On October 13, the Patent Trial and Appeal Board (“board”) granted a petition filed by Inari requesting a post-grant review of U.S. Patent No. 11,371,055 B2 owned by Corteva. The patent is referred to as the “055 patent” of an herbicide resistance gene for soybeans and cotton. The '055 patent identifies its preferred enzyme and gene as AryloxyAlkanoate Dioxygenase and shortened it to "AAD-12". Corteva patented AAD-12 with up 85% variability of the amino acids that comprise AAD-12. Inari challenged the issuance of the patent stating that claims of the patent are unpatentable due to “lack of written description” and “lack of enablement.”

In response, Corteva asked the board to invoke their power of discretion to deny the review because the “same or substantially the same arguments” were already examined by the USPTO prior to the issuance of the patent. The board rejected this argument finding that Inari raises a new argument when it claims structure outside the disclosed AAD-12 can also affect herbicidal resistance. The court also found that the USPTO materially errored when it did not issue a rejection for lack of enablement. Therefore, the board chose not to invoke its power to deny the review request.

On the merits of the petition, the board found that Inari successfully brought both claims. The ‘055 patent had a lack of written description since the description was overly broad when it claimed up to 85% variability of the amino acids in AAD-12 would still achieve herbicide resistance. The board noted that Corteva did not show proof herbicide resistance in any combination less than 99% the same as the sequence disclosed in the patent. This shortfall was also cited as the reason the board found that there was a lack of enablement in the patent. The board found that the ‘055 patent would not lead someone skilled in plant genetics to be able to produce a variable AAD-12 that would still retain the intended herbicide resistance.

Inari Agric. v. Corteva Agriscience LLC, PGR2023-00022, Patent 11,371,055 B2 (P.T.A.B Oct 13, 2023).