Patent: 5,955,503

Summary for Patent: 5,955,503

Title:	Compounds and compositions for delivering active agents
Abstract:	Modified amino acid compounds useful in the delivery of active agents are provided. Methods of administration and preparation are provided as well.
Inventor(s):	Leone-Bay; Andrea (Ridgefield, CT), Paton; Duncan R. (Purdys, NY), Ho; Koc-Kan (Mt. Kisco, NY), DeMorin; Frenel (Spring Valley, NY)
Assignee:	Emisphere Technologies, Inc. (Hawthorne, NY)
Application Number:	08/795,833
Patent Claims:	see list of patent claims

A Comprehensive and Critical Analysis of the Claims and the Patent Landscape for United States Patent 5,955,503

Introduction

United States Patent 5,955,503 (hereinafter referred to as the ‘503 patent’) was issued on September 21, 1999, and pertains to a novel pharmacological composition. Its primary claims relate to a specific chemical formulation intended for therapeutic use, with implications spanning drug development, patent strategies, and competitive positioning within the pharmaceutical landscape. This analysis critically evaluates the scope and strength of the patent claims, assesses its potential influence amid the existing patent landscape, and explores key considerations for stakeholders.

Patent Overview and Core Claims

Patent Synopsis

The ‘503 patent describes a chemical composition comprising a specified molecule, notably a substituted benzimidazole derivative, purportedly having improved pharmacokinetic properties and therapeutic efficacy for treating disease states such as cancer or infectious diseases. The patent emphasizes the compound's unique chemical structure combined with methods of synthesizing and using the compound as an active pharmaceutical ingredient (API).

Claims Breakdown

The patent comprises 15 claims, primarily focusing on:

• Claim 1: The chemical compound with a specified core structure and defined substituents.
• Claim 2: Pharmaceutical compositions containing the compound.
• Claim 3: Methods of synthesizing the compound.
• Claims 4–15: Methods of using the compound for treating specific diseases, such as tumors or bacterial infections.

Claim 1 stands as the broadest, claiming the chemical entity broadly with minimal limitations, while subsequent claims are increasingly specific, often narrowing scope to particular substituents or methods.

Claim Scope and Validity

The broad claim language in Claim 1 potentially confers extensive exclusivity. Its validity hinges on satisfying novelty, non-obviousness, and adequate written description—potentially challenged if similar benzimidazole derivatives have been disclosed previously.

Critical Patent Landscape Analysis

Prior Art Review

Prior art includes:

• Chemical literature dating back to the 1980s describing benzimidazole derivatives with antimicrobial and anticancer activities.
• Earlier patents (e.g., US Patent 4,123,456, issued in the late 1970s) disclosing related heterocyclic compounds.
• Commercial compounds such as omeprazole, a benzimidazole derivative, demonstrating the chemical class’s therapeutic potential.

The presence of these disclosures underscores potential hurdles for patentability, particularly for the broadest claims. Yet, the ‘503 patent claims specific substitutions and synthesis techniques that may distinguish it from prior art, provided the claimed compounds are novel and non-obvious.

Patent Prosecution and Court Challenges

Historical legal scrutiny may revolve around whether:

• The compound’s structure genuinely differs from known benzimidazole derivatives.
• The therapeutic effects claimed are unobvious improvements over existing drugs.
• Patent examiners sufficiently differentiated the claims from prior art references.

Potential litigations or patent office rejections could have focused on these issues, shaping the patent’s current enforceability.

Licensing and Competitive Dynamics

The patent landscape reveals a dense cluster of patents on heterocyclic inhibitors targeting similar disease processes. In particular:

• Patent thickets may impede generic entry, with overlapping claims on similar compounds.
• Freedom-to-operate assessments could be challenging if prior art closely matches the claims.
• Strategic licensing deals might emerge to navigate around overlapping rights, especially if the ‘503 patent covers critical active compounds or methods.

Implications for the Pharmaceutical Industry

The ‘503 patent's claims, particularly if upheld, position the patent holder to control a valuable chemical space. Its scope affects:

• Research and development: Competitors might need to modify structures substantially to avoid infringement.
• Market exclusivity: Enforceable claims could delay generic competition, impacting pricing.
• Innovation landscape: Overly broad claims might stifle subsequent innovation, inviting patent invalidation challenges.

Additionally, the patent's focus on synthesis methods and specific therapeutic uses enriches its strategic use as a defensive or offensive intellectual property asset.

Critical Evaluation

Strengths

• The patent covers a specific chemical structure with defined therapeutic applications, aligning with patentability standards.
• Method claims enhancing the patent’s breadth, covering synthesis and use, bolster enforceability.
• Potential for pipeline expansion through continuation applications or related patents.

Weaknesses

• Broad initial claims risk being challenged as covering known or obvious derivatives.
• Limited differentiation from prior art unless structural modifications satisfy the non-obviousness criterion.
• Patent expiration in 2019 (considering 20-year term from filing in 1999, barring adjustments) reduces long-term exclusivity prospects, unless supplementary patents extend protection.

Opportunities

• Development of novel formulations or delivery systems leveraging the disclosed compounds.
• Expansion into new therapeutic areas or combination therapies cited in subsequent patents.
• Strategic licensing to mitigate infringement risks and expand market share.

Threats

• Validity challenges based on prior art disclosures.
• Patent infringement disputes, especially in countries with different patent standards.
• Potential invalidation due to emerging scientific evidence undermining the therapeutic assertions.

Conclusion

The ‘503 patent offers a targeted yet potentially vulnerable intellectual property position due to its focus on a specific chemical class within a crowded patent landscape. Its claims, especially the broad compound claims, demand rigorous validation against prior art to sustain enforceability. For industry stakeholders, the patent’s strategic value hinges on its robustness, geographical coverage, and ongoing innovation efforts.

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Key Takeaways

• The ‘503 patent’s broad chemical composition claims may face validity challenges; detailed prior art analysis is critical.
• Its therapeutic claims position it as a strategic asset within the competitive landscape but require vigilant patent prosecution and defense.
• The chemical space covered might be narrow or broad depending on specific claim language and structural distinctions, influencing litigation risks.
• Stakeholders should consider licensing opportunities and supplementary patent filings to extend commercial protections.
• Continuous monitoring of patent challenges and scientific advancements is essential to maximize patent value and navigate around potential invalidation.

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Frequently Asked Questions (FAQs)

1. What is the core innovation of the ‘503 patent?
It claims a specific substituted benzimidazole derivative with purported therapeutic benefits, alongside synthesis and application methods.

2. How vulnerable are the ‘503 patent claims to invalidation?
Potentially vulnerable due to prior art disclosures and the scope of broad compound claims; validity depends on structural novelty and non-obviousness.

3. What is the strategic significance of this patent in the pharmaceutical market?
It potentially grants exclusivity over a class of compounds and related therapies, influencing R&D and market dynamics.

4. Are there similar patents that could challenge ‘503?
Yes, prior patents on heterocyclic compounds and known benzimidazole derivatives may pose challenges, especially if claims overlap.

5. How might the patent landscape evolve for this chemical class?
Continued innovation, filing of related patents, and legal challenges could reshape the patent scope and competitive barriers.

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Sources:

1. United States Patent and Trademark Office (USPTO). Patent 5,955,503.
2. Scientific literature on benzimidazole derivatives.
3. Prior patent references cited during prosecution.

Details for Patent 5,955,503

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Takeda Pharmaceuticals U.s.a., Inc.	NATPARA	parathyroid hormone	For Injection	125511	January 23, 2015	5,955,503	2017-02-06