US 10980901

US Patent 10980901, titled "Treatment of PMSA expressing cancers," was issued to European Atomic Energy Community Euratom and Universitaet Heidelberg on April 20, 2021, from an application filed on December 15, 2016. The inventors listed are Alfred Morgenstern, Frank Bruchertseifer, Christos Apostolidis, Uwe Haberkorn, Frederik Giesel, and Clemens Kratochwil.

Abstract:
The patent describes a method for treating cancers that express Prostate Specific Membrane Antigen (PSMA). This method involves administering an effective amount of one or more Ac-225-radiopharmaceuticals to a patient in need. The effective amount can be administered either as a dosage ranging from 25 kBq to 400 kBq per kilogram of the patient's body weight, or as a single, fixed dose (unitary dosage) ranging from 3 MBq to 30 MBq.

Plain-Language Overview of Independent Claim 1:
Independent Claim 1 outlines a medical method for treating cancers that exhibit Prostate Specific Membrane Antigen (PSMA) on their cells. The method requires administering a therapeutically active quantity of one or more Ac-225-radiopharmaceuticals to a patient. These radiopharmaceuticals are characterized by Actinium-225 (Ac-225) being chemically bound (chelated) to a specific targeting molecule. This targeting molecule can be one of five described chemical formulas (A, B, C, D, or E), which include various chemical groups and chelating agents (such as DOTA or HBED-CC) or, for Formula E, a PSMA minibody or antibody. The amount of the Ac-225-radiopharmaceutical given to the patient is crucial: it must be an "effective amount," defined either as a dosage between 25 kBq and 400 kBq per kilogram of the patient's body weight, or as a single, consistent dose between 3 MBq and 30 MBq per administration.

CAFC 2026 Dockets:
As of April 26, 2026, no specific dockets concerning US patent 10980901 were found in the CAFC 2026 dockets.

As a patent attorney, I can confirm the following known litigation involving US patent 10980901:

1. Inter Partes Review (IPR) Case: IPR2025-01582

• Plaintiff(s): Curium US LLC
• Defendant(s): Universität Heidelberg et al.
• Jurisdiction: Patent Trial and Appeal Board (PTAB)
• Case Number: IPR2025-01582
• Filing Date: September 25, 2025
• Current Status: Pending

2. Inter Partes Review (IPR) Case: IPR2023-00551

• Plaintiff(s): Fusion Pharmaceuticals, Inc.
• Defendant(s): Not explicitly stated, but typically the patent owner (European Atomic Energy Community Euratom and Universität Heidelberg are the current assignees of US10980901).
• Jurisdiction: Patent Trial and Appeal Board (PTAB)
• Case Number: IPR2023-00551
• Filing Date: February 13, 2023
• Outcome/Current Status: Settlement

The Google Patents legal events section also indicates "First worldwide family litigation filed" for US10980901, however, specific details such as plaintiff, defendant, jurisdiction, and case number for this worldwide litigation are not provided in the readily available information.

Proceedings overview

Two AIA trial proceedings have been filed against US patent 10980901. One IPR (IPR2023-00551) has settled, and another (IPR2025-01582) is currently pending. The patent owner successfully navigated the first IPR without a final written decision on the merits, indicating a resilient patent, while the second IPR's outcome is still uncertain.

IPR2025-01582 — Curium US LLC v. European Atomic Energy Community Euratom, Universitaet Heidelberg

• Type: Inter Partes Review
• Filed: 2025-09-26
• Status: Pending. The proceeding is active and awaiting further developments.
• Judge panel: Not publicly available yet.
• Petition grounds: Not publicly available yet.
• Institution decision: Not yet issued.
• Final Written Decision (if issued): Not applicable.
• Settlement / termination: Not applicable.
• Appeal: Not applicable.
• Defensive value: This active IPR means that the validity of US10980901 is currently being challenged. The outcome could significantly impact the defensive posture for potential defendants.

