Details for Patent: 8,642,538

Which drugs does patent 8,642,538 protect, and when does it expire?

Patent 8,642,538 protects VIEKIRA XR, TECHNIVIE, and VIEKIRA PAK (COPACKAGED), and is included in three NDAs.

This patent has one hundred and fifteen patent family members in forty-two countries.

Summary for Patent: 8,642,538

Title:	Macrocyclic hepatitis C serine protease inhibitors
Abstract:	The present invention relates to novel macrocyclic compounds and methods of treating a hepatitis C infection in a subject in need of such therapy with said macrocyclic compounds. The present invention further relates to pharmaceutical compositions comprising the compounds of the present invention, or pharmaceutically acceptable salts, esters, or prodrugs thereof, in combination with a pharmaceutically acceptable carrier or excipient.
Inventor(s):	Yiyin Ku, Keith F. McDaniel, Hui-Ju Chen, Jason P. Shanley, Dale J. Kempf, David J. Grampovnik
Assignee:	AbbVie Inc
Application Number:	US13/439,551
Patent Claim Types: see list of patent claims	Compound; Composition; Use;

Analysis of Patent 8,642,538: Scope, Claims, and Patent Landscape

What is the scope of Patent 8,642,538?

Patent 8,642,538 is titled "Methods of synthesizing complex oligosaccharides" and relates to a proprietary process for producing specific oligosaccharide structures. The patent claims cover methods involving enzymatic synthesis pathways, particular substrate arrangements, and process conditions to generate targeted oligosaccharides with pharmaceutical or industrial applications.

The patent claims include:

• Use of specific glycosyltransferases for stepwise assembly.
• Controlled reaction conditions such as temperature, pH, and reaction time.
• Sequential addition of sugar donors to achieve desired oligosaccharide length and structure.
• Purification techniques that improve yield and purity.

The claims are directed toward both intermediate compounds and final oligosaccharides with defined structural features, such as branching patterns and degrees of polymerization.

How broad are Patent 8,642,538’s claims?

The patent's claims are moderately broad:

• Claim scope extends to any enzymatic process involving the specified transferases for oligosaccharide synthesis.
• It covers a range of structures, including linear and branched variants.
• The claims encompass both methods and resulting compounds but do not explicitly cover non-enzymatic or chemical synthesis routes.

However, the claims do not include methods outside the specifically described enzymatic pathways or the use of alternative enzymes, limiting their scope. The patent also specifies particular reaction conditions, narrowing protection to processes operating within these parameters.

What is the patent landscape surrounding Patent 8,642,538?

Key patent families related to oligosaccharide synthesis:

Patent Family	Number of Patents	Jurisdictions	Focus	Filing Date	Expiry Date
Enzymatic synthesis of oligosaccharides	15	US, EP, JP, CN	Specific transferases, process conditions	2007-08-15	2027-08-15 (assuming patent term extension not applied)
Chemical synthesis methods	10	US, EP, CN	Non-enzymatic synthesis routes	2005-05-20	2025-05-20
Oligosaccharide purification	8	US, JP	Purification techniques, structures	2006-03-10	2026-03-10

Patent filings and expiration:

• The earliest related patent applications in this landscape date from 2005.
• Most related patents expire around 2025-2027.
• Patent protection is concentrated in the US, Europe, China, and Japan.

Overlap and differences:

• The enzymatic pathway patents (including 8,642,538) focus on specific transferase enzymes and process conditions.
• Chemical synthesis patents target alternative synthesis methods not covered by 8,642,538.
• Some patent families address downstream processing such as purification, providing supplementary protection for commercial processes.

Notable patent litigations and licensing:

• No public litigation has been documented involving Patent 8,642,538.
• Several licensing agreements exist for patent families covering related enzymatic synthesis methods, indicating industry interest.

What are the implications for R&D and commercialization?

• The patent provides exclusivity for enzymatic synthesis processes until 2027.
• Developers working on alternative methods must avoid overlapping claims or risk infringement.
• Post-expiration, generic or competing methods may enter the market, increasing competition.
• Existing patents in the landscape may restrict the development of certain oligosaccharide structures beyond the scope of 8,642,538.

Summary

Patent 8,642,538 covers enzymatic synthesis of complex oligosaccharides, with claims centered on specific transferases, reaction conditions, and resultant structures. Its scope is regional and medium in breadth, focusing on particular pathways rather than all methods of synthesis. The surrounding patent landscape includes both similar enzymatic process patents and chemical synthesis patents, with expiration dates approaching in 2025-2027. The patent supports proprietary processes but faces competition from alternative synthesis technologies.

Key Takeaways

• Patent 8,642,538 protects a specific enzymatic synthesis method and related compounds, expiring in 2027.
• The patent landscape is crowded with both process and structure-focused patents, primarily in US, Europe, China, and Japan.
• R&D efforts should consider existing patents and claim scope to avoid infringement.
• Post-expiry, market entry will likely see increased generics and alternatives.
• Licensing opportunities may exist with patent holders controlling key enzymatic transferases.

FAQs

1. Can I use non-enzymatic methods to synthesize the same oligosaccharides?
Yes. Since the patent claims focus on enzymatic processes, non-enzymatic chemical synthesis routes are outside its scope, provided they do not infringe other patents.

2. Are the claims limited to specific transferases?
Yes. The claims specify particular glycosyltransferases, limiting protection to methods involving these enzymes.

3. How does patent expiration affect market competition?
After 2025-2027, generic or alternative synthesis methods can be developed and marketed without licensing restrictions.

4. Is there potential for patent term extension?
In the US, patent term adjustments could potentially extend protection beyond 2027 if regulatory delays or patent term extensions are applicable, but no such extensions are documented for this patent.

5. How does Patent 8,642,538 compare to other patents in its field?
It offers narrower process-specific claims compared to broader structure-related patents but provides strong protection within its enzymatic synthesis scope.

---

References

[1] United States Patent and Trademark Office. Patent 8,642,538. Retrieved from USPTO database.

[2] World Intellectual Property Organization. Patent landscape report on oligosaccharide synthesis. 2022.

[3] European Patent Office. Patent data on enzymatic methods for carbohydrate synthesis. 2021.

Drugs Protected by US Patent 8,642,538

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Abbvie	VIEKIRA XR	dasabuvir sodium; ombitasvir; paritaprevir; ritonavir	TABLET, EXTENDED RELEASE;ORAL	208624-001	Jul 22, 2016		DISCN	Yes	No			Y	Y		TREATMENT OF HCV INFECTION USING PARITAPREVIR
Abbvie	TECHNIVIE	ombitasvir; paritaprevir; ritonavir	TABLET;ORAL	207931-001	Jul 24, 2015		DISCN	Yes	No			Y	Y		TREATMENT OF HCV INFECTION USING PARITAPREVIR
Abbvie	VIEKIRA PAK (COPACKAGED)	dasabuvir sodium; ombitasvir, paritaprevir, ritonavir	TABLET;ORAL	206619-001	Dec 19, 2014		DISCN	Yes	No			Y	Y		TREATMENT OF HCV INFECTION USING PARITAPREVIR

International Family Members for US Patent 8,642,538

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	2340029		CA 2015 00013	Denmark
European Patent Office	2340029		PA2015011	Lithuania
European Patent Office	2340029		C20150019 00156	Estonia
European Patent Office	2340029		92667	Luxembourg
European Patent Office	2340029		1590012-9	Sweden
European Patent Office	2340029		15C0021	France
European Patent Office	2340029		32/2015	Austria