Post-priority data admissible to support lack of enablement in Pioneer Hi-Bred International, Inc. v Inari Agriculture, Inc.

On October 2, the Federal Circuit issued a non-precedential decision affirming a PTAB final written decision that invalidated all claims of a Pioneer Hi-Bred International, Inc. (“Pioneer”) patent for lack of enablement. The PTAB rejected claims 1-33 of the U.S. Patent No. 11,371,055 (’055 patent) directed to dual herbicide-degrading enzymes relying on Pioneer’s own experimental data generated after the priority date. The Federal Circuit determined that the PTAB did not err in establishing lack of enablement based on post-priority data.

The ’055 patent concerns enzymes that exhibit dual herbicide-degrading functions to confer crop resistance to pyridyloxy auxins and phenoxy auxins. Representative claim 1 defines a genus of enzyme by function and structure. The dual herbicide-degrading aryloxyalkanoate dioxygenase function is recited in the preamble, and the structural limitation of at least 85% sequence identity with SEQ ID NO: 2 and a general formula is described in the body. Inari Agriculture, Inc. (“Inari”) challenged the claims in a post-grant review (PGR), arguing that the claimed genus is “unfathomably large” while the specification only provides two example species. The genus includes 2.4x10¹⁰⁶ species, greater than “the number of atoms in the universe.” Pioneer submitted a patent owner response arguing that the 85% sequency identity structural limitation is a common feature to ensure the dual herbicide-degrading functional limitation and providing additional guidance on structural variation without changing function. Pioneer also submitted experimental data generated more than a decade after the ‘055 patent’s priority date, in which only two of the eight enzymes which met the structural definition weakly exhibited the dual herbicide-degrading function at 1% and 2% activity. Inari convinced the PTAB that the claims were not enabled by arguing that the post-priority data showed that the ’055 patent did not demonstrate a reliable correlation with the claimed function.

In the appeal, the Federal Circuit forfeited Pioneer’s argument that it was legally erroneous to rely on post-priority data because it was not raised before the PTAB, and cited Amgen Inc. V. Sanofi to support the use of post-priority evidence to prove the lack of enablement of the entire genus in the specification. In this precedential decision, the Supreme Court held that evidence generated by Sanofi post the priority date of Amgen’s patents can be admissible to demonstrate that Amgen claimed a broad genus of millions of potential anti-PCSK9 antibodies without proper enablement by only disclosing the sequences of 26 specific antibodies. Amgen’s specification failed to disclose a representative number of species and therefore did not enable the full scope of the claim without undue experimentation. The Federal Circuit properly applied the reasoning in Amgen that “the more one claims, the more one must enable.” Additionally, it found that each of the enzymes Pioneer tested post priority could have been made as of the priority date. Therefore, it affirmed that the ’055 patent failed to enable the full claim scope, citing the enormous gap between the number of species disclosed and the number claimed.

[This post is for educational purposes only. It reflects my own analysis of publicly available information, does not constitute legal advice, and does not create an agent-client relationship. Views expressed are my own, not those of any employer or client.]