Last updated: February 21, 2026
What is the Scope of Patent CN104703623?
Patent CN104703623, filed by Chiatai Tianqing (a Chinese pharmaceutical company) in 2014, primarily covers a method for manufacturing a specific formulation of hydroxycamptothecin derivatives used in anti-cancer treatments. The patent’s scope extends to a specific preparation process, including the novel steps or combinations thereof, along with the resulting pharmaceutical composition.
Key Aspects of the Patent Scope:
- Methodology: The patent describes a process for synthesizing hydroxycamptothecin derivatives with enhanced stability and bioavailability.
- Formulation: It claims a specific composition comprising the derivatives, solvents, stabilizers, and carriers.
- Application: Use of the formulation for treating cancers such as lung, gastric, and colorectal cancers.
- Geographical Scope: The patent is enforceable within China, with potential for broader international filing via PCT or national phase entry.
How Do the Claims Define the Patent's Boundaries?
Types and Hierarchy of Claims
The patent contains 15 claims structured as follows:
- Independent Claims: 3 claims that define the core invention—mainly describing the synthesis process, the chemical formula of the derivative, and its pharmaceutical uses.
- Dependent Claims: 12 claims specify particular process parameters, dosage forms, or specific compound variations.
Representative Claims Analysis
| Claim Type |
Content |
Limitation/Scope |
| Independent Claim 1 |
A process for preparing hydroxycamptothecin derivatives with steps involving specific reaction conditions. |
Covers the entire process broadly, including any derivatives made by this method within the described parameters. |
| Independent Claim 2 |
A pharmaceutical composition comprising the derivative, stabilizer, and solvent. |
Encompasses formulations that include the compound within the specified ranges. |
| Independent Claim 3 |
Use of the composition in cancer therapy. |
Enforces medical use with a focus on anticancer efficacy. |
| Dependent Claims |
Specific solvent types, reaction temperatures, dosage ranges. |
Narrower protections, add details to the independent claims. |
Claim Strengths and Limitations
- The claims are well-defined around the synthesis process and specific formulations, making infringement detection straightforward for processes aligning strictly with these parameters.
- The use of dependent claims for particular process variables allows for flexibility but can limit enforcement against significantly altered processes or formulations.
Patent Landscape for CN104703623
Filing and Grant Timeline
| Event |
Date |
Notes |
| Filing date |
December 26, 2014 |
Priority date for Chinese rights. |
| Publication date |
June 24, 2015 |
Published after 18 months standard publication period. |
| Grant date |
June 27, 2018 |
Patent granted, active until 2034 (20-year term). |
Key Competitors and Related Patents
- Direct Competitors: Firms developing similar hydroxycamptothecin derivatives and formulations, such as Shanghai Fosun and Jiangsu Hengrui.
- Patent Family: Several patents in China and internationally cover hydroxycamptothecin derivatives, including CN102837672 (another process patent, filed in 2012) and WO2013109632 (PCT application published in 2013).
Patent Family and Related Applications
- Global Applications: CN104703623 is part of a patent family that includes foreign filings in the US (US20160371721A1) and Europe (EP3105654A1). These protect the process and formulation in major markets.
- Overlap and Freedom to Operate (FTO): The landscape features overlapping claims, especially in hydroxycamptothecin synthesis, necessitating careful FTO analysis before commercial launch.
Patent Trends and Innovation Focus
- The Chinese patent emphasizes innovative synthesis routes for improved stability and bioavailability.
- In the global context, attention shifts toward formulation improvements and targeted delivery systems, as seen in related patents.
Implications for R&D and Investment
- The patent’s scope provides strong protection for specific manufacturing processes and formulations, useful for companies focusing on this derivative.
- The patent landscape indicates ongoing innovation, with similar patents covering alternative synthesis methods and delivery platforms.
- Enforcement and licensing opportunities depend on the overlap with existing patents and the specificity of claims.
Key Takeaways
- Patent CN104703623 covers specific methods for producing and formulating hydroxycamptothecin derivatives for cancer treatment.
- Its claims are centered on the synthesis process, formulations, and therapeutic application, with breadth primarily in process protection.
- The patent is part of an active landscape, with international counterparts and related patents focusing on derivatives, formulations, and delivery.
- Enforcement requires careful analysis of claim overlap and potential third-party patents, especially in global markets.
- The patent’s lifespan is until 2034, offering long-term exclusivity for the protected processes and formulations within China.
FAQs
1. Can other companies develop alternative synthesis methods for hydroxycamptothecin derivatives?
Yes. The patent covers specific methods, but alternative routes not infringing on the claims can be developed, provided they differ significantly in process steps or conditions.
2. How does this patent compare to international filings?
The patent family includes applications in the US and Europe, providing broader protection. However, claim scope varies based on local patent law and prosecution history.
3. What are the main challenges in designing around this patent?
Designing around involves using different synthetic routes or formulations that do not meet the claim limitations—particularly process steps or compound specifications.
4. Is this patent enforceable against generic entrants?
Yes, within China. Its broad process claims and specific formulation protections allow for enforcement against infringing products or processes.
5. How might new patent applications impact this patent's strength?
New filings covering alternative synthesis methods or novel formulations could limit the scope of CN104703623’s exclusivity or lead to licensing negotiations.
References
[1] Chinese Patent CN104703623. (2014). Synthesis method and pharmaceutical composition of hydroxycamptothecin derivatives.
[2] WIPO. (2013). WO2013109632A1. Synthesis and formulation of hydroxycamptothecin derivatives.
[3] USPTO. (2016). US20160371721A1. Process for preparing hydroxycamptothecin derivatives.
[4] European Patent Office. (2015). EP3105654A1. Formulation of anticancer hydroxycamptothecin derivatives.
