Details for Patent: 7,601,758

US Patent 7,601,758: Colchicine, Clarithromycin, Erythromycin, and Gout-Flare Patent Landscape

US Patent 7,601,758 covers reduced-dose colchicine treatment for an acute gout flare when the patient is receiving clarithromycin or erythromycin. The core regimen is a dose reduction of approximately two-thirds, followed by no repeat colchicine administration for at least three days. The patent issued October 13, 2009, and was listed for Colcrys, Takeda Pharmaceuticals’ colchicine product.

The patent’s practical value was narrowed by litigation. In Takeda Pharmaceuticals U.S.A., Inc. v. West-Ward Pharmaceutical Corp., the Federal Circuit affirmed a ruling that the asserted claims were obvious over the prior art. The patent therefore remains relevant to Orange Book history, label design, and patent-landscape analysis, but its enforceability against competing colchicine products is materially limited. [1]

What does US Patent 7,601,758 protect?

The patent claims a drug-treatment method rather than colchicine itself, a colchicine formulation, or the use of colchicine for gout generally.

Its central combination requires:

1. A human patient experiencing a gout flare.
2. Colchicine treatment.
3. Concomitant administration of clarithromycin or erythromycin.
4. A reduced colchicine dosage.
5. A reduction of approximately two-thirds from the ordinary colchicine dose, or a reduced amount of approximately 50% to 75% under claim 10.
6. No repeat colchicine administration for at least three days.

Claim 1 is the primary method claim. It requires determining an ordinary colchicine amount, determining a second amount reduced by about two-thirds, administering that second amount orally, and withholding repeat colchicine for at least three days.

Claim 10 is a second independent method claim. It focuses on reducing colchicine toxicity by administering approximately 50% to 75% of the manufacturer’s recommended dose.

Patent identification and prosecution data

The patent does not claim a new colchicine molecule. Its subject matter is the clinical use of a known drug in a defined drug-drug-interaction setting.

How do the claims of US 7,601,758 operate?

Claim 1: The broadest principal claim

Claim 1 is limited by several cumulative requirements. A competing product or treatment protocol would need to satisfy each material limitation for literal infringement.

The claim requires a clinician or treatment protocol to:

• identify the normal colchicine dose for an acute gout flare;
• reduce that amount by about two-thirds;
• administer the reduced dose orally;
• treat a patient receiving clarithromycin or erythromycin within the specified concomitant-use period; and
• avoid repeating colchicine for at least three days.

The claim is narrower than a general claim covering all dose reductions with macrolide antibiotics. It is limited to two named antibiotics and to an acute gout flare.

Claims 2 through 4: How the reduction is implemented

These claims divide the two-thirds reduction into three possible mechanisms:

This structure attempts to capture different dosing schedules. A regimen can fall within the dependent claims even if the reduction is achieved by changing frequency rather than tablet strength.

Claims 5 and 6: Patient age

Claim 5 limits the patient to an adult. Claim 6 narrows the adult population to patients younger than 70.

These limitations reduce the scope of the claims but may align with the patient population studied or reflected in the product labeling. They also create potential evidentiary issues because age is a patient characteristic, not a property of the drug product.

Claim 7: Clarithromycin-only treatment

Claim 7 narrows claim 1 to clarithromycin. It excludes erythromycin from the dependent claim but remains subject to the other limitations of claim 1.

The clarithromycin limitation is commercially significant because clarithromycin is a strong CYP3A4 and P-glycoprotein interaction concern for colchicine. The interaction can increase systemic colchicine exposure and the risk of neuromuscular, hematologic, renal, and multisystem toxicity. [2]

Claims 8 and 9: The 1.8 mg to 0.6 mg regimen

Claim 8 identifies a specific example:

• ordinary amount: approximately 1.8 mg per day;
• reduced amount: approximately 0.6 mg per day.

Claim 9 narrows this further to a single 0.6 mg dose followed by no repeat colchicine administration for at least three days.

This is the claim set most closely associated with the clinically recognizable reduced-dose regimen for an acute gout flare in a patient receiving clarithromycin or erythromycin.

