When "Good Enough" Is Good Enough For Finding Obviousness

• Published date: 02 August 2022
• Subject Matter: Intellectual Property, Patent
• Law Firm: Finnegan, Henderson, Farabow, Garrett & Dunner, LLP
• Author: Ms Emma N. Ng, Hira Javed, Shannon Patrick, Amanda Murphy and Stacy Lewis

Holding:

In Cornell Research Foundation, Inc. v. Vidal, No. 2020-2334, 2022 WL 1634223 (Fed. Cir. May 24, 2022) (non-precedential), the Court of Appeals for the Federal Circuit affirmed the final written decision of the Patent Trial and Appeal Board's decision finding the challenged claims in six inter partes review proceedings unpatentable as anticipated or obvious.¹², The Federal Circuit held that substantial evidence supported the Board's determination that the claims were obvious.

Background:

The patents at issue are related to phytase enzymes, which are incorporated into livestock feed and aid animals in absorbing phosphates. Phytase enzymes are typically produced by taking a phytase gene from one organism and incorporating the gene into a host cell that expresses the phytase protein. U.S. Patent No. 8,993,300 ("the '300 patent") claims a heterologous method of producing phytase. Id. at *2-*3. The '300 patent uses a phytase gene derived from the Escherichia coli bacteria species and a fungal host. Claim 1 and dependent claims 10-12 of the '300 patent were representative for the purposes of this appeal.

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.

Claim 1 recited a heterologous method of producing phytase, and dependent claims 10-12 added "thermostability limitations" to the phytases produced by the heterologous method described in independent claim 1. Id. at *3.

Associated British Foods PLC ("ABF") challenged Cornell's claims based on two categories of prior-art combinations-one involving U.S. Patent No. 5,876,996 ("Kretz"), and the other not involving Kretz. The Kretz-based challenges applied only to the '300 patent; however, the parties agreed that the Board's six IPR decisions "stand and fall" with the Board's...