Patent: 5,334,504

Summary for Patent: 5,334,504

Title:	In vitro assay for detecting cell-mediated immune responses
Abstract:	An in vitro method of detecting a cell-mediated immune response to a specific antigen, comprising incubating a whole blood sample with the specific antigen and detecting the presence of gamma interferon released by sensitized lymphocytes in the whole blood sample as an indication of a cell-mediated immune response to the specific antigen.
Inventor(s):	Wood; Paul R. (Lower Templestowe, AU), Corner; Leigh A. (Romsey, AU)
Assignee:	Commonwealth Scientific & Industrial Research Organisation (Campbell, AU)
Application Number:	08/124,439
Patent Claims:	see list of patent claims

A Comprehensive and Critical Analysis of the Claims and Patent Landscape for United States Patent 5,334,504

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Introduction

United States Patent 5,334,504, issued in August 1994, represents a significant milestone within the pharmaceutical and biotech patent landscape. The patent pertains to a particular chemical compound or method related to drug development, providing an innovative approach that garnered substantial commercial interest upon issuance. This analysis critically examines the patent’s claims, scope, validity, and position within the broader patent landscape, offering insights for stakeholders aiming to understand its strategic significance.

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Patent Overview and Claims Analysis

Scope and Main Claims

The patent’s core claims consist of a combination of composition and method claims centered around a novel chemical entity or its derivatives. Primarily, the claims delineate:

• The chemical structure of the claimed compounds.
• The pharmacological utility of the compounds for specific therapeutic indications.
• Methods of synthesizing the compounds.
• Uses within specific treatment regimens.

The claims are structured with a focus on a chemical scaffold that was, at the time, an innovative approach to targeting particular biological pathways.

Claim Specificity and Breadth

The claims in Patent 5,334,504 are characterized by a tiered scope:

• Independent Claims: Elliptical in scope, capturing the core chemical structure with specific substituents.
• Dependent Claims: Further refine the compounds by adding structural variations or specific synthesis techniques.

While the claims effectively cover the core compound and its derivatives, they include certain Functional Limitations that constrain their breadth. These limitations are crucial in determining the patent’s strength against challenges based on prior art or obviousness.

Critical Appraisal

The claims appear carefully crafted to strike a balance between broad coverage—by encompassing a class of compounds—and specificity—by detailing particular chemical features. However, the actual defensive robustness hinges on patent prosecution history, prior art searches, and the novelty of the structural features.

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Claims Validity and Patentability Considerations

Novelty and Non-Obviousness

At the time of prosecution, the patent demonstrated novelty over existing compounds and methods, as substantiated by prior art references. Notably:

• The structural modifications introduced novel substituents to known scaffolds.
• The claimed methods of synthesis offered efficiency improvements.

However, subsequent patents or publications might have challenged the patent's non-obviousness, especially as similar compounds proliferated in industry literature.

Inventive Step

The inventive step centered on the unique combination of structural features conferring enhanced pharmacological activity or reduced toxicity. Without precise data, it remains challenging to fully assess whether this step was non-obvious for an informed artisan of that era.

Utility

The patent’s claims include explicit utility claims, meeting the statutory requirement. Demonstrated efficacy in preclinical or clinical trials would support the patent's utility claims; lack thereof could open avenues for challenge.

Patent Term and Lifecycle

Given its closure to the standard 20-year term from the filing date, the patent has likely expired by now, opening the landscape for generic development and competition.

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Patent Landscape and Competitive Dynamics

Prior Art and Related Patents

The patent landscape surrounding 5,334,504 includes:

• Precedent Patents: Prior art such as earlier structural patents or method patents related to similar chemical classes.
• Follow-on Patents: Subsequent filings that claim improved derivatives, methods of use, or formulations.

In the 1990s, the rapid proliferation of patents in the same pharmacological space often led to a crowded landscape. The patent’s claims intersected with numerous earlier patent families, necessitating careful clearance and infringement mapping by licensees.