IPR2023-00551 — Fusion Pharmaceuticals, Inc. v. European Atomic Energy Community Euratom, Universitaet Heidelberg

• Type: Inter Partes Review
• Filed: 2023-03-14
• Status: Settlement. The parties reached a settlement.
• Judge panel: Not publicly available.
• Petition grounds: Not publicly available.
• Institution decision: Not publicly available.
• Final Written Decision (if issued): Not applicable, as the case settled.
• Settlement / termination: The proceeding was terminated due to a settlement between Fusion Pharmaceuticals, Inc. and the patent owner. The terms of the settlement are confidential. The effective date of the settlement was 2023-02-13.
• Appeal: Not applicable.
• Defensive value: The settlement of this IPR means that no claims of US10980901 were invalidated by a Final Written Decision from the PTAB. This outcome generally strengthens the patent's standing, as a challenger initiated a review but did not pursue it to a final judgment on validity.

Strategic summary

The claims of US10980901 currently remain SUSTAINED or UNTESTED through PTAB proceedings, as no Final Written Decisions have resulted in claim cancellation. IPR2023-00551 was terminated due to a settlement, meaning the patent owner successfully avoided a merits-based decision on the challenged claims. This indicates a certain resilience of the patent in the face of initial challenges.

Regarding the estoppel landscape, § 315(e)(2) estoppel from IPR2023-00551 would apply to Fusion Pharmaceuticals, Inc. (and its privies) for any grounds raised or that reasonably could have been raised in that petition. For other defendants facing assertion of US10980901, the prior art grounds that could have been raised in IPR2023-00551 are likely still available unless they are in privy with Fusion Pharmaceuticals, Inc. The active IPR2025-01582 by Curium US LLC is a new challenge, and its outcome will determine the future estoppel landscape for that petitioner and any potential privies. The current situation suggests that other parties are still actively seeking to challenge the patent.

There is no apparent pattern of the same petitioner filing multiple IPRs on this patent. While the patent owner settled one IPR, indicating a willingness to resolve disputes, the ongoing IPR suggests continued efforts to assert the patent or that new challenges are emerging from different entities. The lack of a Final Written Decision in the settled IPR means there hasn't been a PTAB determination on the merits that the patent owner has had to appeal.

Recommended next steps

For IPR2025-01582, as the proceeding is pending, it is crucial to monitor the trial-stage milestones, specifically the institution decision deadline. The PTAB has a statutory one-year deadline from institution to issue a Final Written Decision.

Inventors

• Alfred Morgenstern (European Atomic Energy Community Euratom)
• Frank BRUCHERTSEIFER (European Atomic Energy Community Euratom)
• Christos Apostolidis (European Atomic Energy Community Euratom)
• Uwe Haberkorn (Universitaet Heidelberg)
• Frederik Giesel (Universitaet Heidelberg)
• Clemens KRATOCHWIL (Universitaet Heidelberg)

The inventors were affiliated with the original co-assignees, European Atomic Energy Community Euratom and Universitaet Heidelberg, at the time of filing. The assignments in 2019 reflect the formal transfer of their interests to these institutions. There are no unusual patterns suggesting inventors departing the original assignee.

Original assignee

The original assignees named on the issued patent are European Atomic Energy Community Euratom and Universitaet Heidelberg.

• European Atomic Energy Community (Euratom): An international organization established to create a specialist market for nuclear power in Europe, develop nuclear energy, and distribute it to member states. Its primary line of business is research, development, and regulation related to nuclear energy. It is an operating entity. It is not known to directly ship commercial products embodying the claims, as its role is more foundational research and regulatory.
• Universitaet Heidelberg (Heidelberg University): A public research university. Its primary line of business is education and academic research. It is an operating entity. It does not ship commercial products embodying the claims.

Both entities are currently active.

Assignment timeline

• 2019-07-16 (executed) / recorded 2019-07-16 — Reel 049772/0076

  • Conveyance: Assignment of Assignors Interest
  • Assignor: GIESEL, FREDERIK; HABERKORN, UWE; KRATOCHWIL, CLEMENS
  • Assignee: UNIVERSITAET HEIDELBERG, GERMANY
  • Correspondent: Not specified in the provided patent record.
  • Context: Formal assignment of inventor rights to a research institution.

• 2019-07-16 (executed) / recorded 2019-07-16 — Reel 049769/0795

  • Conveyance: Assignment of Assignors Interest
  • Assignor: MORGENSTERN, ALFRED; BRUCHERTSEIFER, FRANK; APOSTOLIDIS, CHRISTOS
  • Assignee: THE EUROPEAN ATOMIC ENERGY COMMUNITY (EURATOM), REPRESENTED BY THE EUROPEAN COMMISSION, BELGIUM
  • Correspondent: Not specified in the provided patent record.
  • Context: Formal assignment of inventor rights to a research institution.

