United States Patent 8,415,396: Colchicine Gout-Flare Claims, Patent Scope, and Generic-Entry Risk

United States Patent No. 8,415,396 protects a low-dose colchicine regimen for acute gout flares: 1.2 mg orally at flare onset followed by 0.6 mg about one hour later. The patent does not claim colchicine as a molecule, a new chemical formulation, or chronic gout prophylaxis. Its principal protection is a method-of-treatment regimen combined with pharmacokinetic limitations.

The claims cover the regimen when it produces specified ranges for apparent clearance, apparent volume of distribution, colchicine plasma concentration, maximum concentration, time to maximum concentration, and area under the concentration-time curve. The broadest independent claims are claims 1, 6, 11, and 19.

Public FDA and patent records associate this patent family with the Colcrys colchicine product and the URL Pharma/Takeda commercial franchise. The Orange Book-listed patent term is generally reported through February 27, 2029, subject to the controlling USPTO patent-term calculation and any applicable regulatory adjustments. [1–4]

What does United States Patent 8,415,396 protect?

The patent protects a specific acute-gout dosing sequence and not colchicine use generally.

Element	Required limitation
Patient	Human patient having a gout flare
First dose	Oral administration of 1.2 mg colchicine
Timing	At onset of the gout flare
Second dose	Oral administration of 0.6 mg colchicine
Second-dose timing	About one hour after the first dose
Total dose	1.8 mg over the two administrations
Dosage forms	In dependent claims, one or more 0.6 mg dosage forms
Tablet limitation	Certain dependent claims require a tablet
Release profile	Certain dependent claims require an immediate-release tablet
Food condition	Certain dependent claims expressly cover administration with or without food
Pharmacokinetics	One or more specified PK outcomes must be achieved

The claims use the transitional phrase “consisting of.” That wording narrows the claimed method to the recited treatment steps. The core regimen is therefore materially different from a claim using “comprising,” which would more readily accommodate additional unrecited treatment steps.

The patent does not expressly require the commercial brand Colcrys. A nonbranded colchicine product may fall within the claims if the product is used in the claimed manner and the required pharmacokinetic limitations are met.

How are the 26 claims organized?

The claims divide into four principal pharmacokinetic groups.

Claims 1 through 5: apparent total body clearance

Claim 1 requires an apparent total body clearance, designated CL/F, between 2.4 and 5.3 L/hour.

Claims 2 through 5 narrow the method by requiring:

One or more dosage forms containing 0.6 mg colchicine;
Tablets;
Immediate-release tablets; and
Administration with or without food.

The clearance limitation is a post-administration pharmacokinetic result. It is not a formulation composition limitation. A product may therefore have a different excipient profile from Colcrys and still raise infringement issues if the same regimen produces the claimed CL/F range.

Claims 6 through 10: apparent volume of distribution

Claim 6 requires an apparent volume of distribution, designated Varea/F, within 0.77 to 1.7 L/hr as written in the supplied claim text.

Claims 7 through 10 add the same dosage-form, tablet, immediate-release, and food-related limitations found in claims 2 through 5.

The unit in claim 6 is unusual because volume of distribution is ordinarily reported in liters rather than liters per hour. The issued patent text and prosecution record control claim interpretation. A technical challenge may focus on whether the unit is a drafting error, how the parameter was calculated, and whether a person of ordinary skill would understand the limitation as a volume rather than a rate.

Claims 11 through 18: individual-subject PK ranges

Claim 11 requires:

Cmax of 3.2 to 11.4 ng/mL; and
Tmax of 1.0 to 2.5 hours.

Claim 12 adds an AUC0-t range of 28.8 to 58.9 ng-hour/mL.

Claim 13 adds an AUC0-infinity range of 34.2 to 74.1 ng-hour/mL.

Claim 14 requires both AUC ranges.

Claims 15 through 18 add the 0.6 mg dosage-form, tablet, immediate-release, and food limitations.

These claims are potentially broader than the mean-PK claims because they are written around a measured patient or study result rather than an expressly averaged population value.

Claims 19 through 26: mean PK ranges

Claim 19 requires:

Mean Cmax of 3.8 to 8.6 ng/mL; and
Mean Tmax of 1.4 to 2.2 hours.

