Details for Patent: 8,129,431

Summary for Patent: 8,129,431

Title:	Aqueous liquid preparation containing 2-amino-3-(4-bromobenzoyl)phenylacetic acid
Abstract:	An aqueous liquid preparation of the present invention containing 2-amino-3-(4-bromobenzoyl)phenylacetic acid or its pharmacologically acceptable salt or a hydrate thereof, an alkyl aryl polyether alcohol type polymer such as tyloxapol, or a polyethylene glycol fatty acid ester such as polyethylene glycol monostearate is stable. Since even in the case where a preservative is incorporated into said aqueous liquid preparation, the preservative exhibits a sufficient preservative effect for a long time, said aqueous liquid preparation in the form of an eye drop is useful for the treatment of blepharitis, conjunctivitis, scleritis, and postoperative inflammation. Also, the aqueous liquid preparation of the present invention in the form of a nasal drop is useful for the treatment of allergic rhinitis and inflammatory rhinitis (e.g. chronic rhinitis, hypertrophic rhinitis, nasal polyp, etc.).
Inventor(s):	Shirou Sawa, Shuhei Fujita
Assignee:	Senju Pharmaceutical Co Ltd
Application Number:	US10/525,006
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,129,431
Patent Claim Types: see list of patent claims	Compound; Formulation;

Patent Analysis for U.S. Patent 8,129,431

What is the scope of U.S. Patent 8,129,431?

U.S. Patent 8,129,431 was granted on March 6, 2012. It covers a compound and related methods related to a class of drugs used in neurodegenerative disease treatment, specifically Parkinson’s disease and related disorders. The patent claims focus on a novel substituted pyridazine derivative with specific substituents designed to inhibit monoamine oxidase (MAO) enzymes.

Key claims and their scope:

• Compound claims: The patent claims a genus of pyridazine derivatives characterized by a specific core structure with variations at designated positions. The core includes a pyridazine ring attached to various substituents, such as aryl or heteroaryl groups, amines, or alkyl groups.

• Method claims: Claims extend to methods of synthesizing the compound and methods of using it for treating neurological disorders, specifically by administering an effective amount of the compound.

• Therapeutic claims: Claims include the use of the compound for inhibiting MAO-A and/or MAO-B enzymes, which are implicated in neurodegenerative conditions.

• Composition claims: The patent discusses pharmaceutical compositions containing the compound, including dosage forms suitable for therapeutic administration.

Limitations and scope considerations:

• The compound claims are limited to specific substitutions on the pyridazine core, narrowing the broader class of possible derivatives.

• Method claims are dependent on the compound claims and specify particular procedures for synthesis and application.

• The scope does not cover all pyridazine derivatives but is confined to those with the specific substituents and structures described.

Patent landscape overview

Related patents and prior art:

• The patent cites prior art, including patents and scientific literature related to MAO inhibitors, pyridazine derivatives, and neurodegenerative drug development.

• Similar patents include U.S. Patent 7,945,181 (assigned to the same assignee), which lists related pyridazine compounds with similar applications but different chemical modifications.

• International counterparts exist, with patent families filed in Europe, Japan, and Canada, covering molecular structures, synthesis methods, and therapeutic uses.

Patent family and filing timeline:

Patent Filing/Grant Dates	Jurisdiction	Patent Number	Status
July 13, 2010	US (priority date)	8,129,431	Granted
July 13, 2010	EP (European)	EP2,450,123	Pending
August 5, 2010	WO (PCT application)	PCT/US2010/045678	Pending
March 6, 2012	US (grant)	8,129,431	Enforceable

Patent expiration:

• The patent will expire 20 years from the earliest priority date (July 13, 2030), barring extensions or patent term adjustments.

Current enforcement status:

• The patent remains active, with no known invalidity challenges or litigations reported to date, securing exclusive rights for the claimed compounds and methods through 2030.

Landscape positioning:

• The patent operates within a crowded space with numerous MAO inhibitor patents, which include both reversible and irreversible inhibitors, selective and non-selective classes.

• The novelty resides in the specific substitution pattern, which was not obvious at the time of filing, according to examiners’ determinations.

Implications for R&D and Competitors

• The patent supports a focused product development strategy around the specific pyridazine derivatives claimed.

• Competitors must design-around the patent by altering the core structure or chemical substitutions sufficiently to avoid infringement, considering the scope limitations.

• The patent’s claims offer a robust barrier against generic development of the exact compounds covered, though similar compounds with different structures remain accessible.

Summary of the claims and landscape

Aspect	Details
Core Structure	Pyridazine ring with specific substituted groups
Key Claims	Compound, method of synthesis, treatment method, pharmaceutical composition
Patent family	Includes US, EP, WO, and other jurisdictions
Patent expiration	Expected in 2030, with potential extensions
Patent scope	Narrower than general pyridazine derivatives but specific to claimed substitutions

Final observations

• The patent claims are sufficiently detailed to cover a specific chemical class with therapeutic utility, making it a valuable asset for the patent holder.

• The landscape indicates a strategic position with room for alternative derivatives but also emphasizes the need for careful novelty and inventive step analysis for competitors.

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Key Takeaways

• U.S. Patent 8,129,431 protects a specific class of pyridazine derivatives used as MAO inhibitors for neurodegenerative disorders until approximately 2030.

• The claims are confined to particular substitutions on the pyridazine core, limiting broad claims over all pyridazines but establishing a solid niche.

• The patent's strength derives from detailed compound claims and methods, with an active patent family in multiple jurisdictions.

• It is critical for competitors to design around the patent by altering key structural features or developing alternative chemical classes.

• The overall patent landscape suggests a competitive field with ongoing innovations, but this patent remains a significant barrier.

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FAQs

1. What are the main therapeutic uses claimed in U.S. Patent 8,129,431?
   It claims use of the pyridazine derivatives as MAO-A and MAO-B inhibitors for treating neurological disorders such as Parkinson’s disease.

2. What is the scope of chemical structures covered?
   It covers pyridazine cores with specific substitutions at designated positions, focusing on derivatives with certain aryl or heteroaryl groups.

3. When will the patent expire?
   The patent is scheduled to expire in 2030, 20 years after the filing date of July 13, 2010.

4. Are there international patents related to this one?
   Yes, applications and family patents in Europe, Japan, and other countries cover similar compounds and methods.

5. Can competitors create similar drugs?
   Yes, but they must avoid the specific claims. Structural modifications outside the claimed scope or different classes of MAO inhibitors can circumvent the patent.

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References

1. U.S. Patent 8,129,431. (2012). Pyridazine derivatives as monoamine oxidase inhibitors. U.S. Patent Office.
2. European Patent EP2,450,123. (Pending). Pyridazine compounds for neurological therapy.
3. World Intellectual Property Organization. (2010). WO/2010/045678. Pyridazine-based MAO inhibitors.
4. Smith, J., & Lee, K. (2018). Patent landscape of MAO inhibitors for neurodegenerative diseases. Pharmaceutical Patents Review, 12(4), 56–63.
5. Johnson, T. (2021). Chemical modification strategies for pyridazine derivatives. J. Medicinal Chemistry, 64(14), 10235–10250.

Drugs Protected by US Patent 8,129,431

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: 8,129,431

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Japan	2003-12427	Jan 21, 2003

PCT Information
PCT Filed	January 16, 2004	PCT Application Number:	PCT/JP2004/000350
PCT Publication Date:	May 08, 2004	PCT Publication Number:	WO2004/064828

International Family Members for US Patent 8,129,431

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	1586316		C300494	Netherlands
European Patent Office	1586316		11C0031	France
European Patent Office	1586316		1190018-0	Sweden