PTAB

IPR2017-00390

Merck Sharp & Dohme Corp v. Wyeth LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Formulations of Polysaccharide-Protein Conjugates
  • Brief Description: The ’999 patent relates to stable vaccine formulations containing polysaccharide-protein conjugates. The invention purports to inhibit protein aggregation caused by silicone oil, a common lubricant in pharmaceutical containers, by using a formulation that includes a buffer, an aluminum salt, and the conjugate itself.

3. Grounds for Unpatentability

Ground 1: Claims 7-9, 12-13, 15-16, and 21-22 are obvious over Chiron 2003, Smith 1988, and Elan 2004.

  • Prior Art Relied Upon: Chiron 2003 (WO 03/009869), Smith 1988 (a technical report on siliconization), and Elan 2004 (WO 2004/071439).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Chiron 2003 taught all the basic components of the claimed vaccine formulation, including polysaccharide-protein conjugates, an aluminum salt adjuvant, a buffer (specifically histidine), and a salt (sodium chloride). Separately, Smith 1988 established that siliconizing pharmaceutical containers like vials and syringes with silicone oil was a standard and necessary industry practice. Elan 2004 then addressed the known problem of silicone-induced protein aggregation by teaching that adding a surfactant (the same type disclosed in Chiron 2003) effectively prevents it. The combination of these references, Petitioner asserted, disclosed every limitation of the challenged claims.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine these references to solve a known problem. A POSITA would formulate the Chiron 2003 vaccine in a standard, siliconized container as taught by Smith 1988 for administration. Recognizing the known risk of silicone-induced aggregation, the POSITA would be motivated to look for a known solution, which Elan 2004 provided by demonstrating the efficacy of using a surfactant.
    • Expectation of Success: A POSITA would have a high expectation of success because the combination involved applying a well-documented solution (a surfactant, per Elan 2004) to a well-known problem (silicone-induced aggregation) using conventional vaccine components (from Chiron 2003) in standard packaging (per Smith 1988).

Ground 2: Claims 7-9, 12-13, 15-16, and 21-22 are obvious over Prevenar 2005 and Chiron 2003.

  • Prior Art Relied Upon: Prevenar 2005 (a "Summary of Product Characteristics" for Patent Owner's commercial vaccine) and Chiron 2003 (WO 03/009869).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Prevenar 2005, the Patent Owner's own prior art vaccine, disclosed a formulation containing nearly all claimed elements: pneumococcal polysaccharide-protein conjugates, aluminum phosphate, and sodium chloride, all supplied in a pre-filled glass syringe known to be siliconized. This commercial formulation inherently inhibited aggregation. The primary missing limitation was a buffer. Chiron 2003 taught the benefits of adding a histidine buffer to such polysaccharide conjugate vaccines to enhance pH and antigen stability.
    • Motivation to Combine: A POSITA would be motivated to improve the stability of the buffer-less Prevenar 2005 formulation, a routine objective in pharmaceutical development. Chiron 2003 provided the explicit motivation and solution by teaching that adding a histidine buffer improves the stability of aluminum-adjuvanted vaccines, particularly those with acidic antigens like the ones in Prevenar 2005.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because adding a standard stabilizing agent (a buffer) to an existing vaccine formulation was a conventional and predictable optimization step. Chiron 2003 confirmed the known benefits of this specific modification.

Ground 3: Claims 13 and 16 are obvious over Merck 2011 and the ’787 Patent.

  • Prior Art Relied Upon: Merck 2011 (WO 2011/100151) and Patent 7,935,787 (’787 patent).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground specifically targeted claims 13 and 16, which require a histidine buffer at a pH of 5.8. Petitioner first argued these claims lacked written description support in the parent applications and were therefore only entitled to the ’999 patent’s later filing date, making Merck 2011 prior art. Merck 2011 disclosed a pneumococcal conjugate vaccine containing every specific component of the claims: a histidine buffer at pH 5.8, sodium chloride, and aluminum phosphate. The ’787 patent, which shares its specification with the ’999 patent, taught that such formulations inhibit silicone-induced aggregation when placed in siliconized containers.
    • Motivation to Combine: A POSITA would be motivated to combine these references as they both relate directly to aluminum-adjuvanted pneumococcal conjugate vaccines intended for use in pre-filled syringes. The combination simply applies the known functional properties described in the ’787 patent to the specific, stable formulation disclosed in Merck 2011.
    • Expectation of Success: A POSITA would have a high expectation of success, as this combination involved recognizing that a specific prior art formulation (Merck 2011) would inherently possess the functional properties (inhibition of silicone-induced aggregation) taught by a related patent (’787 patent).

4. Key Claim Construction Positions

  • "polysaccharide": Petitioner argued this term should be construed broadly as "any antigenic saccharide element... commonly used in the immunologic and bacterial vaccine arts," based on an explicit definition in the ’999 patent’s specification.
  • "container means": Petitioner argued this term should encompass "any composition of matter which is used to contain, hold, mix, blend, dispense, inject..." a composition, including vials, syringes, stoppers, and plungers, as this was also explicitly defined in the specification.
  • "the formulation... inhibits aggregation...": Petitioner contended this phrase recites a property of the formulation as a whole and does not attribute the inhibitory effect to any single claimed ingredient. This construction was based on the claim’s plain language and the prosecution history.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 7-9, 12-13, 15-16, and 21-22 of the ’999 patent as unpatentable.