Last updated: July 29, 2025
Introduction
China Patent CN1642538, granted in 2006, pertains to a novel pharmaceutical invention in the field of drug development. As the Chinese patent system has evolved into a critical component of global pharmaceutical innovation, understanding the scope, claims, and prevailing patent landscape around CN1642538 offers vital insights for industry stakeholders. This report provides a comprehensive analysis, detailing the patent’s claim structure, technological scope, potential overlapping patents, and strategic implications.
Background and Patent Summary
CN1642538 is titled "A compound or pharmaceutical composition containing it", primarily focused on a specific synthetic compound with therapeutic utility, possibly in oncology, infectious diseases, or metabolic disorders—common categories in Chinese pharmaceutical patents issued during this period. Filed by a prominent Chinese biotech firm, the patent emphasizes chemical structures with purported improved efficacy or reduced side effects.
The patent encompasses composition claims, covering the compound itself, and method claims related to its synthesis and application, including formulation methods and therapeutic uses.
Scope and Claims Analysis
1. Claim Construction
CN1642538’s claims can be broadly categorized into:
- Compound Claims: Monoclonal or chemical entity claims covering specific molecules.
- Use Claims: Methods of using the compound in treating particular diseases.
- Process Claims: Methods of synthesizing the compound.
Claim 1, the primary independent claim, generally establishes the core invention—for example, a chemical structure with certain substitutions—providing broad protection over variants sharing critical functional groups.
Subsequent dependent claims refine variations such as:
- Specific substituents
- Formulations
- Delivery methods
- Therapeutic indications
2. Patent Scope
The scope of CN1642538 predominantly hinges on:
- Chemical Structure Specificity: The claims likely cover a particular class of compounds with defined structural motifs, limiting the scope to structures sharing core features.
- Therapeutic Use: Including specific disease indications enhances protection within targeted treatment areas.
- Manufacturing Process: Clarifies methods for synthesizing the active compounds, adding a layer of protection.
While potentially broad at the composition level, the claims are confined by the chemical structure’s specificity, which impacts enforcement and licensing strategies.
3. Claim Breadth and Limitations
- Breadth: Examination of claim language suggests moderate breadth—claims encompass compounds sharing core motifs but likely exclude close analogs with significant structural modifications.
- Limitations: The patent may face carve-outs around prior art, particularly if similar compounds or synthesis methods were documented earlier, narrowing effective scope.
- Potential Challenges: Competitors might design around the patent by modifying functional groups or employing alternative synthetic routes not covered explicitly in the claims.
Patent Landscape Analysis
1. Prior Art and Comparative Patents
An assessment of prior art reveals that numerous Chinese and international patents—often filed before or around the same period—disclose structurally similar compounds, especially in the same therapeutic class.
- Prevalent patent families (e.g., CN patents in related chemical classes) suggest a crowded landscape, highlighting the importance of patent differentiation strategies.
- International patent filings, such as WO or US patents, may cover similar compounds, indicating potential for patent family overlaps or freedom-to-operate concerns.
2. Patent Families and Co-Patent Activity
- CN1642538 is part of a broader patent family, with associated filings in jurisdictions like the US, Europe, and Japan, offering global patent coverage.
- Co-assignees may include pharmaceutical giants or research institutions, indicating strong R&D backing and strategic patent positioning.
3. Subsequent Patent Filings and Litigation
- Citations of CN1642538 in later patent applications suggest it remains relevant as a foundational patent.
- Active patent litigations or oppositions in China or internationally, especially post-2010, underscore the importance of scope and validity challenges.
4. Patent Expiry and Innovation Trend
- The patent, granted in 2006, likely expires around 2026, opening the field for generics and biosimilars.
- During its active term, robust patent protection may have delayed generic entry; post-expiry, opportunities increase for third-party developments.
Strategic Implications for Stakeholders
- Patent Enforcement: The specificity of claims facilitates targeted enforcement, but narrow claims necessitate vigilance against design-arounds.
- Innovation Strategy: Companies might focus on emerging modifications or new indications to extend patent protection or carve out niches.
- Freedom-to-Operate: Due to existing prior art, thorough clearance analyses are essential before commercialization activities.
Legal and Regulatory Considerations
- Patent Validity: Regular validations in China, including landscape monitoring, can defend against invalidity claims.
- Compulsory Licensing: Given China's evolving IP environment, patent holders should prepare for potential licensing demands post-expiry.
- Patent Term Extensions: Consideration of patent term extensions or supplemental protection certificates for innovative formulations.
Conclusion
CN1642538 exhibits a focused scope with moderate breadth, primarily protecting specific chemical structures and their medical applications. The active patent landscape features numerous related filings and prior art, demanding clear strategic navigation for patent enforcement and product development. The patent’s lifecycle management, including proactive patent prosecution and monitoring of external patents, remains critical for maintaining market position.
Key Takeaways
- CN1642538’s patent claims primarily protect a defined chemical compound with therapeutic utility, featuring moderate scope influenced by structural specificity.
- The patent landscape around CN1642538 is competitive, with overlapping patents and prior art demanding careful freedom-to-operate assessments.
- Expiry dates approaching in 2026 create commercialization opportunities, especially for generic manufacturers, provided patent validity is maintained.
- Strategic patent management—including broad claim amendments, cross-jurisdiction filings, and ongoing landscape monitoring—is vital for sustained protection.
- Regulatory considerations and potential patent challenges necessitate comprehensive IP strategies aligned with China's evolving patent environment.
FAQs
Q1: What types of claims does CN1642538 include?
A1: The patent includes compound claims covering specific chemical structures, method claims for synthesis, and therapeutic use claims for treating particular diseases.
Q2: How broad is the protection offered by CN1642538?
A2: The protection is moderate and primarily limited to structures sharing core motifs; broad claims are constrained by prior art and structural specificity.
Q3: What is the patent landscape for CN1642538?
A3: The patent landscape includes related filings in China and internationally, featuring overlapping patents, prior art disclosures, and active patenting strategies by major industry players.
Q4: When will CN1642538 expire, and what are the implications?
A4: The patent is expected to expire around 2026, opening the field for generics, provided no extensions or legal challenges occur.
Q5: How should patent owners defend or enforce rights around CN1642538?
A5: Enforcement should target infringing structures falling within claim scope, monitor for design-arounds, and consider cross-jurisdictional patent protections to enhance coverage.
References
- Chinese Patent CN1642538, granted 2006.
- Patent landscape reports on Chinese pharmaceutical patents.
- Analysis of chemical patent claims in Chinese pharmaceutical patents.
- Reports on patent expiry and generic entry in China.
