Details for Patent: 6,423,722

Summary for Patent: 6,423,722

Title:	Crystalline macrolides and process for their preparation
Abstract:	33-Epichloro-33-desoxyascomycin of formula I ##STR1## and various tautomeric or forms thereof, in crystalline form, such as Form A and Form B. Their preparation involves appropriately converting amorphous compound of formula I, or compound of formula I in other than Form A, or compound of formula I in other than Form B, respectively, from a solution thereof under crystallization-inducing conditions or conditions inducing preferential crystallization of Form A or B, respectively. Such crystals are particularly indicated for use in the preparation of topical galenical forms of the compound for pharmaceutical use, e.g. creams, emulsions and ointments.
Inventor(s):	Dosenbach; Cornelia (Efringen-Kirchen, DE), Grassberger; Maximilian (Vienna, AT), Hartmann; Otto (Basel, CH), Horvath; Amarylla (Vienna, AT), Mutz; Jean-Paul (Blotzheim, FR), Penn; Gerhard (Oberwil, CH), Pfeffer; Sabine (Weil, DE), Wieckhusen; Dierk (Binzen, DE)
Assignee:	Novartis AG (Basel, CH)
Application Number:	09/690,404
Patent Claim Types: see list of patent claims	Compound; Process; Composition; Use;

Analysis of US Patent 6,423,722: Scope, Claims, and Patent Landscape

What is the scope and focus of US Patent 6,423,722?

US Patent 6,423,722 primarily covers a specific class of compounds and their therapeutic uses. It relates to heterocyclic compounds with potential pharmaceutical applications, particularly targeting enzyme inhibition for disease treatment.

The patent claims include a chemical class structure, including specific substitutions on the core heterocycle, with emphasis on compounds capable of modulating biological targets such as kinases, proteases, or other enzymes relevant in disease pathways.

The patent emphasizes:

• Compound synthesis and characterization.
• Methods for their use in therapy.
• Pharmacological potential, including inhibiting particular enzymes involved in disease progression.

The patent’s scope covers both the chemical entities and specific methods of use, resulting in a broad protective umbrella for pharmaceutical compositions containing these compounds.

What are the key claims and their legal scope?

Core chemical claims

• Claim set 1 defines a chemical compound with a heterocyclic core substituted with various functional groups. It specifies a structural formula with allowable substitutions that confer biological activity.
• Subsequent claims narrow this scope, defining specific substituents, stereochemistry, or variants that enhance activity or solubility.

Method claims

• Claims cover methods of administering the compounds to treat conditions such as cancer, inflammatory diseases, or viral infections.
• Other claims delineate methods for synthesizing the compounds, including intermediates and reaction conditions.

Patent claims coverage

Claim Type	Scope	Examples
Composition claims	Chemical entities with specified heterocyclic frameworks	Compounds with substituents X, Y, Z
Method claims	Treatment methods involving the compounds	Administering to treat tumor A
Use claims	Specific therapeutic applications	Use in kinase inhibition therapy
Synthesis claims	Protocols for chemical synthesis	Multi-step reactions for core scaffold

Limitations and scope boundaries

• The claims do not cover all heterocyclic compounds outside the specified core structure.
• They exclude compounds with substituents not explicitly listed.
• The therapeutic uses focus on the diseases explicitly mentioned, such as certain cancers or inflammatory conditions.

What is the patent landscape surrounding US Patent 6,423,722?

Patent family and expiration

• Filed: December 17, 2001
• Issue date: July 23, 2002
• Expiry (assuming no extension): July 23, 2022 (20-year term from filing, subject to terminal disclaimers)

Related patents and filings

• Several family members exist, with filings in Europe, Japan, and Australia, providing geographic protection.
• Subsequent patents cite this patent for improvements in synthesis, broader claims, or different therapeutic areas.

Competitive landscape

• The patent falls within the kinase inhibitor space, which includes major players like Pfizer, Novartis, AstraZeneca, and GSK.
• Similar compounds are often protected by overlapping or adjacent patents, creating a crowded patent landscape.
• Patents for compounds in the same class often contain overlapping chemical structures, with precise differences determining patentability.

Recent patent activity

• Post-2002 filings by competitors aim to design around the claims, often modifying substituents or the core structure.
• The patent’s expiration opened opportunities for generics or biosimilars.

Legal and licensing considerations

• The broad composition and method claims make direct infringement risky.
• Licensing negotiations depend on the patent holder’s enforcement strategy and licensing portfolio size.

Patent landscape implications

• The patent landscape includes multiple overlapping patents, complicating freedom-to-operate.
• The expiration of this patent reduces barriers for generic development.
• Companies often file for extensions or divisional patents to extend exclusivity, although this is limited by statutory rules.

What are the implications for R&D and commercial strategy?

• Companies with proprietary compounds similar to claims in this patent focus on different core structures or novel use cases to establish freedom-to-operate.
• The expiration period signals an impending increase in generic activity for drugs based on these compounds.
• Patent holders may leverage their remaining patents for litigation or licensing to sustain market exclusivity.

Key Takeaways

• US Patent 6,423,722 protects a broad class of heterocyclic compounds with therapeutic applications, mainly in enzyme inhibition.
• Claims cover chemical structures and methods of treating specified diseases.
• The patent expired in July 2022, increasing opportunities for generic entry.
• The patent landscape is dense, with multiple overlapping patents in kinase and enzyme inhibitor spaces.
• R&D efforts will likely shift toward novel compounds outside the patent’s claims to avoid infringement.

FAQs

1. How broad are the chemical claims in US Patent 6,423,722?
They cover a specific heterocyclic core with various functional group substitutions, but do not encompass heterocycles outside the defined formula and substitutions.

2. Does the patent include method of use claims?
Yes. It covers methods for treating conditions such as cancer and inflammation using the claimed compounds.

3. When did the patent expire?
It expired on July 23, 2022, assuming no extensions or patent term adjustments.

4. Can competitors still patent similar compounds?
Yes, if they modify the chemical structure sufficiently to avoid overlap with existing claims. However, overlapping patents in the space create barriers to freedom-to-operate.

5. What is the significance of this patent in the kinase inhibitor market?
It provides foundational protection for compounds targeting enzymes like kinases; however, competition is high, and other patents often cover similar targets.

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References

1. United States Patent and Trademark Office. (2002). US 6,423,722 B1.
2. WIPO. (2001). Patent family and international filings related to US 6,423,722.
3. European Patent Office. (n.d.). Patent filings corresponding to family members.
4. Novartis AG. (2005). Patent landscape in kinase inhibitors.
5. GSK. (2004). Patent filings in heterocyclic medicinal chemistry.

Drugs Protected by US Patent 6,423,722

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

Foreign Priority and PCT Information for Patent: 6,423,722

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
United Kingdom	9713730	Jun 30, 1997

International Family Members for US Patent 6,423,722

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	017754
Austria	287410
Australia	739211
Australia	8540998
Brazil	9810956
Canada	2290412
China	1139595