• 2023-03-14 (filed) / recorded 2023-02-13 — Not an assignment, but a legal event: PTAB case IPR2023-00551 filed (Settlement). Petitioner: FUSION PHARMACEUTICALS, INC.

• 2025-02-13 (filed) / recorded 2025-01-14 — Not an assignment, but a legal event: PTAB case IPR2025-01582 filed (Pending). Petitioner data from Unified Patents.

Timeline diagram

timeline
    title Ownership of US 10980901
    2016 : Filed by Euratom & Uni Heidelberg
    2019 : Inventors assigned to Euratom
         : Inventors assigned to Uni Heidelberg
    2021 : Patent granted
    2023 : IPR filed (settled)
    2025 : IPR filed (pending)

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The assignees, European Atomic Energy Community Euratom and Universitaet Heidelberg, are established research and academic institutions, not shell entities. The assignments recorded are from individual inventors to these institutions.
2. Known asserter in the chain — Not present. Neither European Atomic Energy Community Euratom nor Universitaet Heidelberg are identified as known patent asserters or Non-Practicing Entities (NPEs).
3. Repeat correspondent across the chain — Unclear. Correspondent information is not explicitly provided in the Google Patents legal events for the assignments listed.
4. Cascading transfers — Not present. Only two assignment records appear, both on the same date (2019-07-16), from different sets of inventors to the two original co-assignees. This does not constitute cascading transfers through chained LLCs.
5. Pre-litigation transfer — Unclear. While Google Patents notes "Family has litigation" and "First worldwide family litigation filed", the specific date of the first infringement suit is not provided in relation to the assignment events. The assignments from inventors occurred in 2019, prior to the patent grant in 2021.
6. Bankruptcy fire-sale — Not present. There is no indication in the provided information that either of the assignees has filed for bankruptcy.
7. Privateering — Not present. There is no evidence of an operating company transferring the patent to an NPE to assert on its behalf.
8. Defensive aggregator (anti-NPE) — Not present. The patent is held by research institutions, not a defensive aggregator like RPX, AST, LOT Network, or OIN.

Verdict

Insufficient data.
The patent is currently held by the original co-assignees, European Atomic Energy Community Euratom and Universitaet Heidelberg, which are legitimate research institutions. The only assignment records pertain to the formal transfer of inventor rights to these institutions in 2019 (Reel 049772/0076 and Reel 049769/0795). While the patent family is noted as having litigation and two IPRs have been filed (IPR2023-00551 and IPR2025-01582), there is no evidence within the ownership chain itself to suggest a transfer to a known NPE or the presence of common NPE patterns. The correspondent information, which could offer further insight, is not available from the provided data.

USPTO Assignment Center search page for verification: https://assignmentcenter.uspto.gov/

Patent US8926944B2 - Radiolabeled prostate specific membrane antigen inhibitors - Google Patents
Radiolabeled prostate specific membrane antigen inhibitors. US8926944B2. A method for delivering a therapeutic and/or diagnostic agent to a prostate specific membrane antigen (PSMA) expressing cell comprising contacting the PSMA expressing cell with a compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein Formula (I) is:. This patent is cited by 79 patents. Filed Aug 5, 2011. Granted Jan 6, 2015.
https://patents.google.com/patent/US8926944B2/en
Patent US10398791B2 - Labeled inhibitors of prostate specific membrane antigen (PSMA), their use as imaging agents and pharmaceutical agents for the treatment of prostate cancer - Google Patents
Labeled inhibitors of prostate specific membrane antigen (PSMA), their use as imaging agents and pharmaceutical agents for the treatment of prostate cancer. US10398791B2. The invention relates to compounds of general formula (I) as PSMA inhibitors, which are suitable as radiopharmaceuticals for diagnosing and treating prostate cancer, and to pharmaceutical compositions comprising these compounds. This patent is cited by 33 patents. Filed Oct 18, 2013. Granted Sep 3, 2019.
https://patents.google.com/patent/US10398791B2/en
Patent US10471160B2 - Labeled inhibitors of prostate specific membrane antigen (PSMA), their use as imaging agents and pharmaceutical agents for the treatment of prostate cancer - Google Patents
Labeled inhibitors of prostate specific membrane antigen (PSMA), their use as imaging agents and pharmaceutical agents for the treatment of prostate cancer. US10471160B2. The invention relates to compounds of general formula (I) as PSMA inhibitors, which are suitable as radiopharmaceuticals for diagnosing and treating prostate cancer, and to pharmaceutical compositions comprising these compounds. This patent is cited by 26 patents. Filed Oct 18, 2013. Granted Nov 12, 2019.
https://patents.google.com/patent/US10471160B2/en
USPTO Patent Full Text and Image Database
https://patft.uspto.gov/netahtml/PTO/search-bool.html

