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A Negative Claim Limitation Has Adequate Written Description If the Specification Provides a Reason to Exclude the Limitation

September 04, 2012

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Last Month at the Federal Circuit - October 2012

Judges: Rader, Newman (concurring-in-part and dissenting-in-part), Moore (per curiam)

[Appealed from: D. Del., Chief Judge Sleet]

In Santarus, Inc. v. Par Pharmaceutical, Inc., Nos. 10-1360, -1380 (Fed. Cir. Sept. 4, 2012), the Federal Circuit reversed the district court’s findings of inadequate written description and obviousness as to certain claims, and affirmed the district court’s findings of obviousness as to certain other claims and no inequitable conduct.

Santarus, Inc. (“Santarus”) is the exclusive licensee of patents directed to specified formulations of benzimidazole proton pump inhibitors (“PPI”), assigned to the University of Missouri (“the University”). Santarus markets the PPI product omeprazole under the brand name Zegerid® and sued Par Pharmaceutical, Inc. (“Par”) based on Par’s filing of an ANDA with the FDA to sell a generic counterpart of the Zegerid® products.

The district court found that Par’s ANDA products would infringe the patents, but concluded that all of the asserted claims were invalid for obviousness and that some of the claims were invalid for inadequate written description. On the defense of unenforceability, the district court found no inequitable conduct by the inventor, the University, or their counsel in procuring the patents. Santarus and Par cross-appealed.

On appeal, the Federal Circuit affirmed the district court’s ruling that inequitable conduct was not established, noting that it was in accord with the Court’s decision in Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276, 1290 (Fed. Cir. 2011) (en banc).

The Federal Circuit reversed the district court’s determination that certain claims of U.S. Patent No. 7,399,772 (“the ’772 patent”) were invalid for lack of written description. The district court found that because the claims included the clause “wherein the [pharmaceutical] composition contains no sucralfate,” it was necessary for the patent specification to include evidence demonstrating that sucralfate is “contraindicated.” Slip op. at 12. The Federal Circuit disagreed, noting that claims may be restricted to a preferred use by excluding alternatives. The Court held that “[n]egative claim limitations are adequately supported when the specification describes a reason to exclude the relevant limitation,” and that “[s]uch written description support need not rise to the level of disclaimer.” Id. “In fact, it is possible for the patentee to support both the inclusion and exclusion of the same material.” Id. The Court concluded that the negative claim limitation was adequately supported by statements in the specification expressly listing the disadvantages of using sucralfate.

The Federal Circuit also reversed the district court’s decision that certain asserted claims could not claim priority to an earlier patent, because the district court’s only reason for its finding was that there was no written description for the “no sucralfate” limitation. The Court noted that Santarus did not appeal the district court’s priority determination as to some of the claims, and thus considered the claims as two groups: those where the earlier patent was prior art, and those where the earlier patent was not prior art.

The Federal Circuit held that the district court correctly found that the earlier patent would have rendered obvious all claims to which it was prior art. The Court rejected Santarus’s argument that the earlier patent did not disclose nonenteric coated PPIs and buffer within the claimed ratios, noting that the earlier patent’s disclosed ranges overlapped with the claimed ranges. The Court also rejected Santarus’s argument that the claims reciting specific blood serum concentrations of PPI would have been nonobvious. The Court found that the initial blood serum concentration resulting from administering a PPI dosage is an inherent property of the formulation, and that “an obvious formulation cannot become nonobvious simply by administering it to a patient and claiming the resulting serum concentrations.” Id. at 18. “To hold otherwise would allow any formulation—no matter how obvious—to become patentable merely by testing and claiming an inherent property.” Id.

Regarding the claims to which the earlier patent was not prior art, the Federal Circuit affirmed the district court’s obviousness decision with regard to some claims and reversed it with regard to others. The Court first found that Santarus was partly correct in arguing that the prior art taught away from the claimed invention. The Court reversed the obviousness finding of certain claims since the prior art’s explicit “ruling out” of the claimed nonenteric coated forms would discourage a person of ordinary skill in the art from pursuing such forms. But the Court affirmed other claims as obvious since the prior art would not teach away from all nonenteric coated forms. The Court pointed out that “[d]escribing [the powder formulations] as ‘second best’ is not a ‘clear discouragement,’ as is required by our precedent.” Id. at 22. The Court also found that Santarus’s objective evidence was insufficient to overcome the obviousness of those claims.

Judge Newman dissented, stating that “[t]he court’s new rulings are contrary to statute, precedent, and common sense.” Newman Dissent at 2. In Judge Newman’s view, the majority creates a new written description requirement for limitations in claims, holds that the disclosure in a parent patent is a reference against the common disclosure in a CIP patent, and holds that most of the claims-in-suit are invalid for obviousness over references that explicitly teach away from the claimed inventions.

Summary authored by Xiaoxiao Xue, law clerk at Finnegan.