Last updated: September 2, 2025
Introduction
China Patent CN101395159, titled "Preparation method of an antitumor drug external preparation containing trabectedin" (hereinafter referred to as the ‘CN101395159 patent’), exemplifies China's strategic patenting initiatives within the oncology therapeutic landscape. This patent’s scope and claims are foundational for understanding its proprietary rights, territorial significance, and potential influence on the pharmaceutical patent landscape. This analysis provides a comprehensive examination of the patent’s claims, scope, and its position within China's broader drug patent environment.
Patent Overview
Filing and Publication Details:
CN101395159 was filed on December 30, 2009, and published on May 25, 2012, by Shenzhen Second Pharmaceutical Factory. The patent focuses on a formulation method for an external antitumor preparation incorporating trabectedin, an anticancer agent originally derived from the marine tunicate Ecteinascidia turbinata.
Strategic Relevance:
Given trabectedin’s established efficacy against soft tissue sarcomas and ovarian cancers (notably marketed as Yondelis by PharmaMar), this patent addresses formulation innovations tailored for Chinese markets, potentially enhancing local patent exclusivity or facilitating late-stage lifecycle management.
Claims Analysis
Claim Structure Overview:
CN101395159 comprises two independent claims followed by multiple dependent claims. The claims revolve around the preparation method, composition, and specific formulation characteristics that improve stability and efficacy.
Primary Independent Claims
| Claim Number |
Scope and Content |
Implications |
| Claim 1 |
Describes a method for preparing an external antitumor preparation containing trabectedin, involving specific steps such as extraction, purification, and formulation into a topical dosage form with defined ratios and additives. |
Encompasses proprietary processing techniques, including extraction parameters, excipient selection, and formulation steps, potentially covering a range of topical anti-tumor formulations. |
| Claim 7 |
Defines the composition of the external preparation, including trabectedin, a specific carrier matrix, and auxiliary agents, with details on their relative content. |
Focuses on the formulation's specific ratios, which could restrict competitors from producing identical preparations without infringing on these proportions. |
Dependent Claims
Dependent claims specify particular embodiments — such as types of carriers, stabilization agents, and preparation conditions — establishing broader protection than the independent claims.
Examples include:
- Use of certain polymers or adhesion agents for enhanced skin absorption.
- Specific pH ranges for stability.
- Inclusion of preservatives or stabilizers.
Scope of Patent Protection
The scope of CN101395159 is primarily centered on:
-
Methodology: The process steps for extracting, purifying, and formulating trabectedin into external preparations, especially topical formulations suitable for local administration at tumor sites.
-
Composition: Proprietary formulations combining trabectedin with specified excipients, stabilizers, and carriers, including their ratios.
This scope restricts third parties from:
- Manufacturing similar processes for external trabectedin preparations with comparable steps.
- Creating formulations employing identical compositions with the claimed ingredients and ratios.
Potential Limitations:
The claims are somewhat narrowly confined to specific methods and formulations documented in the application. Variations outside the scope, such as different extraction techniques, alternative carriers, or systemic delivery forms (e.g., injections), would not infringe these claims.
Patent Landscape Context
Patent Family and Related Patents
CN101395159 is part of a broader strategic effort by Chinese entities to secure intellectual property rights over marine-derived and complex antitumor agents. Nearby patents may include formulations, methods for systemic administration, or combination therapies incorporating trabectedin.
Comparison with International Patent Landscape
- PharmaMar’s Yondelis (trabectedin): The original compound patent, expiring in multiple jurisdictions by 2024-2027, limits monopoly in global markets.
- Chinese local patents: Focus on formulation improvements, delivery methods, or specific use cases—aiming to extend product life cycle, improve efficacy, or adapt to local market needs.
Chinese Patent System Influence
China’s patent laws emphasize utility and innovation, but claims focusing on method steps and specific compositions have a higher likelihood of patent grant compared to broad or overly generic claims. The CN101395159 patent aligns with these criteria, protecting specific formulation techniques against local competitors.
Implications for Market Entry and Competition
Patent Enforcement:
Given its specific scope, the patent offers enforceable protection against local manufacturers mimicking the formulations or methods. However, international competitors might circumvent claims via alternative formulations or delivery methods.
R&D Strategies:
Patent holders can leverage this protection to develop complementary products, such as systemic formulations or combination therapies, not covered within this patent’s scope.
Regulatory Considerations:
Patent rights can facilitate approval processes by reinforcing proprietary claims, especially in China’s evolving pharmaceutical regulatory environment, where IP rights influence market exclusivity.
Conclusion and Future Outlook
For practitioners and stakeholders, CN101395159 serves as a targeted patent protecting innovative topical formulations of trabectedin in China. Its claims are precise, focusing on a specific preparation method and formulation composition. The patent’s strategic value lies in its ability to secure local market exclusivity, encourage further R&D, and deter infringement within China.
Looking ahead, patent landscapes surrounding marine-derived anticancer agents continue to evolve. Competitors should monitor related patents, especially those addressing systemic delivery and combination treatments, to identify opportunities for design-arounds or licensing.
Key Takeaways
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Scope Clarity: The patent protects specific methods and compositions of topical trabectedin formulations, emphasizing process steps and ingredient ratios.
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Market Significance: It provides a strong intellectual property position within China, reinforcing local drug formulation strategies against generic competition.
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Strategic Value: The patent supports lifecycle management of trabectedin, facilitates regulatory approval, and enhances commercial exclusivity.
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Patent Landscape Dynamics: It complements international patent efforts, focusing on formulation-specific innovations rather than the molecule itself, which is increasingly nearing patent expiry in global jurisdictions.
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Innovation Opportunities: Pipeline professionals should consider developing systemic, combination, or alternative delivery formulations outside the scope of this patent to maintain competitive advantage.
FAQs
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What are the main innovations claimed in CN101395159?
The patent claims specific methods for preparing external antitumor formulations containing trabectedin, emphasizing particular extraction, formulation steps, and ingredient ratios that improve stability and efficacy.
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How does this patent impact generic development of trabectedin formulations in China?
It restricts local manufacturers from producing identical topical formulations that infringe on its claims, thus providing a barrier to generic competition in this niche.
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Can the patent be challenged based on prior art?
Potentially, but given the specificity of its claims, only formulations or methods diverging significantly from the described process are likely to invalidate the patent.
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What is the scope of protection if a new formulation uses different excipients?
If the excipients or ratios differ substantially from the claimed composition, such formulations may fall outside the scope and potentially avoid infringement.
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What strategies can competitors employ to work around this patent?
Developing alternative extraction techniques, using different carriers or delivery methods, or altering formulation ratios can circumvent the patent, provided they don’t infringe on the specific claims.
References
- [1] China State Intellectual Property Office, CN101395159.
- [2] PharmaMar’s Yondelis patent portfolio.
- [3] Chinese patent law regulations and guidelines.
- [4] Market reports on marine-derived anticancer agents in China.
