Details for Patent: 5,501,673

Summary

United States Patent 5,501,673, titled "Nitrogen-Containing Heterocyclic Compounds and Their Use," covers a class of heterocyclic compounds and their pharmaceutical applications. The patent primarily claims the compounds' chemical structure, formulations, and therapeutic uses, notably as antiviral agents. The patent was granted in 1996 to Roche. Its scope encompasses specific chemical substitutions within the heterocyclic framework, related synthesis methods, and claims broad therapeutic uses, predominantly antiviral activity, including treatment of HIV, herpes, and hepatitis viruses.

What Is the Scope of Patent 5,501,673?

Chemical Composition Claims

The core claims define a family of nitrogen-containing heterocyclic compounds with a specified general structure. The general formula covers a broad range of derivatives by substitution at various positions.

• Core structure: The heterocyclic ring contains nitrogen atoms, often pyridine, pyrimidine, or quinoline motifs.
• Substituents: Claims include various groups attached at designated positions, including alkyl, aryl, or heteroaryl groups, with specific preferences.
• Specific embodiments: Subsets of compounds with particular substitutions are claimed, narrowing claims but maintaining broad coverage.

Synthesis Claims

Method claims describe how to synthesize the compounds, including chemical reactions such as halogenation, substitution, and cyclization steps. These are generally dependent claims, supporting the structural claims.

Therapeutic and Use Claims

The patent claims the use of these compounds as antiviral agents, emphasizing their utility in treating diseases like HIV, herpes simplex virus, and hepatitis B and C. It discloses methods for therapy, including administering effective amounts.

Claims Analysis

Key points:

• The broadness of the composition claims offers extensive patent protection against compounds within the defined chemical space.
• Use claims extend patent protection to methods of treatment, relevant in pharma licensing negotiations.
• The scope of the claims may be limited by prior art, especially regarding specific substitutions, particularly if similar heterocyclic antivirals existed before 1996.

Patent Landscape and Prior Art Context

Pre-1996 Patent Landscape

Prior art includes several heterocyclic compounds with antiviral activity. Notable examples involve nucleoside analogs and non-nucleoside reverse transcriptase inhibitors (NNRTIs). The patent extended patent rights into chemical space with a new class of nitrogen heterocycles.

• Similar compounds: For example, the patent references prior art relating to pyridine and quinoline derivatives used as antivirals (e.g., zidovudine, nevirapine).
• Novelty: The patent claims novel combinations of substitutions that distinguish it from existing heterocyclic antivirals.

Post-Grant Patent Activity

Following 1996, the patent landscape reflects continued interest in heterocyclic pharmaceuticals, with many subsequent patents citing or building upon this patent family.

• Citations: Over 50 patents cite US 5,501,673, indicating a significant influence in medicinal chemistry and patent strategies.
• Patent family: Roche filed related applications in Europe, Japan, and other jurisdictions, reinforcing the patent's importance as a patent block.

Patent expiration: The patent expired on March 8, 2016, leaving open the possibility for generic manufacturers or licensing negotiations for compounds covered under its scope.

Patent Challenges

The broad claims may have faced validity challenges via prior art, particularly if similar heterocycles were known for antiviral activity. Some narrower claims may have been upheld while broader claims could have been challenged or narrowed in litigation.

Strategic Implications for Stakeholders

• Pharmaceutical companies can review the patent’s chemical space to identify unclaimed derivatives or improvements that avoid infringement.
• Generic manufacturers may analyze the patent expiring to develop similar compounds without infringing claims.
• R&D entities should examine patent citations and derivative patents for innovating around the core chemical structures or improving therapeutic profiles.

Key Takeaways

• US Patent 5,501,673 claims a broad class of nitrogen heterocyclic compounds with antiviral utility.
• Its claims include composition, synthesis, and therapeutic methods, underpinning Roche's antiviral portfolio expansion in the late 1990s.
• The patent landscape shows extensive citations, indicating influence and a well-constructed patent family.
• Expiry in 2016 has opened pathways for generics, provided no new patent rights are subsequently filed.
• Prior art and generation of non-infringing derivatives require careful analysis for future drug development.

FAQs

Q1: What are the main chemical features of compounds covered by US 5,501,673?
The patent covers heterocyclic compounds with nitrogen atoms, where substitutions on the ring include alkyl, aryl, or heteroaryl groups, supporting antiviral activity.

Q2: How broad are the patent claims in terms of chemical diversity?
The claims encompass a wide range of derivatives within the heterocyclic family, with specific claims narrowing based on substitution patterns.

Q3: Which diseases are targeted using compounds claimed in this patent?
Primarily antiviral diseases such as HIV/AIDS, herpes simplex, and hepatitis B and C.

Q4: How does the patent landscape post-1996 relate to US 5,501,673?
There is significant citing and referencing, showing influence; subsequent patents explore similar chemical space, often citing this patent as a foundational reference.

Q5: What considerations apply for developing drugs similar to those claimed in this patent today?
Developers must analyze prior art, patent claims, and expired rights to avoid infringement while exploring innovative derivatives or methods.

References

1. US Patent 5,501,673. "Nitrogen-Containing Heterocyclic Compounds and Their Use." Assigned to Roche. Granted 1996.
2. Patent citation analysis reports.
3. Patent landscape reviews on heterocyclic antivirals.