Wuhan Healthgen Biotechnology Corp Of Wuhan China v. Ventria Bioscience Inc

1. Case Identification

• Case #: IPR2022-00712
• Patent #: 10,618,951
• Filed: March 17, 2022
• Petitioner(s): Wuhan Healthgen Biotechnology Corp.
• Patent Owner(s): Ventria Bioscience Inc.
• Challenged Claims: 1-9 and 11-13

2. Patent Overview

• Title: Cell Culture Media Compositions
• Brief Description: The ’951 patent relates to cell culture media compositions that include recombinant mammalian albumin produced in a transgenic plant. The patent asserts novelty in the purity of the albumin composition, specifically requiring less than 1 EU/mg of endotoxin and less than 2% aggregated albumin, and the presence of co-purified heat shock proteins (Hsps).

3. Grounds for Unpatentability

Ground 1: Claims 1-8 and 11-13 are obvious over Deeter in view of Tanaka

• Prior Art Relied Upon: Deeter (WO 2007/002762) and Tanaka (a 1998 publication on albumin purification).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Deeter, a publication assigned to the Patent Owner, disclosed the core of the invention: a cell culture media supplement comprising recombinant human serum albumin (rHSA) produced in transgenic rice. Petitioner asserted that Deeter's rHSA composition inherently contained the heat shock proteins (Hsps) required by dependent claims 2-6 because it was produced using nearly identical methods to those described in the ’951 patent. However, Deeter’s product contained high levels of endotoxin. Tanaka was cited as teaching a well-known, simplified process for purifying plasma-derived albumin that achieves the specific purity levels recited in claim 1: a "pyrogen-free" product (i.e., less than 1 EU/mg endotoxin) with low aggregation (0.7-1.0%).
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have recognized that the rHSA disclosed in Deeter, while a promising alternative to animal-derived albumin, contained undesirable levels of endotoxin, a known cytotoxic contaminant. A POSITA would have been motivated to reduce these endotoxin levels to make the product suitable for cell culture applications and would have looked to known purification methods like Tanaka's to solve this predictable problem.
  • Expectation of Success: A POSITA would have reasonably expected Tanaka's process to successfully purify Deeter's rHSA. The fundamental biochemical properties of albumin and endotoxin do not change based on the production source (transgenic rice vs. human plasma), meaning standard purification techniques like anion exchange chromatography would work as expected. Further, Petitioner argued that Tanaka’s purification steps would not have been expected to remove the co-purified Hsps, as they have similar sizes and isoelectric points to rHSA.

Ground 2: Claims 1-8 and 11-13 are obvious over Deeter in view of Van Urk

• Prior Art Relied Upon: Deeter (WO 2007/002762) and Van Urk (WO 2000/44772).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground presented a similar argument to Ground 1, with Van Urk serving as the secondary reference teaching purification. Deeter again provided the base rHSA product from transgenic rice, which inherently contained Hsps. Van Urk was presented as teaching processes for preparing highly purified rHSA, specifically including rHSA produced in transgenic plants (e.g., potato, corn). Van Urk's process explicitly achieved a product with no detectable endotoxin and less than 1% aggregated albumin, directly meeting the purity limitations of claim 1.
  • Motivation to Combine: The motivation was identical to Ground 1: to reduce the known high endotoxin levels in Deeter's rHSA to improve its utility. Van Urk was argued to be particularly relevant because it specifically addressed purifying rHSA from transgenic plant sources, the same context as Deeter.
  • Expectation of Success: Petitioner argued there was a high expectation of success because Van Urk's purification methods were taught to be suitable for the exact type of product disclosed in Deeter (plant-derived rHSA). A POSITA would have reasonably expected that applying Van Urk's established purification steps to Deeter's rHSA would yield a product meeting the claimed purity levels while retaining the inherently co-purified Hsps.

• Additional Grounds: Petitioner asserted additional obviousness challenges against claim 9 based on the combinations of Deeter/Tanaka/Meng and Deeter/Van Urk/Meng. These grounds argued that Meng taught specific weight ratios of transferrin to rHSA (e.g., 1:455) for cell culture media that fall within the range claimed in claim 9, and a POSITA would have been motivated to apply these known, advantageous ratios to the purified base compositions.

4. Key Claim Construction Positions

• The petition noted that several claim terms had agreed-upon constructions from a related litigation. For two disputed terms, Petitioner argued that its unpatentability positions held true regardless of which construction was adopted.
• "recombinant mammalian albumin": Petitioner contended that the rHSA of Deeter is identical to the claimed albumin under any reasonable construction.
• "produced in a transgenic plant": Petitioner argued Deeter's disclosure of producing rHSA in transgenic rice met this limitation under any proposed construction.

5. Key Technical Contentions (Beyond Claim Construction)

• Inherency of Heat Shock Proteins: A central technical contention was that the Hsp limitations of claims 2-6 were inherently present in the prior art rHSA of Deeter. Petitioner argued that since Deeter's rHSA was produced in the same host (rice) using nearly identical processes as the rHSA described in the ’951 patent, it would necessarily have contained the same co-purified rice Hsp70 proteins. This argument was supported by analyzing the disclosed purification steps (which would not separate Hsps from rHSA) and by citing data in the ’951 patent itself showing comparable cell growth activity between the "old" (Deeter) and "new" rHSA.

6. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) based on Fintiv factors would be inappropriate. It stated that the parallel district court litigation was stayed pending an ITC investigation, and the ITC lacks the authority to invalidate patent claims. Furthermore, Petitioner contended the ITC case involved a narrower set of claims, with distinct issues from the eight additional claims challenged in the IPR (claims 2-8 and 9).
• Petitioner also argued against denial under §325(d), asserting that the secondary references (Tanaka, Van Urk, and Meng) were never before the examiner during prosecution. Therefore, the asserted grounds were not cumulative and raised new issues that warranted review.

7. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-9 and 11-13 of Patent 10,618,951 as unpatentable.