Scope and Claims Analysis of U.S. Patent 5,633,169
What does Patent 5,633,169 cover?
Patent 5,633,169 covers a method for treating hyperglycemia using a specific class of protein kinase C (PKC) inhibitors. The patent claims relate to compositions that improve glucose uptake and reduce symptoms associated with diabetes mellitus.
Issuance and Filing Details
- Filing Date: April 7, 1995
- Issue Date: May 27, 1997
- Assignee: Lilly Research Laboratories
- International Classification: A61K31/269, A61K31/537, C07D491/02
What are the primary claims?
The patent contains 24 claims, primarily encompassing:
- Claims 1-8: Methods of treating hyperglycemia or preventing diabetic complications through administering a class of PKC inhibitors with specific chemical structures.
- Claims 9-16: Specific chemical compounds that serve as PKC inhibitors, characterized by certain substitutions and functional groups.
- Claims 17-24: Pharmaceutical compositions comprising these inhibitors and their use in combination therapy.
Claim Breakdown
Method Claims (Claims 1-8):
- Focus on therapeutic methods involving administering a PKC inhibitor that suppresses hyperglycemia.
- Specify inhibitors have a core structure with substitutions at particular positions to enhance activity or selectivity.
- Covering both prophylactic and therapeutic applications.
Compound Claims (Claims 9-16):
- Detail specific chemical entities within the inhibitor class.
- Include structure types such as naphthalene derivatives, quinoline derivatives, and related heterocycles.
- Reiterate high purity and specific substitutions for pharmaceutical use.
Formulation and Use Claims (Claims 17-24):
- Describe pharmaceutical formulations.
- Cover methods of administration, including oral, injectable, or topical delivery.
- Emphasize combinations with other antidiabetic agents.
What is the scope of protection?
The scope centers on small-molecule PKC inhibitors targeting diabetic complications. It explicitly claims both the chemical compounds and their use in medical treatments.
- The claims are broad enough to encompass variations of the chemical scaffold with different substituents, provided they retain PKC inhibitory activity.
- They include derivatives with similar core structures designed for improved potency or selectivity.
However, they do not claim other classes of PKC inhibitors, such as peptide-based molecules or large biologics.
Patent landscape context
Related patents and prior art
- Several patents prior to 1995 address PKC inhibitors (e.g., U.S. Patents 4,785,103; 4,888,353).
- Patent 5,633,169 builds on these, focusing on specific chemical structures suitable for diabetes treatment.
- Post-issue, multiple patents have emerged with improved PKC inhibitors, some citing this patent as foundational.
Competitor filings
- Companies like Bristol-Myers Squibb and Novo Nordisk have filed patents on PKC inhibitors targeting diabetic complications.
- Patent landscapes show a cluster of filings from 1995-2005 focusing on naphthalene and quinoline derivatives.
Geographic extension
- Similar patents filed in Europe (EP patents) and Japan (JP patents).
- Patent families often have corresponding PCT applications to extend protection internationally.
Patent expiration
- Filed in 1995, likely expired around 2015-2017 due to 20-year patent term from filing date, subject to terminal disclaimers or extension policies.
Patent landscape implications
- The patent's expiration opens opportunities for generic development if no other active patents restrict the class.
- Its broad chemical claims protect a significant subclass of PKC inhibitors, impacting R&D freedom-to-operate.
- Continued innovation focuses on improving pharmacokinetics, selectivity, and reducing off-target effects.
Summary
Patent 5,633,169 secures rights to a class of PKC inhibitors used to treat hyperglycemia, with broad claims covering compounds and methods of use. Its expiration enables new entrants to explore the chemical space for similar or improved inhibitors. The patent landscape around PKC inhibitors for diabetes has been crowded but remains competitive due to ongoing research.
Key Takeaways
- Patent 5,633,169 claims chemical compounds and their therapeutic use for diabetes-associated hyperglycemia.
- The claims are broad, covering various substitutions within a chemical class.
- It has a significant place in the PKC inhibitor patent landscape, influencing subsequent filings.
- Expiry allows for potential development or generic manufacturing.
- Ongoing innovation is driven by modifications in chemical structure to improve drug profiles.
FAQs
1. What is the chemical structure primarily protected by this patent?
A class of heterocyclic compounds, notably naphthalene and quinoline derivatives with specific substitutions advantageous for PKC inhibition.
2. Can I develop PKC inhibitors similar to those claimed in the patent now?
Post-expiration, the patent’s chemical claims are in the public domain, but check for other active patents covering specific compounds or delivery methods.
3. How does this patent relate to current diabetes treatments?
It laid groundwork for PKC inhibitor research, though current treatments favor other mechanisms like GLP-1 receptor agonists or SGLT2 inhibitors.
4. What are the risks of patent infringement if developing similar PKC inhibitors?
Active patents on specific chemical entities or formulations may exist. Conduct a freedom-to-operate analysis for precise compounds and claims.
5. Are there regulatory barriers tied to this patent’s claims?
The patent itself does not impose regulatory barriers but obtaining approval depends on demonstrating safety and efficacy under FDA guidelines.
References
[1] U.S. Patent and Trademark Office. (1995). Patent 5,633,169.
[2] Nissen, M. S., & Wyllie, S. (2000). PKC inhibitors and their therapeutic applications. Journal of Medicinal Chemistry, 43(17), 3175–3190.
[3] World Intellectual Property Organization. (2006). WO Patent application for PKC inhibitors.
[4] Food and Drug Administration. (2022). Guidance for Industry: Patents and Exclusivity Purposes.
[5] European Patent Office. (1998). Patent EP Patent 761235.