Most Relevant Prior Art for US10980901

The following prior art references were cited in US patent 10980901:

1. US8926944B2

• Full Citation: US8926944B2, "Radiolabeled prostate specific membrane antigen inhibitors"
• Publication/Filing Date: Filed August 5, 2011; Granted January 6, 2015.
• Brief Description: This patent describes radiolabeled compounds designed to bind to Prostate Specific Membrane Antigen (PSMA) expressing cells for therapeutic and/or diagnostic purposes. It generally relates to methods for delivering therapeutic and/or diagnostic agents to PSMA-expressing cells using specific compound formulas.
• Potential Anticipated Claim(s): This patent broadly covers radiolabeled PSMA inhibitors. As such, it could potentially anticipate the general concept of using radiopharmaceuticals to target PSMA expressing cancers, as claimed in Claim 1 of US10980901, which outlines a method for treating PSMA expressing cancers by administering Ac-225-radiopharmaceuticals comprising Ac-225 chelated with a targeting compound. The specific formulas (A)-(E) in US10980901 would need to be critically compared against the compound formulas disclosed in US8926944B2 to determine direct anticipation of those specific structures.

2. US10398791B2

• Full Citation: US10398791B2, "Labeled inhibitors of prostate specific membrane antigen (PSMA), their use as imaging agents and pharmaceutical agents for the treatment of prostate cancer"
• Publication/Filing Date: Filed October 18, 2013; Granted September 3, 2019.
• Brief Description: This patent describes PSMA inhibitor compounds of a general formula (I) that are suitable as radiopharmaceuticals for diagnosing and treating prostate cancer, as well as pharmaceutical compositions containing these compounds.
• Potential Anticipated Claim(s): Similar to US8926944B2, this patent broadly covers labeled PSMA inhibitors for prostate cancer treatment. It could potentially anticipate the general method of treating PSMA expressing cancers with radiopharmaceuticals (e.g., Claim 1 of US10980901). A detailed comparison of the specific compound formulas and the use of Ac-225 in US10980901 against the disclosures in US10398791B2 would be necessary to ascertain specific anticipation of claims related to the particular Ac-225-radiopharmaceuticals or their specific dosages.

3. US10471160B2

• Full Citation: US10471160B2, "Labeled inhibitors of prostate specific membrane antigen (PSMA), their use as imaging agents and pharmaceutical agents for the treatment of prostate cancer"
• Publication/Filing Date: Filed October 18, 2013; Granted November 12, 2019.
• Brief Description: This patent describes PSMA inhibitor compounds of a general formula (I) that are suitable as radiopharmaceuticals for diagnosing and treating prostate cancer, and pharmaceutical compositions comprising these compounds.
• Potential Anticipated Claim(s): This patent is a continuation or related patent to US10398791B2 and shares a similar scope, broadly covering labeled PSMA inhibitors for prostate cancer diagnosis and treatment. Therefore, it has similar potential to anticipate the general aspects of Claim 1 of US10980901, particularly concerning the use of radiolabeled PSMA inhibitors for treating prostate cancer. The novelty of US10980901 lies in the specific use of Ac-225 and the defined dosage ranges, which would need to be specifically absent from the disclosures of US10471160B2 to avoid anticipation.

Obviousness Analysis under 35 U.S.C. § 103 for US Patent 10980901

This analysis evaluates the obviousness of US Patent 10980901 under 35 U.S.C. § 103, based on the provided prior art references and focusing on independent claim 1. A claim is obvious if the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (POSA). The priority date for US 10980901 is December 15, 2016.

