Merck Sharp & Dohme LLC v. Pogona LLC

1. Case Identification

• Case #: IPR2026-00221
• Patent #: 11,058,757
• Filed: January 26, 2026
• Petitioner(s): Merck Sharp & Dohme LLC
• Patent Owner(s): Pogona, LLC
• Challenged Claims: 1-19

2. Patent Overview

• Title: Pneumococcal Saccharide-Polypeptide Conjugate Vaccines
• Brief Description: The ’757 patent relates to pharmaceutical compositions comprising at least two unique immunogenic saccharide-polypeptide conjugates. The novelty of the patent is predicated on the selection of specific capsular polysaccharides from Streptococcus pneumoniae serotypes 23A, 23B, and/or 35B.

3. Grounds for Unpatentability

Ground 1: Anticipation by Porro - Claims 1, 3, and 12 are anticipated by Porro.

• Prior Art Relied Upon: Porro (WO 2014/118201).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Porro, which was not considered during prosecution, disclosed all limitations of the challenged claims. Porro described multivalent conjugate vaccines and specifically identified S. pneumoniae serotypes 23A and 35B as "preferred embodiments" for its constructs. Petitioner asserted that because claim 1 recites a Markush group, Porro’s express disclosure of these two members anticipated the entire claim element. Porro also disclosed the use of CRM197 as a carrier protein, anticipating claim 3, and listed numerous other serotypes that anticipated the additional conjugates required by claim 12.
  • Key Aspects: Petitioner emphasized that the examiner for the ’757 patent erroneously concluded the claimed serotypes were "free of prior art," while an examiner in a related continuation application later found substantially similar claims to be anticipated by this same reference.

Ground 2: Anticipation by Mekalanos - Claims 1-5, 8-9, 11-12, 15, and 18-19 are anticipated by Mekalanos.

• Prior Art Relied Upon: Mekalanos (WO 2017/011338).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Mekalanos, also not considered during prosecution, taught immunogenic polysaccharide-protein conjugates and methods for their use that anticipated the claims. Mekalanos disclosed pharmaceutical compositions comprising a plurality of conjugates and explicitly listed a wide array of S. pneumoniae serotypes for inclusion, including 23B and 35B. As with Porro, Petitioner argued this disclosure anticipated the Markush group of claim 1. Mekalanos further disclosed using carrier proteins like CRM197 (claim 3), standard adjuvants and excipients (claim 4), intramuscular administration (claims 5 and 15), and methods of making the composition (claim 19).
  • Key Aspects: The allowance of the ’757 patent was based on the examiner's erroneous belief that these serotypes were novel. Petitioner argued that a sufficient prior art search would have uncovered Mekalanos, which squarely taught the use of these serotypes in conjugate vaccine compositions.

Ground 3: Obviousness over Combination Art - Claims 1-19 are obvious over Mekalanos in view of Porro and Siber.

• Prior Art Relied Upon: Mekalanos (WO 2017/011338), Porro (WO 2014/118201), and Siber (Patent 8,808,707).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that even if not anticipated, the claims were obvious over the combined teachings of the prior art. Mekalanos and Porro together disclosed all claimed serotypes (23A, 23B, and 35B) as targets for inclusion in pneumococcal conjugate vaccines. Siber described the established state of the art, including conventional multivalent vaccine structures (e.g., Prevnar®), prime-boost administration schedules, and the routine practice of modifying vaccines to include new serotypes based on epidemiological data.
  • Motivation to Combine: A POSITA would combine these references because they all address the same technical problem: creating effective, broad-spectrum pneumococcal conjugate vaccines. It would have been obvious to incorporate the emerging serotypes identified by Mekalanos and Porro into the well-established vaccine platforms and administration strategies described by Siber to improve coverage against prevalent strains.
  • Expectation of Success: A POSITA would have a reasonable expectation of success. The underlying technology of conjugating polysaccharides to carrier proteins was mature and predictable. Mekalanos taught that its conjugation methods could be used with any antigenic polysaccharide, and Siber confirmed that adding new serotypes to existing vaccine platforms was a routine and successful strategy in the field.

• Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 1-12, 15, and 18-19 based on Mekalanos alone, arguing that even without Porro and Siber, a POSITA would have found it obvious to select the claimed serotypes from the finite list provided in Mekalanos based on known epidemiological trends.

4. Key Claim Construction Positions

• Petitioner argued that no specific claim term constructions were necessary. However, it emphasized that independent claims 1 and 12 are written in Markush format. Therefore, prior art that discloses any single member of the recited group (e.g., serotype 23A) anticipates the entire claim element, precluding the Patent Owner from arguing non-anticipation based on other members of the group (e.g., 23B or 35B).

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) would be inappropriate due to material prosecution error. The examiner's allowance was premised on the demonstrably false assertion that the claimed serotypes were "free of prior art," and the examiner failed to discover or consider the highly material Porro and Mekalanos references.
• Petitioner also argued that discretionary denial under Fintiv was unwarranted because no case schedule was in place for the parallel district court litigation, and any trial was likely years away, ensuring the IPR would conclude first.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-19 of the ’757 patent as unpatentable.