Merck Sharp & Dohme Corp v. Pfizer Inc

1. Case Identification

• Patent #: 9,492,559
• Filed: September 20, 2017
• Petitioner(s): Merck Sharp & Dohme Corp.
• Patent Owner(s): Pfizer Inc.
• Challenged Claims: 11-15 and 20-37

2. Patent Overview

• Title: Immunogenic Pneumococcal Conjugate Compositions
• Brief Description: The ’559 patent discloses immunogenic compositions containing a Streptococcus pneumoniae serotype 22F glycoconjugate. The invention is defined by specific claimed ranges for the glycoconjugate's molecular weight (1,000 to 12,500 kDa) and its polysaccharide-to-carrier protein ratio (0.4 to 2.0), aimed at expanding vaccine coverage against emerging pneumococcal serotypes not covered by then-existing commercial vaccines.

3. Grounds for Unpatentability

Ground 1: Obviousness over Core Vaccine References - Claims 11-14, 23-27, 29-33, and 35-37 are obvious over [Merck 2011](https://ai-lab.exparte.com/case/ptab/IPR2017-01195/doc/1006) in view of [Pfizer 2012](https://ai-lab.exparte.com/case/ptab/IPR2017-01195/doc/1008).

• Prior Art Relied Upon: Merck 2011 (International Publication No. WO 2011/100151) and Pfizer 2012 (a scientific symposium presentation by the Patent Owner).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Merck 2011, a publication from a major competitor, disclosed all key features of independent claim 1 except for the specific molecular weight range. It taught immunogenic, multivalent pneumococcal vaccine compositions containing a serotype 22F conjugate with a CRM197 carrier protein and a polysaccharide-to-protein ratio of approximately 1.0, which falls within the claimed 0.4-2.0 range. To supply the missing molecular weight, Petitioner cited Pfizer 2012, a presentation from the Patent Owner itself, which taught that the "Typical Mass" for such glycoconjugates is 500-5,000 kDa. This range substantially overlaps the patent's claimed range of 1,000-12,500 kDa, creating a prima facie case of obviousness.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) developing a multivalent vaccine like that in Merck 2011 would combine it with the teachings of Pfizer 2012. The motivation would be to apply the typical and effective molecular weight parameters for glycoconjugates, as disclosed by the Patent Owner, to achieve a predictable and functional vaccine conjugate.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in achieving the claimed invention. The combination involved standard CRM197-based pneumococcal conjugates, and routine experimentation with well-known conjugation chemistries (disclosed in Merck 2011) would have been sufficient to produce a serotype 22F conjugate within the molecular weight range taught by Pfizer 2012.

Ground 2: Obviousness of Lyophilized Formulation - Claim 28 is obvious over Merck 2011, Pfizer 2012, and [GSK 2008](https://ai-lab.exparte.com/case/ptab/IPR2017-01195/doc/1007).

• Prior Art Relied Upon: Merck 2011, Pfizer 2012, and GSK 2008 (International Publication No. WO 09/000825).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground builds on the base combination from Ground 1 to address the limitation of claim 28, which recites a composition "formulated in a lyophilized form." Petitioner introduced GSK 2008, which explicitly taught that vaccines containing serotype 22F conjugates may be stored in lyophilized (freeze-dried) form.
  • Motivation to Combine: A POSITA would combine GSK 2008's teaching with the base vaccine composition for the well-known benefit of increased product stability and shelf-life, a routine and desirable objective in vaccine formulation.

Ground 3: Obviousness of Syringe Type - Claim 15 is obvious over Merck 2011, Pfizer 2012, and the ['787](https://ai-lab.exparte.com/case/ptab/IPR2017-01195/doc/1010) Patent.

• Prior Art Relied Upon: Merck 2011, Pfizer 2012, and the ’787 patent (Patent 7,935,787).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground addresses claim 15, which recites a syringe that is "siliconized or made of glass." Petitioner pointed to the ’787 patent, also owned by Pfizer, which disclosed polysaccharide-protein conjugate formulations in siliconized containers, specifically including siliconized glass syringes, to improve syringeability and inhibit protein aggregation.
  • Motivation to Combine: A POSITA would be motivated to use the well-known, commercially standard packaging taught in the ’787 patent for the vaccine composition of Ground 1 to ensure proper delivery, stability, and administration, representing a simple substitution of one known container for another.

• Additional Grounds: Petitioner asserted additional obviousness challenges for other dependent claims based on the core combination of Merck 2011 and Pfizer 2012, with the addition of a single, well-known reference to teach the final element. These included challenges to:

  • Claims 20-21 (combining with other non-pneumococcal antigens) based on Obaro 2002.
  • Claim 22 (combining with a meningococcal conjugate) based on Sigurdardottir 2008.
  • Claim 34 (administering to immunocompromised humans) based on MMWR 2012.

4. Key Claim Construction Positions

• Petitioner argued that the term "immunogenic," which appears in the preamble of claim 1 and is repeated in most dependent claims, requires construction and should be interpreted to mean "elicits functional antibody against at least pneumococcus serotype 22F."
• This proposed construction was based on the prosecution history, where Petitioner contended the Patent Owner repeatedly and explicitly relied on evidence of eliciting functional antibodies (specifically, opsonophagocytic activity, or OPA) to distinguish the invention from prior art and secure the patent's allowance, thereby making it a limiting feature of the claims.

5. Key Technical Contentions (Beyond Claim Construction)

• A central contention of the petition was establishing the prior art status of the Pfizer 2012 reference, which was a slide deck from a scientific symposium.
• Petitioner argued the reference was "otherwise available to the public" under post-AIA §102. It provided evidence including archived webpages from the conference organizer (CASSS), the scientific program, and an expert declaration to corroborate the presentation date and public availability. Petitioner argued this evidence was reliable and admissible.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and cancellation of claims 11-15 and 20-37 of Patent 9,492,559 as unpatentable.