ITM ISoTope Technologies Munich Se v. Johns Hopkins University

1. Case Identification

• Case #: PGR2025-00012
• Patent #: 11,938,201
• Filed: December 24, 2024
• Petitioner(s): ITM Isotope Technologies Munich SE
• Patent Owner(s): The Johns Hopkins University
• Challenged Claims: 1-3

2. Patent Overview

• Title: Compounds for Diagnostic Imaging and Radiotherapeutics
• Brief Description: The ’201 patent discloses low molecular weight compounds for imaging and treating diseases related to fibroblast-activation protein-α (FAP-α). The compounds have a general B-L-A structure, where A is a FAP-α targeting moiety, B is an optical or radiolabeled functional group, and L is a bifunctional linker.

3. Grounds for Unpatentability

Ground 1: Obviousness Over Jansen I/II, Zimmerman, and Pomper

• Legal Basis: Claims 1-3 are obvious under 35 U.S.C. §103 over Jansen I and/or Jansen II in view of Zimmerman and Pomper.
• Prior Art Relied Upon: Jansen I (Patent 9,346,814), Jansen II (a 2013 journal article), Zimmerman (Application # 2010/0098633), and Pomper (Application # 2012/0009121).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the claimed invention is an obvious combination of known elements. Jansen I and Jansen II disclosed the specific FAP-α targeting moiety (A) recited in the claims, with Jansen II teaching that a quinolinoyl ring provides superior FAP affinity. Zimmerman taught the use of FAP inhibitors attached to radiopharmaceuticals (B) via a bifunctional linker (L) for diagnostic imaging and radiotherapy. Pomper taught the benefits of low molecular weight imaging agents, including better tumor access compared to larger antibodies.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine the superior FAP-α inhibitors from Jansen I/II with the radiopharmaceutical imaging and linker concepts from Zimmerman to create an effective imaging agent. Pomper provided further motivation by teaching the known advantages of using low molecular weight compounds for this purpose, which would have encouraged the selection of smaller, well-defined inhibitors like those in Jansen over larger antibodies.
  • Expectation of Success: A POSA would have a reasonable expectation of success in combining these known components, as it involved applying established principles of medicinal chemistry to link a known targeting agent to a known imaging agent for a predictable purpose.

Ground 2: Obviousness Over Dvořáková and Pomper

• Legal Basis: Claims 1-3 are obvious over Dvořáková in view of Pomper.
• Prior Art Relied Upon: Dvořáková (a 2017 journal article) and Pomper (Application # 2012/0009121).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Dvořáková disclosed a high molecular weight polymer conjugate that met every limitation of the claims except for being "low molecular weight." Dvořáková's compound included a FAP-α targeting moiety (A) overlapping with the claimed genus, an optical dye (B), and a PEG linker (L) connecting them.
  • Motivation to Combine: Pomper explicitly taught the benefits of low molecular weight agents for imaging, stating they have better tumor access than larger molecules and have "shown promise in preclinical imaging studies." A POSA would therefore be motivated to modify Dvořáková’s large polymer conjugate to create a smaller, low molecular weight version to gain these known advantages in pharmacokinetic properties and imaging signal.
  • Expectation of Success: Lowering the molecular weight of the Dvořáková conjugate would be a predictable optimization for a POSA. This could be achieved through understood methods, such as using a single targeting/imaging unit instead of a large polymer backbone, leading to a reasonable expectation of achieving the desired improved properties.

Ground 3: Lack of Enablement

• Legal Basis: Claims 1-3 are unpatentable under §112 for lack of enablement.

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that the claims cover a vast functional genus without providing sufficient guidance to enable a POSA to practice the full scope without undue experimentation, citing Amgen v. Sanofi. The claims functionally define the B moiety as "any...group suitable for" imaging and the L moiety as a "linker having bi-functionalization," encompassing a virtually infinite number of structures. The specification provided only two working examples.
  • Key Aspects: This lack of structural guidance and reliance on functional language forces a POSA to engage in a "make-and-screen" research project to discover which of the countless potential compounds satisfy the claimed functions. Petitioner contended this is precisely the type of overbroad, functional claiming that the Supreme Court found to be non-enabling.

• Additional Grounds: Petitioner asserted additional challenges that claims 1-3 lack adequate written description under §112, as the specification fails to disclose a representative number of species or common structural features to demonstrate possession of the vast claimed genus. Petitioner also argued claims 1-3 are indefinite under §112 because the critical term "low molecular weight" is not defined in the specification and has no objective boundary in the art.

4. Key Claim Construction Positions

• "Low Molecular Weight": Petitioner argued this term is indefinite. It was added during prosecution to overcome prior art but is not defined in the specification. The Patent Owner’s attempt to define it as "about 50 to 1,500 Daltons" during prosecution was based on literature from the unrelated field of metabolomics and would improperly exclude fluorescent dyes explicitly disclosed in the specification that have molecular weights greater than 1,500 Da. This creates contradictory and uncertain claim scope.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) is inappropriate. The Examiner committed a material error by withdrawing obviousness rejections based on an insufficient showing of unexpected results that was not commensurate with the broad scope of the claims. Furthermore, the Examiner never considered the substantial §112 issues of enablement, written description, or indefiniteness. Finally, the Pomper reference, which directly teaches the benefits of the "low molecular weight" limitation added to secure allowance, was of record but never applied by the Examiner.

6. Relief Requested

• Petitioner requested institution of a Post Grant Review and cancellation of claims 1-3 of the ’201 patent as unpatentable.