Claim 20 adds mean AUC0-t of 32.4 to 55.2 ng-hour/mL.

Claim 21 adds mean AUC0-infinity of 38.4 to 65.8 ng-hour/mL.

Claim 22 requires both mean AUC ranges.

Claims 23 through 26 add dosage-form and food limitations.

Mean-value claims typically depend on the defined study population, statistical method, sampling schedule, bioanalytical method, and treatment conditions. Those issues can materially affect infringement analysis.

What is the broadest practical scope of the patent?

The practical center of gravity is the acute-flare regimen itself:

1.2 mg orally at flare onset;
0.6 mg orally approximately one hour later; and
A PK profile within one of the claimed ranges.

The most commercially relevant dependent claims are claims 3, 4, 8, 9, 16, 17, 24, and 25. Together, they target 0.6 mg immediate-release tablets administered as either two tablets for the initial 1.2 mg dose or one tablet for the second 0.6 mg dose.

The claims do not require that the patient receive no other treatment during the flare. They also do not expressly exclude renal impairment, hepatic impairment, concomitant drugs, or a particular colchicine manufacturer. Those factors may affect whether the PK limitations are met, but they are not affirmative claim limitations unless incorporated through the patent specification or prosecution history.

What is excluded from the patent claims?

The patent does not, on its face, cover the following uses without additional facts establishing that the claimed regimen and PK limitations are met:

Use or product	Apparent claim position
Chronic prophylaxis of gout flares	Outside the express acute-flare method
Familial Mediterranean fever treatment	Outside the claimed indication
A single 1.2 mg dose without the second dose	Does not meet the complete regimen
0.6 mg followed by 0.6 mg	Does not meet the claimed first dose
1.8 mg administered all at once	Does not meet the two-step sequence
A second dose several hours later	Potentially outside “about one hour”
Intravenous colchicine	Outside the oral-administration limitation
Non-immediate-release dosage form	Outside claims requiring immediate release, but not necessarily outside every independent claim
Pediatric use	Not expressly excluded, but the patient must be human and the PK limitations must be satisfied
A different total dose	Outside the literal dosing sequence unless claim interpretation supports equivalence

The independent claims do not all require tablets or immediate release. A non-tablet oral dosage form could potentially implicate claims 1, 6, 11, or 19 if all other limitations are satisfied.

When does United States Patent 8,415,396 lose exclusivity?

Patent expiration

Public Orange Book and patent-family records report an expiration date of February 27, 2029 for the relevant Colcrys patent estate. [1, 2] The date should be distinguished from FDA regulatory exclusivity.

Exclusivity category	Relevant timing
Patent term	Reported through February 27, 2029
New-drug exclusivity for Colcrys	Three-year exclusivity associated with the 2009 approval
Generic approval timing	Controlled by ANDA patent certifications, litigation, settlements, and any regulatory stay
Post-expiration status	Generic launch is possible if FDA approval requirements and other listed patents do not block entry

The three-year FDA exclusivity period did not independently provide protection through 2029. The longer commercial barrier came from listed patents and associated litigation.

FDA regulatory status

FDA approved Colcrys 0.6 mg tablets for acute gout flares and gout prophylaxis in 2009. The FDA approval followed the agency’s effort to require approved applications for previously marketed unapproved colchicine products. [3] The approved acute-flare regimen corresponds to the 1.2 mg followed by 0.6 mg dosing sequence.

Colchicine is a small-molecule drug, not a biologic. Biosimilar rules under the Public Health Service Act therefore do not apply. Competition proceeds through the ANDA pathway, with applicants required to address listed patents through Paragraph IV certifications or other applicable certifications.

What is the Orange Book status of Patent 8,415,396?

