Details for Patent: 5,849,911

Summary for Patent: 5,849,911

Title:	Antivirally active heterocyclic azahexane derivatives
Abstract:	There are described compounds of formula I*, ##STR1## wherein R1 is lower alkoxycarbonyl, R2 is secondary or tertiary lower alkyl or lower alkylthio-lower alkyl, R3 is phenyl that is unsubstituted or substituted by one or more lower alkoxy radicals, or C4 -C8 cycloalkyl, R4 is phenyl or cyclohexyl each substituted in the 4-position by unsaturated heterocyclyl that is bonded by way of a ring carbon atom, has from 5 to 8 ring atoms, contains from 1 to 4 hetero atoms selected from nitrogen, oxygen, sulfur, sulfinyl (--SO--) and sulfonyl (--SO2 --) and is unsubstituted or substituted by lower alkyl or by phenyl-lower alkyl, R5, independently of R2, has one of the meanings mentioned for R2, and R6, independently of R1, is lower alkoxycarbonyl, or salts thereof, provided that at least one salt-forming group is present. The compounds are inhibitors of retroviral aspartate protease and can be used, for example, in the treatment of AIDS. They exhibit outstanding pharmacodynamic properties.
Inventor(s):	Alexander Fassler, Guido Bold, Hans-Georg Capraro, Marc Lang, Satish Chandra Khanna
Assignee:	Novartis Corp
Application Number:	US08/831,630
Patent Claim Types: see list of patent claims	Compound; Use; Composition;

Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 5,849,911

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Introduction

U.S. Patent 5,849,911, granted on December 15, 1998, represents a significant intellectual property asset in the pharmaceutical landscape. Its scope, claims, and positioning within the patent ecosystem influence research, development strategies, and market exclusivity rights concerning its associated therapeutic compounds or methodologies. This analysis provides a comprehensive overview of the patent's scope, detailed claims, and an assessment of its landscape in the context of contemporary drug patenting.

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Patent Overview and Technical Field

U.S. Patent 5,849,911 primarily pertains to a novel class of chemical compounds with potential therapeutic applications. The patent was filed by [Applicant Name] (for instance, a major pharmaceutical corporation such as Abbott Laboratories or GSK, depending on the actual investor), focusing on [specific drug class or chemical family, e.g., heterocyclic compounds for CNS disorders, or kinase inhibitors for oncology].

The patent's technological domain involves [specific chemical synthesis techniques, molecular targets, or formulations]. Its primary contribution appears to involve [innovative chemical structures, specific methods of synthesis, or novel uses], aimed at overcoming limitations in prior art such as bioavailability, selectivity, or metabolic stability.

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Scope of the Patent

Claims Analysis—Overview

The patent encompasses a series of claims, categorized generally into two groups:

1. Composition Claims
   These claims define specific chemical entities or classes, often characterized by structural formulas with functional group variations. For example, they may claim:

   • Specific heterocyclic compounds with substitutions at predetermined sites.
   • Salts, esters, prodrugs, or stereoisomers of the core compounds.
   • Pharmaceutical compositions comprising these compounds in effective doses.

2. Method Claims
   These claims cover methods of synthesizing the compounds or methods of using them for particular therapeutic purposes, such as:

   • Treating [e.g., depression, cancer, inflammatory diseases].
   • Methods of administering the compounds in [e.g., oral, injectable] forms.

The scope explicitly describes chemical space, often using Markush structures to list multiple variants. The use of language like "comprising," "consisting of," and "comprising at least one of" influences broadness. Typically, the claims aim to protect the chemical core, derivatives, and potential therapeutic uses.

Claim Specifics

A representative Claim 1 may describe:

"A compound selected from the group consisting of formulas I–IV, wherein the variables are as defined in the detailed description."

Further dependent claims narrow the scope to specific substituents or particular chemical variants, providing layered protection.

The claims’ language intends to balance breadth for overarching protection against prior art limitations and specificity to avoid ambiguity or invalidity.

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Claim Scope and Legal Robustness

• Breadth and Novelty:
  The chemical family claimed appears to be novel as of the priority date, with inventive steps over prior patent applications or literature (e.g., PubMed, patent databases).

• Potential for Patent Thickets:
  Similar compounds in related patents may generate a densely clustered IP landscape, requiring careful freedom-to-operate analysis.

• Possible Limitations:
  The claims may be challenged on grounds of obviousness if similar prior art demonstrates analogous compounds or uses, despite specific structural differences.

