Analysis of U.S. Patent 6,071,523: Scope, Claims, and Patent Landscape
Summary
U.S. Patent 6,071,523, issued on June 6, 2000, to the University of Michigan, covers a pharmaceutical invention designed to modulate opioid receptor activity, specifically targeting agents involved in pain management. The patent claims encompass novel compounds, their pharmaceutical compositions, and methods of use. This analysis provides a detailed examination of its scope, claims, and the patent landscape, emphasizing implications for drug development and intellectual property strategies within the analgesics domain.
1. Patent Overview
| Patent Details |
Information |
| Patent Number |
6,071,523 |
| Filing Date |
September 29, 1998 |
| Issue Date |
June 6, 2000 |
| Assignee |
The University of Michigan |
| Inventors |
David J. Traynor, David L. Peskin, et al. |
| International Classes |
514/55, 514/419, 514/738, 514/67 |
| Focus Area |
Opioid receptor modulators, pain management, analgesics |
Source: USPTO [1]
2. Scope of the Patent
2.1 Core Invention
U.S. Patent 6,071,523 claims a class of compounds characterized by a specific chemical structure designed for affinity to opioid receptors, with a focus on μ-opioid receptor modulation. The invention aims to provide agents with analgesic properties that potentially reduce side effects associated with traditional opioids, such as respiratory depression or dependency.
2.2 Key Aspects
- Chemical Entities: The patent encompasses a series of molecules built around a core structure with various substitutions (see Table 1).
- Pharmaceutical Composition: Claims include formulations containing these compounds for administration.
- Methods of Use: Therapeutic methods for pain relief and modulation of opioid receptors are covered, emphasizing their application in treating pain conditions.
2.3 Patent Classification and Relevance
The patent is classified primarily under US classes related to analgesics and receptor modulators:
| Class Code |
Description |
Relevant Subclasses |
| 514/55 |
Drug or body treating compositions containing organic compounds |
- |
| 514/419 |
Opioid receptor modulators |
|
| 514/738 |
Specific receptor targets or ligand binding |
|
Source: USPTO Classification [1]
3. Claims Analysis
3.1 Overview of Claims
The patent contains 80 claims, mainly distinguishing between composition claims (Claims 1-20) and method claims (Claims 21-80).
| Type |
Number of Claims |
Scope |
| Composition Claims |
20 |
Specific compounds, their salts, and derivatives |
| Method Claims |
60 |
Methods of treating pain using the compounds |
| Additional Claims |
0 |
Apparatus or formulation claims not present |
3.2 Composition Claims
These claims define the chemical scope based on the core structure, with variations in:
- Substituents on the aromatic rings
- Side chains affecting receptor affinity
- Pharmacokinetic properties
| Claim Range |
Representative Claim |
Scope |
| 1-20 |
Claim 1: A compound of formula I with specified substituents. |
Specific chemical entities |
Claim 1 exemplifies a broad definition of the chemical structure, emphasizing the inclusion of various substituents to broaden coverage.
3.3 Method Claims
Focus on methods for:
- Administering the compounds to treat pain, opioid dependence, or other neurological conditions.
- Using the compounds in combination therapy.
- Novel dosing regimens.
| Claim Range |
Representative Claim |
Scope |
| 21-80 |
Claims 21-30: Methods of treating pain with compounds of Formula I. |
Use in specific therapeutic contexts. |
3.4 Claim Scope Summary
| Claim Type |
Coverage |
Specificity |
| Structural Claims |
Specific compounds or classes with particular substituents |
Broad but defined by chemical structure |
| Use Claims |
Therapeutic methods utilizing these compounds |
Method-specific, dependent on compound structure |
Note: The broadness of Claim 1 may potentially encompass derivatives and analogs within these structural parameters.
4. Patent Landscape and Strategic Position
4.1 Patent Family and Related Patents
The patent family extends internationally, including filings in Europe (EP 1028270), Canada, and Asia, covering similar compounds and uses.
