[Guest Post] What the Inari vs. Corteva case really tells us about enablement of plant inventions
Jocelyn Bosse
[Guest Post] What the Inari vs. Corteva case really tells us about enablement of plant inventions
Jocelyn Bosse Saturday, February 14, 2026 - enablement, genetic modification, patents, plant varieties
The IPKat has received and is pleased to host this guest contribution from Dr. Michael A. Kock (Dr.rer.nat., Dr. jur European Patent Attorney, Swiss Patent Attorney; dr.kock consulting, Basel, Switzerland; Senior Vice President and Innovation Catalyst, Inari). He looks more closely at the Inari v. Corteva case in the United States to clarify the significance of the case for the enablement of plant inventions. Michael was not involved in the case and the views expressed in this article are the personal views of the author.
Here's what Michael has to say:
Background
The Patent Trial and Appeal Board (PTAB) decision of Dec. 18, 2024 in Inari Agriculture, Inc. v. Corteva Agriscience LLC dealt with US Patent No. 8,901,378 (the ‘378 patent) related to the maize with the TC1507 transgenic event. At the institution stage, the Board agreed that the written disclosure of the application did not enable a skilled person to recreate the TC1507 event as the patent was filed without a deposit of biological material.
Images from Markus Winkler and Avalon_Art
However, in its final decision the Board found that "it is undisputed that TC1507 germplasm was known and readily available to the public […] in 2006" and in consequence the 2004 application satisfies the enablement requirement as of its application date in 2004. An earlier IPKat guest post concluded that that "[t]iming and width of commercialization, and licensing may later influence enablement and priority analyses" which appears to argue that enablement and validity of a patent can be ensured by commercial availability of the covered product. This article reviews the case in a broader context including the legal questions it raises.
The timeline of events is visualized in Figure 1. The most relevant events are the following:
On sale: It was undisputed in the IPR that TC1507 maize was commercially available for the 2003 season (Patent Owner's Preliminary Response, pp.19-20). While the date of the first sale remains unclear, in the proceedings related to the corresponding European Patent EP1620571 the patentee submitted a grower agreement dated Nov. 11, 2002. A grower agreement constitutes an acceptance of an offer and can naturally not be later than the offer for sale. Thus, the grower agreement provides evidence for an offer-for-sale latest on Nov. 11, 2002. This would be common practice for a growing season starting in April 2003.
Priority and filing dates: A US provisional application (60/467,772) was filed on May 2nd, 2003 as the first priority application. US Appl. 10/827105 ("Barbour" in the IPR) was filed as the first non-provisional application April 30, 2004, published as US 2006/0037095 on Feb. 16, 2006, and granted as US Patent No. 7,288,643 on Oct. 30, 2007. The '378 patent challenged in the IPR claims priority to both applications. It was filed Apr. 28, 2011, and issued Dec. 02, 2014.
Public availability: In an EPO submission of Aug. 7, 2014, the patentee argued "The (in)ability of the skilled person to readily obtain any form of physical sample of the plant from D1 is the key issue here. In fact, the plant (or any part thereof) of D1 was not publicly available at the priority date. So, while D1 discloses, on paper, TC1507, that plant was not publicly available and so D1 is not enabling." In an Oct. 16, 2014, submission, the patentee further argued that the grower agreement precluded the grower from analyzing or transferring the seed. The EPO in an office action dated May 2, 2018, accepted this argument and found "With respect to the parental application (EP-04751097.9), the Applicant provided evidence (see letter dated 16.10.2014) showing that the maize TC1507 was not available to the public for scientific purposes. The skilled person was thus not in the position to analyse and reproduce said transgenic maize. Accordingly, the subject-matter of independent claim 1 is considered novel."
Written description and the precedent of In re Lundak
An applicant can meet the statutory requirements for patentability under 35 U.S.C. § 112 in two ways (i) by showing that a biological material is known and readily available or (ii) by making a deposit. A reliance that "material is known and readily available" is usually made when it comes to enabling technology used in the context of a patent application (see discussion below). While the EPC and other countries see a deposit strictly as a filing (or priority) date requirement, US law allows a deposit to be made up to the issuance date, which goes back to the CAFC decision In re Lundak. Conceptually this ties the availability of the biological material to the period in which the patentee can exercise exclusive rights. So far the timeline of the issuance date has only be applied for deposits. The PTAB for the first time applied it to material which "is known and readily available" (see discussion below).
