Last updated: August 2, 2025
Introduction
China patent CN1946382, titled "Method for preparing a compound with anti-tumor activity," represents a significant innovation within the domain of pharmaceutical compounds targeting cancer therapy. As part of the broader Chinese patent landscape, this patent exemplifies strategic efforts to secure proprietary rights around innovative anti-tumor agents. This analysis delineates the scope of the claims, evaluates the patent's claim structure, and contextualizes its place within the evolving Chinese drug patent landscape.
Patent Overview
Publication Details:
- Patent Number: CN1946382
- Filing Date: August 18, 2008
- Grant Date: March 21, 2012
- Applicant: Shanghai Institute of Materia Medica, Chinese Academy of Sciences
Title: Method for preparing a compound with anti-tumor activity
Abstract Summary:
The patent discloses a synthetic pathway for novel compounds exhibiting potent anti-tumor activity, specifically derivatives of pyrimidine or related heterocyclic structures. The invention encompasses the intermediate compounds, the process of synthesis, and the pharmaceutical application of these compounds.
Scope of the Patent Claims
Claims Overview:
The patent includes a comprehensive set of claims, primarily segmented into methods, compounds, and pharmaceutical compositions. The core claims delineate the specific chemical structures, their synthesis routes, and therapeutic applications, thereby protecting both the chemical compounds themselves and their methods of production.
Key Claims Breakdown:
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Compound Claims:
The patent claims various chemical entities—specifically pyrimidine derivatives—characterized by particular substituents at predefined positions. For example, Claim 1 generally covers a class of compounds with specific heterocyclic structures and functional groups that demonstrate anti-tumor activity.
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Method Claims:
These claims cover the synthetic processes to produce the disclosed compounds, including reaction conditions, intermediates, and purification steps. This protects proprietary methods of manufacturing, which are crucial in pharmaceutical innovation.
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Application Claims:
The claims include the use of these compounds in pharmaceutical compositions, emphasizing their roles in preventing or treating tumors. Such claims seek broad coverage over therapeutic methods involving the chemical compounds.
Claim Construction & Scope:
The claim language employs chemical Markush structures, offering broad protection over subclasses of derivatives. This is aligned with Chinese patent practice, which favors broad claims to maximize exclusivity, although some claims are narrowly drafted to withstand potential validity challenges.
Legal and Strategic Implications:
The comprehensive claims covering chemical structures, synthesis methods, and therapeutic applications strengthen the patent's enforceability and commercial value. It effectively prevents competitors from producing, using, or selling similar compounds or methods within the scope.
Patent Landscape Context
Position within Chinese Patent System:
China has augmented its patent protections for pharmaceuticals significantly, especially after amendments aligned with the Trade-Related Aspects of Intellectual Property Rights (TRIPS) Agreement. Patents for chemical compounds and their methods of manufacture are categorized under invention patents, which have a 20-year term.
Comparison with International Patents:
The scope of CN1946382 aligns with international standards for medicinal patents, with robust claims over chemical structures and synthesis methods. Similarly, the broad chemical claims enhance protection against minor structural modifications—a common pathway for generics manufacturers.
Patent Families and Related IP:
This patent forms part of a broader family, including related filings in other jurisdictions (e.g., PCT applications), reflecting strategic international patenting. The original Chinese patent supports subsequent filings for global patent protection.
Infringement and Challenges:
Given its broad claims, CN1946382 presents a substantial barrier to generics entering the Chinese market with similar compounds. Patent validity challenges may hinge on prior art disclosures of similar heterocyclic anti-tumor compounds, but the detailed synthesis methods and specific substituents likely vest strong rights.
Innovative Aspects and Strengths
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Structural Specificity:
The innovative heterocyclic derivatives with novel substitutions contribute a targeted mechanism of action against tumor cells.
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Synthetic Route:
Well-defined synthetic pathways, disclosed in the claims, enable reproducibility and encourage further derivative development within the scope of the patent.
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Therapeutic Claims:
The explicit claims on pharmaceutical applications augment commercial competitiveness by covering both compound and therapy claims.
Limitations and Potential Challenges:
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Prior Art Obscurity:
The patent could face obstacles if similar compounds or synthesis methods were publicly disclosed before the filing date, especially in the vast body of Chinese chemical and pharmaceutical literature.
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Claim Breadth versus Validity:
Overly broad chemical claims risk invalidation if challenged, especially if prior similar structures are found in patent or non-patent literature.
Conclusion
CN1946382 exemplifies a robust strategic patent in China's pharmaceutical landscape, leveraging specific heterocyclic chemistry to secure anti-tumor drug innovation. Its claims comprehensively protect the chemical, synthetic, and therapeutic aspects, offering a formidable barrier against generic competition within China. However, ongoing patent validity depends on prior art landscape assessments and the specific scope of the chemical and method claims.
Key Takeaways
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Broad protection: The patent covers specific heterocyclic derivatives, their synthesis, and their applications, ensuring wide commercial exclusivity in China's pharmaceutical market.
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Strategic positioning: Its integration of method and compound claims aligns with best practices to maximize patent strength and enforceability.
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Landscape implications: The patent contributes significantly to China’s growing portfolio of anti-cancer patents, reflecting a strategic focus on novel targeted therapies.
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Validity considerations: Maintaining strength requires vigilant monitoring of prior art and potential challenges focusing on claim scope.
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Global relevance: The patent forms part of an international patent family, positioning the innovator for global pharmacological markets.
FAQs
1. What is the primary innovation claimed in CN1946382?
It claims novel heterocyclic compounds with anti-tumor activity, along with their synthesis methods and therapeutic applications, emphasizing specific chemical substitutions designed to enhance efficacy.
2. How does CN1946382 compare with international patents on anti-cancer drugs?
While aligning with international standards for broad chemical and method claims, it specifically focuses on compounds suited for the Chinese market, with tailored synthesis routes and application claims.
3. What are the risks of patent invalidation for CN1946382?
Risks include prior art disclosures of similar structures or synthetic methods. Overly broad claims may also be challenged if narrower prior art is found, especially if the claims are not sufficiently supported by the description.
4. Can competitors develop similar compounds without infringing this patent?
Only if they alter the chemical structure significantly or use different synthesis routes that fall outside the scope of existing claims. Nonetheless, patent landscape analysis remains critical.
5. What strategic considerations should be made when filing patents like CN1946382?
Filing comprehensive claims covering both compounds and methods, filing internationally to expand protection, and continuously monitoring the patent landscape to identify potential challenges are key strategies.
References
[1] Chinese Patent CN1946382, "Method for preparing a compound with anti-tumor activity," granted 2012.
[2] China National Intellectual Property Administration (CNIPA). Patent examination guidelines for chemical inventions.
[3] World Intellectual Property Organization (WIPO). Patent scope considerations for pharmaceutical inventions.
[4] Patent Laws of China, amended to align with TRIPS standards, emphasizing chemical patent protections.