Claims 10 and 11: Toxicity-reduction formulation

Claim 10 is independently drafted and does not require the precise two-thirds reduction in claim 1. It covers:

• an adult human gout patient;
• concomitant clarithromycin or erythromycin;
• a colchicine amount equal to about 50% to about 75% of the manufacturer’s recommended amount; and
• no repeat colchicine administration for at least three days.

Claim 11 narrows the reduced amount to approximately 0.6 mg per day.

Claim 10 is potentially broader in percentage terms than claim 1 but still contains the macrolide, gout-flare, adult-patient, and three-day non-repetition limitations.

What are the key claim-construction and infringement issues?

What does “about” mean?

The claims use “about two thirds,” “about 1.8 mg,” “about 0.6 mg,” and “about 50% to about 75%.” These terms create numerical flexibility but do not eliminate the need to show that the accused regimen falls within the claimed range.

A 0.6 mg tablet given once is the clearest example for claims 8, 9, and 11. A protocol using a different tablet strength or dose frequency would require a fact-specific analysis.

What does “concomitant administration” require?

The claims expressly define concomitant administration as administration of clarithromycin or erythromycin within one to two days of oral colchicine administration.

This limitation is important. The patent does not cover every historical use of colchicine by a patient who previously received a macrolide. The timing relationship must fall within the claim’s defined window.

What does “not repeating colchicine” require?

The claims require no repeat colchicine for at least three days. A regimen that administers an initial reduced dose and then repeats colchicine within the three-day period presents the strongest literal-infringement distinction.

The limitation applies to administration, not merely prescribing. A patent analysis would therefore examine the label, physician instructions, dispensing information, and actual use pattern.

Are product claims implicated?

No. US 7,601,758 does not claim:

• colchicine as a chemical compound;
• a colchicine tablet;
• a fixed-dose colchicine formulation;
• a sustained-release formulation;
• a manufacturing process;
• a pharmaceutical composition; or
• a method of treating gout without the specified macrolide interaction.

The patent is a method-of-use patent.

What is the Orange Book status of US 7,601,758?

US 7,601,758 was listed in the FDA Orange Book for Colcrys. Orange Book listing gives the patent regulatory significance in the ANDA process, but listing does not establish that the patent claims are valid or infringed. The listed patent was directed to the drug’s use in acute gout flares when clarithromycin or erythromycin is administered concomitantly. [3]

FDA approval and labeling timeline

The FDA-approved label describes dose reductions and restrictions for colchicine used with strong CYP3A4 or P-glycoprotein inhibitors. Clarithromycin is specifically important because of its interaction profile. [2]

When does US 7,601,758 lose exclusivity?

The patent’s public Orange Book term date is commonly reported as October 2, 2028. That date should be distinguished from practical enforceability.

The Federal Circuit’s decision in Takeda v. West-Ward affirmed invalidity based on obviousness for the asserted claims. As a result, the patent’s nominal term does not represent an intact enforceable barrier through 2028. [1]

What patent litigation affects US 7,601,758?

Takeda Pharmaceuticals v. West-Ward Pharmaceutical

The principal reported litigation was brought after West-Ward submitted an ANDA for colchicine tablets. Takeda asserted Colcrys-related patents, including US 7,601,758.

The Federal Circuit affirmed the district court’s obviousness determination. The decision focused on whether the claimed dose reduction was an inventive application of known information about colchicine toxicity and interactions with CYP3A4-inhibiting drugs. [1]

The litigation established several commercial points:

• the patent was exposed to an ANDA Paragraph IV challenge;
• the claims were evaluated as method claims tied to clinical dosing;
• prior-art warnings about colchicine toxicity and macrolide interactions were central;
• the patent did not provide a durable barrier to generic colchicine competition.

Paragraph IV significance

An ANDA applicant can submit a Paragraph IV certification asserting that an Orange Book-listed patent is invalid, unenforceable, or not infringed. The certification can trigger litigation under the Hatch-Waxman Act.

For this patent, an applicant could challenge:

• the validity of the two-thirds reduction;
• the obviousness of the 0.6 mg regimen;
• the adequacy of the written description;
• the meaning of “about”;
• the defined concomitant-use period; and
• whether the proposed label induces use within the claims.

