PTAB

IPR2023-01036

Bayer CropScience LP v. Corteva Agriscience LLC

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1. Case Identification

2. Patent Overview

  • Title: Herbicide Resistance Genes
  • Brief Description: The ’555 patent describes transgenic plants and plant cells containing recombinant DNA that encodes an aryloxyalkanoate dioxygenase (AAD-1) protein. This protein is engineered to have a specific amino acid sequence and motif, granting the plant resistance to certain classes of herbicides.

3. Grounds for Unpatentability

Ground 1: Claims 1-34 are anticipated by or obvious over Corteva ’437 based on a corrected priority date.

  • 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 its claimed priority date of April 30, 2004. The predecessor applications allegedly failed to provide adequate written description for two key limitations introduced in 2016: the specific "AAD-1 motif" and an amino acid sequence with "at least 85% sequence identity" to SEQ ID NO: 9. Petitioner contended the predecessor applications only disclosed a broader, prior-art motif for a general family of enzymes and provided a "laundry list" of sequence identities without specific support for the 85% threshold linked to SEQ ID NO: 9.
    • Motivation to Combine (for §103 grounds): With the effective priority date moved to no earlier than October 7, 2016, the Patent Owner's own international application, Corteva ’437 (published in 2005), becomes prior art. Petitioner argued that Corteva ’437 anticipates all challenged claims by disclosing transgenic plants expressing AAD-1 proteins (SEQ ID NO: 9 and 10) that meet the functional and structural requirements of the claims, including having over 99% sequence identity and embodying the claimed AAD-1 motif. The obviousness argument asserted that anticipation is the epitome of obviousness.

Ground 2: Claims 1-10, 13-16, and 34 are obvious over the Saari References, Schleinitz, and Streber.

  • Prior Art Relied Upon: Saari 1998 (a doctoral thesis) or Saari 1999 (a journal article), in combination with Schleinitz (Accession No. AF516751) and Streber (Patent 6,153,401).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground assumed, for the sake of argument, that the claims were entitled to the April 2004 priority date. Petitioner argued that the Saari References taught that the naturally occurring RdpA protein (which the ’555 patent renames AAD-1) could degrade (R)-enantiomer phenoxy herbicides and suggested using its gene to create herbicide-resistant crops. Schleinitz disclosed the exact nucleotide and amino acid sequence for RdpA (SEQ ID NO: 9), which inherently meets the claimed motif and sequence identity limitations. Streber taught established methods for transforming plants with bacterial genes, like the related TfdA gene, to impart herbicide resistance.
    • Motivation to Combine: A POSITA would combine these references to create plants resistant to phenoxy herbicides. The Saari References provided the specific, promising enzyme (RdpA) and the motivation for its use. A POSITA would have naturally looked to Schleinitz for its sequence and to Streber for proven methods of expressing such enzymes in plants.
    • Expectation of Success: A POSITA would have a high expectation of success because Streber and other art demonstrated successful expression of TfdA, a similar enzyme from the same family, in various crop plants to achieve herbicide resistance. Applying these known methods to the specific RdpA enzyme identified by Saari was presented as a straightforward, predictable endeavor.

Ground 3: Claims 11-12 and 17-33 are obvious over the Saari References, Schleinitz, Streber, and Jepson.

  • Prior Art Relied Upon: The references from Ground 2, in further view of Jepson (Application # 2003/0041357).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground extended the logic of Ground 2 to claims requiring a "second herbicide resistance gene" (e.g., for glyphosate) and methods of applying multiple herbicides. Petitioner argued that Jepson explicitly taught combining the TfdA gene with glyphosate resistance genes to create plants with multiple herbicide resistance traits. This teaching was aimed at preventing or delaying the evolution of herbicide-resistant weeds, a well-known problem.
    • Motivation to Combine: A POSITA, having already been motivated to use the RdpA gene as outlined in Ground 2, would have been further motivated by Jepson to combine it with another resistance trait, such as glyphosate resistance. The motivation was to provide broader-spectrum weed control and better long-term weed management, which were established goals in the field.
    • Expectation of Success: The expectation of success was high, as Jepson provided an express template for creating "stacked" trait plants. A POSITA would reasonably expect to be able to substitute the RdpA gene from Saari/Schleinitz for the TfdA gene in Jepson's multi-resistance framework using the methods of Streber.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under §325(d), asserting that the petition raised new art and arguments not before the examiner. Specifically, Saari 1998 was never presented, and the combination of the Saari References with Schleinitz, Streber, and Jepson was never considered. Petitioner also alleged material examiner error in allowing the claims without a proper priority date analysis.
  • Petitioner argued against discretionary denial under Fintiv, stating the parallel district court case was in an early stage, with claim construction and expert discovery not yet completed. Petitioner also stipulated that it would not pursue any invalidity grounds in the district court action that were raised or reasonably could have been raised in the IPR, mitigating concerns of duplicative efforts.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-34 of Patent 10,947,555 as unpatentable.