Patent 8,415,396 is associated with the Orange Book patent estate for colchicine products marketed under Colcrys. Orange Book listing is commercially significant because an ANDA applicant must address the listed patent through a certification under section 505(j)(2)(A)(vii) of the Federal Food, Drug, and Cosmetic Act. [1, 4]

A Paragraph IV certification asserts that a listed patent is invalid, unenforceable, or will not be infringed by the proposed generic product. The submission can trigger patent litigation and, if litigation is filed within the statutory period, a stay of FDA approval for up to 30 months. [4]

The practical issue is not simply whether the generic tablet contains 0.6 mg colchicine. The proposed labeling, reference-product equivalence, manufacturing process, and intended dosing instructions determine whether the applicant must address method-of-use patents and whether a carve-out is feasible.

Which companies have challenged or competed against Colcrys?

The U.S. colchicine market has included generic manufacturers and applicants such as Hikma, West-Ward, Actavis/Watson, Mylan, Par Pharmaceutical, and other ANDA sponsors. The relevant competitive activity has involved Paragraph IV challenges, settlement arrangements, authorized-generic strategies, and later commercial launches.

Public patent and court records should be read together because a company may have:

Filed an ANDA without launching;
Settled litigation with a permitted future entry date;
Launched an authorized generic;
Entered after patent expiry; or
Obtained approval with a label that excludes a patented indication.

A generic colchicine product can be therapeutically substitutable while still facing litigation risk if its labeling directs the patented acute-flare regimen.

What patent litigation and settlement issues affect generic entry?

The key litigation issues for this patent are likely to involve claim construction and proof of the pharmacokinetic limitations.

“About one hour”

The phrase “about one hour” creates a timing boundary. A generic label that instructs administration one hour after the first dose is more exposed than a label that omits or narrows the patented regimen. The scope may depend on intrinsic evidence, examples, prosecution amendments, and how the Federal Circuit treats the term in context.

PK-range proof

The claimant would need to establish that the accused method produces the claimed PK outcome. Potential disputes include:

Whether PK values must be measured in every treated patient;
Whether the ranges describe expected results or mandatory outcomes;
Whether a population mean is required;
Whether the accused product must use the same assay;
Whether fed and fasted administration produce separate claim outcomes;
Whether variability outside the claimed range defeats infringement; and
Whether a product’s label alone can establish induced infringement.

Label-based infringement

Because the patent is a method-of-use patent, an ANDA label may create substantial risk if it instructs the patented dosing sequence. A skinny-label strategy may reduce risk for a carved-out indication, but it is less effective where the patented regimen is part of the remaining approved labeling or where the label encourages the patented use.

How strong is the patent estate for Colcrys?

The patent estate is technically narrow but commercially relevant.

Strength factor	Assessment
Product composition protection	Weak or absent in this patent
Acute-gout regimen protection	Strong on the literal dosing sequence
Formulation protection	Narrow; dependent claims focus on dosage form and release profile
PK protection	Potentially significant but fact-intensive
Chronic prophylaxis protection	Not the focus of the supplied claims
Generic substitution risk	High if the generic label mirrors the acute-flare regimen
Design-around potential	Meaningful through timing, label, formulation, or indication strategy
Litigation complexity	High because of “about,” PK variability, and mean-versus-individual parameters

The patent’s main vulnerability is that PK limitations can be difficult to enforce predictably. The main strength is that the claimed regimen is simple, clinically standard, and likely to appear in generic labeling that references the FDA-approved acute-flare dosing instructions.

How does this patent compare with formulation and method-of-use patents?

Patent 8,415,396 is a regimen and pharmacokinetic patent.

Patent type	Typical protection	Relevance to 8,415,396
Active-ingredient patent	Colchicine molecule	Not the subject of these claims
Composition patent	Tablet ingredients or solid form	Not the subject of these claims
Formulation patent	Release profile, excipients, dosage form	Present only through dependent claims
Method-of-use patent	Treating a defined disease with a defined regimen	Primary protection
PK patent	Treatment producing defined exposure values	Central to claims 1, 6, 11, and 19
Manufacturing patent	Synthesis, purification, or tablet production	Not claimed in the supplied text

A generic manufacturer may avoid a formulation patent through a different excipient system while still infringing a method patent. Conversely, a product can be chemically and pharmaceutically different from Colcrys yet face risk if its label directs the same dosing method and produces the claimed PK profile.

What generic launch scenarios exist?

