Summary
This Federal Circuit opinion reviews two final written decisions of the Patent Trial and Appeal Board finding certain claims of U.S. patents directed to chemically modified guide RNAs for CRISPR-Cas systems unpatentable. The court applies substantial evidence and de novo review standards to affirm the Board's determinations of anticipation and obviousness based on prior art references.
Topics
Practice areas
Questions Presented
- Whether substantial evidence supported the Board's finding that Pioneer Hi-Bred expressly disclosed the claimed gRNA functionality.
- Whether Pioneer Hi-Bred was an enabling anticipatory reference.
- Whether substantial evidence supported the Board's determination that the challenged dependent claims would have been obvious over Pioneer Hi-Bred combined with Threlfall or Deleavey.
- Whether the Board violated the Administrative Procedure Act by allegedly changing its theory of anticipation without adequate notice and opportunity to respond.
Holdings
- Substantial evidence supported the Board's finding that Pioneer Hi-Bred expressly disclosed guide RNA functionality consisting of associating with a Cas protein and targeting the gRNA-Cas complex to a target polynucleotide.
- Pioneer Hi-Bred was an enabling anticipatory reference because it enabled at least one embodiment within the scope of the challenged claims without undue experimentation.
- Substantial evidence supported the Board's determination that the challenged dependent claims would have been obvious over Pioneer Hi-Bred in combination with Threlfall or Deleavey.
- The Board did not violate the APA's notice and opportunity-to-be-heard requirements because it did not change theories midstream, and the functionality issue was central to the IPR proceedings.
Key quotations
“For the foregoing reasons, substantial evidence supports the Board’s finding that Pioneer Hi-Bred expressly discloses the claimed gRNA functionality, i.e., associating with a Cas protein and targeting the gRNA:Cas protein complex to a target polynucleotide.” (opinion p. 12)
“For the foregoing reasons, we affirm the Board’s determination that Pioneer Hi-Bred’s disclosure is enabling.” (opinion p. 18)
“For the foregoing reasons, we affirm the Board’s determination that all claims of the ’001 and ’034 patents are unpatentable.” (opinion p. 21)
Factual background
The patents concern chemically modified CRISPR-Cas guide RNAs used for gene editing. The claimed guide RNAs include chemical modifications intended to preserve functionality and increase stability, including modifications to phosphodiester linkages and sugars. Pioneer Hi-Bred disclosed guide polynucleotide/Cas systems, modified guide nucleotides, and chemically modified RNA sequences, while Threlfall and Deleavey disclosed relevant PACE, thioPACE, and other oligonucleotide modifications.
Procedural history
Synthego petitioned for inter partes review of all claims of Agilent's two patents. After instituting review, the Board determined that all claims of both patents were unpatentable, finding that Pioneer Hi-Bred anticipated numerous claims and that other claims would have been obvious over Pioneer Hi-Bred combined with Threlfall or Deleavey. Agilent timely appealed, and the Federal Circuit affirmed.