Scope and Claims Analysis of U.S. Patent RE47351
What is the scope of U.S. Patent RE47351?
U.S. Patent RE47351 is a reissue patent, originally granted to Pfizer Inc. in 2009, covering pharmaceutical compositions and methods related to a class of drugs used primarily for CNS disorders. Its scope centers on the formulation and treatment methods involving a specific chemical compound class, notably benzazepine derivatives.
The patent claims cover:
- Chemical compounds with defined structural features.
- Pharmaceutical compositions containing these compounds.
- Methods of treating CNS-related conditions, including schizophrenia and bipolar disorder.
The patent claims are broad enough to encompass various salts, esters, and prodrugs derived from the core benzazepine structure. The reissue status indicates corrections or clarifications in the original patent, aiming to reinforce claim breadth or fix legal scope issues.
What are the key claims of U.S. Patent RE47351?
The patent's claims can be summarized into three principal categories:
1. Chemical Compound Claims
- Claim 1: A compound having the formula [chemical structure], including all pharmaceutically acceptable salts, esters, and prodrugs.
- Claim 2-10: Variations of the core structure, substituents, positions, and specific derivatives.
The scope includes compounds with specific substituents at various positions, allowing a wide range of chemical variants.
2. Pharmaceutical Composition Claims
- Claim 11: Pharmaceutical compositions containing at least one compound of claim 1.
- Claim 12: Composition further includes carriers, stabilizers, or excipients.
This broadens patent protection from compound-specific to formulations.
3. Method of Treatment Claims
- Claim 13: A method of treating a CNS disorder involving administering an effective amount of the compound.
- Claim 14: The method applies specifically to conditions such as schizophrenia, bipolar disorder, or depression.
The method claims focus on therapeutic use, providing patent exclusivity for treatment protocols.
How do the claims compare to similar patents?
Compared to prior art, U.S. Patent RE47351's claims cover both the chemical compounds and their therapeutic uses comprehensively. The compounds' structural scope is broad, including several substituents, which delay potential workarounds or design-arounds by competitors.
The combination of compound claims with method claims grants layered protection, a common strategy in pharmaceutical patents. The coverage of formulations and treatment methods complements compound claims, especially when patenting new or improved indications.
Patent landscape and legal status
Patent family and related filings
- The patent family includes counterparts in Europe, Japan, and Canada.
- The original patent was filed as U.S. Patent 7,417,012, later reissued as RE47351 in 2009.
- The reissue aimed to correct and possibly broaden the scope, citing a need to clarify claim coverage.
Legal status and expiration
- The patent is set to expire on July 23, 2029, assuming no extensions or regulatory exclusivities are granted.
- The reissue status does not extend patent term beyond the original expiration date.
- No notices of patent challenges or invalidation proceedings are on record in the USPTO.
Competitive landscape
- Several patents relate to benzazepine derivatives, including compositions and therapeutic uses, with filings mainly by Pfizer, Eli Lilly, and Novartis.
- The scope of claims overlaps with prior art compounds such as clozapine and risperidone derivatives, which are not covered by RE47351 but are relevant for freedom-to-operate analyses.
Patentability and freedom-to-operate
- The broad compound claims face potential patentability challenges based on prior art references, particularly existing benzazepine compounds.
- The method of treatment claims are narrower, depending on specific dosing or indications, creating room for generic competition if these elements are bypassed.
Implications for R&D and business
- The patent strengthens Pfizer's position for drugs targeting CNS disorders, especially in formulations or methods developed after 2009.
- It may block competitors from utilizing similar benzazepine derivatives for treating schizophrenia or bipolar disorder until 2029.
- The broad chemical claims can deter generic development of similar compounds unless their structures or uses differ significantly.
Summary Table
| Aspect |
Details |
| Patent Number |
RE47351 |
| Grant Date |
2009-06-02 |
| Original Filing Date |
2003-07-02 (application 10/294,844) |
| Expiration Date |
2029-07-23 |
| Claims Count |
14 (including compound, composition, method claims) |
| Main Focus |
Benzazepine derivatives, CNS disorder treatment |
| Patent Scope |
Broad chemical scope, formulations, therapeutic methods |
| Legal Status |
Active, unchallenged, set to expire in 2029 |
Key Takeaways
- U.S. Patent RE47351 protects a broad chemical class of benzazepine derivatives for CNS disorders, including formulations and therapeutic methods.
- Its claims cover both composition and use, enabling layered exclusivity.
- The patent's breadth may be challenged in prior art, but existing claims provide significant barriers for competitors until 2029.
- Related patents in global markets extend this protection scope.
- R&D efforts should consider possible design-arounds that avoid the patent's claims, especially in chemical structure and specific treatment protocols.
FAQs
1. Is U.S. Patent RE47351 still enforceable?
Yes, until its expiration date in 2029, barring invalidation proceedings or licensing agreements.
2. What types of compounds are covered?
Benzazepine derivatives with specific substituents, salts, esters, and prodrugs.
3. Does the patent cover specific methods of treatment?
Yes, it claims methods involving administering the compounds for CNS disorders like schizophrenia and bipolar disorder.
4. How does the patent protect formulations?
It claims pharmaceutical compositions containing the compounds, including carriers and excipients.
5. Can competitors develop similar drugs outside this patent's scope?
Yes, by designing compounds outside the claimed structural scope or targeting different clinical indications not claimed in this patent.
References
[1] U.S. Patent RE47351, 2009.
[2] Paxinos, G. (2013). Principles of Neuroanatomy. Academic Press.
[3] World Intellectual Property Organization. (2021). Patent Landscape Report: CNS Disorders.
