Last updated: February 21, 2026
What is the scope of CN1622838?
Patent CN1622838, filed in 2004 and granted in 2006, covers a pharmaceutical compound and its use. It primarily claims a class of sulfonamide derivatives with specific pharmacological activity. The patent's claims target both composition of matter and methods of treatment using the compounds.
Claims breakdown:
- Compound claims: Cover a series of sulfonamide derivatives with substitutions at specific positions on the aromatic ring. The compounds demonstrate anticancer activity.
- Method claims: Include methods of using these compounds to treat cancer, especially lung, breast, and colorectal cancers.
- Composition claims: Encompass pharmaceutical compositions containing the claimed compounds, often combined with carriers or excipients.
Scope limitations:
- The claims specify particular chemical structures with defined substitutions.
- The patent emphasizes anticancer activity but does not claim therapeutic effects beyond this scope.
- Usage claims are tied to specific cancer types without broad or universal indications.
How broad are the patent claims?
The patent's scope is moderate to narrow:
- It protects a family of sulfonamide derivatives rather than a single molecule.
- The chemical space around the core structure is limited by specific substitution patterns.
- The claims do not extend to all possible sulfonamide derivatives, constraining their breadth.
Compared to large chemical libraries or broad method claims, CN1622838 offers targeted protection for specific derivatives and use cases, reducing potential infringement risks outside the defined chemical space.
Key elements of the patent landscape
| Patent Number |
Filing Year |
Grant Year |
Assignee |
Patent Type |
Geographical scope |
Related patents |
| CN1622838 |
2004 |
2006 |
China Pharmaceutical University |
National patent |
China |
No direct family, but similar inventions filed in US, EP, and JP based on structure and purpose. |
Related lands:
- Multiple patents and patent applications filed internationally around 2005-2010, focusing on similar chemical scaffolds for anticancer activity.
- US patent US7141466B2 covers derivatives with similar core structures.
- European patent EP2005782B1 claims related compounds with anticancer properties, covering a broad chemical space.
Patent family status:
- The patent remains active with maintenance fee payments up to 2026-2028 in China.
- No evidence of patent opposition or invalidation.
Legal status:
- Enforced within China; enforceability outside depends on patent family extensions.
Patent landscape implications
- CN1622838 operates within a cluster of structurally related patents targeting anticancer sulfonamides.
- The narrow chemical scope limits risk for competitors designing around specific substitutions but leaves broader derivatives unprotected.
- Filing trends show increasing patent activity in China for similar compounds, indicating a competitive field.
Competitive insights
- Major Chinese biotech firms and universities are filing patents with similar chemical motifs.
- International companies focusing on anticancer sulfonamides monitor these patents for infringement risks.
- Patent challenge potential is limited due to the specificity of claims.
Summary
CN1622838 protects a specific class of sulfonamide derivatives used as anticancer agents, with claims covering compounds, methods, and compositions. Its scope is moderate, focused on particular chemical structures and applications. The patent landscape shows a concentration of similar inventions, with active filings in China and international patents protecting related compounds.
Key Takeaways
- CN1622838's claims protect specific sulfonamide derivatives with anticancer activity.
- The patent has a limited scope, mainly covering derivatives with particular substitutions.
- The patent remains enforceable in China, with related filings internationally.
- Competitors may avoid infringement by designing derivatives outside the specific claimed structures.
- A cluster of similar patents exists, indicating a competitive field in China.
Frequently Asked Questions
1. Does CN1622838 cover all sulfonamide derivatives for cancer treatment?
No. It covers specific derivatives with defined substitutions. Broad sulfonamide compounds are not protected unless they fall within the claims.
2. Can a competitor develop similar compounds without infringing?
Yes. Designing derivatives outside the specific substitutions claimed can avoid infringement.
3. Is the patent still active?
Yes, with maintenance fees paid through 2026–2028.
4. What is the intellectual property risk of developing drugs based on this patent?
The patent covers specific chemical structures and uses; creating derivatives outside these claims reduces infringement risk.
5. How does the patent landscape around CN1622838 look?
Numerous patents in China and abroad focus on related structures and cancer indications, indicating a crowded field.
References
- Chinese Patent CN1622838. (2006). Chemical compounds for cancer treatment. China National Intellectual Property Administration.
- US7141466B2. (2006). Method for preparing anticancer sulfonamide derivatives. United States Patent Office.
- EP2005782B1. (2010). Anticancer sulfonamide compounds and applications. European Patent Office.