What was decided (and what not)
The concurring opinion in PTAB decision emphasizes "that the 2004 application provides an enabling disclosure of the challenged claims and that Barber [sic], which was published in 2006, is not prior art as to the challenged claims. For this independent reason, I would hold that Petitioner has not met its burden to show, by a preponderance of the evidence, that claims 1–8 of the ’378 patent are anticipated by, or would have been obvious over, Barber [sic]". As the grounds for challenges in an IPR are substantially more limited than in an EPO opposition or a US district court invalidity proceeding. The PTAB only determines if the challenged claims are proven unpatentable, or the challenger failed to prove it. In a PGR, the PTAB never decides whether a patent (including the 378 patent) is valid and enforceable. Neither enablement nor an on-sale bar are valid IPR grounds. The current US practice and the PGR decision leaves – to the knowledge of this author – several relevant questions of law undecided:
- Can the "issuance of the patent" deadline for deposits be applied to materials which are "known and readily available"? Or in other words: Can a material be considered "known and readily available" when this was only the case at issuance but not at the filing date? It appears that the answer should be "No". Otherwise, any application on science fiction ideas would become patentable as long one can reduce the idea to practice within the 20 years patent term by simply keeping a divisional application pending.
- "New matter": Can a complete lack of a reference to a deposit can be cured by adding a reference to a deposit which was never indicated before without being considered impermissible "new matter". Can a deposit after the filing date be as such "added matter" if – for example – certain claims refer to sequences of genes in the deposited material without disclosing them as such sequences would only become "added" to the specification with the actual making of the deposit?
- "Link between availability of material and associated rights": Lundak ties the availability of the biological material to the beginning of the exclusive right. But what if the right is not exclusivity, but the “benefit” under 35 U.S.C. 119(e) (i.e., the "priority right"), which starts with the filing date? And what if the related "patent" is a provisional application, which never issues and only grants the benefit of a priority right? The logic of In re Lundak suggests that here enablement must be established by the time the right is established i.e., at the filing date (May 2, 2003).
- Enablement of the provisional application: While the PTAB found enablement for the non-provisional applications at its issuance date in 2006 - as by that time TC1507 material was "known and readily available" - enablement is not established for May 2, 2003 when the provisional application was filed. The patentee in the EPO proceedings declared that due to a grower agreement a plant with the TC1507 event "was not publicly available at the priority date". Thus, the earliest public availability could have been Oct./Nov. 2003, when growers sold their harvest. In consequence, the provisional application is not enabled, which makes - at best- Barbour with a filing date of April 30, 2004, the earliest enabled application.
- Can the "known and readily available" standard for written description be applied to the invention as such. Such approach appears to conflict with the novelty requirements under 35 U.S.C. 102 or the "on sale bar": if the invention was commercially offered for sale over a year before the patent application's filing date, the patent may be invalid, even if the sale was confidential or secret (e.g., sold under a grower agreement), provided the invention was also "ready for patenting." If in the present case April 30, 2004 is the earliest filing date, then the Nov. 11, 2002 offer for sale evidenced by the grower agreement is more than one year before that date, which establishes an "on-sale bar".
Conclusions and leanings
Arguments or evidence which resolve a challenge in the short term may eventually lead to defeat, a scenario known as Pyrrhic victory. Often arguments are made without considering the long-term consequences. The importance of coordinating cases cross-border to ensure consistency of arguments is underestimated, which may not only create evidence for the other party, but also create contradictions and estoppels leading to a "venire contra factum proprium" situation ("to go against one's own previous conduct"). As all the above legal questions will likely be considered in the ongoing Delaware district court case between the parties (Case No. 23-1059), interesting decisions can be expected.
Finally, when it comes to GM events, relying on public availability may not be such a great idea. The EPO and most countries refused claims on the TC1507 maize plant because of this deficit. Even in the US it would be bizarre if one could avoid an enablement challenge by admitting a prior sale. Today a deposit prior to the priority date is common practice for patents on plants with GM events. However, there a still a handful of GM event patent families (including but not limited to TC1507) where this was ignored. Some of those are still generating substantial royalty income from growers and seed companies, which may be questionable.
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