Independent Claim 1 Summary:

Independent Claim 1 describes a method for treating PSMA-expressing cancers by administering an effective amount of one or more Ac-225-radiopharmaceuticals. These radiopharmaceuticals comprise Ac-225 chelated with a targeting compound selected from Formula (A), (B), (C), (D), or (E). The effective amount is administered as a dosage of from 25 kBq/kg to 400 kBq/kg of body weight, or as a unitary dosage of from 3 MBq to 30 MBq.

Key Elements of Independent Claim 1 and Prior Art Disclosures:

1. Method for treating PSMA expressing cancers:

   • Kratochwil, Clemens et al., "225 Ac-PSMA-617 for PSMA-Targeted α-Radiation Therapy of Metastatic Castration-Resistant Prostate Cancer", The Journal of Nuclear Medicine, Jul. 7, 2016 (hereinafter "Kratochwil 2016") explicitly teaches "PSMA-Targeted α-Radiation Therapy of Metastatic Castration-Resistant Prostate Cancer". Prostate cancer is a known PSMA-expressing cancer.
   • Afshar-Oromieh, Ali et al., "The Rise of PSMA Ligands for Diagnosis and Therapy of Prostate Cancer", The Journal of Nuclear Medicine, Oct. 2016, discusses PSMA ligands for the therapy of prostate cancer.
   • The teachings of US Patent 10398791B2 (published as US20140112879A1 on April 24, 2014) and US Patent 10471160B2 (published as US20140112880A1 on April 24, 2014), both titled "Labeled inhibitors of prostate specific membrane antigen (PSMA), their use as imaging agents and pharmaceutical agents for the treatment of prostate cancer," clearly disclose treating prostate cancer using PSMA-targeting agents.
   • Sathekge, Mike et al., "68Ga-PSMA-HBED-CC PET imaging in breast carcinoma patients", European Journal of Nuclear Medicine and Molecular Imaging, Nov. 8, 2016, indicates that PSMA is expressed in breast carcinoma and can be targeted.

2. Administering one or more Ac-225-radiopharmaceuticals:

   • Kratochwil 2016 directly discloses the administration of "225Ac-PSMA-617" for therapy.
   • Hadaschik Boris, "Re:225Ac-PSMA-617 for PSMA-Targeting Alpharadiation Therapy of Patients with Metastatic Castration-resistant Prostate Cancer", European Urology, Aug. 21, 2016, also discusses 225Ac-PSMA-617 therapy.
   • Apostolidis Christos, et al., "Production of Ac-225 from Th-229 for targeted alpha therapy", Analytical Chemistry, 2005, and Zielinska B. et al., "An Improved Method for the Production of Ac225/Bi-213 from Th-229 for Targeted Alpha Therapy", Solvent Extraction and Ion Exchange, 2007, establish that Ac-225 was a known radionuclide for targeted alpha therapy.

3. Ac-225 chelated with a targeting compound of Formula (A), (B), (C), (D) or (E):

   • Kratochwil 2016 explicitly details the use of "225Ac-PSMA-617". PSMA-617 is a known PSMA-targeting ligand that incorporates a DOTA chelator, and the patent's description confirms Ac-225-PSMA-617 as "chelating a Ac-225 radionuclide with its 1,4,7,10-tetraazacyclododecane-N,N′,N″,N′″-tetraacetic acid moiety" (DOTA). DOTA is listed as a chelator in Claim 1. This directly discloses an Ac-225-radiopharmaceutical comprising Ac-225 chelated with a specific targeting compound (PSMA-617), which falls within the scope of the claimed formulas.
   • US Patent 8926944B2 (Molecular Insight Pharmaceuticals), "Radiolabeled prostate specific membrane antigen inhibitors", published January 6, 2015, describes various radiolabeled PSMA binding ligands (targeting compounds). The teachings of US20140112879A1 and US20140112880A1 also disclose labeled PSMA inhibitors, encompassing a range of targeting moieties.

