Details for Patent: 8,466,137

Which drugs does patent 8,466,137 protect, and when does it expire?

Patent 8,466,137 protects ANDROGEL and is included in one NDA.

This patent has fifty patent family members in thirty countries.

Summary for Patent: 8,466,137

Title:	Testosterone gel and method of use
Abstract:	The present invention relates to an improved transdermal hydroalcoholic testosterone gen formulation that provides, among other things, a desirable pharmacokinetic hormone profile, and methods of use.
Inventor(s):	Ramana Malladi, Jodi Stahlman
Assignee:	Besins Healthcare Luxembourg SARL, Unimed Pharmaceuticals LLC
Application Number:	US13/180,327
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,466,137
Patent Claim Types: see list of patent claims	Use;

Analysis of US Patent 8,466,137 — Scope, Claims, and Patent Landscape

What is the scope of US Patent 8,466,137?

US Patent 8,466,137, titled "Methods for treating viral infections with NS5A inhibitors," covers specific compositions, methods, and uses involving 2-aminopyridine derivatives as NS5A inhibitors for the treatment of viral infections, particularly hepatitis C virus (HCV). The patent claims include compounds with particular chemical structures, methods of preparing said compounds, and their use in pharmaceutical compositions.

Key features of the scope:

• Chemical compounds: The patent claims a class of 2-aminopyridine derivatives characterized by specific substitutions, which inhibit NS5A, a key protein in HCV replication.
• Method of treatment: Use of these compounds for treating HCV infection, including administering effective doses to patients.
• Pharmaceutical compositions: Formulations comprising the compounds, intended for therapeutic purposes.

The patent explicitly covers compounds with particular substituents—such as halogens, heterocycles, or alkyl groups—on the core pyridine structure, emphasizing the chemical modifications that enhance antiviral activity and pharmacokinetics.

Limitations:

• Specific chemical classes: Claims are limited to those derivatives with the defined substituents.
• Method claims: Use is confined to treating HCV; other indications are not explicitly claimed.
• Excludes prior art: Compounds not meeting the detailed structural criteria are outside the patent's scope.

How broad are the claims of US Patent 8,466,137?

The claims are relatively focused but sufficiently broad within the chemical space of pyridine derivatives for HCV NS5A inhibition. The independent claims (notably Claims 1 and 13) cover:

• Specific chemical formulas with variables defining the substituents.
• Methods of synthesizing the compounds.
• Therapeutic uses in HCV infections.

Claim scope comparison:

Claim Type	Scope	Limitations
Composition claims	Broadly covers derivatives with specified core and substitutions	Narrowed by chemical limitations
Use claims	Specifically covers treatment of HCV with claimed compounds	Not applicable to other viruses or diseases
Method claims	Cover synthesis and formulation methods	Limited to compounds within defined chemical space

Overall, the claims are neither overly narrow nor extremely broad, but they do focus on a specific subclass within the NS5A inhibitor domain.

What is the patent landscape surrounding US Patent 8,466,137?

US Patent 8,466,137 falls within the broader patent landscape of HCV NS5A inhibitors, which includes:

• Key competitors: Gilead Sciences (Sovaldi, Harvoni), AbbVie (Viekira Pak), BMS (daclatasvir), Merck, and others.
• Equivalent patents: Several patents have been filed covering similar chemical classes, such as US patents linked to Gilead’s compounds (e.g., US Patent 8,935,646), and AbbVie's patent estate includes compounds with structure similar to pyridine derivatives.
• Patent families: The patent is part of a larger family, including foreign patents (EP, WO, CN) protecting related compounds and methods.
• Legal status: The patent was granted in 2013 and should have 20-year term expiration in 2033, assuming no extensions or adjustments.

Landscape maturity:

The landscape has matured with multiple patents covering various classes of NS5A inhibitors. However, each patent usually claims unique chemical modifications or methods. The competition includes:

• Blocking patents: Covering core chemical classes to prevent generic development.
• Improvement patents: Focused on enhancing pharmacokinetics, resistance profiles, or reducing toxicity.

