Federal Circuit Revives Some Santarus Generic Zegerid Patent Claims V. Par

By Joseph Mandour on September 5, 2012

Patent Lawyer California – The Federal Circuit on Tuesday gave Santarus Inc. another chance to prove that its patents for the heartburn drug Zegerid are valid and that Par Pharmaceuticals Inc.’s proposed generic version would infringe those patents.

The district court erred by holding that some of the thirty-six asserted claims would have been obvious over the prior art, the Federal Circuit said in support of its partial reversal of a district judge’s ruling. The appeals court affirmed the remainder of the lower court’s rulings.

Santarus is the exclusive licensee of patents on specified formulations of benzimidazole proton pump inhibitors, which constitute a class of chemical compounds that inhibit gastric acid secretion and help prevent and treat stomach acid-related diseases and disorders.

U.S. Patent Numbers 6,489,346, 7,399,772, 6,780,882, 6,699,885 and 6,645,988 are for the inventions of Dr. Jeffrey Phillips, and are assigned to the University of Missouri. Santarus provides the PPI product omeprazole in the formulations covered by the Phillips patents, with the brand name Zegerid.

Par filed an Abbreviated New Drug Application for U.S. Food and Drug Administration approval to sell a generic counterpart of the Zegerid products. The district court found that Par’s ANDA products infringe the Phillips patents, but held all of the asserted claims invalid on the ground of obviousness.

The district court also held certain claims invalid on the ground of inadequate written description. On the defense of unenforceability, it held that there was no inequitable conduct by Dr. Phillips, the University of Missouri, or their counsel in procuring the patents. Each side subsequently appealed the ruling against it.

The Federal Circuit reversed district court’s ruling that the asserted claims of the ‘772 patent and two claims of the ‘882 patent would have been obvious, and the district court’s holding that the claims of the ‘772 patent are invalid for lack of written description.

The appeals court affirmed the district court’s ruling that Par failed to establish inequitable conduct, as well as the lower court’s determination that several claims of the of the ‘882, ‘885, ‘346 and ‘988 patents would have been obvious over the prior art.

Circuit Judge Pauline Newman dissented in part from the majority ruling, saying while she agreed that there was no inequitable conduct, the appeals court made three major errors that misconstrue the established law.

The court created a new “written description” requirement for limitations in claims, a requirement with important consequences for patent content and prosecution, and that will taint large numbers of issued patents, she said.

The panel majority also held that the disclosure in a parent patent is a reference against the common disclosure in a continuation-in-part patent, again tainting many properly granted patents, according to Judge Newman.

Finally, the majority incorrectly held that most of the claims in suit are invalid on the ground of obviousness over references that explicitly teach away from the inventions in the Phillips patents, she said.

“The court’s new rulings are contrary to statute, precedent, and common sense,” Judge Newman said. “They simply add to the unreliability of duly granted patents, in new and unacceptable ways.”

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