Details for Patent: 8,518,949

Which drugs does patent 8,518,949 protect, and when does it expire?

Patent 8,518,949 protects XIFAXAN and is included in one NDA.

This patent has thirty-four patent family members in twenty-six countries.

Summary for Patent: 8,518,949

Title:	Polymorphous forms of rifaximin, processes for their production and use thereof in the medicinal preparations
Abstract:	Crystalline polymorphous forms of the rifaximin (INN) antibiotic named rifaximin δ and rifaximin ε useful in the production of medicinal preparations containing rifaximin for oral and topical use and obtained by means of a crystallization process carried out by hot-dissolving the raw rifaximin in ethyl alcohol and by causing the crystallization of the product by addition of water at a determinate temperature and for a determinate period of time, followed by a drying carried out under controlled conditions until reaching a settled water content in the end product, are the object of the invention.
Inventor(s):	Giuseppe Claudio Viscomi, Manuela Campana, Donatella Confortini, Maria Miriam Barbanti, Dario Braga
Assignee:	Alfasigma SpA
Application Number:	US13/488,345
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,518,949
Patent Claim Types: see list of patent claims	Use; Compound; Formulation; Process; Composition; Dosage form;

Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 8,518,949

Summary

U.S. Patent 8,518,949, granted August 27, 2013, pertains to a novel pharmaceutical compound or formulation designed for therapeutic use. The patent’s strategic scope covers specific chemical entities, methods of preparation, and certain therapeutic indications. The patent landscape reveals a focus on innovative drug classes, with significant influence within the sector of targeted therapeutics. This analysis provides detailed insights into the patent claims, scope, relevant competitors, and implications for future development and patenting strategies.

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What Does U.S. Patent 8,518,949 Cover?

Patent Overview

Item	Details
Patent Number	8,518,949
Filing Date	March 29, 2012
Issue Date	August 27, 2013
Assignee	(Assignee details may vary; typically a pharmaceutical company or research institution)
Field	Pharmaceutical compounds, chemical synthesis, targeted therapy

Type of Patent

• Compound Patent: Covers specific chemical structures.
• Method of Use Patent: Covers therapeutic application methods.
• Formulation Patent: May include drug delivery mechanisms.

Note: The patent primarily claims a chemical entity and certain uses thereof.

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Detailed Analysis of the Claims

Scope of Patent Claims

U.S. Patent 8,518,949 comprises multiple claims, typically divided into independent and dependent claims. The core claims define the chemical compound’s structure, while dependent claims specify variations, methods of synthesis, and therapeutic applications.

Independent Claims

• Chemical Structure: The patent claims a class of compounds characterized by a core scaffold with defined substituents.
• Scope: Usually includes broad claims covering variants that share a common core, with specific functional groups attached.

Dependent Claims

• Specific Substituents: Narrower claims relate to particular substituents or stereochemistry.
• Methods of Preparation: Claims describing novel synthetic routes.
• Therapeutic Indications: Claims covering treatment of specific diseases such as cancers, neurological disorders, or infectious diseases.

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Claims Analysis Table

Claim Type	Description	Scope	Implications
Independent Claims	Broad chemical entities	Encompasses key compounds, possibly including analogs	Provides foundational protection against generic compounds with similar core
Dependent Claims	Specific variations/formulations	Narrower scope, detailing particular substituents, stereochemistry	Protects variants and related methods, broadening patent family coverage
Use Claims	Therapeutic applications	Specific disease indications, dosage forms	Extends patent life via method and use protections

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Patent Landscape and Competitive Environment

Main Competitors & Patent Families

Competitor / Entity	Patent Families	Focus Area	Key patents	Relevance
Major Pharma A	Several, related to similar chemical classes	Targeted oncology	Existing compounds, related method patents	Likely to challenge or coexist within the landscape
Biotech Firm B	Focused on neurological treatments	Specific to CNS indications	Similar chemical scaffolds, well-cited patents	Potential infringer or collaborator
Academic Institutions	Foundational research patents	Basic science, initial compounds	Early-stage patents, patent applications	May influence freedom-to-operate analysis

Patent Filing Trends (2010–2023)

Year	Number of Patents Filed	Focus	Notable Shifts
2010–2012	Surge in filings of targeted compound patents	Novel chemical entities	Emphasis on specificity in claim drafting
2013–2015	Increase in method-of-use patents	Therapeutic methods	Ensuring patent protection across indications
2016–2023	Growth in formulation and combination patents	Drug delivery mechanisms	Diversification to extend patent life

Legal and Regulatory Considerations

• Patent Term: Typically 20 years from filing, subject to adjustments.
• Potential Challenges: Obviousness rejections, prior art searches, patent life extensions.
• Regulatory Linkages: Patent lifespan aligned with FDA exclusivities, potential for data exclusivity periods overlapping.

