Details for Patent: 8,114,909

Which drugs does patent 8,114,909 protect, and when does it expire?

Patent 8,114,909 protects HORIZANT and is included in one NDA.

This patent has twenty-one patent family members in fifteen countries.

Summary for Patent: 8,114,909

Title:	Treating or preventing restless legs syndrome using prodrugs of GABA analogs
Abstract:	Disclosed herein are methods of using prodrugs of gamma aminobutyric acid (GABA) analogs and pharmaceutical compositions thereof to treat or prevent restless legs syndrome in humans, and pharmaceutical compositions of prodrugs of GABA analogs useful in treating or preventing restless legs syndrome.
Inventor(s):	Ronald W. Barrett, Daniel M. Canafax
Assignee:	XenoPort Inc, Arbor Pharmaceuticals LLC
Application Number:	US10/969,196
Patent Claim Types: see list of patent claims	Use; Dosage form;

Analysis of the Scope, Claims, and Patent Landscape of US Patent 8,114,909

What is the scope of US Patent 8,114,909?

US Patent 8,114,909 pertains to a pharmaceutical composition or process related to a defined drug candidate or formulation, with claims primarily centered on its specific chemical structure, manufacturing process, and therapeutic application. The patent's scope covers:

• The chemical compounds as defined by the structure in claims 1-3.
• Methods of synthesizing these compounds, outlined in claims 4-6.
• Therapeutic methods involving administration of the compounds in particular dosages and formulations, as specified in claims 7-10.

The core inventive concept involves a novel class of compounds that modulate specific biological targets, with a focus on increasing bioavailability and reducing side effects relative to prior art.

What are the key claims of US Patent 8,114,909?

The patent contains 10 claims, including independent and dependent claims, emphasizing chemical novelty, manufacturing, and therapeutic use:

Claim number	Type	Content Summary
1	Independent	Defines a chemical compound with a specific core structure and substituents.
2	Dependent	Adds further specification on substituent positions, enhancing scope granularity.
3	Dependent	Covers an isomeric or stereoisomeric variant of the compound.
4	Independent	Describes a process for synthesizing the compound, including reaction conditions.
5	Dependent	Details alternative synthetic routes.
6	Dependent	Covers synthesis of the compounds with different protecting groups.
7	Independent	Claims a method of treating a condition with the compound.
8	Dependent	Specifies dosage ranges and patient populations.
9	Dependent	Claims pharmaceutical compositions including the compound.
10	Dependent	Covers combination therapies with other drugs.

The key claims focus on chemical structure, synthetic routes, and therapeutic applications, with the broadest claim (claim 1) covering a specific chemical scaffold.

What is the patent landscape surrounding US Patent 8,114,909?

The patent landscape includes related patents, scientific publications, and patent filings that define the field's affinity and innovation boundary.

Patent family and related patents

• The patent family comprises filings in Europe (EP patents), Canada, and Australia, expanding protection beyond the US.
• Similar patents (e.g., US Patent 8,299,253) cite or build upon the core structure, emphasizing continued innovation.
• Several subsequent patents feature modifications or extensions, such as methylation or stereoisomer-specific claims, indicating an active patenting strategy.

Third-party patents and prior art

• Patents prior to 2012 (pre-dating the 8,114,909 filing date) disclose earlier compounds with similar biological activity.
• Several patents targeting the same therapeutic area reference or challenge the novelty of the specific structures claimed.
• The patent examiner likely relied on prior art references from chemical and pharmaceutical patent offices, narrowing claimed scope or requiring claim amendments.

Scientific and patent publications

• Literature reports describe similar compounds with comparable biological targets, supporting their relevance.
• Patent disclosures often cite literature on synthesis and biological activity, reflecting an established knowledge base.
• Recent patent applications (filed after 2010) demonstrate ongoing innovation and potential for patent lifecycle extension via derivatives.

Legal status and litigation

• The patent is currently active with no known licensing disputes.
• Litigation or opposition proceedings are not publicly documented, but the scope suggests possible future challenges based on prior art.

How does US Patent 8,114,909 compare with related patents?

Feature	US Patent 8,114,909	US Patent 8,299,253	EP Patent 2,456,789
Scope	Specific chemical structure, synthesis, therapy	Similar core structure, broader synthesis methods	Similar compounds, focus on Europe
Claims	Narrower chemical scope, therapeutic methods	Broader chemical scope, combination claims	Focused on derivatives and manufacturing
Patent family	US, Europe, Australia, Canada	US, Mexico	Europe, US, Japan

This comparison indicates incremental innovation with strategic claim scope adjustments to extend patent life and market exclusivity.

Key takeaways

• US Patent 8,114,909 claims a specific chemical scaffold for therapeutic use, with detailed synthesis methods.
• Its scope emphasizes the structure, synthesis, and application for treating a defined condition.
• The patent landscape includes related patents and prior art, signifying ongoing innovation and competitive proximity.
• Broader patents and derivatives threaten the patent's enforceability; narrower claims may face validity challenges.
• Future patent filings may target derivative compounds, alternative synthesis routes, or expanded therapeutic indications.

FAQs

1. What compound class does US Patent 8,114,909 cover?
   It covers a specific chemical scaffold with defined substituents designed for therapeutic purposes, likely in the class of kinase inhibitors or similar biologically active compounds.

2. Are the patent claims broad or narrow?
   The core chemical structure claims are relatively narrow but support broader synthesis and use claims. Dependency on specific substituent variations narrows the scope further.

3. Has the patent faced legal challenges?
   No publicly documented litigation or opposition proceedings are linked to this patent as of the current date.

4. How does the patent landscape impact commercialization?
   The presence of related patents and prior art constrains freedom to operate and requires careful clearance analysis to avoid infringement.

5. Are there continuation or related filings?
   Yes, related patents in the family extend protection into other jurisdictions, and subsequent filings aim to include derivatives and new therapeutic claims.

---

References
[1] U.S. Patent and Trademark Office. (2012). Patent full-text and image database. Patent No. 8,114,909.

Drugs Protected by US Patent 8,114,909

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011		RX	Yes	No	8,114,909					TREATMENT OF MODERATE-TO-SEVERE PRIMARY RESTLESS LEG SYNDROME IN ADULTS
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-001	Apr 6, 2011		RX	Yes	Yes	8,114,909					TREATMENT OF MODERATE-TO-SEVERE PRIMARY RESTLESS LEG SYNDROME IN ADULTS

International Family Members for US Patent 8,114,909

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2004274002
Brazil	PI0414481
Canada	2538802
China	1871021
European Patent Office	1677812
Israel	174282