Paul Hastings LLP was named a “runner-up” in The American Lawyer’s “Litigator of the Week” recognitions for helping Allergan revive a Hatch-Waxman lawsuit seeking to protect the company’s Viberzi irritable bowel drug from early generic competition.

A federal judge in Delaware last year found after a trial (which did not involve Paul Hastings) the underlying patent claims invalid under the doctrine of obviousness-type double patenting and for lack of written description. But the Federal Circuit last week found that “a first-filed, first-issued, later-expiring claim” could not be invalidated by “a later-filed, later-issued, earlier-expiring reference claim having a common priority date,” as was the case with one of the Allergan patents at issue. The Federal Circuit also reversed the district court’s written description ruling relating to the remaining four patents-in-suit, resulting in a sweeping win for Allergan.

Litigation partner Eric Dittmann handled the oral argument and led Allergan’s appellate team, which also included Paul Hastings partners Stephen Kinnaird and Melanie Rupert and associates Peter Conway and Molly Teague.