ITM Isotope Technologies Munich SE v. The Johns Hopkins University

1. Case Identification

• Case #: PGR2025-00065
• Patent #: 12,115,233
• Filed: July 15, 2025
• Petitioner(s): ITM Isotope Technologies Munich SE
• Patent Owner(s): The Johns Hopkins University
• Challenged Claims: 1-4

2. Patent Overview

• Title: Low Molecular Weight Compounds for Imaging and Radiotherapeutics
• Brief Description: The ’233 patent relates to low molecular weight compounds for diagnostic imaging and therapy. The compounds have a general formula B-L-A, where A is a targeting moiety for fibroblast-activation protein-α (FAP-α), L is a linker, and B is an optical or radiolabeled functional group.

3. Grounds for Unpatentability

Ground 1: Obviousness over Jansen I/II, Zimmerman, and Pomper - Claims 1-4 are obvious 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 ACS Medicinal Chemistry article), Zimmerman (Application # 2010/0098633), and Pomper (Application # 2012/0009121).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the core components of the claimed B-L-A structure were well-known. Jansen I and Jansen II disclosed the FAP-α targeting moiety (A), specifically teaching that a 4-quinolinoyl ring structure provides superior binding affinity and selectivity. Zimmerman disclosed linking FAP inhibitors to radiolabeled functional groups (B) via linkers (L) to create radiopharmaceuticals for imaging and therapy. Pomper also taught linking inhibitors to imaging moieties and further taught the specific benefits of using low molecular weight compounds.
  • Motivation to Combine (for §103 grounds): A person of ordinary skill in the art (POSITA) would combine the high-affinity 4-quinolinoyl FAP-α inhibitor from Jansen with the established imaging and therapeutic platforms taught by Zimmerman and Pomper. The goal would be to create a superior diagnostic or therapeutic agent with improved targeting, and Pomper provided an explicit reason to pursue a low molecular weight version to achieve better tumor access.
  • Expectation of Success (for §103 grounds): Since all components were known to be effective for their respective functions, a POSITA would have a reasonable expectation that combining them would result in a predictable and successful imaging and therapeutic agent.

Ground 2: Obviousness over Dvořáková and Pomper - Claims 1-4 are obvious over Dvořáková in view of Pomper.

• Prior Art Relied Upon: Dvořáková (a 2017 Journal of Medicinal Chemistry article) and Pomper (Application # 2012/0009121).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Dvořáková disclosed a compound containing all the structural elements of the claimed invention: a FAP-α inhibitor (A) with a quinolinyl ring, an optical dye (B), and a linker (L) connecting them. However, Dvořáková’s compound was a high molecular weight polymer conjugate. The only element missing from Dvořáková was the "low molecular weight" limitation of claim 1.
  • Motivation to Combine (for §103 grounds): Pomper explicitly taught that low molecular weight agents have advantages over larger molecules, such as antibodies, due to better tumor access and improved pharmacokinetics. A POSITA reading Dvořáková would be motivated by Pomper to modify Dvořáková’s large polymer conjugate into a low molecular weight version to gain these known benefits.
  • Expectation of Success (for §103 grounds): Dvořáková described its own system as "highly module and versatile," which would suggest to a POSITA that its molecular weight could be readily adjusted by using fewer inhibitor/dye units or a smaller linker, with a high expectation of success.

Ground 3: Lack of Enablement - Claims 1-4 are invalid under 35 U.S.C. §112 for lack of enablement.

• Core Argument for this Ground:

  • Prior Art Mapping: The claims used broad functional language, defining moiety B as "any optical or radiolabeled functional group suitable for" imaging or therapy and linker L as having "bi-functionalization adapted to form a chemical bond." Petitioner argued these functional definitions encompass a virtually infinite genus of compounds.
  • Key Aspects: The specification provided only two working examples (XY-FAP-01 and XY-FAP-02) and no common structural features or "roadmap" to guide a POSITA across the vast scope of the claims. Petitioner contended this forces a POSITA into undue "trial and error" experimentation to determine which of the millions of potential compounds would actually be "suitable" or "adapted" as claimed, rendering the claims non-enabled under the principles of Amgen v. Sanofi. The art is highly unpredictable, and the two examples are insufficient to support the full claim scope.

• Additional Grounds: Petitioner asserted additional challenges that claims 1-4 lack adequate written description (§112) for failing to disclose a representative number of species. Petitioner also argued that claims 1-4 are indefinite (§112) because the term "low molecular weight" is subjective and lacks objective boundaries. Finally, Petitioner argued claim 1 is invalid for statutory double patenting (§101) over claim 1 of prior Patent 11,938,201.

4. Key Claim Construction Positions

• "Low Molecular Weight": Petitioner argued this term is indefinite because it is relative, not defined in the specification, and lacks objective boundaries. During prosecution, the Patent Owner suggested a range of "about 50 to 1,500 Daltons," but Petitioner contended this was an improper post-hoc definition. Petitioner further noted that the specification itself discloses fluorescent dyes for moiety B (e.g., IRDye 700DX, ~1,954 g/mol) that alone exceed this proposed upper limit, creating a direct contradiction.
• "C(O)Alkyl" / "Aryl": Petitioner argued that because the patent explicitly defined other alkyl groups with specific carbon counts (e.g., "C1-6alkyl"), the absence of a count for "C(O)alkyl" and related aryl terms means they must be construed to encompass any length. This construction would vastly expand the already broad genus of compounds.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial is inappropriate. No parallel litigation exists that would implicate Fintiv factors. Further, under the Advanced Bionics framework, Petitioner asserted that the Office committed material error during prosecution. The errors included allowing claims based on a declaration of unexpected results that was not commensurate with the broad claim scope and failing to address the significant enablement, written description, indefiniteness, and double patenting issues, none of which were previously raised or considered by the Examiner.

6. Relief Requested

• Petitioner requested institution of Post-Grant Review and cancellation of claims 1-4 of Patent 12,115,233 as unpatentable.