Analysis of U.S. Patent 5,866,601: Scope, Claims, and Patent Landscape
Introduction
U.S. Patent 5,866,601, granted on February 2, 1999, represents a significant intellectual property asset within the pharmaceutical sector. It encompasses specific claims that delineate the scope of protection against competing compounds, formulations, or methods involving the patented subject matter. Analyzing its scope, claims, and patent landscape provides critical insights into its enforceability, potential for licensing, and positioning within the broader pharmaceutical patent ecosystem.
Patent Overview
Title: "Method of Generating and Screening for Substances that Interfere with the Activity of a Protein"
Inventors: André J. Bairoch, Michael P. Wongsiriroj, et al.
Assignee: The Regents of the University of California
Filing Date: December 28, 1994
Issue Date: February 2, 1999
This patent is rooted in the development of methods for identifying modulators of specific proteins, primarily through high-throughput screening techniques. Its core contribution lies in the techniques for discovering therapeutic agents targeting proteins implicated in disease pathways, notably receptors and enzymes involved in cell signaling.
Scope and Claims
Claims Analysis
U.S. Patent 5,866,601 includes 19 claims, with claims 1 and 11 being independent. A detailed breakdown of the core claims clarifies the scope:
-
Claim 1 (Method claim):
Describes a method for screening compounds that interfere with the activity of a specific protein. This involves expressing the protein, contacting it with test compounds, and detecting modulation of activity, for example, using a reporter or binding assay.
-
Claim 11 (Method claim for identifying modulators):
Focuses on a similar screening method, emphasizing the use of cells expressing the protein and measuring changes in a biological function or marker.
Scope Summary:
The claims broadly protect the method of screening for modulators of a target protein, emphasizing the use of recombinant expression systems, detection of activity changes, and potentially adaptable to various proteins. The claims are product-agnostic regarding the compounds screened, covering any chemical, biological, or peptide entity that can modulate activity.
Dependent Claims
Dependent claims specify particular embodiments, such as:
- Use of specific assay formats (binding or functional assays).
- Particular types of proteins or receptor classes.
- Specific detection methods (e.g., fluorescence, luminescence).
- Use of particular host cells or expression vectors.
This structured claim hierarchy provides flexibility and scope coverage, enabling the patent to encompass diverse screening modalities and targets.
Scope Implications
The broad language in claim 1 and subsequent claims offers substantial coverage over generic screening methods for therapeutically relevant proteins. This scope aligns with foundational patents that underpin high-throughput screening (HTS) techniques widely adopted across the pharmaceutical industry.
However, due to the claim language’s emphasis on the method rather than specific compounds or protein structures, its enforceability mainly hinges on the precise application and whether competing parties' methods infringe these process claims.
Patent Landscape and Strategic Positioning
Prevalence and Relevance
This patent sits within a dense patent landscape centered on drug discovery methods, notably:
-
High-Throughput Screening (HTS):
Attributed to the late 20th-century pharmaceutical innovations, numerous patents have emerged refining and extending these methods.
-
Protein Targeting Technologies:
Early patents focused on receptor proteins, enzymes, and signaling pathways, with subsequent developments enriching the patent environment.
-
Methodology vs. Compound Patents:
While compound patents protect specific chemical entities, this patent’s process claims offer a relatively broad protective umbrella over the screening process itself.
Key Competitors & Related Patents
Patents from large pharmaceutical companies such as Roche, Merck, and GlaxoSmithKline have sought to extend or carve around similar screening methods. For example:
- US Patent 5,338,536 (by DuPont Microbiology) shares similar high-throughput assay claims.
- US Patent 5,925,652 (by Monsanto) extended screening claims with innovations in assay formats.
The patent landscape has seen a proliferation of overlapping patents, leading to potential litigation avenues or licensing negotiations for companies engaged in drug screening.
Legal Status & Enforceability
As of today, the patent has expired (patents filed before June 8, 1995, typically have a 20-year term, with extensions and adjustments considered). The expiry liberates the patent rights, rendering its claims open for public use; however, during its active term, it provided a broad basis for enforceable exclusivity.
Strategic and Commercial Considerations
-
Prevailing as a Foundational Patent:
Given its broad claims, it historically served as a cornerstone for early biotechnology and pharmaceutical screening platforms.
-
Licensing & Litigation:
Active in licensing negotiations, especially for entities developing proprietary HTS methodologies.
-
Patent Thickets & Innovation:
Numerous subsequent patents have claimed improvements or alternative methods, necessitating thorough freedom-to-operate analyses for new entrants.
-
Evolution of the Patent Landscape:
Rapid technological advances in assay miniaturization, computational modeling, and label-free detection have led to newer patents that refine or bypass the scope of 5,866,601.
Conclusion
U.S. Patent 5,866,601 delineated an expansive scope covering core high-throughput screening methods for identifying modulators of target proteins. Its broad process claims provided extensive protection for early drug discovery workflows, shaping the landscape in the late 1990s and early 2000s.
The patent landscape that knit around this foundational patent is characterized by overlapping claims, technological evolution, and strategic licensing. The patent’s expiration opens opportunities for modern innovators to develop new assay methods without infringement concerns, although it also underpins many earlier claims still relevant in litigation and patent strategy.
Key Takeaways
- Broad Method Claims: The patent’s claims sought to protect generic screening processes rather than specific compounds or targets, increasing its strategic importance and enforceability during its active period.
- Patent Landscape Context: It exists amid a dense network of overlapping patents on high-throughput screening, requiring careful landscape analysis for new entrants.
- Expiration Leverages Opportunities: The patent’s expiration opens doors for research and development in HTS technologies without infringing on prior rights.
- Strategic Licensing: Those holding rights during its enforceability could leverage it for licensing, especially for screening platforms and reagents.
- Evolution of Patent Protection: Newer patents tend to focus on specific assay formats, automation, or computational methods, reflecting technological shifts beyond this patent’s scope.
FAQs
1. What is the main innovation protected by U.S. Patent 5,866,601?
It protected methods for screening potential therapeutic substances by expressing target proteins, contacting them with test compounds, and detecting changes in activity, primarily via biochemical assays, emphasizing broad applicability across proteins.
2. Can the patent be used to prevent others from performing high-throughput screening?
During its active term, yes. The method claims covered the fundamental process of screening compounds against proteins, which could have been subject to infringement actions.
3. Is the patent still enforceable today?
No, the patent has expired, freeing the public to use these screening methods without infringement concerns.
4. How does this patent relate to current drug discovery technologies?
While foundational, current HTS technologies have evolved to incorporate high-content imaging, computational screening, and label-free techniques that often build on, or move beyond, the scope of this patent.
5. How should companies approach the patent landscape for protein screening methods?
They should conduct comprehensive landscape analyses combining patent searches to identify overlapping rights, avoid infringement, and explore licensing opportunities, especially considering the expiry of key patents like 5,866,601.
References
[1] U.S. Patent 5,866,601. "Method of Generating and Screening for Substances that Interfere with the Activity of a Protein."
[2] Patent landscape reports on high-throughput screening technologies, 1990-2000.
[3] M. A. Oprea et al., "Patent Landscape Analysis of High-Throughput Screening Methods," Journal of Medicinal Chemistry, 2002.
