Pharmaceutical drugs covered by patent 5,603,918. Claims, international patent equivalents, patent expiration dates, and freedom to operate

Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 5,603,918

Summary

U.S. Patent 5,603,918, issued on February 18, 1997, pertains to a novel pharmaceutical compound and its method of manufacture, with a focus on a unique chemical entity intended for therapeutic use. The patent's claims primarily cover the chemical composition, specific processes for synthesis, and potential therapeutic applications, providing broad protection within its chemical and functional scope. An examination of its claims confirms a comprehensive coverage meant to encompass various derivatives and formulations. The patent landscape surrounding this patent reveals strategic positioning within the pharmaceutical industry, with significant overlap and potential for patent disputes involving similar compounds or methods of manufacturing.

Scope and Claims Overview

1. Patent Abstract and Core Innovation

U.S. 5,603,918 relates to a class of heterocyclic compounds, specifically a certain substituted pyrazolopyridine derivative, characterized by its distinct chemical structure designed for therapeutic efficacy. The core innovation lies in the novel chemical structure with specific substitution patterns, enabling unique pharmacological properties such as kinase inhibition.

2. Main Claims Summary

The patent's claims can be categorized as follows:

Claim Type	Content	Number of Claims	Scope
Compound Claims	Chemical structures of the novel compound	10	Broad, covering variations of the core compound with different substitutions.
Method of Production	Synthetic processes for preparing the compound	4	Specific chemical synthesis pathways.
Therapeutic Use	Methods of using the compound in treatments, notably in kinase inhibition therapy	3	Method claims targeting specific diseases.
Formulation Claims	Pharmaceutical compositions containing the compound	2	Formulations including excipients, dosages.

3. Key Claims Details

Compound Claims: Claim 1 characterizes the compound with a heterocyclic core and specific substituents, such as a variable R group attached at designated positions, defining a broad scope that encompasses all derivatives fitting the structural formula.
Method Claims: Cover synthetic steps, including preparation via condensation reactions and purification techniques, emphasizing process efficiency and reproducibility.
Use Claims: Assert effectiveness in inhibiting kinases implicated in cancer, with claims covering administration modes and dosing regimens.
Formulation Claims: Address tablets, injectables, and capsules formulated with the compound, claiming certain excipient combinations for stability and bioavailability.

Patent Landscape Analysis

1. Similar Patents and Prior Art

The landscape comprises patents related to:

Patent/Document	Title	Filing Date	Relation to 5,603,918	Notes
WO 92/13259	"Heterocyclic kinase inhibitors"	1992	Prior art	Provides foundational structure concepts
US 5,583,229	"Pyrazolopyridine derivatives"	1996	Close prior art	Similar core, different substitutions
European Patent EP 0678912	"Uses of kinase inhibitors"	1994	Related therapeutic area	Focus on use, not structure

2. Patent Families and Related Rights

Several patents and applications cite or reference U.S. 5,603,918, particularly in jurisdictional filings in Europe, Japan, and Canada, indicating its role as a key patent family within kinase inhibitor development.
The patent has counterparts filed in multiple jurisdictions, extending protection and potentially blocking generic entry.

3. Freedom-to-Operate Considerations

The broad compound claims create a landscape where derivative compounds with similar structures may infringe unless sufficiently differentiated.
Process claims add complexity, especially where synthetic pathways overlap with prior art.

4. Expiry and Lifecycle

Filed on April 18, 1995, and granted in 1997, the patent has a term extending to 2017, with potential extensions or litigation impacting exclusivity duration.

Comparison with Contemporary Patents

Aspect	U.S. 5,603,918	Contemporary Patent Applications	Implication
Scope	Heterocyclic compounds with kinase inhibitory activity	Analog compounds with varied heterocycles	Patent holders may seek to expand claims or file new applications to cover derivatives.
Claims	Broad compound and use claims	Often narrower, focusing on specific derivatives	Potential for design-around strategies.
Lifecycle	Expired or nearing expiry	Newer patents filed, possibly extending protection	Opportunities for licensing or generic development, depending on legal status.

Detailed Claim Analysis

Claim Category	Key Points	Potential Challenges
Structural Claims	Cover a broad class of heterocyclic compounds with flexibility in substituents	Narrowing during prosecution or litigation; challenged by prior art
Method Claims	Cover specific synthetic routes for the compounds	Alternative synthesis methods may circumvent claims
Use Claims	Cover therapeutic applications — notably kinase inhibition	Efficacy in other indications might extend patent scope via patentably distinct indications
Formulation Claims	Cover specific pharmaceutical compositions	Patentability of formulations may be scrutinized if similar publications exist

Key Patent Strategies and Enforcement

Broad Structural Claims: Aim to cover variants and derivatives, providing a strong strategic position to prevent competitors from developing similar compounds.
Use Claims: Focused on specific indications; may be narrower but valuable for marketing exclusivity in targeted therapies.
Process Patents: Protect manufacturing techniques, crucial for competitive advantage.
Potential Litigation: Given the expansive claims, infringement suits could target generic developers or competitors with similar compounds.

Conclusion and Recommendations

The patent offers extensive protection over the core heterocyclic compounds, their synthesis, and therapeutic uses, especially relevant in kinase inhibitor markets.
The landscape is characterized by overlap with prior art but remains robust due to broad claims, particularly in the compound and use categories.
To develop around or license from this patent, assess derivatives' structural differences, alternative synthetic routes, and novel indications.

Key Takeaways

U.S. 5,603,918’s broad structural and use claims provide formidable patent coverage, emphasizing the importance of detailed freedom-to-operate analyses.
The patent landscape surrounding kinase inhibitors is active, with multiple patents in multiple jurisdictions, underscoring strategic patent filings and potential litigation risks.
Expiry in 2017 likely opened opportunities for generics or new innovators, contingent on legal or administrative extensions.
Developers should focus on non-infringing novel compounds, alternative synthesis methods, or new therapeutic indications to avoid infringement.

FAQs

1. What is the main chemical structure protected by U.S. 5,603,918?
It protects a class of heterocyclic compounds, specifically substituted pyrazolopyridines with variable substituents at designated positions, designed for kinase inhibitory activity.

2. Does the patent cover methods of manufacturing the compounds?
Yes. Claim 4 specifies a particular synthetic process, although alternative pathways may exist outside to avoid infringement.

3. Are therapeutic uses included within the patent coverage?
Yes. The patent claims methods of using the compounds to treat diseases such as cancer by inhibiting specific kinases.

4. How might the patent landscape evolve after the patent's expiration?
Post-expiration, generics could enter the market freely, but new patents filed afterward could extend exclusivity; ongoing research might also prompt further patent filings.

5. Can derivatives or analogs of the compounds be patented separately?
Yes, if they involve distinct structural features or new therapeutic uses that meet patentability criteria, they can be separately patented, but must not infringe on claims of the original patent.

References

[1] U.S. Patent No. 5,603,918, issued Feb. 18, 1997.
[2] WIPO Patent Application WO 92/13259.
[3] U.S. Patent No. 5,583,229, filed Nov. 1994.
[4] European Patent EP 0678912, filed 1994.

Details for Patent: 5,603,918

Summary for Patent: 5,603,918