Full-label launch after patent expiry

This is the lowest patent-risk scenario once all relevant Orange Book patents have expired or become unenforceable. The generic can market the acute-flare regimen and prophylaxis if approved labeling supports both uses.

Paragraph IV launch

An ANDA sponsor may certify that the patent is invalid, unenforceable, or not infringed. Launch risk depends on litigation outcome, settlement terms, damages exposure, and the sponsor’s ability to defend the PK and timing limitations.

Label carve-out

A sponsor may omit a patented method from its labeling when FDA permits a section viii statement. This strategy is more workable where the patented use is separable from an unpatented indication. It is less effective if the challenged regimen is embedded in the core acute-gout labeling.

Authorized generic or settlement entry

The brand owner may permit entry before patent expiry through an authorized generic, license, or litigation settlement. Such an arrangement can materially reduce the value of an independent Paragraph IV launch while preserving branded economics until the agreed entry date.

What revenue exposure does the patent create?

The patent protects the acute-flare dosing method rather than the entire colchicine market. Revenue exposure therefore depends on:

The share of Colcrys prescriptions used for acute flares;
Whether generic labels reproduce the 1.2 mg plus 0.6 mg regimen;
The ability to enforce PK limitations;
The presence of other listed patents;
Settlement-controlled entry dates;
Authorized-generic economics; and
Pricing erosion after generic launch.

The principal commercial risk is substitution of 0.6 mg generic tablets for branded Colcrys tablets. Because the patented regimen uses three 0.6 mg units in total, a generic product does not need a new strength or complex delivery system to compete.

Key Takeaways

Patent 8,415,396 covers oral colchicine treatment of an acute gout flare using 1.2 mg followed by 0.6 mg about one hour later.
The independent claims add PK limitations involving CL/F, Varea/F, Cmax, Tmax, AUC0-t, AUC0-infinity, or mean values.
Dependent claims narrow the regimen to 0.6 mg dosage forms, tablets, immediate-release tablets, and administration with or without food.
The patent does not claim colchicine as a molecule or broadly cover chronic gout prophylaxis.
The patent is associated with the Colcrys Orange Book estate, with public records reporting expiration through February 27, 2029.
Generic risk is highest where an ANDA label reproduces the FDA acute-flare dosing sequence.
The main litigation pressure points are “about one hour,” PK measurement methodology, individual versus mean values, and whether label instructions establish induced infringement.
Colchicine is a small molecule, so biosimilar law is irrelevant. Competition proceeds through the ANDA pathway.

FAQs

Can a generic company sell 0.6 mg colchicine before February 2029?

Potentially, but only through a permitted pathway such as a successful Paragraph IV challenge, a settlement or license, an authorized-generic arrangement, a label carve-out, or another approval structure that avoids blocking patents.

Does Patent 8,415,396 cover colchicine prophylaxis?

The supplied claims focus on treatment of a gout flare. They do not expressly claim chronic prophylactic administration.

Does taking three 0.6 mg tablets infringe the patent automatically?

No. Tablet count alone is insufficient. The claimed regimen also requires the timing, acute-flare indication, oral administration, and applicable pharmacokinetic result.

Can a different colchicine formulation avoid this patent?

Possibly, but not automatically. The independent claims do not uniformly require tablets or immediate release. A different formulation may still implicate an independent method claim if it is used in the claimed regimen and produces the required PK profile.

Are biosimilar applicants relevant to Colcrys?

No. Colchicine is a small-molecule drug. The relevant competitors are ANDA applicants and generic manufacturers, not biosimilar sponsors.

References

U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book.
United States Patent and Trademark Office. (2013). U.S. Patent No. 8,415,396, Methods of treating gout with colchicine.
U.S. Food and Drug Administration. (2009). Colcrys prescribing information.
U.S. Food and Drug Administration. (2024). ANDA submissions: Patent certification and suitability petitions.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Takeda Pharms Usa	COLCRYS	colchicine	TABLET;ORAL	022352-001	Jul 29, 2009		DISCN	Yes	No	8,415,396	⤷ Start Trial				METHOD OF TREATING GOUT FLARES	⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Details for Patent: 8,415,396

Which drugs does patent 8,415,396 protect, and when does it expire?

Summary for Patent: 8,415,396