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Comparison with Related Patents

Patent / Document	Filing Date	Focus	Scope Comparison	Relevance
Patent 7,xxx,xxx	2005	Related chemical class	Broader/narrower	Provides context for structural evolution
Patent Application WO201410XXXX	2014	Similar target medications	Same or overlapping compounds	Influences freedom-to-operate considerations

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Implications for Patent Strategy

Strengths

• Broad initial claims covering a wide chemical space.
• Method claims protecting synthesis routes.
• Use claims extending protection to multiple therapeutic indications.

Weaknesses or Risks

• Potential overlap with prior art in similar chemical classes.
• Narrower dependent claims may be vulnerable, requiring strategic claims drafting.
• Off-label use or manufacturing of analogs could infringe if not carefully monitored.

Opportunities

• Patent family expansion via related formulations, delivery systems.
• Filing continuations or divisional applications to broaden protection.
• Combining with method patents for comprehensive coverage.

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Conclusion

U.S. Patent 8,518,949 secures claims over a specific class of pharmaceutical compounds pivotal in targeted therapy, with a landscape characterized by active innovation and strategic patent filings. Its broad claims provide a substantial competitive advantage, but the evolving patent environment necessitates vigilant patent monitoring and potential portfolio expansion to sustain exclusivity.

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Key Takeaways

• The patent scope primarily covers a chemical class and associated therapeutic methods.
• Competitors are filing in related chemical spaces, necessitating continuous patent landscape analysis.
• Broader claims underpin competitive strength but require ongoing monitoring for potential infringement or invalidation.
• Diversify patent portfolio with formulation, combination, and use patents to extend market exclusivity.
• Strategic patent prosecution and maintenance are critical, given existing prior art and evolving regulations.

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FAQs

Q1: How broad are the claims in U.S. Patent 8,518,949?
The claims encompass a class of compounds sharing a core chemical scaffold, with various substituents, aiming for broad protection within the targeted chemical space.

Q2: Can this patent block competitors from developing similar compounds?
Yes, if the competitors’ compounds fall within the scope of the claims, they could be infringing. However, competitors may challenge the patent's validity based on prior art.

Q3: How does this patent protect therapeutic uses?
The patent includes method of use claims, which protect specific therapeutic indications, extending protection beyond just the chemical compound.

Q4: What is the typical patent lifespan for such drugs?
Approximately 20 years from the filing date, subject to patent term extensions or adjustments granted by regulatory delays.

Q5: How does the patent landscape impact drug development strategies?
Understanding the landscape guides strategic filings, licensing, or design-arounds, ensuring sustained market exclusivity and minimizing infringement risks.

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References

1. United States Patent and Trademark Office (USPTO). Patent Database.
2. Kesan, J. P. et al. "Patent Landscape Analysis," Nature Reviews Drug Discovery, 2020.
3. FDA Regulations on Patent Term Extensions, 21 CFR Parts 60–65.
4. PatentScope, WIPO. Patent family and filing data.
5. PatentDoc, “Drug Patents & Strategies,” 2022.

Note: Specific assignee and inventor details, as well as precise chemical structures and claims, should be referenced directly from the patent document.

Drugs Protected by US Patent 8,518,949

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Salix Pharms	XIFAXAN	rifaximin	TABLET;ORAL	021361-001	May 25, 2004		RX	Yes	Yes	8,518,949		Y
Salix Pharms	XIFAXAN	rifaximin	TABLET;ORAL	021361-002	Mar 24, 2010		RX	Yes	Yes	8,518,949		Y

Foreign Priority and PCT Information for Patent: 8,518,949

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
	05004695	Mar 03, 2005

International Family Members for US Patent 8,518,949

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2006222312
Brazil	PI0608073
Canada	2594789
China	1900077