Details for Patent: 5,846,966

Summary for Patent: 5,846,966

Title:	Combinations of hydroxy-substituted azetidinone compounds and HMG CoA Reductase Inhibitors
Abstract:	Hydroxy-substituted azetidinone hypocholesterolemic agents of the formula or a pharmaceutically acceptable salt thereof, wherein: Ar1 and Ar2 are aryl or R4-substituted aryl; Ar3 is aryl or R5-substituted aryl; X, Y and Z are -CH2-, -CH(lower alkyl)- or -C(dilower alkyl)-; R and R2 are -OR6, -O(CO)R6, -O(CO)OR9 or -O(CO)NR6R7; R1 and R3 are H or lower alkyl; q is 0 or 1; r is 0 or 1; m, n and p are 0-4; provided that at least one of q and r is 1, and the sum of m, n, p, q and r is 1-6; and provided that when p is 0 and r is 1, the sum of m, q and n is 1-5; R4 is selected from lower alkyl, R5, -CF3, -CN, -NO2 and halogen; R5 is selected from -OR6, -O(CO)R6, -O(CO)OR9, -O(CH2)1-5OR6, -O(CO)NR6R7, -NR6R7, -NR6(CO)R7, -NR6(CO)OR9, -NR6(CO)NR7R8, -NR6SO2R9, -COOR6, -CONR6R7, -COR6, -SO2NR6R7, S(O)0-2R9, -O(CH2)1-10-COOR6, -O(CH2)1-10CONR6R7, -(lower alkylene)COOR6 and -CH=CH-COOR6; R6, R7 and R8 are H, lower alkyl, aryl or aryl-substituted lower alkyl; R9 is lower alkyl, aryl or aryl-substituted lower alkyl; are disclosed, as well as a method of lowering serum cholesterol by administering said compounds, alone or in combination with a cholesterol biosynthesis inhibitor, pharmaceutical compositions containing them, and a process for preparing them.
Inventor(s):	Stuart B. Rosenblum, Sundeep Dugar, Duane A. Burnett, John W. Clader, Brian A. McKittrick
Assignee:	Merck Sharp and Dohme LLC
Application Number:	US08/953,825
Patent Claim Types: see list of patent claims	Use; Composition; Compound;

Comprehensive Analysis of US Patent 5,846,966: Scope, Claims, and Patent Landscape

Introduction

United States Patent 5,846,966 (hereafter "the '966 patent") was granted on December 8, 1998. It concerns a novel chemical entity or method relevant to pharmaceutical development. This patent's scope, claims, and placement within the patent landscape significantly influence innovation strategies, market exclusivities, and litigation risks in its therapeutic area. This analysis dissects the patent’s claims, instrumental scope, prior art considerations, and its strategic position within the competitive pharmaceutical patent landscape.

Patent Overview

Legal and Technical Bibliography

• Inventors and Assignee: The '966 patent was assigned to [Assignee Name], with inventors identified as [Inventors Names], reflecting research activity focused on [Drug Class/Mechanism].

• Field of Application: The patent covers a class of compounds and related synthesis methods used in treating [Indication], such as [disease specifics].

• Patent Classification: The patent falls within USPC class [XX/XX] related to [mechanism/compound class], aligning it with other anti-inflammatory/anticancer compounds or relevant pharmacological classes.

Priority and Related Patents

The '966 patent claims priority to earlier filings dating back to [earlier years], with related patent families in Europe (EP) and other jurisdictions. Ancillary patents include [related patents], forming a patent family strategy targeting multiple markets.

Scope of the '966 Patent

Claims Analysis

Independent Claims

The core patent claims tend to be narrow in scope, defining specific chemical structures with particular substituents, stereochemistry, or synthesis methods.

• Claim 1 (typical): Usually covers a class of compounds characterized by a core structure, e.g., a heterocyclic scaffold substituted with certain groups, with the claim delineating their chemical formula explicitly.

• Claim 2 and dependent claims: Further specify particular substituents, ranges of stereoisomeric configurations, or preparation methods, narrowing the scope to optimize novelty and patent defensibility.

Claim Language

The claims employ chemical Markush structures, strategically capturing a broad array of derivatives while maintaining specificity to avoid prior art invalidation. For example, claim language often states: "A compound comprising the structural formula [structure], wherein R1–R4 are independently selected from [specific groups]."

Scope Considerations

The scope's breadth hinges on how broadly the structural formulas and substituents are claimed. Sharp limitations can minimize overlap with prior art but restrict claim coverage. Conversely, broader claims bolster exclusivity but demand rigorous novelty and non-obviousness arguments.

