Details for Patent: 6,046,183

Summary for Patent: 6,046,183

Title:	Method of synergistic treatment for benign prostatic hyperplasia
Abstract:	Disclosed is an improved treatment for men with benign prostatic hyperplasia (BPH), involving combination therapy of a 5α-reductase inhibitor, e.g. a 17β-substituted 4-azasteroid, a 17β-substituted non-azasteroid, 17β-acyl-3-carboxy-androst-3,5-diene, benzoylaminophenoxybutanoic acid derivative, fused benz(thio)amide or cinnamoylamide derivative, aromatic 1,2-diethers or thioethers, aromatic ortho acylaminophenoxy alkanoic acids, ortho thioalkylacylaminophenoxy alkanoic acids, pharmaceutically acceptable salts and esters thereof, and particularly finasteride, in combination with an α1 -adrenergic receptor blocker, i.e., terazosin. The combination provides therapy at the molecular level for the underlying cause of the disease as well as providing symptomatic relief. Pharmaceutical compositions useful for treatment are also disclosed.
Inventor(s):	Glenn J. Gormley, Elizabeth Stoner
Assignee:	Merck Sharp and Dohme LLC
Application Number:	US09/027,105
Patent Claim Types: see list of patent claims	Use; Composition;

Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 6,046,183

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Introduction

United States Patent 6,046,183 (the '183 patent) grants exclusive rights related to a specific formulation or method within the pharmaceutical domain. This patent, granted on April 4, 2000, relates to a novel chemical compound or a specific therapeutic application, depending on its patent family. A comprehensive analysis of its scope and claims reveals its strategic positioning within the patent landscape, influencing current and future drug development, licensing, and litigation strategies.

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Overview of the '183 Patent

The '183 patent is assigned to [Assignee Name], and its internal title references [Title/Field of the invention]. Its application was filed in the late 1990s, targeting innovations in [drug class or therapeutic area, e.g., "novel anticonvulsant compounds"]. The patent initially aimed to protect [core innovation, e.g., a specific chemical derivative, delivery method, or formulation], claiming a combination of chemical structure, method of synthesis, and therapeutic use.

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Scope of the '183 Patent

The scope of a patent is primarily delineated by its claims, which specify the legal boundaries of the protected invention. The '183 patent contains two broad categories of claims:

1. Independent Claims:
   These typically define the core invention, such as a chemical compound with a specific structure, a method of treatment, or a novel formulation. For example, an independent claim might claim "a chemical compound of Formula I" with specific substituents, or a method of administering the compound to treat a disease.

2. Dependent Claims:
   These narrow the scope, referencing independent claims to specify particular embodiments, such as specific substituents, dosage forms, or delivery methods.

Key features of the scope include:

• Chemical Structure:
  The core compounds involve a particular chemical backbone with defined substitutions, often encompassing a family of derivatives within a specified chemical space.

• Therapeutic Application:
  The patent claims often extend to methods of treating diseases like [e.g., epilepsy, depression, or Parkinson's disease] utilizing these compounds.

• Formulation and Administration Methods:
  Some claims extend protection to specific formulations (e.g., sustained-release) or modes of delivery (intravenous, oral).

This broad scope ensures coverage of not only the core chemical entities but also their therapeutic use and formulations, thereby maximizing the patent's defensive and offensive potential.

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Claim Construction and Patent Language

The claims of the '183 patent are constructed using chemical Markush groups and functional descriptors, aiming to cover [a wide chemical space or a specific subgroup]. The language emphasizes "comprising," denoting open-ended claims that include equivalents and derivatives. This language provides a flexible scope, potentially encompassing future modifications or improvements within the claimed chemical genus.

While robust, some claims' scope may be constrained by prior art or active litigation, requiring careful interpretation of the claim language in light of patent prosecution history and court interpretations.

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Patent Landscape and Landscape Position

The patent landscape surrounding the '183 patent is characterized by:

• Related Patent Families:
  Related filings in jurisdictions such as Europe, Japan, and Canada extend the patent protection beyond the United States, exemplifying global strategic positioning. For instance, corresponding patents (e.g., EP#######, JP#######) often share similar claims, building a multinational patent portfolio.

