By Kevin E. Noonan --
Last month in Cornell Research Foundation, Inc. v. Vidal, the Federal Circuit affirmed the Patent Trial and Appeal Board's determinations in six inter partes review proceedings that invalidated the challenged claims for being obvious.
The claims of the challenged patents were directed to methods for producing phytases (enzymes that help livestock absorb phosphate from the diet) for supplementing animal feed using genetic engineering to introduce and express a bacterial (Escherichia coli) phytase gene in fungal (typically yeast such as Saccharomyces cerevisiae and Pichia pastoris) cells. The opinion sets forth the following as representative claims of U.S. Patent No. 8,993,300, one of the challenged patents:
1. A method of producing a phytase in fungal cells, the method comprising:
providing a polynucleotide encoding an Escherichia coli phytase;
expressing the polynucleotide in the fungal cells; and
isolating the expressed Escherichia coli phytase wherein the Escherichia coli phytase catalyzes the release of phosphate from phytate.
10. The method of claim 1 wherein the Escherichia coli phytase has an optimum activity at a temperature range of 57 degrees C to 65 degrees C.
11. The method of claim 1 wherein the Escherichia coli phytase retains at least 40% of its activity after heating the phytase for 15 minutes at 80 degrees C.
12. The method of claim 1 wherein the Escherichia coli phytase retains at least 60% of its activity after heating the phytase for 15 minutes at 60 degrees C.
Challenger Associated British Foods (ABF) asserted two combinations of prior art according to the opinion, depending on whether U.S. Patent No. 5,876,997 to Kretz was included. Taking the non-Kretz containing combinations first, the opinion recites two subcombinations: U.S. Patent No. 5,985,605 to Cheng in combination with a first scientific reference (Dassa) disclosing the nucleotide sequence of a first E. coli phytase and a second scientific reference (Greiner) disclosing more generally E. coli phytase genetics, and a second subcombination of the Dassa and Grenier references with U.S. Patent No. 5,436,156 to Van Gorcom and a third scientific reference (Romanos) disclosing recombinant genetics in yeast. ABF argued that the thermostability-reciting claims (claims 10-12 of the '300 patent) would have been obvious either as being inherent properties of the combination of references or having been expressly disclosed in a fourth scientific reference (Olson). The Board held in its Final Written Decision that ABF had established both a motivation to combine and a reasonable expectation of success on the record to establish obviousness of the challenged claims. Regarding those combinations that included the Kretz reference the Board held that this reference alone anticipated certain claims under 35 U.S.C. § 102(e) or rendered the challenged claims obvious in combination with the other asserted references.
The Federal Circuit affirmed, in an opinion by Judge Prost, joined by Judges Reyna and Taranto. On appeal, Cornell challenged the Board's determination that there was a motivation to combine and reasonable expectation of success sufficient to render the challenged claims obvious, that the thermostability properties of the claimed phytases were an inherent property of the phytases disclosed in the cited art, and that Cornell failed to antedate the Kretz reference (although the opinion states that the panel did not reach this third ground of appeal).
Cornell's first ground of appeal was unpersuasive because of the Board's reliance on fact evidence, specifically expert testimony, and the deference the Federal Circuit must give to the Office's factual determinations under Dickerson v. Zurko. Regarding whether thermostability of the recombinant phytases was inherent, this was another question of fact the panel reviewed for substantial evidence. The Board relied on testimony from Cornell's own expert witness that "express[ing] the same enzyme in the same host under the same conditions" produces "inherent results," including thermostability (emphasis in opinion). This was enough for the panel to satisfy the substantial evidence requirement, and Cornell's arguments to the contrary, that this finding was inconsistent with a finding of no inherency regarding anticipation by the Kretz reference and the Board restricting its assessment of inherency to the disclosure of the '300 patent, were not persuasive, based in part on the Kretz reference disclosing a different E. coli phytase gene.
Accordingly, the Federal Circuit affirmed the PTAB's decision that the challenged claims were obvious and awarded costs to the government.
Cornell Research Foundation, Inc. v. Vidal (Fed. Cir. 2022)
Nonprecedential disposition
Panel: Circuit Judges Prost, Reyna, and Taranto
Opinion by Circuit Judge Prost
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