Welcome to Winston & Strawn’s Federal Circuit Patent Decision Summaries. This bulletin provides a short summary of, and links to, the precedential patent cases decided by the Federal Circuit last week. We hope that these summaries are useful in keeping you updated on the Federal Circuit’s patent decisions.

Patentee’s excuse for non-disclosure that “strains credibility” does not by itself provide clear and convincing evidence of intent for an inequitable conduct finding; negative claim limitations do not require disclaimer for adequate written description; claimed inherent properties of combinations do not render obvious combinations patentable; conclusion that prior art teaches away must be based on “clear discouragement” to support a conclusion of nonobviousness.

Santarus, Inc. v. Par Pharmaceutical, Inc., No. 2010-1360, -1380 (Fed. Cir. Sep. 4, 2012)

The parties in a Hatch-Waxman litigation cross-appealed rulings from a bench trial decision that found no inequitable conduct had occurred during prosecution of the patents, but that held the asserted patents invalid as either lacking sufficient written description or being obvious over prior art. 

The defendants asserted that prior art disclosed during continuations, but not during the parent application, should have been disclosed earlier, and thus, the earlier non-disclosure constituted inequitable conduct. The trial court agreed that the internal references were material, but found a lack of clear and convincing evidence of intent by the patentee to deceive the examiner despite finding that the patentee’s excuse “strained credibility.” The panel affirmed that even such a weakly supported excuse for non-disclosure did not constitute clear and convincing evidence of intent necessary to find inequitable conduct.

The panel overturned the district court’s determination that a negative claim limitation lacked written description. A negative claim limitation has sufficient support if the specification states a reason to exclude the relevant structure. The specification need not include a disclaimer or contraindication to satisfy the written description requirement of 35 U.S.C. § 112.

The panel affirmed obviousness determinations where the prior art and asserted claims had overlapping numerical ranges. Additional but inherent limitations on blood serum levels did not confer patentability for the obvious formulation combination. “To hold otherwise would allow any formulation — no matter how obvious — to become patentable merely by testing and claiming an inherent property.”

Finally, the trial court’s other obviousness determinations were affirmed in part and reversed in part based on teaching away in the cited reference. Teaching away requires “clear discouragement of the combination.” Describing a combination as “second best” is not “clear discouragement.” The district court’s obviousness findings were reversed on those claims where the prior art discouraged the combination. On the other hand, the district court’s findings were affirmed as to some claims where the prior art disclosed the combination. 

A copy of the opinion can be found here.