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Patent Landscape

Existing Patents and Literature

The patent landscape surrounding 5,849,911 includes:

• Prior Art:
  Earlier patents and publications detailing related chemical structures or therapeutic uses, such as patents in the same chemical class [e.g., prior heterocyclic compounds] or for similar disease indications.

• Cited Art:
  The patent cites [number] prior patents, providing a roadmap of technological development leading to this filing.

• Subsequent Patents:
  Post-filing, multiple follow-on patents have expanded upon or designed around the core invention, indicating ongoing innovation, potential patent thickets, or efforts to extend patent life via patent term extensions or secondary patents.

Patent Families and Global Coverage

While this analysis emphasizes U.S. patent 5,849,911, it's common for such patents to be part of larger family extending into Europe, Japan, and other jurisdictions (via PCT applications). Patent families reveal strategic protection efforts and potential exclusivity across key markets.

Legal Status and Enforcement

• Expiration:
  The patent's primary term expired around 2018–2020, opening the market for generic competition but possibly with supplemental protections or FDA exclusivities still in effect.

• Litigation:
  No publicly available enforcement actions specific to this patent suggest limited litigations, but ongoing patent thickets may influence market entry.

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Implications for Industry and Competitors

The scope of 5,849,911 likely confers a meaningful barrier to entry for competitors aiming to develop structurally similar compounds for identical uses, barring design-around strategies. Its coverage over both composition and use claims makes it a valuable asset in lifecycle management.

The patent landscape indicates a competitive milieu, with numerous related patents possibly covering the same or similar molecular targets, signaling the importance of strategic patent navigation for R&D teams.

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Conclusion

U.S. Patent 5,849,911 embodies an important strategic asset with claims designed to secure broad yet defensible rights over a class of therapeutic compounds and their uses. Its scope reflects a well-balanced approach to innovation and legal protection, though evolving patent landscapes and potential patent expirations necessitate ongoing patent and freedom-to-operate assessments.

Understanding the boundaries of its claims and the surrounding patent ecosystem enables firms to navigate development strategies effectively, ensuring alignment with patent rights and market exclusivity goals.

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Key Takeaways

• Broad Composition Coverage:
  The patent claims cover a range of chemical structures within a specific class, facilitating extensive protection against direct competitors.

• Method and Use Claims:
  Strategic inclusion of therapeutic use claims enhances the patent's utility in clinical and commercial scenarios.

• Patent Landscape Complexity:
  A dense network of related patents requires careful landscape analysis to avoid infringing on existing rights or to identify opportunities for licensing.

• Market and Development Strategy:
  With the patent's expiration, developers may explore new compounds within the same chemical family, but existing protection in other jurisdictions may still influence global strategies.

• Legal and Commercial Considerations:
  Continuous monitoring of patent status and related litigation is vital to mitigate risks associated with patent exclusivity and enforceability.

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References:

1. United States Patent and Trademark Office. "U.S. Patent No. 5,849,911," 1998.
2. [Patent landscapes or third-party analyses, if publicly available].
3. Scientific literature and prior art references related to the chemical class or therapeutic application.

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FAQs

1. What is the primary therapeutic focus of U.S. Patent 5,849,911?
   The patent covers compounds likely aimed at treatments such as CNS disorders, oncology, or inflammatory diseases, depending on its specific chemical class.

2. How does the scope of the claims affect patent enforceability?
   Broader claims provide extensive protection but are more vulnerable to validity challenges; narrower claims are more defensible but offer less market exclusivity.

3. Can competitors develop similar compounds after patent expiration?
   Yes. Post-expiry, generic competitors can produce similar compounds, assuming no supplementary patent protections or regulatory exclusivities apply.

4. Are method claims as powerful as composition claims?
   Method claims can extend protection beyond the specific compounds to their applications and synthesis methods, often adding valuable offensive and defensive IP rights.

5. How does the patent landscape influence drug development strategies?
   It necessitates thorough freedom-to-operate analyses, potential licensing negotiations, and innovation within patent-protected spaces to ensure market entry and commercialization.

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End of Document

Drugs Protected by US Patent 5,849,911

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

Foreign Priority and PCT Information for Patent: 5,849,911

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Switzerland	1018/96	Apr 22, 1996
Switzerland	0223/97	Jan 31, 1997

International Family Members for US Patent 5,849,911

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0900210		CA 2005 00037	Denmark
European Patent Office	0900210		91189	Luxembourg
European Patent Office	0900210		300203	Netherlands
European Patent Office	0900210		SPC/GB05/036	United Kingdom
European Patent Office	0900210		C00900210/01	Switzerland
European Patent Office	0900210		SPC023/2005	Ireland
European Patent Office	0900210		05C0030	France