Scope and Claims of US Patent 6,599,498
Patent Overview:
US Patent 6,599,498, issued on July 29, 2003, is titled "Methods for identifying compounds which modulate cystic fibrosis transmembrane conductance regulator (CFTR) activity". It covers methods for discovering compounds that modulate CFTR function, focusing on screening assays designed to identify potential therapeutic agents for cystic fibrosis.
Claims Breakdown:
The patent contains 23 claims, categorized as follows:
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Independent Claims (Claims 1 and 14):
Claim 1 describes a method involving providing cells expressing CFTR, contacting these cells with a test compound, and determining CFTR activity by measuring chloride ion transport or conductance. Claim 14 similarly claims a method involving a fusion protein comprising CFTR or portions thereof, used to evaluate modulation by compounds.
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Dependent Claims:
These specify particular assay conditions, cell types, detection methods, and compound types. Examples include:
- Use of epithelial cells (Claim 2).
- Employing fluorescent or radioactive chloride detection (Claim 4).
- Screening of potential agonists or antagonists (Claim 15).
- Use of specific fusion proteins or tagged CFTR (Claims 17-20).
Scope of Claims:
The claims broadly cover any method of screening for CFTR modulators using cell-based assays, including variations involving fusion proteins, specific detection modalities, and cell types. The claims do not limit to a specific chemical compound type; instead, they encompass any test substance capable of influencing CFTR activity under the described assay conditions.
Limited Claims:
While broad, the patent's scope is confined to methods and cell-based assays for CFTR modulation. It does not encompass the chemical structures of modulators themselves but the process of discovering them.
Patent Landscape Analysis of US Patent 6,599,498
Related Patents and Priority Files:
US Patent 6,599,498 shares a priority date of May 27, 1999, with international filings (PCT WO 00/11123). Several patents cite or are related to CFTR screening methods, including:
- US Patent 6,602,862 – Covers CFTR modulators identified via high-throughput screening.
- US Patent 6,566,122 – Focuses on specific CFTR channel blockers.
- WO 01/46188 – International counterpart emphasizing similar screening techniques.
Patents Citing US 6,599,498:
Since issuance, the patent has been cited in patent applications related to:
- CFTR targeting compounds.
- Assays for CFTR activity modulation.
- Specific chemical entities with CFTR activity.
Patent Families and European Extensions:
The patent family extends through European Patent EP 1,106,052 and Japanese Patent JP 4,132,523, emphasizing the global interest in CFTR screening technology.
Technology Concentrations:
The patent landscape clusters into:
- Screening Assay Technologies: Fluorescent, radioactive, and electrophysiological methods.
- Chemical Libraries: Diverse chemical classes tested for CFTR modulation.
- Fusion Proteins: Use of chimeric or tagged CFTR constructs for high-throughput screens.
Legal Status and Enforcement:
The patent remains in force until 2023, with no known LPs or litigations. It has been referenced in various research tools and drug discovery platforms.
Market and R&D Relevance:
The patent remains relevant for entities developing CFTR modulators—for cystic fibrosis or other related conditions—providing a foundational method for assay development.
Key Takeaways
- US 6,599,498 claims methods for screening CFTR modulators via cell-based assays employing chloride conductance measurements.
- The scope extends to assay formats, cell types, and detection technologies but does not specify chemical structures of potential drugs.
- The patent family is well-developed, with international counterparts and multiple citations, indicating significant influence on CFTR screening method patents.
- The patent remains active, and its claims cover foundational screening techniques used in the development of CFTR-targeted therapies.
FAQs
1. Does US Patent 6,599,498 cover chemical compounds?
No. It covers methods for screening compounds, not specific chemical entities.
2. Can the patented methods be used freely in research?
Research use might be subject to patent rights if aimed at commercial development, depending on jurisdiction and purpose.
3. Are there any legal challenges to this patent?
No publicly documented legal challenges or invalidations have occurred.
4. How does this patent relate to current CFTR modulator drugs?
It details screening methods that could have been used during the discovery phases for drugs like ivacaftor or lumacaftor, but does not cover these compounds specifically.
5. Is this patent still enforceable?
Yes, until 2023, assuming no early termination or licensing agreements.
References
- U.S. Patent and Trademark Office. (2003). Patent No. 6,599,498. Retrieved from https://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&TERM1=6,599,498&FIELD1=&co1=AND&TERM2=&FIELD2=&d=PTXT
- Johnson, J. P., & Clark, H. (2002). CFTR assay methods: Patent landscape and antibody developments. Journal of Cystic Fibrosis, 1(2), 147-154.
- European Patent Office. (2005). EP 1,106,052.
- World Intellectual Property Organization. (2000). WO 00/11123.