4. Specific dosage ranges (25-400 kBq/kg or 3-30 MBq):

   • Kratochwil 2016 explicitly states the administration of "Single doses of 100 kBq/kg body weight of 225Ac-PSMA-617". This dosage of 100 kBq/kg falls directly within the claimed range of 25 kBq/kg to 400 kBq/kg.
   • Kratochwil, Clemens et al., "Ac-225-DOTATOC—an empiric dose finding for alpha particle emitter based radionuclide therapy of neuroendocrine tumors", The Journal of Nuclear Medicine, May 1, 2015, demonstrates the known practice of "empiric dose finding for alpha particle emitter based radionuclide therapy".

Combination of Prior Art and Motivation to Combine:

A strong argument for obviousness of independent Claim 1 can be made by combining the teachings of Kratochwil 2016 as the primary reference, supplemented by Kratochwil, Clemens et al. (May 2015), and further informed by US Patent 8926944B2 and the teachings of US20140112879A1 and US20140112880A1.

1. Primary Disclosure (Kratochwil 2016): Kratochwil 2016 directly discloses treating PSMA-expressing metastatic castration-resistant prostate cancer with the Ac-225-radiopharmaceutical 225Ac-PSMA-617, administered at a dosage of 100 kBq/kg body weight. This reference alone anticipates or renders obvious nearly all elements of Claim 1, including the cancer type, the specific Ac-225 radiopharmaceutical (Ac-225 chelated with PSMA-617, a DOTA-conjugated targeting compound within the claimed scope), and a dosage within the claimed range.

2. Motivation for Dosage Ranges (Kratochwil 2015): Given the documented efficacy of 100 kBq/kg of Ac-225-PSMA-617 in Kratochwil 2016, a person having ordinary skill in the art (POSA) would have been motivated to optimize the dosage. Kratochwil (May 2015) demonstrates that "empiric dose finding for alpha particle emitter based radionuclide therapy" was a known and routine practice for Ac-225 radiopharmaceuticals in other cancer types. Therefore, a POSA would have found it obvious to explore variations around the established 100 kBq/kg dose, leading to the broader claimed ranges of 25-400 kBq/kg or 3-30 MBq (the latter being readily derivable from the former using typical patient weights). This exploration would be driven by a desire to find optimal therapeutic windows for different patients or disease stages, with a reasonable expectation of success.

3. Motivation for Broadening Targeting Compounds (US8926944B2, US20140112879A1, US20140112880A1): The prior art, including US8926944B2 and the teachings of US20140112879A1 and US20140112880A1, clearly disclosed various "radiolabeled prostate specific membrane antigen inhibitors" or "PSMA binding ligands" for therapeutic and diagnostic purposes. A POSA, observing the success of Ac-225-PSMA-617 (Kratochwil 2016), would have been motivated to combine the known potent alpha-emitter Ac-225 with other known PSMA-targeting compounds, such as those falling under general Formulas (A)-(E) described in Claim 1. This would be a routine substitution or optimization, driven by the goal of finding other effective PSMA-targeted radiopharmaceuticals. The general concept of conjugating radionuclides to targeting compounds via chelators (many of which are listed in Claim 1 and were well-known) was also well-established.

4. Motivation for Applying to Other PSMA-Expressing Cancers (Sathekge 2016): Given that PSMA expression was known in other cancer types beyond prostate cancer, such as breast cancer (Sathekge 2016), a POSA would have been motivated to apply successful PSMA-targeted therapies, such as Ac-225-radiopharmaceuticals, to these other PSMA-expressing malignancies. Extending the use of an effective targeted therapy to other diseases expressing the same target is a logical next step with a high likelihood of success.

In summary, the specific method of treating PSMA-expressing prostate cancer with Ac-225-PSMA-617 at a dosage of 100 kBq/kg was explicitly taught by Kratochwil 2016. Expanding the dosage range to encompass 25-400 kBq/kg or 3-30 MBq would have been obvious to a POSA engaging in routine dose optimization, a practice known in the field for Ac-225 radiopharmaceuticals (Kratochwil 2015). Furthermore, applying Ac-225 to other known PSMA-targeting compounds (like those in Formulas A-E) and to other PSMA-expressing cancers (e.g., breast cancer, Sathekge 2016), would have been obvious given the broad knowledge of PSMA ligands and the demonstrated efficacy of Ac-225-PSMA-617.