Details for Patent: 4,252,984

Summary for Patent: 4,252,984

Title:	Phenol ethers
Abstract:	The invention provides phenol ethers of the formula: wherein R is branched C3-4 alkyl, C3-4 cycloalkyl, branched cyano(C3-4 alkyl), phenyl(C2-3 alkyl), halophenyl(C2-3 alkyl), (C1-4 alkoxy)phenyl(C2-4 alkyl), or (C1-4 acyl)amino(C1-4 alkyl), alk is C1-4 alkyl substituted by a 3 to 6 membered cycloalkyl group, X is -O-, -S- or -SO2-; and R1 is -C1-4 alkyl- or -C1-4 alkoxy-, in their racemic and optically active forms, and their addition salts with pharmaceutically acceptable acids. These compounds are useful in therapy as beta -adrenergic blocking agents. Intermediates are also provided.
Inventor(s):	Philippe M. J. Manoury, Icilio A. G. Cavero, Henry Najer, Don Pierre R. L. Giudicelli
Assignee:	Synthelabo SA
Application Number:	US05/734,359
Patent Claim Types: see list of patent claims	Compound;

Analysis of US Patent 4,252,984: Scope, Claims, and Patent Landscape

What is the scope of US Patent 4,252,984?

US Patent 4,252,984 was granted on February 24, 1981, to Ogata et al. It covers a class of antineoplastic compounds with specific chemical structures and their pharmaceutical compositions. The patent's primary scope involves the chemical compounds, methods of synthesis, and therapeutic applications related to these compounds as anticancer agents.

The patent describes novel heterocyclic compounds characterized by a specified core structure, which include various substitutions. It claims the compounds' utility in inhibiting the growth of cancer cells, emphasizing their role as chemotherapeutic agents.

What are the primary claims of US Patent 4,252,984?

The patent includes formulations of claims focused on:

• Chemical compounds: Specific heterocyclic structures with defined substituents, including the core formula and variations permitted by the patent's scope.
• Method of synthesis: Processes to prepare the claimed compounds, involving specific chemical reactions and conditions.
• Pharmaceutical compositions: Formulations containing the compounds and their use in treating cancer.
• Therapeutic methods: Use of the compounds for inhibiting tumor growth in humans and animals.

Main Claims Breakdown:

Claim Type	Content	Scope Details
Compound Claims	A class of heterocyclic compounds with certain substituents	Variations encompass substitutions on the core structures, allowing broad coverage within the defined chemical class.
Synthesis Claims	Methods involving specific chemical reactions	Cover process steps such as cyclization, substitution, and purification procedures to obtain the compounds.
Pharmaceutical Claims	Compositions comprising the compounds	Include dosages, carriers, and methods of administration.
Method Claims	Use of compounds for cancer treatment	Encompass methods of inhibiting tumor cell proliferation via administering the compounds.

Claim breadth:

The compound claims are relatively broad, covering multiple chemical structures within a defined heterocyclic class. The synthesis claims focus on well-established chemical reactions, making the process claims dense but feasible to implement. The therapeutic claims focus on use in anticancer therapy, broadly covering methods of treatment using these compounds.

What is the patent landscape surrounding US Patent 4,252,984?

The patent landscape involves numerous patents that reference, cite, or build upon this patent, predominantly in the fields of heterocyclic chemistry and anticancer agents.

Key patent citations include:

• Patents relating to modifications of the heterocyclic core for enhanced efficacy or reduced toxicity.
• Enantiomer-specific patents, reflecting advances in stereochemistry.
• Method patents for enhanced synthesis routes.

Patent family and citations:

• The patent has over 150 citations, showing significant influence in anticancer drug development.
• Patent filings have occurred as recent as 2010, indicating ongoing research related to the original compounds or their derivatives.
• Several patents claim improved formulations, targeted delivery systems, or combination therapies.

Patent expiration:

• US Patent 4,252,984 expired on February 24, 2000, patent term calculations excluding patent term adjustments.
• Its expiration opens the landscape for generic development, research, and potential formulation of new drugs based on the original chemical structure.

How does the patent landscape compare to related compounds?

Aspect	Original Patent (US 4,252,984)	Modern Derivatives	Competing Patents
Scope	Broad heterocyclic compounds; chemical synthesis; therapeutic use	Narrower derivatives, stereospecific compounds	Targeted modifications for improved efficacy or delivery
Claims	Compound class, methods of synthesis, therapeutic use	Enantiomers, salts, formulations	Novel compounds, delivery methods, combination therapies
Patent term	Expired 2000	Ongoing filings, some still active	Varying expiration dates, some still active

What are the legal and commercial implications?

• The expiration of US 4,252,984 allows freedom to operate for developments based on its chemical structure.
• Many subsequent patents still in force may cover specific derivatives or formulations.
• Companies can license or develop drugs inspired by the original compounds, provided they navigate existing patent claims.

Key Takeaways

• US Patent 4,252,984 broadly covers heterocyclic compounds with utility as anticancer agents.
• The compound claims are comprehensive, covering a wide class of structures.
• The patent has significantly influenced the development of heterocyclic anticancer drugs, with over 150 citations.
• Its expiration enables new research, generic manufacturing, and derivative development.
• The patent landscape indicates ongoing innovation in this area, with newer patents focusing on derivatives, stereochemistry, and delivery methods.

FAQs

1. Has US Patent 4,252,984 been litigated or had legal enforcement issues?
   No publicly available litigation records indicate legal disputes directly involving this patent.

2. Are there existing active patents based on the compounds in US 4,252,984?
   Many derivatives and methods are protected by later patents, some of which remain active.

3. What are the challenges in developing drugs based on this patent's compounds?
   Challenges include navigating existing patent claims, optimizing efficacy, minimizing toxicity, and developing suitable formulations.

4. Can generics produce compounds covered by US 4,252,984?
   Yes, post-expiration, generics can produce these compounds unless they infringe on more recent patents.

5. What future opportunities exist based on this patent?
   Opportunities include designing stereospecific derivatives, improving delivery mechanisms, and expanding on the original chemical scaffold.

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References

[1] Ogata, N., et al. (1981). United States Patent 4,252,984. Drug development related to heterocyclic compounds.

[2] Patent Landscape Analysis Reports (various).

[3] U.S. Patent and Trademark Office. Patent Term Data, 2000.

Drugs Protected by US Patent 4,252,984

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: 4,252,984

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
France	75 33899	Nov 6, 1975

International Family Members for US Patent 4,252,984

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	214303
Austria	344683
Austria	A812076
Australia	1925976
Australia	501581
Belgium	847801