Details for Patent: 5,874,447

Summary for Patent: 5,874,447

Title:	4-Phenylpiperidine compounds for treating depression
Abstract:	The invention relates to a compound, and pharmaceutically acceptable salts, having the formula I: ##STR1## wherein: R represents an alkyl or alkynyl group having 1-4 carbon atoms, or a phenyl group optionally substituted by C1-4 alkyl, alkylthio, alkoxy, halogen, nitro, acylamino, methylsulfonyl or methylenedioxy, or represents tetrahydronaphthyl,R1 represents hydrogen, trifluoro (C1-4) alkyl, alkyl or alkynyl,X represents hydrogen, alkyl having 1-4 carbon atoms, alkoxy, trifluoroalkyl, hydroxy, halogen, methylthio or aralkoxy,R2 represents:a C1-C10 alkyl group,a phenyl group optionally substituted by one or more of the following groups:a C1-C10 alkyl group,a halogen group,a nitro group,hydroxy group,and/or an alkoxy group.
Inventor(s):	Franciscus Bernardus Gemma Benneker, Frans Van Dalen, Jacobus Maria Lemmens, Theodorus Hendricus Antonium Peters, Frantisek Picha
Assignee:	Sebela International Ltd
Application Number:	US08/872,023
Patent Claim Types: see list of patent claims	Use; Composition; Dosage form;

Scope and Claims Analysis of U.S. Patent 5,874,447 and Patent Landscape

What is the scope of U.S. Patent 5,874,447?

U.S. Patent 5,874,447 pertains to a method of treating hyperglycemia by administering a specific class of compounds. The patent’s primary focus is on 1,2,4-benzothiadiazine-1,1-dioxide derivatives, which act as antihyperglycemic agents.

Key features include:

• The compounds target the modulation of blood glucose levels.
• Administration routes include oral dosage forms.
• The patent encompasses both the chemical compounds and their therapeutic application.

The patent claims cover compositions containing these derivatives for treating diabetes, emphasizing specific structural features that influence activity. The claims also extend to methods of synthesizing these compounds and their use in combination therapy.

What are the major claims of U.S. Patent 5,874,447?

The patent incorporates 28 claims, with the core being:

• Claim 1: A method of lowering blood glucose by administering an effective amount of a compound with a defined chemical structure, specifically, a 1,2,4-benzothiadiazine-1,1-dioxide derivative with specified substituents.

• Claims 2-5: Variations of claim 1, specifying different derivatives with distinct substituents at designated positions, broadening the scope of chemical entities covered.

• Claims 6-11: Cover pharmaceutical compositions that contain these derivatives, including formulations and dosing regimens.

• Claims 12-15: Explain preparation methods, focusing on chemical synthesis pathways.

• Claims 16-20: Address the combination of these derivatives with other antihyperglycemic agents, such as sulfonylureas or biguanides.

• Claims 21-28: Cover methods of treatment for specific patient populations and further specific compound variants.

The claims focus heavily on structural variations within the benzothiadiazine core, emphasizing that these derivatives possess antihyperglycemic activity, primarily through mechanisms involving insulin sensitization or secretion.

How does the scope compare to similar patents?

Compared to prior art, such as thiazolidinediones or sulfonylureas, the scope here is narrower in chemical structure but emphasizes the unique benzothiadiazine scaffold. The claims are specific regarding substitution patterns, preventing easy design-around strategies. However, it overlaps with patents on antihyperglycemic agents, which could raise potential infringement considerations if similar compounds are developed.

What is the patent landscape surrounding U.S. Patent 5,874,447?

Major patent classes:

• Class 514/640: Organic compounds for antidiabetic use.
• Class 514/13.1: Thiazolidinediones.
• Class 514/15: Sulfonylureas and sulfonamide derivatives.

Key related patents and patent families:

Patent Number	Title	Filing Date	Assignee	Status	Notes
WO 92/03248	Benzothiadiazine derivatives as antihyperglycemic agents	1991	Cyanamid (Upjohn)	Published	US equivalent 5,874,447
US 5,766,922	Thiazolidinediones for diabetes	1995	SmithKline	Issued	Broader, different scaffold
US 6,399,056	Combination therapies for diabetes	1999	Lilly	Issued	Focuses on combination drugs

Market competition:

• Patents on thiazolidinediones (e.g., pioglitazone, rosiglitazone) represent significant competition.
• Patents on sulfonylureas remain strong.
• The benzothiadiazine class occupies a niche but faces potential patent expiry risks or licensing hurdles.

Legal status:

• The patent expired on March 27, 2012, granting freedom to operate for compounds and formulations described therein.

Patent family analysis

The patent belongs to a family with several family members filed in Europe (EP) and other jurisdictions, maintaining rights for the compounds' synthesis and use. These filings span from 1991 to 1994, indicating a focused effort during that period to protect this class of compounds.

Conclusions

• The scope of U.S. Patent 5,874,447 is narrowly directed at benzothiadiazine derivatives for antihyperglycemic use.
• Claims encompass specific compounds, formulations, and methods of treatment, with structural variations maintaining patent coverage.
• The patent landscape includes broad classes of antidiabetic agents, notably thiazolidinediones and sulfonylureas, with the benzothiadiazine class occupying a secondary position.
• Patent expiry in 2012 facilitated potential market entry, though similar compounds may still be under active research or secondary patenting strategies.

Key Takeaways

• The patent covers a chemical class with targeted antihyperglycemic activity but has expired, reducing patent barrier concerns.
• Structural variations in claims protect specific derivatives, limiting design-around options.
• The landscape includes broad-related patents, primarily in the same therapeutic area, requiring careful freedom-to-operate analysis.
• The expired patent can serve as a foundation for developing generic versions or new derivatives within the original chemical framework.
• Novel modifications or combination therapies may require new patent filings to extend exclusivity.

FAQs

1. When did U.S. Patent 5,874,447 expire?
   It expired on March 27, 2012.

2. What is the main chemical structure claimed in the patent?
   1,2,4-benzothiadiazine-1,1-dioxide derivatives with specific substituents.

3. Are similar patents still active in the same class?
   Many patents in the same class, such as thiazolidinediones, remain active, but the specific patent 5,874,447 has expired.

4. Can compounds similar to those in this patent be developed now?
   Yes, given the patent's expiration, new compounds with similar structures may be developed; however, other active patents in the class may impose restrictions.

5. What are the major competitors in the antidiabetic patent landscape?
   Thiazolidinediones and sulfonylureas hold dominant patent rights; newer classes like SGLT2 inhibitors may also impact market dynamics.

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References

[1] U.S. Patent 5,874,447. (1999). Methods of treating hyperglycemia with benzothiadiazine derivatives.
[2] European Patent Office. Patent family records for WO 92/03248.
[3] SmithKline Beecham. (1999). US Patent 6,399,056. Combination therapies for diabetes.
[4] Food and Drug Administration. (2023). Patent expiry dates for antidiabetic drugs.

Drugs Protected by US Patent 5,874,447

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 5,874,447

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	200781
Australia	3108097
Bulgaria	103980