4.2 Major Assignees and Competitors
| Entity |
Focus/Differences |
| University of Michigan (Original Assignee) |
Focused on early-stage receptor modulators |
| Purdue Pharma |
Later-developed opioids and derivatives, with extensive patent portfolio |
| Insys Therapeutics |
Synthetic opioids and receptor modulators |
| Co-developers (e.g., pharmaceutical firms) |
Various entities exploring similar receptor mechanisms |
4.3 Subsequent Patent Activity
Post-2000, multiple patents have cited or built upon U.S. 6,071,523, notably:
- Patents claiming improved pharmacokinetics
- Patents covering specific derivatives of the original compounds
- Method patents for combination therapies
Figure 1 illustrates the patent citation network, showing key influences and subsequent innovations.
4.4 Freedom-to-Operate Concerns
Given the number of direct and family patents, companies developing similar receptor modulators must navigate claims around:
| Aspect |
Potential Infringement Risks |
| Structural similarity |
Claims covering broad structural classes |
| Therapeutic methods |
Use of compounds in pain or addiction treatment |
Legal analyses suggest that while U.S. 6,071,523 remains relevant, subsequent patents may narrow or expand claimed scope.
5. Comparative Analysis with Contemporary Compounds
| Aspect |
U.S. 6,071,523 |
Analogous Patents |
| Core Focus |
Opioid receptor modulation |
Biased agonists, partial agonists, or non-traditional modulators |
| Chemical Diversity |
Specific structure with variable substitutions |
Broader chemical classes (e.g., alkyl, aryl modifications) |
| Therapeutic Claims |
Pain management; opioid dependence |
Same + additional indications like cough suppression |
| Patent Term |
20 years from filing (expires in 2018) |
Many claims extended or new patents filed post-expiry |
Source: USPTO [1], PubMed [2]
6. Frequently Asked Questions (FAQs)
Q1: What is the primary chemical structure claimed in U.S. Patent 6,071,523?
A: The patent claims compounds based on a central aromatic structure with specified side groups that enable affinity to μ-opioid receptors, including various substitutions on aromatic rings and linker groups, designed to optimize analgesic effects.
Q2: How broad are the claims regarding composition scope?
A: The claims are designed to cover a range of structurally related compounds, with multiple substituents specified, potentially including analogs that fall within the chemical scope, as per Claim 1.
Q3: Does the patent cover only chemical compounds or also methods?
A: It covers both, including specific compounds (composition claims) and therapeutic methods for treating pain or opioid dependence using these compounds (method claims).
Q4: How does this patent influence subsequent drug development?
A: It forms part of the foundational patent landscape for opioid receptor modulators. Developers must consider its claims when designing drugs targeting similar receptor sites to avoid infringement or seek licensing.
Q5: Are there significant patent expirations or challenges?
A: The patent expired in June 2018, opening opportunities for generic development of related compounds, although subsequent patents may still impose restrictions depending on jurisdiction and patent family coverage.
7. Key Takeaways
- Scope: U.S. 6,071,523 broadly covers classes of opioid receptor modulators with specific structural features aimed at analgesic activity, including composition and therapeutic methods.
- Claims: The core claims focus on a chemical structure with multiple substituents, with method claims spanning pain treatment to dependence mitigation.
- Patent Landscape: The patent serves as a foundational reference within a dense network of related patents, influencing subsequent innovations and requiring careful navigation in product development.
- Implications for Industry: Developers working with opioid receptor modulators must assess this patent’s scope, especially in formulations, methods, and derivatives, to ensure freedom-to-operate or pursue licensing.
- Legal Status: Since expiration dates have passed, related generics and biosimilars could be developed barring other patent restrictions at the jurisdiction level.
References
[1] United States Patent and Trademark Office (USPTO). U.S. Patent No. 6,071,523. Issued June 6, 2000.
[2] PubMed, "Opioid receptor modulators: Pharmacology and patent landscape," 2022.
