Ge Healthcare Ltd v. Johns Hopkins University

1. Case Identification

• Case #: PGR2025-00059
• Patent #: 12,115,233
• Filed: July 14, 2025
• Petitioner(s): GE Healthcare Ltd.
• Patent Owner(s): Johns Hopkins University
• Challenged Claims: 1-4

2. Patent Overview

• Title: Low Molecular Weight Compounds for FAP Imaging
• Brief Description: The ’233 patent discloses low molecular weight compounds for imaging and radiotherapy that target Fibroblast Activation Protein (FAP). The compounds employ a modular three-component design with the formula B-L-A, where "A" is a FAP-targeting moiety, "B" is a reporter moiety (e.g., a radiolabeled group), and "L" is a linker connecting them.

3. Grounds for Unpatentability

Ground 1: Claims 1-4 are obvious over US-633, Meletta, and Jansen.

• Prior Art Relied Upon: US-633 (Application # 2010/0098633), Meletta (a 2015 publication), and Jansen (a 2014 publication).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that US-633 taught the same modular, three-component radiopharmaceutical design as the ’233 patent, including various reporter moieties ("B") and linkers ("L") suitable for FAP-targeting agents. The sole distinction was the specific structure of the FAP-targeting moiety ("A"). Jansen disclosed "compound 60," a potent and highly selective FAP inhibitor whose structure falls within the genus of the "A" moiety claimed in the ’233 patent.
  • Motivation to Combine (for §103 grounds): Meletta explicitly identified a critical problem with the radiotracer in US-633, reporting that its boronic acid-based targeting moiety was insufficiently selective for FAP, leading to non-specific tissue accumulation. Meletta stated a need for "more selective inhibitors" for future studies. This created a clear motivation for a person of ordinary skill in the art (POSITA) to search for a more selective FAP-targeting moiety to improve the US-633 platform. A POSITA would have found Jansen, which disclosed compound 60 as a superior, highly selective FAP inhibitor, thereby providing the solution to Meletta's identified problem.
  • Expectation of Success (for §103 grounds): A POSITA would have had a reasonable expectation of success in replacing the poorly selective targeting moiety of US-633 with the highly selective compound 60 from Jansen, given the modular nature of the radiotracer design taught in US-633, which facilitates the swapping of components.

Ground 2: Claims 1-4 are obvious over US-121 and Jansen.

• Prior Art Relied Upon: US-121 (Application # 2012/0009121) and Jansen (a 2014 publication).
• Core Argument for this Ground:
  • Prior Art Mapping: US-121, which shares an inventor and assignee with the ’233 patent, taught a proven, successful modular B-L-A radiotracer design for imaging tumors. However, US-121's compounds targeted prostate-specific membrane antigen (PSMA), not FAP. Petitioner contended that the reporter moieties ("B") and linkers ("L") in US-121 are analogous to those claimed in the ’233 patent. Jansen provided the FAP-targeting moiety, compound 60.
  • Motivation to Combine (for §103 grounds): A POSITA would have been motivated to adapt the successful radiotracer scaffold from US-121 to target FAP, which was widely recognized as an appealing and compelling target for cancer imaging due to its high expression in tumors and low expression in healthy tissue. A POSITA would have sought a potent and selective FAP-targeting moiety to substitute for the PSMA-targeting moiety of US-121. Jansen's compound 60 was an ideal candidate for this substitution due to its demonstrated high selectivity and comparable molecular size to the PSMA-targeting moiety in US-121.
  • Expectation of Success (for §103 grounds): The straightforward substitution of one small-molecule targeting moiety for another of similar size within a known modular scaffold would have been a predictable design choice with a high expectation of success.

Ground 3: Claims 1-4 are unpatentable under 35 U.S.C. §112(a) for lack of written description and enablement.

• Core Argument for this Ground:
  • Prior Art Mapping: This ground is based on the ’233 patent's specification itself.
  • Core Argument: Petitioner argued the claims are directed to immense genera of compounds, calculating the number of possible B-L-A combinations to be greater than 10^36 for claim 1. The specification, however, only describes two working examples, which are derived from a single intermediate and are not representative of the vast claimed scope. The claims use broad functional language for the "B" and "L" components and allow attachment at numerous positions on the "A" moiety, creating a field where properties are highly unpredictable. Petitioner asserted that the disclosure provides no "blaze marks" or common structural features to guide a POSITA to the useful species within the vast genus. Therefore, the specification fails to demonstrate that the inventors were in possession of the full scope of the invention (written description) and fails to teach a POSITA how to make and use the full scope without undue, and likely impossible, experimentation (enablement).

4. Key Claim Construction Positions

• "B" (Radiolabeling Moiety) and "L" (Linker) Components: Petitioner argued these terms are defined purely by function in the claims (e.g., "B" is "any... functional group suitable for... imaging," and "L" is a linker "adapted to form a chemical bond"). This broad functional claiming contributes to the immense and unpredictable scope of the claims for the §112 analysis.
• "Low Molecular Weight": Petitioner contended that while the Patent Owner argued for a limit of ~1,500 Da during prosecution, the intrinsic evidence only distinguishes the claimed compounds from vastly larger antibody-based agents (e.g., ~150,000 Da). Petitioner argued that the term means "having a molecular weight at least an order of magnitude less than an antibody-based radiopharmaceutical" and that a precise numerical boundary is not supported by the specification. This construction further broadens the scope of the claims for the §112 challenge.

5. Relief Requested

• Petitioner requests institution of a Post Grant Review and cancellation of claims 1-4 of the ’233 patent as unpatentable.