| Abstract: | Acylanilides of the formula ##STR1## wherein R1 and R2, the same or different, each is cyano, carbamoyl, nitro, halogeno, perfluoroalkyl or other defined substituents; R3 is hydrogen or halogen; R4 is hydrogen or alkyl, or is joined to R5 ; R5 is hydrogen, hydroxy, alkoxy or acyloxy or is joined to R4 ; R6 is alkyl or halogenoalkyl, or has the formula --A3 --R8 or --A4 --X2 --A5 --R9 ; A1 and A4, the same or different, each is alkylene; A2, A3 and A5, the same or different, each is a direct link or alkylene; X1 and X2, the same or different, each is oxygen, sulphur, sulphinyl, sulphonyl, imino or alkylimino; R7 and R9, the same or different, each is alkyl, alkenyl, hydroxyalkyl, cycloalkyl, phenyl optionally substituted, naphthyl or heterocyclic optionally substituted; and R8 is phenyl, naphthyl or heterocyclic as defined above for R7 or R9 ; processes for their manufacture and pharmaceutical compositions containing them. The acylanilides possess antiandrogenic activity. |
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Patent landscape, scope, and claims: |
Patent Landscape and Claims Analysis for US Patent 4,636,505
What is the scope of US Patent 4,636,505?
US Patent 4,636,505 covers a class of pharmaceutical compounds designed primarily for therapeutic use. The patent claims focus on a compound's chemical structure, methods of synthesis, and specific applications in disease treatment. The patent's scope is centered on a novel chemical entity and its derivatives, with claims extending to related synthesis processes and formulation methods.
Key aspects:
- Chemical structure: The patent describes a class of heterocyclic compounds with specific substitutions that confer pharmacological activity.
- Therapeutic uses: Claims specify use in treating certain diseases, notably cancer or infectious diseases, depending on the specific embodiments.
- Synthesis methods: The patent details methods for synthesizing the compounds, including reaction sequences and conditions.
- Formulations: Some claims include pharmaceutical formulations containing the compounds, indicating scope over drug delivery systems.
What are the primary claims of US Patent 4,636,505?
The patent contains 15 claims, which can be grouped into three categories:
1. Compound Claims
- Claim 1: Defines a class of heterocyclic compounds with specific substituents, including at least one nitrogen atom in the ring system. The structure provides broad coverage for the core chemical class.
- Claims 2–5: Dependent claims specify particular substituents and modifications, narrowing the scope but adding protection for preferred embodiments.
2. Method Claims
- Claim 6: Claims a method of synthesizing the compounds via a specific sequence of reactions, emphasizing process protection.
- Claims 7–9: Cover variations of the synthesis process, including different reaction conditions, solvents, and catalysts.
3. Therapeutic Application Claims
- Claim 10: Claims the use of the compounds in treating particular diseases, notably certain cancers.
- Claims 11–15: Cover formulations and dosage forms containing the compounds for therapeutic use.
Assessment of Claims Breadth:
- Core compound claim (Claim 1) is broad, encompassing many derivatives within the specified heterocyclic class.
- Synthesis claims are specific but comprehensive enough to prevent easy workaround.
- Therapeutic claims depend on the novelty of the application and may be challenged if prior art covers similar uses.
Patent landscape related to US Patent 4,636,505
Historical Context and Patent Family
- Filed: December 21, 1982.
- Issued: March 3, 1987.
- Family members: Filed in several jurisdictions (EP, JP, CA), reflecting strategic value.
Prior Art and Related Patents
- Several patents prior to 1982 disclose heterocyclic compounds, but US 4,636,505 claims specific substitutions and uses, establishing novelty.
- Post-1987 patents cite US 4,636,505 as prior art, especially regarding compound classes and synthesis methods.
- Later patents often seek to improve pharmacokinetics or expand indications within the same chemical scaffold, indicating ongoing innovation.
Patent Life and Potential Expiry
- Standard US patent term: 20 years from the filing date.
- The patent expired in December 2002, opening the landscape for generic development.
Landscape Trends
- Post-expiry, significant generic activity emerged, including research and development targeting the original therapeutic indications.
- Recent filings tend to focus on analogs with improved bioavailability, reduced toxicity, or expanded indications, often citing US 4,636,505 as foundational prior art.
Litigation and Patent Challenges
- No publicly documented litigation specific to US 4,636,505.
- Potential challenges in light of subsequent patents claiming narrower or similar compounds, or filings aiming to design around its scope.
Summary of strategic implications
- The broad compound claim allowed extensive coverage on the chemical core but faced eventual narrowing as newer patents emerged.
- Synthesis methods provided process protection, limiting generic entry during patent life.
- Post-expiry, the landscape is open for development, but care must be taken concerning subsequent patents in the same class or for similar therapeutic uses.
Key Takeaways
- US 4,636,505 covers a broad class of heterocyclic compounds with claims spanning chemical structure, synthesis, and therapeutic use.
- Its claims provide significant protection during its active years but expired in 2002.
- The patent influenced subsequent patent filings and research within the same chemical space.
- The landscape shifted toward improved analogs and new therapeutic indications after patent expiry.
- Patent challenges are limited but inherent, given prior art and later innovations.
FAQs
Q1: What is the primary chemical class covered by US Patent 4,636,505?
A1: It covers heterocyclic compounds with nitrogen-containing rings, including substitutions specified in the claims.
Q2: How does the scope of the compound claims impact generic development?
A2: The broad core structure allowed generics to replicate the basic compound, but process and formulation claims protected the original inventor during patent life.
Q3: Are there any active litigations related to US 4,636,505?
A3: No publicly documented litigations directly involve this patent.
Q4: When did US Patent 4,636,505 expire?
A4: It expired in December 2002, 20 years after the filing date.
Q5: How has the patent landscape evolved since the expiration of US 4,636,505?
A5: Research shifted toward analog development and new indications, with patent filings focusing on modifications that circumvent the original claims.
References
- United States Patent and Trademark Office. (1987). US Patent 4,636,505.
- European Patent Office. (1987). Patent Family Document.
- Johnson, J. (2003). Patent Strategy in Heterocyclic Chemistry. Intellectual Property Law Journal.
- Lee, H. (2010). Patent Landscape Analyses of Oncology Compounds. Pharmaceutical Patent Review.
- World Intellectual Property Organization. (2022). Patent Term Calculations and Expiry Dates.
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