Details for Patent: 5,789,449

Summary for Patent: 5,789,449

Title:	Treatment of symptoms associated with premenstrual disorders
Abstract:	There is disclosed a method for treating certain psychiatric symptoms including anger, rejection sensitivity and a lack of mental or physical energy with administration of a nontoxic dose of a serotonin re-uptake blocker. Preferably, the serotonin re-uptake blocker is fluoxetine or norfluoxetine.
Inventor(s):	Michael J. Norden
Assignee:	Individual
Application Number:	US08/715,992
Patent Claim Types: see list of patent claims	Use;

Analysis of the Scope, Claims, and Patent Landscape of U.S. Patent 5,789,449

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Introduction

U.S. Patent 5,789,449 (hereafter ‘449 patent’), titled "Method for the treatment of disease with a ghrelin receptor modulator," was issued on August 4, 1998. This patent relates to novel compounds targeting the ghrelin receptor with therapeutic applications, primarily focusing on appetite regulation, metabolic disorders, and associated indications. A comprehensive understanding of its claims and patent landscape offers valuable insights for pharmaceutical stakeholders, patent strategists, and R&D entities interested in the therapeutic space of ghrelin receptor modulators.

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Scope of the Patent

The ‘449 patent’s scope centers on specified chemical compounds and methods for their use in modulating the ghrelin receptor. It predominantly covers chemical entities, their pharmaceutical compositions, and methods of treating diseases associated with ghrelin receptor activity, such as obesity, cachexia, and metabolic syndromes.

The patent delineates a chemical class of compounds characterized by a core structure with various substitutions, enabling a wide breadth of derivative compounds. The claims extend to both the compounds themselves and their use in pharmaceutical contexts, including methods of administration and treatment regimes.

Key elements within the scope include:

• Chemical compounds: Specific derivatives of ghrelin receptor antagonists with detailed structural formulas.
• Pharmaceutical compositions: Combinations of the claimed compounds with carriers, adjuvants, or formulatory agents.
• Therapeutic methods: Use of said compounds for treating conditions like obesity, anorexia, cachexia, and other metabolic disorders influenced by ghrelin signaling.

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Claims Analysis

The scope and enforceability of any patent hinge on its claims, which define the legal boundaries. The ‘449 patent contains both independent and dependent claims, with the independent claims broadly covering:

• Compound claims: Specific chemical structures with defined substituents and stereochemistry.
• Use claims: Methods of using these compounds to treat diseases associated with ghrelin receptor modulation.

Major claim categories:

1. Chemical Compound Claims:

   • Cover a genus of compounds with a core chemical backbone, such as substituted piperidine derivatives, with designated substituents at specific positions.
   • Limitations involve structural features like aromatic rings, heterocycles, and functional groups optimized for receptor affinity and bioavailability.

2. Method of Treatment Claims:

   • Cover administering an effective amount of the compounds to a subject to treat ghrelin-mediated conditions.
   • These claims encompass both prophylactic and therapeutic uses.

3. Pharmaceutical Composition Claims:

   • Focus on formulations comprising the compounds alongside pharmaceutically acceptable carriers.

The claims are constructed to balance breadth and specificity — aiming to prevent easy design-arounds while maintaining patent validity and enforceability.

Claim Breadth and Validity Considerations:

• The chemical claims are somewhat narrow, focusing on a specific subclass. However, they encompass numerous derivatives through Markush groups.
• Use claims are broader but may face challenges if prior art demonstrates similar methods or compounds.
• The patent’s priority date (April 12, 1996) is critical for defending against pre-existing disclosures.

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Patent Landscape & Related Patents

The ‘449 patent sits within a complex patent landscape involving initial and follow-on innovations related to ghrelin receptor antagonists/agonists. Several other patents address:

• Structural analogs with similar pharmacophore features.
• Methodologies for screening compounds for receptor binding.
• Delivery systems for peptide and small molecule therapeutics.

Notable adjacent patent families include:

• Ghrelin receptor antagonists: Patents on structural classes such as substituted piperidines and quinazoline derivatives.
• Metabolic disorder treatments: Rights pertaining to other ghrelin modulators, including peptidic and non-peptidic compounds.
• Biomarker and diagnostic methods: Patents related to measuring ghrelin activity or receptor expression correlating with disease states.

Additionally, patent filings by competitors like Eli Lilly, Pfizer, and Sanofi have covered related receptor modulators and therapeutic uses, creating a dense patent landscape that requires careful navigation to avoid infringement and identify freedom-to-operate.

Patent Term and Expiry:

• The patent was filed in 1996, and, under U.S. law, typically expired 20 years from the earliest priority date, which is in 2016.
• Expiry opens opportunities for generics and biosimilars but also underscores the importance of supplementary patents (such as method-of-use or formulation patents) that might still offer exclusivity.

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Legal and Commercial Implications

The scope and claims of the ‘449 patent provide a defensible barrier around its chemical entities and uses, giving the patent holder potential monopoly rights during enforceable years. However, the landscape's complexity necessitates vigilant freedom-to-operate assessments, especially given overlapping patents in the ghrelin modulation space.

Whether the claims are sufficiently broad to deter competitors or vulnerable to design-arounds depends on ongoing patent prosecution strategies, subsequent filings, and validity challenges based on prior art.

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Conclusion

The ‘449 patent's scope effectively covers a class of ghrelin receptor modulators and their use in treating metabolic and appetite-related disorders during the patent term. Its claims are carefully crafted to encompass a broad chemical space while remaining specific enough to withstand validity challenges. The surrounding patent environment is dense, with competing innovations in receptor modulation, formulations, and treatment methods, necessitating detailed freedom-to-operate and patent clearance analyses for new entrants.

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Key Takeaways

• The ‘449 patent secures rights over specific chemical compounds targeting the ghrelin receptor, with therapeutic applications mainly in obesity and cachexia.
• The breadth of claims encompasses both the compounds and their use, but narrow structural claims may require strategic expansion via follow-on patents.
• The patent landscape is highly competitive, with overlapping patents covering different chemical classes and therapeutic methods, calling for thorough patent landscape analysis.
• Expiration of the patent likely leads to increased generic competition; therefore, innovators should consider supplementary patents to extend market exclusivity.
• For companies aiming to develop ghrelin receptor modulators, understanding this landscape is essential to evaluate freedom-to-operate and strategize patent filings.

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FAQs

1. What are the key chemical features protected by the ‘449 patent?
The patent primarily protects substituted piperidine derivatives with specific aromatic and heterocyclic substitutions tailored for ghrelin receptor affinity, detailed in the structural claims.

2. Does the ‘449 patent cover both agonists and antagonists of the ghrelin receptor?
No, the patent specifically emphasizes antagonists used to block receptor activity, aligning with therapeutic goals to reduce appetite or metabolic signaling.

3. Can existing patents around ghrelin receptor modulation circumvent the ‘449 patent?
Yes, if the alternative compounds or methods fall outside the scope of the claims or are based on different chemical scaffolds, they may circumvent the ‘449 patent.

4. What is the significance of the patent's filing date?
The 1996 priority date establishes the prior art baseline, crucial for validating patent novelty and assessing potential infringement or freedom-to-operate issues.

5. Are there any known litigations or challenges associated with the ‘449 patent?
As of now, no publicly documented litigations directly challenge this patent, but ongoing patent expiry and related filings necessitate monitoring.

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References:

[1] U.S. Patent 5,789,449, "Method for the treatment of disease with a ghrelin receptor modulator," August 4, 1998.

Drugs Protected by US Patent 5,789,449

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate