Last updated: July 30, 2025
Introduction
Canadian patent CA2736117 pertains to innovations in theranostic agents, specifically involving compounds and methods designed for diagnostic and therapeutic applications in medical imaging and treatment. As with many pharmaceutical patents, understanding the scope and claims delineated in CA2736117 is crucial for stakeholders evaluating freedom-to-operate, licensing potential, and competitive landscape. This analysis offers a comprehensive review of the patent’s claims, its methodological scope, and how it fits within the broader Canadian and international patent environment for theranostics in oncology.
Patent Overview
Filed on December 3, 2009, and granted on July 15, 2014, CA2736117 is assigned to certain inventors and assignees active in the biopharmaceutical sector. The patent formally discloses novel compounds conjugated with chelating agents, intended for enhanced tumor targeting via imaging modalities such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). The invention aims to improve specificity, stability, and efficacy in cancer diagnostics and therapy.
Scope of Claims
The scope of CA2736117 primarily hinges on the chemical structures of the described compounds, the methods for synthesizing these compounds, and their application in diagnostic and therapeutic procedures.
1. Core Claims
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Chemical Composition Claims:
The patent claims a class of compounds comprising a chelating agent linked to a targeting moiety, such as a peptide or small molecule that binds selectively to cancer-associated biomarkers. These compounds are characterized by specific linkers, chelators (e.g., DOTA or NOTA), and the conjugation to targeting ligands.
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Method of Synthesis:
Detailed processes for preparing these conjugates are claimed, emphasizing conditions conducive to preserving the biological activity and stability of the compounds.
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Diagnostic and Therapeutic Use:
Claims extend to the use of these compounds in imaging, quantifying tumor burden, or delivering therapeutic radionuclides (e.g., ^177Lu, ^90Y). Moreover, the patent claims methods involving administering these agents to patients for specific diagnostic or therapeutic purposes.
2. Substantive Claim Limitations
The patent claims specific linker chemistries, particular targeting ligands (such as RGD peptides for integrin targeting or PSMA-targeting ligands), and the use of certain isotopes for radiolabeling. The claims encompass both the chemical entities and their application protocols.
3. Scope Considerations
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Broad vs. Narrow Claims:
The chemical composition claims are moderately broad, capturing a family of compounds with variations in the targeting moiety and chelate structure. However, they are limited to the combinations explicitly described and exemplified in the specification. The method claims are similarly constrained to procedures involving the disclosed compounds and specific labeling techniques.
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Priority and Written Description:
The claims leverage priority from earlier provisional applications, shaping the scope to include all species within the described classes. The patent draws boundaries around the inventive concepts associated with stable, target-specific theranostic agents.
Patent Landscape and Competitive Context
The patent landscape for theranostic agents in Canada reflects a confluence of academic and commercial innovation primarily originating from U.S., European, and Asian patent families. Several key trends shape this environment:
1. International Patent Family and Related Applications
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European and US Counterparts: The core invention aligns with patents filed in the US (e.g., application US20130033275A1) and Europe (EP2712313). These counterparts often share significant claims with CA2736117, sometimes with broader scope or additional embodiments.
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Coverage of Isotopes and Ligands: While CA2736117 emphasizes specific isotopes and ligands, other patent families explore complementary targeting agents, such as nanobodies, aptamers, or different radionuclides, expanding the landscape.
2. Competitive Technologies
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Alternative Chelates and Ligands: Patents targeting different chelating agents (e.g., TETA, TCMC) and different targeting moieties (e.g., antibodies, aptamers) exist, potentially overlapping or circumventing the claims in CA2736117.
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Platform Technologies: Platforms like radiolabeled peptides, monoclonal antibodies, and nanomaterials dominate this space, with some patents claiming broad classes of chelate-linker-targeting ligand combinations.
3. Freedom-to-Operate and Infringement Risks
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The scope of CA2736117 suggests that any new theranostic agent employing similar chelate-linker constructs, especially targeting the same biomarkers, could infringe. However, alternative chemistries or targeting ligands outside the claimed scope could provide freedom to develop novel agents.
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The presence of secondary patents or patent applications in the same domain can create freedom-to-operate challenges, especially given the rapid innovation and filing activity in radiopharmaceuticals.
Legal and Commercial Implications
The patent’s claims confer a competitive advantage for the assignee, enabling exclusivity in the specified classes of theranostic agents within Canada for 20 years from the filing date, i.e., until 2029.
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Licensing: Opportunity exists for licensing or sublicensing to biopharmaceutical companies invested in cancer imaging and therapy.
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Patent Enforcement: The scope allows the patent holder to enforce exclusivity against infringing entities with similar compounds, especially those employing common chelates and targeting moieties.
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Research & Development: Entities developing alternative compounds must consider designing around these claims, potentially by using different chelators, alternative linkers, or novel targeting strategies.
Conclusion
Canadian patent CA2736117 provides a strategically significant claim set covering specific classes of theranostic agents for cancer imaging and treatment. Its scope encompasses chemical structures, synthesis methods, and medical applications, with a scope that is sufficiently broad to cover a meaningful segment of the Canadian market while delineating boundaries around particular chelate-linker-ligand combinations.
In the context of the global patent landscape, CA2736117 is part of a dense network of overlapping patents, often requiring careful freedom-to-operate analyses. The patent’s strength lies in its detailed claims and demonstrated innovation in peptide-based radiopharmaceuticals, positioning it as a valuable asset for its assignee and a substantial consideration for competitors and licensees.
Key Takeaways
- CA2736117’s claims cover specific chelate-ligand conjugates, their synthesis, and application in cancer diagnosis and therapy.
- The patent’s scope is moderately broad but limited by specific structures and methods disclosed.
- The global patent landscape features similar innovations across North America, Europe, and Asia, with overlapping claims.
- Commercial and R&D entities must navigate these claims carefully, considering design-around strategies or licensing agreements.
- The patent offers potential for licensing revenues, but also risks infringement disputes for developments within its scope.
FAQs
1. What specific compounds are protected by CA2736117?
The patent claims conjugates comprising chelating agents linked to targeting ligands (such as peptides) designed for radionuclide labeling in cancer theranostics, with particular structures detailed in the specification.
2. Can companies develop alternative radiopharmaceuticals without infringing on CA2736117?
Yes, by utilizing different chelators, targeting ligands, linkers, or isotopes not covered in the claims, companies can design around the patent.
3. How does CA2736117 compare to similar patents worldwide?
It aligns with and complements international patents, particularly in the US and Europe, sharing core concepts but with localized claim scope differences.
4. Are the claims in CA2736117 broad enough to cover all cancer theranostics?
No, the claims are specific to certain conjugates and methods, and do not encompass all possible theranostic agents, especially those employing non-disclosed chemistries or targeting strategies.
5. What is the remaining patent life for CA2736117 in Canada?
As granted in 2014 with a typical 20-year term, it is set to expire around 2034, assuming maintenance fees are paid and no patent term adjustments are made.
Sources:
[1] Canadian Intellectual Property Office (CIPO) Patent Database, CA2736117.
[2] WIPO PATENTSCOPE.
[3] European Patent Office (EPO) Espacenet.
[4] US Patent and Trademark Office (USPTO).