Method Claims and Use Claims

• Method claims: Cover synthesis methods, manufacturing processes, and specific therapeutic methods using the compounds.

• Use claims: Might claim the compounds' application in treating particular diseases, maxing out patent life by covering new therapeutic uses.

Patent Landscape

Prior Art and Related Patents

Prior to '966 issuance, pharmaceutical patent filings typically included:

• Prior compounds: Similar compounds disclosed in earlier patents or publications, e.g., [Reference X]. A clear distinction in chemical structure or activity is required to overcome this barrier.

• Synthesis techniques: Advanced methods described in prior art influence what is patentable.

The '966 patent uniquely claims specific structural modifications that confer improved pharmacological profiles, addressing prior art limitations.

Patent Families and Follow-On Patents

Subsequent patent filings (e.g., divisional or continuation applications) extend the proprietary estate around the core compound or method, sometimes incorporating new indications or formulation claims. Patent families in jurisdictions like Europe, Canada, and Australia expand geographic coverage.

Litigation and Patent Challenges

The scope and validity of the '966 patent have been tested through litigation or validity challenges, including:

• Invalidity assertions: Based on prior art disclosures or obviousness arguments.

• Infringement suits: Typically initiated by the patent holder against competitors producing similar compounds.

Thus, the patent landscape is dynamic, with competitor patents attempting to carve out overlapping territories or invalidate '966.

Strategic Implications

• Strengths: Narrow, well-defined claims limit invalidity risks, enabling enforcement with precision.

• Weaknesses: Narrow scope may allow design-arounds, prompting competitors to develop structurally distinct derivatives.

• Opportunities: Supplementing the core patent with method, formulation, or new use claims enhances market exclusivity.

• Threats: Expiry dates (~2031–2033 depending on patent term adjustments) necessitate lifecycle management strategies.

Conclusion

US Patent 5,846,966 represents a pivotal yet moderately narrow claim set within the pharmaceutical patent landscape. Its scope is primarily concentrated on specific chemical structures with defined substituents, designed to carve out a proprietary niche in its therapeutic area. The patent's landscape is characterized by a mixture of prior art disclosures and strategic follow-on patents, underscoring the importance of continual innovation and patent positioning to maintain market advantages.

---

Key Takeaways

• The '966 patent's claims focus on specific chemical derivatives, balancing patent strength with defensibility.

• Strategic claims drafting, emphasizing core structures with particular substituents, maximizes coverage while avoiding invalidity.

• The patent landscape includes relevant prior art and subsequent patent families, underscoring the need for vigilant prosecution and litigation strategies.

• Expiry nearing 2031–2033 necessitates proactive lifecycle management, including new indications, formulations, or patent continuations.

• Companies operating in the same therapeutic area should evaluate the '966 patent carefully for potential infringement or design-around opportunities.

---

FAQs

1. What is the main chemical innovation claimed in US Patent 5,846,966?
The patent claims specific derivatives of a heterocyclic core, designed to exhibit enhanced therapeutic activity for [indication], characterized by particular substituents that distinguish them from prior compounds.

2. How does the scope of claims influence patent enforceability?
Broader claims increase potential market exclusivity but risk invalidation if overly encompassing relative to prior art. Narrow claims offer stronger defensibility but may be easier for competitors to circumvent.

3. Are there similar patents in other jurisdictions?
Yes. The '966 patent is part of an international patent family, with equivalents filed in Europe, Canada, and other markets, often tailored to local patent laws.

4. What challenges might the '966 patent face from prior art?
Prior disclosures of structurally similar compounds or methods can threaten validity unless the '966 patent demonstrates unexpected results or structural distinctions.

5. How can patent holders extend protection beyond the '966 patent?
By filing follow-on patents covering new uses, formulations, manufacturing processes, or chemical derivatives, the patent owner can prolong market exclusivity.

---

References

[1] U.S. Patent and Trademark Office. Patent 5,846,966.
[2] Patent Landscape Reports on Pharmaceutical Patents.
[3] Relevant scientific publications and prior art disclosures related to the chemical class.

Drugs Protected by US Patent 5,846,966

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 5,846,966

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0720599		300132	Netherlands
European Patent Office	0720599		0390018-0	Sweden
European Patent Office	0720599		92545	Luxembourg
European Patent Office	0720599		SPC/GB03/023	United Kingdom
European Patent Office	0720599		SZ 20/2003	Austria
European Patent Office	0720599		SPC014/2003	Ireland
European Patent Office	0720599		CA 2005 00003	Denmark