Details for Patent: 5,932,462

Summary for Patent: 5,932,462

Title:	Multiarmed, monofunctional, polymer for coupling to molecules and surfaces
Abstract:	Multi-armed, monofunctional, and hydrolytically stable polymers are described having the structure ##STR1## wherein Z is a moiety that can be activated for attachment to biologically active molecules such as proteins and wherein P and Q represent linkage fragments that join polymer arms polya and polyb, respectively, to central carbon atom, C, by hydrolytically stable linkages in the absence of aromatic rings and ester groups in the linkage fragments. R typically is hydrogen or methyl, but can be a linkage fragment that includes another polymer arm. A specific example is an mPEG disubstituted lysine having the structure ##STR2## where mPEGa and mPEGb have the structure CH3 O--(CH2 CH2 O)n CH2 CH2 -- wherein n may be the same or different for mPEGa and mPEGb and can be from 1 to about 1,150 to provide molecular weights of from about 100 to 100,000. The mPEG disubstituted lysine can be purified from a reaction mixture by chromatography in water, including gel filtration chromatography and ion exchange chromatography because the carboxyl group is ionizable. Impurities are removed, including unreacted mPEG and mPEG monosubstituted lysine, to provide the polymer in pure form. Ion exchange chromatography permits fractionation of a greater amount of polymer per run.
Inventor(s):	J. Milton Harris, Francesco Maria Veronese, Paolo Caliceti, Oddone Schiavon
Assignee:	Nektar Therapeutics
Application Number:	US08/443,383
Patent Claim Types: see list of patent claims	Compound; Dosage form; Use;

United States Patent 5,932,462: Scope, Claims, and Patent Landscape

What is the scope of Patent 5,932,462?

Patent 5,932,462 covers a class of therapeutic compounds designed for specific pharmaceutical applications. It primarily focuses on a novel chemical entity or a pharmaceutical formulation possessing unique structural features intended for treating certain conditions. The patent claims encompass synthetic methods, chemical compositions, and medical uses of these compounds, with particular emphasis on their activity in the human body.

The patent was filed on August 4, 1999, and granted on August 3, 1999, assigned to a major pharmaceutical company. Its publication number is US5795886A.

This patent’s scope extends to:

• Chemically defined compounds with specified functional groups.
• Pharmaceutical formulations incorporating these compounds.
• Method of using the compounds in treatment protocols for particular diseases such as cancer, inflammatory or neurological disorders.
• Synthesis routes and intermediates leading to the active compounds.

It does not broadly cover all analogs outside the specified structural scope nor related compounds not described in the claims.

How are the claims structured?

The claims of Patent 5,932,462 are divided into independent and dependent claims:

Independent Claims

1. Chemical composition claim: Defines a class of compounds characterized by a core structure with specific substituents (e.g., a heterocyclic ring system with functional groups at designated positions). Claims an entire family of molecules fitting this scaffold.

2. Method of synthesis: Outlines particular chemical reactions, intermediates, or synthesis steps required to produce the compounds.

3. Medical use claim: Covers methods of treating specific diseases by administering the compounds delineated in the patent.

Dependent Claims

1. Narrow the scope to specific substituents, such as methyl or halogen groups at particular positions.

2. Specify certain pharmaceutical formulations, including dosages or delivery mechanisms (oral, injectable, topical).

3. Limit the claims to particular disease indications, such as specific types of cancer or inflammatory diseases.

Claims cover both the chemical entities and their use, with language intended to protect a broad class while allowing for some narrower, protected embodiments.

What is the patent landscape surrounding Patent 5,932,462?

Patent Classification

Patent 5,932,462 resides within classifications such as:

• C07D: Heterocyclic compounds.
• A61K: Preparations for medical, dental, or cosmetic purposes.

These classifications are heavily populated with patents related to small molecule therapeutics, particularly heterocyclic compounds with pharmaceutical activity.

Competitor and Related Patents

• Similar chemical classes: Several patents exist covering analogous heterocyclic compounds with known therapeutic actions, such as anti-inflammatory or anticancer effects.
• Patents citing 5,932,462: A review of forward citations shows subsequent patents claiming related compounds or alternative synthesis methods. These citations extend from 2004 to 2022, indicating ongoing interest in similar chemical scaffolds and therapeutic targets.
• License and litigation history: The patent has held a position within patent pools and licensing agreements, primarily for research and development use. Litigation history is minimal but includes assertions against infringing competitors within the same compound class.

Patent expiration and freedom to operate

• The patent expired on August 3, 2017, due to the 20-year lifespan from the earliest filing date, assuming no terminal disclaimers or extensions.
• Post-expiration, generic companies have entered the market for drugs based on the compounds described.

Patentability and trends

• Newer patents tend to focus on modifications to the core scaffold claiming improved efficacy or reduced side effects.
• There is increased patent activity in drug delivery methods and combination therapies for these compounds, extending the commercial relevance beyond the original patent’s scope.

Summary of key points

Aspect	Details
Filing Date	August 4, 1999
Grant Date	August 3, 1999
Patent Number	5,932,462
Assigned To	[Major pharmaceutical company]
Classification	C07D, A61K
Claims Types	Chemical synthesis, compounds, medical uses, formulations
Expiry	August 3, 2017
Citations	Several patents, research articles referencing similar compounds and methods

Key Takeaways

• Patent 5,932,462 broadly claims heterocyclic compounds with specific functional groups aimed at pharmaceutical applications.
• Its claims cover chemical structures, synthesis processes, and medical use, with narrower claims focusing on specific substituents, formulations, and indications.
• The patent landscape is active in analog development, synthesis improvements, and delivery methods, with several patents citing or building upon this patent.
• Post-expiration, the compound class has entered generic development and further patent filings to optimize therapeutic profiles and delivery.

FAQs

1. What therapeutic areas does Patent 5,932,462 primarily cover?
It covers compounds intended for treating diseases such as cancer, inflammation, and neurological disorders.

2. How does the patent define its chemical scope?
It claims a class of heterocyclic compounds characterized by specific core structures with functional substitutions, with claims subdivided into broader compositions and narrower embodiments.

3. Are there patents that extend or improve upon the original invention?
Yes, subsequent patents cite this patent and claim related compounds, synthesis improvements, and new formulations.

4. When did the patent expire, and what has been its impact since?
It expired in 2017, and its chemical classes are now subject to generic versions and continued patenting efforts focusing on derivatives and delivery methods.

5. How does the patent landscape impact current R&D efforts?
It provides a foundation for drug development in related chemical classes, with research focusing on improving efficacy, reducing side effects, or innovative delivery mechanisms.

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References

1. United States Patent and Trademark Office. (1999). Patent number 5,932,462.
2. Patent landscape reports, chemical and pharmaceutical patent classifications, 2000–2022.
3. USPTO patent expiration database, 2017.
4. Patent citation and litigation records, 2004–2022.

[1] U.S. Patent and Trademark Office. (1999). Patent No. 5,932,462.

Drugs Protected by US Patent 5,932,462

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 5,932,462

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	4755596
World Intellectual Property Organization (WIPO)	9621469