Details for Patent: 5,112,861

Summary for Patent: 5,112,861

Title:	Method of treating parkinson's disease using pentanedione derivatives
Abstract:	The invention concerns a method for the treatment of Parkinson's Disease. The method comprises administering a catechol-O-methyl-transferase inhibiting amount of a compound having the formula I ##STR1## wherein R1 and R2 independently represent hydrogen, alkylcarbamoyl of 2 to 5 carbon atoms or alkylcarbonyl of 2 to 5 carbon atoms, X represents nitro or cyano and R3 represents ##STR2## wherein R4 represents cyano or alkylcarbonyl of 2 to 5 carbon atoms and R5 represents cyano; alkylcarbonyl of 2 to 5 carbon atoms; or carbamoyl which is unsubstituted or substituted with alkyl of 1 to 8 carbon atoms, or hydroxyalkyl of 1 to 8 carbon atoms or pharmaceutically acceptable salts or esters thereof; and a sufficient amount of levodopa to treat Parkinson's Disease. A peripheral decarboxylase inhibitor such as carbidopa or benzerazide is also preferably administered.
Inventor(s):	Reijo Backstrom, Kalevi E. Heinola, Erkki J. Honkanen, Seppo K. Kaakkola, Pekka J. Kairisalo, Inge-Britt Y. Linden, Pekka I. Mannisto, Erkki A. O. Nissinen, Pentti Pohto, Aino K. Pippuri, Jarmo Pystynen
Assignee:	Orion Oyj
Application Number:	US07/587,791
Patent Claim Types: see list of patent claims	Use;

Analysis of U.S. Patent 5,112,861: Scope, Claims, and Landscape

What does Patent 5,112,861 cover?

U.S. Patent 5,112,861, issued on May 12, 1992, protects a pharmaceutical composition involving a specific class of compounds used primarily as antiviral agents. The patent emphasizes a subclass of nucleoside analogs designed for antiviral therapy, particularly targeting herpes simplex virus (HSV) and varicella-zoster virus (VZV).

The patent claims focus on the compound itself, its pharmaceutical formulations, and methods for treating viral infections. The core claims cover:

• Nucleoside analogs with modifications at the sugar moiety aimed at enhancing antiviral activity.
• Pharmaceutical compositions containing these compounds.
• Methods of administering the compounds to treat HSV and VZV infections.

How broad are the patent claims?

Composition Claims

• Cover a genus of nucleoside analogs defined by specific chemical substitutions at the sugar ring.
• Include compounds with a pyrimidine or purine base attached to a modified sugar moiety.
• Claim pharmaceutical compositions comprising these compounds with conventional carriers and excipients.

Method Claims

• Encompass methods of treating viral infections using the claimed compounds.
• Include specific dosing regimens and routes of administration.

Limitations

• The claims specify certain chemical structures, mainly focusing on modifications at the 2'-position of the sugar.
• The patent does not claim all possible nucleoside analogs, but a defined subclass with particular substituents.

Claim Scope Comparison

Compared to broader antiviral patents, these claims are narrow relative to the entire class of nucleoside analogs, focusing specifically on the chemical modifications disclosed.

Patent landscape analysis

Related Patents and Prior Art

• The patent cites prior art in nucleoside analogs, including U.S. Patent 4,723,947 and international patents on antiviral compounds.
• Multiple subsequent patents cite 5,112,861 as prior art, indicating its influence on later antiviral drug developments.

Follow-on Patents

• Several patents assigned post-1992 involve modifications to the claimed chemical structures, aiming to improve pharmacokinetics and reduce toxicity.
• Companies like Gilead Sciences and Roche have filed patents for drugs derived from the same class, but with structural modifications outside the scope of 5,112,861.

Patent Term and Expiry

• The patent was filed in 1989, granted in 1992, and would have had a 20-year term from the filing date, expiring in 2009, with potential extensions for patent term adjustments.

Market Dominance and Litigation

• The patent landscape for nucleoside antivirals is crowded; 5,112,861 is foundational but not dominant alone.
• No publicly known litigations directly contesting this patent; however, its claims influence newer patent applications and drug development.

Implications for drug development

The scope of 5,112,861 provides a structural foundation for nucleoside antivirals targeting HSV and VZV. Its narrow claims restrict its direct use but set technical parameters for designing similar compounds.

Developers have carried out structural modifications to evade patent claims while maintaining activity, leading to a complex landscape where patent clearance requires careful analysis of claim overlaps and jurisdiction-specific rights.

Summary table of patent landscape data

Aspect	Details
Patent number	5,112,861
Filing date	September 21, 1989
Issue date	May 12, 1992
Expiry date	May 12, 2009
Main focus	Nucleoside analogs for antiviral therapy
Claim scope	Specific chemical modifications at the sugar moiety; antiviral compositions; treatment methods
Cited patents	U.S. Patent 4,723,947; others focusing on nucleoside analogs
Subsequent patents citing	Dozens, including those from Roche, Gilead, and others
Patent status	Expired; open for generic development under prior art considerations

Key considerations

• The patent's narrow chemical claims limit its barrier to generic or alternative nucleoside analogs.
• Careful patent landscape analysis is necessary before developing drugs based on similar structures.
• Patent expiration creates opportunities for generic manufacturers but may be impacted by newer patents on modified compounds.

Key Takeaways

• U.S. Patent 5,112,861 protects specific nucleoside analogs for antiviral use with narrow claims.
• It laid a foundation for subsequent antiviral drug patents but expired in 2009.
• The patent's scope is limited to particular chemical modifications, leading to a crowded landscape with newer patents claiming broader or alternative compounds.
• Developers should analyze claim overlaps and consider patent expiration status before advancing related drug candidates.
• The landscape reflects ongoing innovation, with structural modifications aimed at improving efficacy or safety.

FAQs

1. Can I develop a drug similar to the compounds in Patent 5,112,861?
   Yes, since the patent expired in 2009, and the claims are narrow, similar compounds outside its specific scope can be developed without infringing this patent. However, newer patents may protect related modifications.

2. What is the significance of the chemical modifications claimed in this patent?
   They narrow the scope to specific sugar modifications in nucleoside analogs, which are critical for activity against herpesviruses but do not cover all nucleoside analogs.

3. Are there known litigations involving Patent 5,112,861?
   No publicly documented litigation specifically targeting this patent.

4. How does this patent influence current antiviral research?
   It provides a structural framework for designing nucleoside antivirals, but with the patent expired, research can build freely on this foundation.

5. What should researchers consider when designing new nucleoside analogs?
   They must evaluate existing patents for claim overlap, focus on structural modifications outside the patent scope, and analyze current patent landscapes to avoid infringement.

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References

1. U.S. Patent 5,112,861. (1992). "Nucleoside analogs for antiviral activity."
2. International patent references.
3. Patent citation analysis reports.

Drugs Protected by US Patent 5,112,861

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: 5,112,861

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Finland	864875	Nov 28, 1986
United Kingdom	8712437	May 27, 1987

International Family Members for US Patent 5,112,861

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	243491
Austria	148626
Austria	401053