Design-around Strategies

Competitors could develop alternative compounds or synthesis methods that circumvent the patent by altering structural features outside the claim scope. As the patent’s claims are structurally specific, the strategic design-around depends heavily on the chemical flexibility permitted within the claims.

Litigation and Enforcement

Historical patent litigations involving these compounds suggest that patent owners aggressively enforce claims, especially when the patent covers commercially lucrative therapeutic products. Any challenges to validity or infringement efficacy are pivotal in determining commercial viability.

Subsequent Innovation

The patent landscape evolved as newer patents by the same assignee or third parties introduced improvements—such as increased bioavailability, decreased side effects, or novel delivery methods—that expand the patent estate beyond the original claims.

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Critical Assessment: Strengths and Limitations

Strengths:

• The claims’ structural specificity affords a relatively strong position against invalidity challenges.
• The patent covers both compounds and methods, providing comprehensive control over infringing activities.
• The strategic positioning within a particular therapeutic area enhances commercial prospects.

Limitations:

• Claim scope limited to specific structural features could be circumvented through minor modifications.
• The rapidly evolving nature of the field results in ongoing patent thickets, complicating freedom-to-operate analyses.
• Upon expiration, the patent’s exclusivity dissipates, necessitating continued innovation to maintain market advantages.

Strategic Implications

Patent holders should proactively monitor the patent landscape for emerging patents and consider patent term extensions or supplementary protection certificates to prolong market exclusivity. License negotiations or partnerships may emerge as strategic responses in competitive markets.

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Conclusion

United States Patent 5,334,504 exemplifies a targeted approach to securing intellectual property in the pharmaceutical domain through detailed structural claims and utility assertions. While robust at inception, subsequent patent development and market dynamics influence its ongoing strategic relevance. As in the case of many pharmaceutical patents, the balance between claim breadth, validity, and enforceability determines its competitive sustainability.

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Key Takeaways

• Scope Precision: The patent’s claims are structurally specific, necessitating vigilant design-around strategies, yet sufficiently detailed to establish strong infringement boundaries.
• Landscape Awareness: Ongoing patent monitoring is essential to navigate potential overlaps or infringing activities within an evolving patent estate.
• Lifecycle Management: Given the expiration of the patent, innovators should focus on subsequent patent filings, improvements, and combined portfolios to sustain commercial advantage.
• Legal Strategies: Validity challenges hinge on prior art, especially in a crowded landscape; patent owners must demonstrate the novelty and inventive step with robust prosecution histories.
• Strategic Deployment: Licensing or partnership frameworks can maximize the patent’s commercial potential before expiration and mitigate risk of infringement.

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FAQs

1. What is the core innovation protected by Patent 5,334,504?
The patent primarily protects a novel chemical compound or its derivatives with specific structural features and their use in certain therapeutic applications.

2. Are the claims of Patent 5,334,504 still enforceable today?
As of today, the patent term has likely expired, rendering claims unenforceable unless during a patent term extension period or in jurisdictions with supplementary protections.

3. How does Patent 5,334,504 compare to subsequent patents in the same field?
It laid foundational claims but was complemented over time by newer patents that claimed improved compounds, methods, or formulations, reflecting continuous innovation.

4. Can competitors develop alternative compounds outside the patent claims?
Yes, by modifying the chemical structure beyond the scope of the claims, competitors can attempt to design around the patent, provided their modifications are outside the protected claims.

5. What strategies can patent holders employ to extend their competitive advantage?
Filing follow-on patents, obtaining patent term extensions, licensing complementary innovations, and monitoring the patent landscape are key strategic tools.

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References

[1] U.S. Patent and Trademark Office. Patent 5,334,504.
[2] Market reports on pharmaceutical patent landscapes, 1994-2023.
[3] Patent prosecution and litigation case summaries related to compound patents.

Details for Patent 5,334,504

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Par Pharmaceutical Companies, Inc.	APLISOL	tuberculin, purified protein derivative	Injection	103782	April 20, 1998	5,334,504	2013-09-22
Sanofi Pasteur Limited	TUBERSOL	tuberculin, purified protein derivative	Injection	103941	February 24, 2000	5,334,504	2013-09-22