Last updated: August 1, 2025
Introduction
Patent CN1325475, titled "Method for preparing an anti-tumor active ingredient", was granted to China National Pharmaceutical Group Company Ltd. This patent plays a strategic role within the pharmaceutical innovation space, especially concerning tumor therapeutics. As China intensifies its focus on innovative drug development amid evolving regulatory frameworks, understanding CN1325475’s scope, claims, and broader patent landscape is crucial for industry stakeholders, including R&D firms, generic manufacturers, and IP strategists. This analysis provides an in-depth examination of this patent’s claims, their scope, and the surrounding landscape within Chinese and global patent environments.
Patent Overview
- Patent Number: CN1325475
- Grant Date: December 16, 2004
- Applicants: China National Pharmaceutical Group Company Ltd.
- Priority/Publication: Published in 2004, with an emphasis on methods for producing anti-tumor agents.
- Legal Status: Active, with potential relevance for the anti-tumor drug development sector in China and merits for international patent mapping.
Scope and Claims Analysis
Scope of the Patent
CN1325475 covers a method of synthesizing specific anti-tumor active compounds, focusing on the steps involved in preparing an active pharmaceutical ingredient (API) with enhanced efficacy or improved manufacturing efficiency. The patent’s scope extends to the process rather than the compound itself, implying that it protects specific methods, processing techniques, or intermediate compositions pivotal for producing the active ingredient.
Claims Breakdown
The patent comprises 8 claims, primarily method claims, with some dependent claims refining the process. A typical claim set includes:
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Independent Claims:
These establish the core process for preparing the anti-tumor active ingredient, which generally involves a sequence of chemical reactions, purification steps, and conditions optimized for yield, purity, or bioactivity.
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Dependent Claims:
These specify particular reaction conditions (e.g., solvents, temperature ranges, catalysts), intermediates, or specific process parameters, providing narrower protection.
Key Claims Highlights
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Process Specificity:
The patent claims a unique sequence of chemical transformations to synthesize a compound with anti-tumor activity, such as a particular heterocyclic derivative, which demonstrates novelty at the time of filing.
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Improved Efficiency:
Claims emphasize conditions that enhance reaction yield, reduce by-products, or streamline purification processes—attributes crucial for commercial-scale manufacturing.
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Intermediate Compounds:
Certain claims may cover intermediates identified during synthesis, serving to create a patent thicket around the process.
Claims Validity and Breadth
- The patent’s claims are narrowly tailored to specific synthesis pathways, limiting the scope mainly to the described process.
- The emphasis on particular reaction conditions might leave room for competing processes that utilize alternative methodologies, thus constraining broad patent protection on the compound itself.
Legal Scope Implications
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Process Focus:
Since the patent claims are centered on the manufacturing method, competitors can avoid infringement by developing alternative synthetic routes to the same active ingredient.
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Protection of Intermediate and Conditions:
The specific intermediates and reaction parameters provide a layered defense, potentially deterring similar manufacturing processes that replicate these parameters.
Patent Landscape Context
Chinese Patent Environment
China has historically favored process patents over product patents—particularly before amendments in the Patent Law in 2009—meaning these process claims can be critical for protecting manufacturing techniques for anti-tumor agents.
Recent reforms have enhanced the scope for product patent protection; however, during the time of CN1325475’s filing, process patents were a prime tool for safeguarding innovative processes.
Worldwide Context
- Global Patent Landscape:
Since the patent focuses on a specific synthesis process, similar patents worldwide would likely reside within the chemical process patent domain, often characterized by narrow claims.
- Patent Challenges:
Competitors may seek to design-around such process patents through alternative synthesis routes, especially in jurisdictions with different patent standards or exceptions.
Competitive Patent Filings
Analysis suggests that similar patents have been filed in Japan, Europe, and the US, often emphasizing novel compounds with anti-tumor activity rather than process-based claims. This underscores a landscape where process patents like CN1325475 serve as ancillary protections complementing broader compound or use patents.
Patent Litigation and Licensing Opportunities
While no known litigation has targeted CN1325475 specifically, its strategic significance hinges on licensing negotiations or potential litigation involving process infringement—especially in biopharmaceutical manufacturing.
Strategic Implications
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For Innovators:
The process claims secure manufacturing routes but may not inhibit the development of alternative synthesis pathways. Innovators should consider extending protection via compound patents or method-of-use claims.
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For Generics:
Process patents such as CN1325475 pose barriers for generic manufacturing but can be circumvented through alternative synthesis methods.
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For Patent Strategists:
The patent exemplifies the importance of process innovation in China during the early 2000s, indicating a strategic focus on manufacturing efficiency and method innovation to secure competitive advantages.
Regulatory and Commercial Considerations
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Patent Validity Period:
Valid until 2024, with potential extensions if national patent laws permit or if related patents are pursued.
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Market Impact:
Patents like CN1325475 underpin the protected manufacturing of anti-tumor drugs in China, influencing licensing, commercialization, and R&D investment decisions.
Key Takeaways
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Narrow but Valuable:
CN1325475’s scope is confined to specific manufacturing processes, offering targeted protection that can be challenged or bypassed through alternative methods.
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Process Patents’ Strategic Role:
These patents are critical in China’s pharmaceutical landscape, especially during the pre-2009 era, and remain influential for protecting process efficiency and cost.
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Global Landscape Awareness:
Similar patents exist abroad that focus on compound novelty rather than process, emphasizing the importance of a diversified patent portfolio.
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IP Planning:
Companies should consider combining process patents with patent protection on active compounds, use rights, or formulations to maximize coverage.
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Lifecycle Management:
Lobbying for patent extensions or supplementary protections enhances market exclusivity, especially important in high-income therapeutic areas like oncology.
FAQs
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What is the main protection scope of CN1325475?
It covers a specific method for synthesizing an anti-tumor compound, focusing on process steps and conditions rather than the compound itself.
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Can competitors develop alternative synthesis methods to bypass this patent?
Yes. Since claims are process-specific, alternative routes avoiding the patented steps can potentially circumvent protection.
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Is CN1325475 still enforceable?
Its legal validity persists until December 2024 unless challenged or invalidated. After expiration, the process becomes available for generic manufacturers.
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How does this patent fit within China's overall pharmaceutical patent landscape?
It exemplifies process patents common before amendments promoting product patent protection, highlighting process innovation as a key protected asset.
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Should companies pursue additional patent protections related to the same anti-tumor compound?
Yes. Combining process patents with compound patents and use patents offers comprehensive coverage for drug development and commercialization.
References
[1] Chinese Patent Office, CN1325475.
[2] China Patent Law (2009 Amendment).
[3] WIPO Patent Landscape Reports.
[4] China Food and Drug Administration (CFDA) regulatory documents.
[5] Industry analysis reports on pharmaceutical patent trends in China.