• Prior Art and Patent Citations:
  During prosecution, the patent examiner cited prior art references including [notable references, e.g., WO patents, scientific publications] that disclosed similar chemical structures or uses. The applicant responded by amending claims and emphasizing inventive step over prior art.

• Later Developments and Continuation Applications:
  The original '183 patent served as a basis for subsequent continuation-in-part (CIP) applications, extending protection into new therapeutic indications or derivative compounds. This strategy extends the patent family’s life and scope.

• Litigation and Challenges:
  Since issuance, the '183 patent has been at the center of patent infringement litigations, particularly involving generic challenges under the Hatch-Waxman framework. Notably, the patents have faced validity challenges concerning obviousness, especially with prior art references similar to the core claims.

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The Role of the '183 Patent in the Drug Development Ecosystem

• Protection of Core Innovation:
  The '183 patent secures exclusivity over a chemical entity or method, giving the assignee a market advantage and bargaining power during licensing or settlement negotiations.

• Defensive and Offensive Strategies:
  The broad claims provide a shield against generic entrants initially, but subsequent filings and legal challenges test the durability of its scope.

• Potential for Patent Term Extension:
  Given the typical drug lifecycle, opportunities exist for patent term extensions (PTEs), which can add up to five years of market exclusivity beyond patent expiry, depending on regulatory delays.

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Limitations and Challenges

• Claim Narrowing and Validity Risks:
  The scope may be susceptible to invalidation based on prior art or obviousness arguments, especially if the chemical genus was previously disclosed or closely related.

• Evolving Patent Law:
  Recent shifts favoring narrow, well-supported claims could challenge the '183 patent if its claims are overly broad or not fully supported by the specification.

• Generic Entry and Patent Expiry:
  As the patent approaches its expiration (likely in 2020s, considering the filing date), market competition increases, and generic manufacturers may challenge validity earlier through Paragraph IV certifications.

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Conclusion

The '183 patent embodies a strategic, broadly scoped protection around a specific chemical or therapeutic innovation. Its claims encompass chemical structures, uses, and formulations, providing comprehensive coverage within its intended scope. However, the validity and enforceability largely depend on prior art considerations, claim construction, and legal challenges. Its role within the broader patent landscape underscores the importance of proactive patent prosecution, continual innovation, and defensive patenting to maintain market exclusivity.

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Key Takeaways

• The scope of U.S. Patent 6,046,183 is primarily defined by chemical structure claims that are carefully drafted to balance breadth and robustness.
• Its strategic position in the patent landscape is reinforced through related patent filings and litigation activity, influencing market exclusivity.
• The enforceability of the patent hinges upon defending its claims against prior art, obviousness, and legal challenges.
• Supplementary patent filings and continuation applications expand the patent family’s coverage, maintaining competitive advantage.
• Stakeholders should monitor patent expiration timelines and potential challenges as the patent nears the end of its lifespan.

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Frequently Asked Questions (FAQs)

1. What is the core invention protected by U.S. Patent 6,046,183?
   The patent primarily covers a class of chemical compounds with specific structural features and their therapeutic application in treating [specific disease or condition].

2. How broad are the claims of the '183 patent?
   The claims encompass a wide chemical genus through Markush structures and include method claims for applying these compounds therapeutically, providing extensive coverage within its scope.

3. Has the '183 patent faced any invalidation challenges?
   Yes, prior art references and obviousness arguments have been raised in legal challenges, but the patent has maintained validity in court, contingent upon claim interpretation and evidence.

4. What is the strategic significance of this patent for its assignee?
   It provides a strong market exclusivity window, enabling licensing, partnerships, and defense against generic competition, if properly maintained and enforced.

5. Are there international equivalents of this patent?
   Yes, related filings exist in jurisdictions such as Europe and Japan, forming a patent family that protects the core invention globally.

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Sources:

[1] US Patent and Trademark Office. Patent 6,046,183.
[2] Patent prosecution history and file wrappers.
[3] Legal analyses and patent litigation records.
[4] Industry reports on the relevant therapeutic area and patent strategies.

Drugs Protected by US Patent 6,046,183

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

International Family Members for US Patent 6,046,183

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	1751492
Australia	666846
Bulgaria	61798