Federal District Court upheld the PTAB decision on the enzyme patent

The United States Court of Appeals for the Federal Circuit issued a decision in the case of Pioneer Hi-Bred International, Inc. v. Inari Agriculture, Inc., affirming the Patent Trial and Appeal Board's (PTAB) final written decision. The court found claims 1–33 of U.S. Patent No. 11,371,055 unpatentable for lack of enablement.

The patent in dispute describes enzymes that confer resistance in a crop to two classes of herbicides: pyridyloxyacetate auxins (including triclopyr and fluroxypyr) and phenoxy auxins (such as 2,4-D and MCPA). Inari Agriculture, Inc. filed a post-grant review (PGR) petition against the patent, owned by Pioneer Hi-Bred International, Inc., pointing out the excessive breadth of the claims given the minimal number of examples in the specification.

During the proceedings, Pioneer provided experimental data on eight enzymes, obtained more than ten years after the patent's priority date. The court ruled that the use of such data is legitimate to demonstrate that the patent lacks a representative number of species of the claimed genus. In addition, the court rejected Pioneer's arguments regarding the improper qualifications of Inari's expert, Dr. Silverstone.

Judge Prost noted that the specification and working examples of the patent do not contain guidance that would help find a path to variants at the 85% sequence identity level. Of the eight enzymes tested by Pioneer, only two exhibited the claimed function, which refuted the predictions of the patent owner's expert, Dr. Bollinger, and confirmed the correctness of the PTAB's conclusions.