, Par agreed not to sell or commercialize generic versions of Zegerid capsules or powder, and make a one-time payment of $100 million into an escrow account. These funds will be allocated between Santarus and Missouri under the terms of their 2001 licensing agreement. Zegerid is a heartburn treatment.

Par also agreed not to initiate or assist in any future challenge to the validity of certain patents that are owned by the University of Missouri and licensed exclusively to Santarus.