Baylor College Of Medicine v. Board Of Regents Of University Of Texas System

1. Case Identification

• Case #: IPR2018-00949
• Patent #: 9,333,248
• Filed: April 18, 2018
• Petitioner(s): Baylor College of Medicine
• Patent Owner(s): The Board of Regents of the University of Texas System and Gensetix, Inc.
• Challenged Claims: 1-29

2. Patent Overview

• Title: Dendritic Cell-Based Cancer Vaccines
• Brief Description: The ’248 patent is directed to methods for inducing an immunologic response to a tumor in a patient. The method involves differentiating a patient’s immature dendritic cells (DCs) into mature DCs by providing them with a tumor antigen composition containing at least one Major Histocompatibility Complex (MHC) Class I epitope and at least one MHC Class II epitope that have a sequence overlap of at least five amino acids.

3. Grounds for Unpatentability

Ground 1: Obviousness over Decker and Zeng - Claims 1, 7, 10, 12, 15, 16, and 24-26 are obvious over Decker in view of Zeng.

• Prior Art Relied Upon: Decker (a 2006 article in Vaccine) and Zeng (a 2002 article in Cancer Research).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Decker taught a method for generating "doubly loaded" DCs for cancer therapy by loading them with matched tumor antigen compositions (lysate) and nucleic acid compositions (mRNA) derived from the same tumor source. While Decker did not explicitly identify overlapping MHC epitopes, Petitioner contended that its method of using a complete tumor lysate inherently provided the claimed overlapping epitopes. Zeng was cited for explicitly teaching the use of peptides with overlapping MHC Class I and Class II epitopes to generate more effective cancer vaccines by engaging both CD8+ and CD4+ T cells simultaneously.
  • Motivation to Combine: A POSITA would combine Decker’s double-loading protocol with Zeng’s specific teachings on using overlapping epitopes. Zeng provided the rationale that linking cytotoxic T-lymphocyte (CTL) responses with helper T-cell (HTC) responses against an overlapping epitope was an important strategy for vaccine development, which would have motivated a POSITA to ensure the antigens used in Decker's method contained such epitopes.
  • Expectation of Success: A POSITA would have an expectation of success because both references operated in the same technical field of DC-based cancer immunotherapy. Applying Zeng's known principle of using overlapping epitopes to Decker's established method of preparing and administering DCs would have been a predictable and straightforward modification to improve vaccine efficacy.

Ground 2: Obviousness over Decker, Zeng, and Tedder - Claims 2 and 3 are obvious over Decker and Zeng in view of Tedder.

• Prior Art Relied Upon: Decker (a 2006 article in Vaccine), Zeng (a 2002 article in Cancer Research), and Tedder (a 1997 article in Current Protocols in Immunology).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground built upon the combination of Decker and Zeng. Claims 2 and 3 add the limitation of selecting mature DCs that express increased levels of the maturation marker CD83 compared to singly-loaded DCs. Petitioner argued that the increased CD83 expression was an inherent result of the double-loading method taught by Decker, citing data from the ’248 patent itself as evidence. Tedder taught methods for isolating homogenous populations of mature, CD83+ DCs, describing them as the most potent stimulators for anti-tumor vaccines.
  • Motivation to Combine: While Decker’s method produced a population of mature DCs, it was not entirely homogenous (80-95% CD83+). A POSITA would be motivated by Tedder to select for a pure CD83+ population from Decker's cells to enhance the therapeutic potency of the final vaccine product, as Tedder taught this would facilitate the development of more effective vaccines.
  • Expectation of Success: Selecting for a known marker of cell maturity and potency (CD83) using established techniques as taught by Tedder was a routine and predictable step for a POSITA seeking to optimize the cell-based therapy described by Decker and Zeng.

• Additional Grounds: Petitioner asserted six additional obviousness challenges based on the core Decker and Zeng combination. These grounds added a single prior art reference to teach specific limitations in dependent claims, including: Cezayirli for applying the method to other cancers (claims 5, 6, 8, 9, 11, 27); Reyes for enriching mRNA via subtraction (claims 13-14); Wang for screening patients and selecting tumor cells (claims 4, 17-18); Renner for using protein fractions (claims 19-20); Lotem for using expression constructs (claims 21-23); and Ossendorp for using separate synthetic peptides (claims 28-29).

4. Key Technical Contentions (Beyond Claim Construction)

• Inherency of Overlapping Epitopes in Decker: The central technical contention of the petition was that the primary prior art reference, Decker, inherently disclosed the key limitation of claim 1—a tumor antigen composition with overlapping MHC Class I and Class II epitopes. Petitioner argued that Decker's method, which used a tumor lysate containing a "full complement of patient-specific tumor antigens," would necessarily include proteins (such as Proteinase 3 and Survivin, known to be expressed in the AML cells used by Decker) that contain naturally occurring, overlapping MHC Class I and II epitopes, even though Decker did not explicitly test for or describe them.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise its discretion to deny review under 35 U.S.C. § 325(d), even though the Decker reference was cited in an Information Disclosure Statement (IDS) during prosecution. Petitioner asserted that Decker was never substantively considered by the examiner, as it was not cited in any Office Action or used as the basis for any rejection. Furthermore, Petitioner alleged that the Patent Owner failed to inform the examiner that Example 1 of the patent application was copied nearly verbatim from the Decker publication, preventing a proper evaluation of its relevance.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-29 of the ’248 patent as unpatentable under 35 U.S.C. § 103.