PTAB

IPR2023-01036

Bayer CropScience LP v. CorTeva AgriScience LLC

Log In

1. Case Identification

2. Patent Overview

  • Title: Herbicide Resistance Genes
  • Brief Description: The ’555 patent claims transgenic plants and plant cells containing recombinant DNA that encodes an aryloxyalkanoate dioxygenase (AAD-1) protein. This protein is engineered to have specific structural features (an "AAD-1 motif" and sequence identity to SEQ ID NO: 9) and functional activity, namely the ability to degrade certain phenoxy auxin and (R)-aryloxyphenoxypropionate herbicides, thereby conferring herbicide resistance to the plant.

3. Grounds for Unpatentability

Ground 1: Claims 1-34 are anticipated under 35 U.S.C. §102 by Corteva ’437.

  • Prior Art Relied Upon: Corteva ’437 (WO 2005/107437).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the ’555 patent is not entitled to a priority date earlier than October 7, 2016, due to a lack of written description support in its predecessor applications (see Section 5 below). This effective date makes Patent Owner’s own international application, Corteva ’437 (published in 2005), invalidating prior art. Petitioner contended that Corteva ’437 discloses every limitation of the challenged claims. Specifically, ’437 allegedly describes transgenic plants and cells expressing AAD-1 proteins (including variants v1 and v2, corresponding to SEQ ID NO: 9 and 10) that degrade both phenoxy auxin and (R)-aryloxyphenoxypropionate herbicides. The disclosed protein sequences in ’437 meet the challenged claims' requirements for sequence identity (e.g., 100% and >99% identity to SEQ ID NO: 9) and possess the claimed AAD-1 motif.
    • Key Aspects: This ground’s success hinges on the argument that the challenged claims lack priority entitlement, which would make the Patent Owner's own earlier publication prior art against the ’555 patent.

Ground 2: Claims 1-10, 13-16, and 34 are obvious under 35 U.S.C. §103 over Saari in combination with Schleinitz and Streber.

  • Prior Art Relied Upon: Saari 1998 (doctoral thesis) or Saari 1999 (journal article), Schleinitz (Accession No. AF516751), and Streber (Patent 6,153,401).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground was presented as an alternative, assuming the claims are entitled to their earliest priority date of April 30, 2004. Petitioner argued that the Saari references identified the naturally occurring RdpA protein (which the ’555 patent renames AAD-1) as having the desired activity of degrading (R)-chiral phenoxy herbicides. Schleinitz disclosed the exact amino acid sequence of RdpA, which is identical to the ’555 patent’s SEQ ID NO: 9 and inherently contains the claimed AAD-1 motif. Streber taught established methods for transforming plants with similar enzymes (e.g., TfdA) to confer herbicide resistance, including resistance to 2,4-D.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to combine these references to solve the known problem of weed control. Specifically, a POSITA would apply the known plant transformation methods taught by Streber to the specific RdpA enzyme suggested by Saari and sequenced by Schleinitz, in order to create a plant with the desired herbicide resistance.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success because the references showed that a closely related enzyme (TfdA) had already been successfully expressed in various crops to impart resistance to phenoxy herbicides. The transformation of a known gene to express a known protein using established methods was considered a predictable art.

  • Additional Grounds: Petitioner asserted that claims 1-34 are obvious over Corteva ’437 (Ground IB) because anticipation is the epitome of obviousness. Petitioner also asserted that remaining claims 11-12 and 17-33 are obvious over the combination of Saari, Schleinitz, and Streber in further view of Jepson (Application # 2003/0041357) (Ground IIB). Jepson was cited for its teaching of stacking multiple herbicide resistance genes (e.g., a tfdA gene with a glyphosate resistance gene) to combat weed resistance, motivating a POSITA to combine the RdpA-based resistance with other known resistance traits.

4. Key Technical Contentions (Beyond Claim Construction)

  • Lack of Written Description and Priority Entitlement: Petitioner’s primary technical contention, underpinning Ground 1, was that the ’555 patent is not entitled to its claimed priority date of 2004. Petitioner argued the predecessor applications failed to provide adequate written description for two key limitations first introduced in 2016:
    • The "AAD-1 motif": The parent applications allegedly only disclosed a much broader, prior-art motif for the general α-ketoglutarate-dependent dioxygenase family, not the specific, narrower AAD-1 motif of the challenged claims.
    • "At least 85% sequence identity": The parent applications allegedly provided only a generic "laundry list" of possible sequence identities ranging from 49% to 99% without specifically identifying 85% or providing a representative number of examples to support such a broad range, especially one reaching as low as 85%.
  • As a result, Petitioner contended the claims’ earliest effective filing date is October 7, 2016, making numerous publications, including Patent Owner's own Corteva '437, prior art.

5. Arguments Regarding Discretionary Denial

  • §325(d) - Same or Substantially Same Art or Arguments: Petitioner argued that discretionary denial under §325(d) is inappropriate. The petition was asserted to be based on prior art and arguments not before the examiner. Specifically, Saari 1998 was never presented to the examiner, and while Saari 1999 was in an IDS, it was never substantively discussed or applied in the combinations now asserted. Petitioner also argued the examiner committed a material error by failing to properly assess priority and allowing the claims based on what Petitioner characterized as legally irrelevant, post-priority-date evidence submitted by the applicant during prosecution.
  • §314(a) - Fintiv Factors: Petitioner argued that the Fintiv factors weigh against discretionary denial. The parallel District Court Action was described as being in an early stage, with initial infringement contentions for the ’555 patent having been served only a few months prior to the IPR filing. Petitioner stipulated that if the IPR is instituted, it would not pursue any invalidity grounds raised or that reasonably could have been raised in the IPR in the district court action. Finally, Petitioner asserted that the petition presents a "compelling unpatentability challenge," which strongly favors institution.

6. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1-34 of Patent 10,947,555 as unpatentable.