Santarus, Inc. v. Par Pharm., Inc.
Because negative claim limitations are adequately supported when the specification describes a reason to exclude the relevant limitation, finding of invalidity is reversed.
October 16, 2012
Case Name: Santarus, Inc. v. Par Pharm., Inc., CaseNo. 2010-1360, 2012 U.S. App. LEXIS 18592 (Fed. Cir. September 4, 2012) (Circuit Judges Rader, Newman and Moore presiding; Opinion per curiam; Concurrence-in-part and Dissent-in-part by Newman, J.) (Appeal from D. Del., Sleet, C.J.)
Drug Product and Patent(s)-in-Suit: Zegerid® (omeprazole with sodium bicarbonate buffer solution); U.S. Pat. Nos. 6,489,346 (“the ’346 patent”), 7,399,772 (“the ’772 patent”), 6,780,882 (“the ’882 patent”), 6,699,885 (“the ’885 patent”), and 6,645,988 (“the ’988 patent”)
Nature of the Case and Issue(s) Presented: The issue here concerns whether a solid dosage form of a non-enteric coated proton pump inhibitor such as omeprazole would have been obvious to one of ordinary skill in the art at the time of invention. Santarus manufactures Zegerid, which is used to treat gastroesophageal reflux disease. The novel aspect of the formulation is that the drug does not require an enteric coating because the buffer solution prevents acid degradation in the patient’s stomach. The combination of omeprazole with sodium bicarbonate obviates the need to deliver the active ingredient with an enteric shield coating.
At trial, Par argued that (i) all of the asserted patents were unenforceable due to inequitable conduct during prosecution, (ii) all claims of the asserted patents were obvious in light of U.S. Patent No. 5,840,737 (the “’737 patent”), and that (iii) certain claims were invalid on the ground of inadequate written description. The trial court held that the patents were enforceable and infringed, but invalid on the basis of obviousness. It further found that some of the asserted claims failed to meet the written description requirement. Par appealed the court’s enforceability ruling, and Santarus appealed the court’s determination that all asserted claims were invalid as obvious, and that some claims were invalid for failure to satisfy the written description requirement. Par did not appeal the court’s determination that its generic product infringed the claims of the asserted patents. The Federal Circuit affirmed the district court’s finding of no inequitable conduct, reversed the lower court’s finding that the ‘772 patent was not adequately supported by the written description, and reversed the lower court’s determination that claims 11 and 15 of the ‘882 patent and claims 20 and 21 of the ‘772 patent were obvious.
Why Santarus Prevailed: The Federal Circuit first addressed Par’s allegations of inequitable conduct. The court of appeals noted that although the district court did find the inventor’s reasons for failing to provide certain test information to the USPTO during prosecution “strained credulity,” Par nonetheless failed to provide clear and convincing evidence at trial that the omission occurred with the requisite intent to deceive the PTO.
Next, the Federal Circuit addressed whether the asserted claims of the ’772 patent were invalid for lack of written description under § 112 ¶1. Par argued that claims of the ’772 patent were indefinite, and also that the ’772 patent could not claim priority to the earlier filed ’737 patent. The ’772 patent contained a negative limitation, indicating that the claimed solution contained no sucralfate. The district court held that in order for the claim to meet the written description requirement, the specification had to include evidence indicating that sucralfate was contraindicated. The district court found the disclosure in the specification, which stated that the claimed solution was advantageous in comparison to solutions with sucralfate, was not sufficient. The Federal Circuit disagreed, finding that negative claim limitations are adequately supported when the specification describes a reason to exclude the relevant limitation. In support of its view, the court noted that the MPEP explains that if alternative elements are positively recited in the specification, they may be explicitly excluded in the claims. Accordingly, the court found that the ’772 patent was adequately supported by the written description, and properly claimed priority to the earlier filed ’737 patent.
Finally, the Federal Circuit addressed Par’s obviousness argument. The ‘737 patent discloses the use of an omeprazole/bicarbonate salt suspension, without an enteric coating on the omeprazole. The Federal Circuit disagreed with the district court that the ’737 patent rendered claims 58-60 of the ’346 patent and the asserted claims of the ’882 and ’772 patents obvious because the ’737 patent did not constitute prior art to those patents. But, the court did find that claims 12 and 27 of the ’882 patent, 58-60 of the ’346 patent were obvious in light of other prior art references. The Federal Circuit held that an obvious formulation cannot become nonobvious simply by administering it to a patient and claiming the resulting serum concentrations. To hold otherwise would allow any formulation—no matter how obvious—to become patentable merely by testing and claiming an inherent property. The Federal Circuit also affirmed the district court’s finding that Santarus’s evidence of objective considerations of nonobviousness was not convincing. The district court had found that Santarus had failed to establish that its drug had experienced commercial success in relation to Zegerid. The Federal Circuit also supported the district court’s determination that one of Santarus’s witness’s testimony was generally unpersuasive, because he was not made available for cross-examination by the defendants. In conclusion, the Federal Circuit reversed the district court’s determination that claims 11 and 15 of the ‘882 patent and claims 20 and 21 of the ‘772 patent were obvious.
In her partial dissent, Judge Newman said that the Federal Circuit opinion erred in several areas, including its interpretation of the written description requirement, disclosures found in parent patents, and evidence of teaching away. Of most significance, Judge Newman criticized the majority’s interpretation of the negative claim limitation issue. Specifically, Judge Newman accused the majority of devising a new rule that a specification must describe a reason for a negative claim limitation; namely, that a negative claim limitation could be appropriately stated in the claims even though the reason for the limitation is not specifically set forth in the specification. Reasons for including a negative claim limitation could include overcoming a rejection during prosecution or to distinguish it from prior art. It would not be necessary for either of these reasons to be stated in the specification. Judge Newman concluded that the majority’s interpretation of the written description requirement “ignores the factual nature of the written description requirement, and impugns the presumption of validity of a duly granted patent.”
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