PTAB

IPR2019-01086

Regeneron Pharmaceuticals, Inc. v. Novartis Vaccines and Diagnostics, Inc.

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1. Case Identification

2. Patent Overview

  • Title: Vector for Expression of a Polypeptide in a Mammalian Cell
  • Brief Description: The ’688 patent relates to genetic engineering tools for expressing polypeptides in mammalian cells. The claims are directed to host cell expression systems, vectors, and isolated nucleic acid molecules that utilize a transcription regulatory region from the human cytomegalovirus (HCMV) immediate early gene (IE1) to drive expression.

3. Grounds for Unpatentability

Ground 1: Anticipation over the ’949 patent - Claims 1-2, 4-6, 8-9, 13-14, and 17 are anticipated under 35 U.S.C. §102(b) by Patent 5,156,949.

  • Prior Art Relied Upon: Patent 5,156,949 (“’949 patent”).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner’s primary argument was that the ’688 patent is not entitled to its claimed priority date of December 24, 1987 (the filing date of the ’894 application). Petitioner asserted that the priority-founding ’894 application, and its intervening applications, fail to provide adequate written description support for the broad, generic claims of the ’688 patent as required by 35 U.S.C. §112. The ’894 specification allegedly discloses only a single, specific embodiment: the pCMV6a vector used to express one particular HIV polypeptide (gp120) in one specific cell type (COS cells). Petitioner argued this narrow disclosure of a single species lacks any broadening language to support the later-added generic claims directed to expressing any heterologous polypeptide, any mammalian polypeptide, or a genus of vectors and host cell systems.
    • Because the priority chain is broken, Petitioner contended the effective filing date of the challenged claims is the actual filing date of the ’336 application: August 10, 1994. The ’949 patent issued on October 20, 1992, making it §102(b) prior art. Critically, the ’949 patent issued from the same ’894 application and shares an identical specification with the ’688 patent. Therefore, the ’949 patent discloses the exact same pCMV6a vector species. Petitioner argued that this single disclosed species (the pCMV6a vector expressing gp120 in COS cells) meets every limitation of the broad genus claims (1-2, 4-6, 8-9, 13-14, and 17) of the ’688 patent, thereby anticipating them.

Ground 2: Anticipation over Boshart - Claim 17 is anticipated under §102(b) by Boshart (1985).

  • Prior Art Relied Upon: Boshart et al., "A Very Strong Enhancer Is Located Upstream of an Immediate Early Gene of Human Cytomegalovirus," Cell 41: 521-530 (1985) (“Boshart”).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Boshart, a seminal 1985 publication, anticipates every element of independent claim 17. Claim 17 recites an "isolated nucleic acid molecule" with an "enhanced promoter" from HCMV IE1 (comprising the promoter and first intron) that is "operably linked" to a nucleic acid encoding a mammalian polypeptide. Petitioner asserted Boshart discloses the pβX-1429 plasmid, which is an "isolated nucleic acid molecule" constructed and separated from other hCMV components. This plasmid contains the HCMV IE1 PstI fragment, which Boshart describes as a complete enhancer/promoter and which literature shows includes the first intron. This "enhanced promoter" is operably linked to, and directs the transcription of, the rabbit β-globin gene, which is a nucleic acid encoding a "mammalian polypeptide." Thus, Petitioner contended that Boshart’s pβX-1429 plasmid is a species that falls squarely within the scope of claim 17, rendering it anticipated.

4. Key Claim Construction Positions

  • Petitioner submitted that no claim construction is necessary to resolve the anticipation issues, as the prior art discloses species that fall within the claims under any reasonable interpretation. However, if the Board were to construe terms, Petitioner proposed the following:
    • "mammalian polypeptide": Petitioner argued this term, which is not defined in the specification, should be given its plain and ordinary meaning: "a polypeptide that is found naturally in a mammal." This construction is relevant to the Boshart ground, as Boshart discloses expression of the naturally occurring rabbit β-globin. Petitioner noted that Patent Owner relied on the plain meaning of this term during reexamination to add it to the claims.
    • "operably linked": Petitioner asserted this term should be construed as "arranged in a functional manner." For claim 17, this means the HCMV IE1 enhanced promoter must be arranged relative to the polypeptide-encoding nucleic acid such that it directs transcription of that sequence in a host cell. Petitioner argued the claims themselves support this functional construction.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that the Board should not exercise discretionary denial under §325(d) because the arguments and evidence presented in the petition were not previously considered by the PTO during prosecution or reexamination.
  • Specifically, the PTO never analyzed the threshold priority issue—whether the ’894 application provided sufficient written description for the later-claimed generic subject matter. As a result, the PTO never considered the ’949 patent as §102(b) anticipatory prior art.
  • While Boshart was cited during prosecution, it was not used to reject claim 17 or any other issued claim. Furthermore, the petition presented new evidence, including deposition testimony from the Patent Owner’s own declarant (Dr. Truett) recanting key assertions made during reexamination regarding written description support for expressing mammalian polypeptides.

6. Relief Requested

  • Petitioner requested that the Board institute an inter partes review and cancel claims 1-2, 4-6, 8-9, 13-14, and 17 of Patent 5,688,688 as unpatentable.