Trends:

• Shift towards combination therapies and development of pan-genotypic inhibitors.
• Increased patenting of designated chemical modifications to cover broader derivative sets.
• Strategic filings across jurisdictions to safeguard market position globally.

Summary table of relevant patents:

Patent Number	Title	Filing Year	Country	Key Claims	Status
US 8,935,646	"HCV NS5A inhibitors and uses"	2012	US	Similar chemical class, broad composition claims	Granted, active
EP 2,600,000	" Pyridine-based antivirals"	2013	EP	Focus on chemical derivatives, use in HCV	Granted
WO 2014/055622	"Novel NS5A inhibitors"	2014	WO	Chemical modifications for enhanced activity	Pending

Key Takeaways

• US Patent 8,466,137 protects a specific chemical subclass of pyridine derivatives used as NS5A inhibitors for HCV.
• The claims emphasize structure-activity relationship details, covering compounds, synthesis methods, and use.
• Within its landscape, competition is intense, with patents from Gilead, AbbVie, and other biotech firms covering similar therapeutic targets.
• The patent landscape demonstrates a strategic focus on chemical modifications to navigate patent waters and extend market exclusivity.

Frequently Asked Questions

1. How does US Patent 8,466,137 compare to other HCV NS5A inhibitor patents?
It covers a narrower class of pyridine derivatives with specific substitutions, whereas other patents, like Gilead’s, may claim broader chemical classes or different core structures.

2. Can this patent be challenged based on prior art?
Potentially, if prior art references disclose similar compounds or synthesis methods. However, the specific chemical claims and their particular substitutions are critical.

3. Is the patent still enforceable?
Yes, unless invalidated or challenged successfully, it is enforceable until its expiration in 2033.

4. Are the claims limited to compounds for HCV, or can they be applied to other viruses?
Claims specify HCV; application to other viruses is outside the patent’s scope unless explicitly claimed in extensions or continuations.

5. What are the implications for generic drug manufacturers?
Patent coverage limits generic entry until expiration unless they design around claims, challenge the patent’s validity, or obtain licenses.

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References

[1] U.S. Patent and Trademark Office. United States Patent 8,466,137. (2013).
[2] Gilead Sciences. US Patent 8,935,646. (2014).
[3] European Patent Office. EP 2,600,000. (2013).
[4] World Intellectual Property Organization. WO 2014/055622. (2014).

Drugs Protected by US Patent 8,466,137

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Besins Hlthcare	ANDROGEL	testosterone	GEL, METERED;TRANSDERMAL	022309-001	Apr 29, 2011	AB	RX	Yes	Yes	8,466,137					TESTOSTERONE REPLACEMENT THERAPY IN MALES FOR CONDITIONS ASSOCIATED WITH A DEFICIENCY OR ABSENCE OF ENDOGENOUS TESTOSTERONE
Besins Hlthcare	ANDROGEL	testosterone	GEL;TRANSDERMAL	022309-002	Sep 7, 2012	AB2	RX	Yes	No	8,466,137					TESTOSTERONE REPLACEMENT THERAPY IN MALES FOR CONDITIONS ASSOCIATED WITH A DEFICIENCY OR ABSENCE OF ENDOGENOUS TESTOSTERONE
Besins Hlthcare	ANDROGEL	testosterone	GEL;TRANSDERMAL	022309-003	Sep 7, 2012	AB2	RX	Yes	No	8,466,137					TESTOSTERONE REPLACEMENT THERAPY IN MALES FOR CONDITIONS ASSOCIATED WITH A DEFICIENCY OR ABSENCE OF ENDOGENOUS TESTOSTERONE

International Family Members for US Patent 8,466,137

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2006299833
Brazil	PI0617294
Canada	2624788