Bayer CropScience LP v. Corteva Agriscience LLC

1. Case Identification

• Case #: IPR2023-01037
• Patent #: 11,149,283
• Filed: June 15, 2023
• Petitioner(s): Bayer CropScience LP and Monsanto Company
• Patent Owner(s): Corteva Agriscience LLC
• Challenged Claims: 1-29

2. Patent Overview

• Title: Herbicide Resistance Genes
• Brief Description: The ’283 patent is directed to transgenic maize plants and plant cells containing recombinant DNA that encodes an aryloxyalkanoate dioxygenase (AAD-1) protein. The claimed protein must have at least 85% sequence identity to a specific amino acid sequence (SEQ ID NO: 9), comprise a defined “AAD-1 motif,” and exhibit enzymatic activity that degrades certain phenoxy auxin and (R)-aryloxyphenoxypropionate herbicides, thereby rendering the plant tolerant.

3. Grounds for Unpatentability

Ground 1: Claims 1-29 are anticipated by or obvious over Corteva ’437

• Prior Art Relied Upon: Corteva ’437 (WO 2005/107437).
• Core Argument for this Ground: Petitioner argued that the ’283 patent is not entitled to its claimed priority date of April 30, 2004. The key limitations—the specific “AAD-1 motif” and an amino acid sequence with “at least 85% sequence identity” to SEQ ID NO: 9—were first introduced in an application filed on October 7, 2016. Petitioner contended that the predecessor applications failed to provide adequate written description for these broad genus claims, disclosing only three specific, highly similar protein examples and a generic, non-enabling "laundry list" of possible sequence identities. Without the benefit of the earlier priority date, the patent’s effective filing date is no earlier than October 2016. Consequently, Corteva ’437, which is the Patent Owner’s own international application published in 2005, qualifies as prior art under 35 U.S.C. §102 and §103.
  • Prior Art Mapping: Petitioner asserted that Corteva ’437 anticipates all challenged claims because it discloses species of the claimed invention. Specifically, Corteva ’437 teaches transgenic maize plants expressing AAD-1 proteins (corresponding to SEQ ID NO: 9 and 10) that possess the required enzymatic activity and confer tolerance to the claimed classes of herbicides. As an earlier disclosure of a species that falls within the scope of the later-claimed genus, Corteva ’437 anticipates claims 1-29. In the alternative, Petitioner argued that because Corteva ’437 anticipates the claims, it necessarily renders them obvious.

Ground 2: Claims 1-6, 9-12, and 29 are obvious over Saari in combination with Schleinitz and Streber

• Prior Art Relied Upon: Saari 1998 (a doctoral thesis) or Saari 1999 (a journal article), Schleinitz (Accession No. AF516751), and Streber (Patent 6,153,401).
• Core Argument for this Ground: This ground assumed, for the sake of argument, that the ’283 patent is entitled to the April 2004 priority date.
  • Prior Art Mapping: Petitioner argued that the Saari references identified the naturally occurring RdpA protein (renamed AAD-1 in the ’283 patent) as having the desired activity of degrading (R)-enantiomer herbicides and expressly suggested its use in creating herbicide-resistant crops. Schleinitz provided the exact amino acid sequence for RdpA (corresponding to SEQ ID NO: 9). Streber taught established methods for transforming plants with a related enzyme (TfdA) from the same family to successfully confer resistance to 2,4-D, a phenoxy auxin herbicide. The remaining limitations, such as the AAD-1 motif and 100% sequence identity to SEQ ID NO: 9, were inherent properties of the native RdpA protein disclosed by the combination.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to combine the references to achieve the claimed invention. The Saari references provided the specific enzyme (RdpA) and the reason for using it—to create crops resistant to (R)-enantiomer herbicides. A POSITA seeking to implement this suggestion would have readily located the enzyme’s sequence in the public database entry of Schleinitz and applied the proven plant transformation methods disclosed in Streber for a closely related enzyme.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success because Streber demonstrated that a similar enzyme from the same α-ketoglutarate-dependent dioxygenase family had already been successfully used to create transgenic, herbicide-resistant plants.

Ground 3: Claims 7-8 and 13-28 are obvious over Saari, Schleinitz, and Streber in view of Jepson

• Prior Art Relied Upon: The combination from Ground 2, further in view of Jepson (Application # 2003/0041357).
• Core Argument for this Ground: This ground addressed the remaining claims, which are directed to plants containing a "second herbicide resistance gene" and methods involving the application of multiple herbicides.
  • Prior Art Mapping: Jepson disclosed the well-known strategy of transforming plants with multiple herbicide resistance traits (e.g., combining the tfdA gene with a glyphosate resistance gene) to control a broader spectrum of weeds and delay the evolution of herbicide resistance. The claims challenged under this ground add limitations for such combinations, including specific second resistance genes (claim 8) and methods of applying multiple herbicides sequentially or concurrently (claims 13-28).
  • Motivation to Combine: A POSITA, having been motivated by Saari/Schleinitz/Streber to create a plant with AAD-1-based herbicide resistance, would have been further motivated by Jepson to incorporate a second, different herbicide resistance gene. This was a known and desirable strategy for improving the agronomic value and durability of herbicide-tolerant crops.
  • Expectation of Success: The expectation of success was high, as combining herbicide resistance traits was a common and proven practice in the field of agricultural biotechnology to achieve more robust weed control.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) is inappropriate because the petition raises new arguments and prior art not considered by the examiner. Specifically, Saari 1998 was never before the examiner, and the specific combination of Saari 1999, Schleinitz, and Streber was never considered. Petitioner also alleged a material error by the examiner in failing to properly assess the patent's priority claim.
• Petitioner further contended that discretionary denial under Fintiv is not warranted. It asserted that the parallel district court action is in its early stages, that it would stipulate not to pursue the same invalidity grounds in court if review is instituted, and that the petition presents a compelling unpatentability challenge that favors institution.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-29 of Patent 11,149,283 as unpatentable.