PTAB

IPR2023-01038

Bayer CropScience LP v. CorTeva AgriScience LLC

Title: Herbicide Resistance Genes
Brief Description: The ’745 patent relates to transgenic soybean 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 SEQ ID NO: 9, comprise a specific "AAD-1 motif," and exhibit enzymatic activity that degrades certain phenoxy auxin and aryloxyphenoxypropionate herbicides, thereby conferring herbicide resistance.

Prior Art Relied Upon: Corteva ’437 (WO 2005/107437).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that the ’745 patent is not entitled to its claimed 2004 priority date because the parent applications lack written description support for the "AAD-1 motif" and the "at least 85% sequence identity" limitations. With an effective priority date of no earlier than October 2016, Corteva ’437 (published in 2005) constitutes prior art. Petitioner argued Corteva ’437 discloses every limitation of the challenged claims, including transgenic soybean cells expressing AAD-1 proteins (SEQ ID NOs: 9 and 10, which have >99% identity to SEQ ID NO: 9) that possess the claimed AAD-1 motif and degrade the specified classes of herbicides.
- Key Aspects: This ground hinges on a successful challenge to the ’745 patent’s priority claim, which is a central technical argument of the petition.

Prior Art Relied Upon: Saari 1998 (a doctoral thesis), Saari 1999 (a journal article), Schleinitz (Accession No. AF516751), and Streber (Patent 6,153,401).
Core Argument for this Ground:
- Prior Art Mapping: This ground was argued assuming, for the sake of argument, an April 2004 priority date. The Saari references disclosed the RdpA protein (which the ’745 patent renames AAD-1 and corresponds to SEQ ID NO: 9) and its ability to degrade (R)-enantiomers of phenoxy herbicides. Schleinitz disclosed the specific amino acid and nucleotide sequences for RdpA. Streber taught standard, successful methods for transforming plants with a similar enzyme (TfdA) to confer herbicide resistance.
- Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references because the Saari references explicitly suggested using RdpA to create herbicide-resistant crops. A POSITA would have turned to the established methods in Streber and the sequence data in Schleinitz to implement this suggestion.
- Expectation of Success: A POSITA would have a reasonable expectation of success because similar enzymes from the same family (TfdA) had already been successfully expressed in various crops to confer resistance to the same class of herbicides, and the methods for doing so were well-known.

Prior Art Relied Upon: Saari 1998, Saari 1999, Schleinitz, Streber, and Jepson (Application # 2003/0041357).
Core Argument for this Ground:
- Prior Art Mapping: This ground builds on Ground 2 by adding Jepson to address claims directed to using multiple herbicides and/or multiple resistance genes (i.e., gene stacking). Jepson disclosed combining genes for glyphosate resistance with the tfdA gene (a close relative of RdpA) and applying multiple classes of herbicides to control a broader spectrum of weeds.
- Motivation to Combine: A POSITA would be motivated to add Jepson’s teachings to the combination in Ground 2 to improve weed management. Jepson explicitly taught that stacking resistance traits and applying multiple herbicides was a known and effective strategy for preventing the development of herbicide-resistant weeds.
- Expectation of Success: Success was expected because it involved applying a known weed control strategy (from Jepson) to a promising herbicide-resistance gene (RdpA, from Saari/Schleinitz) using established genetic engineering techniques (from Streber).
Additional Grounds: Petitioner asserted that claims 1-29 are also obvious over Corteva ’437 (Ground IB), arguing that anticipation is the epitome of obviousness.

Lack of Written Description in Priority Documents: The petition’s primary technical contention, which underpins Ground 1, is that the ’745 patent is not entitled to a priority date earlier than October 2016. Petitioner argued the parent applications fail to provide adequate written description for key limitations, specifically:
- The claimed "AAD-1 motif," which Petitioner contended is a narrower, different structure from the broader, prior-art dioxygenase motif disclosed in the priority documents.
- The claim to proteins with "at least 85% sequence identity" to SEQ ID NO: 9. Petitioner asserted the priority documents only disclose a few examples with nearly 100% identity and a non-enabling "laundry list" of possible percentage ranges, failing to guide a POSITA to the claimed genus.

Petitioner argued that discretionary denial under either §325(d) or §314(a) (Fintiv) would be inappropriate.
§325(d): Denial was argued to be improper because the petition raises new arguments and relies on prior art (Saari 1998) that was never before the examiner. Furthermore, Petitioner alleged the examiner committed a material error by failing to correctly analyze the priority date issue and relying on "legally irrelevant" post-priority date evidence to allow the claims.
Fintiv Factors: Petitioner argued the factors favor institution. The parallel district court case was in an early stage, discovery deadlines were months away, and Petitioner stipulated to not pursue the same grounds in court if the IPR is instituted. Petitioner asserted the petition presents a "compelling unpatentability challenge," which strongly weighs in favor of institution.

Petitioner requests institution of an inter partes review and cancellation of claims 1-29 of the ’745 patent as unpatentable.