The West-Ward litigation demonstrated that a generic applicant did not need to avoid the interaction-related indication merely by using a different commercial presentation. The critical issue was whether the proposed product and label created a legally actionable method-of-use risk.

Which companies challenged or competed against the Colcrys patent estate?

The main competitive pressure came from generic colchicine applicants rather than biosimilar developers. Colchicine is a small-molecule drug, so the relevant pathway is ANDA approval, not the FDA biosimilar pathway under the Public Health Service Act.

Competitive participants

The commercial dispute involved multiple Colcrys-related patents, not only US 7,601,758. Other patents addressed dosing, treatment regimens, or product-related protection. A complete freedom-to-operate review must therefore separate the status of the ’758 patent from the status of other listed patents.

What formulation patents protect colchicine?

US 7,601,758 does not protect a colchicine formulation. It is limited to method-of-use dosing.

The broader Colcrys patent landscape included distinct categories:

A generic colchicine manufacturer could face a different risk profile for the tablet, manufacturing process, and label even if the ’758 patent is invalid or unenforceable.

Are biosimilar risks relevant to this patent?

No. Colchicine is a small molecule. Generic competition proceeds through ANDAs under section 505(j) of the Federal Food, Drug, and Cosmetic Act.

The relevant risks are:

• Paragraph IV litigation;
• skinny-label or carve-out strategy;
• inducement-of-infringement allegations;
• Orange Book patent listing disputes;
• product liability associated with colchicine toxicity; and
• manufacturing and supply-chain controls.

A biosimilar analysis is inapplicable to US 7,601,758.

How strong is the patent estate for Colcrys?

The ’758 patent has a clear clinical concept and a commercially relevant dose regimen, but its legal strength was weakened by the Federal Circuit’s obviousness decision.

Strength assessment

The patent’s strongest commercial feature was that it corresponded to a recognizable FDA-label dosing instruction. Its principal weakness was that the interaction and toxicity rationale could be characterized as an expected clinical adjustment based on known pharmacology.

What generic launch scenarios existed?

A generic colchicine applicant could pursue several routes:

1. File a Paragraph IV certification and challenge the patent.
2. Assert that the proposed product does not induce the claimed method.
3. Use a label that omits the patented interaction-related instruction where legally permissible.
4. Challenge the patent’s validity based on obviousness.
5. Wait for litigation resolution or settlement before commercial launch.
6. Enter through an authorized-generic arrangement.

The commercial distinction between a full-label generic and a carve-out product depends on FDA labeling requirements. If the interaction warning is necessary for safe use, a label carve-out may be difficult even if the applicant seeks to avoid a method-of-use claim.

What manufacturing and geographic barriers remain?

The ’758 patent creates no manufacturing barrier. It does not claim:

• a synthetic route;
• a purification method;
• a specific crystalline form;
• a tablet excipient system; or
• a manufacturing facility.

Geographically, the patent applies only in the United States. Equivalent foreign patents would require separate analysis by jurisdiction. A company can face different outcomes in Europe, Canada, Japan, or emerging markets because patent scope, Orange Book mechanisms, claim construction, and regulatory linkage differ.

US commercial risk is concentrated in:

• FDA-approved labeling;
• ANDA certification strategy;
• patent litigation;
• pharmacy substitution;
• tablet supply;
• API qualification; and
• product-liability controls for drug interactions.

What is the commercial exposure associated with the patent?

Colchicine is used for gout flares, gout prophylaxis, and familial Mediterranean fever. Colcrys revenue was historically exposed to generic-entry risk because the active ingredient was long known and the principal branded differentiation rested on regulatory approval, labeling, and patent protection.

The ’758 patent could support premium pricing only if it blocked generic use of the interaction-related regimen. The adverse litigation result reduced that potential. Generic colchicine competition placed pressure on:

• Colcrys net sales;
• reimbursement;
• formulary position;
• pharmacy substitution;
• authorized-generic economics; and
• licensing leverage.

The patent’s remaining value is primarily evidentiary and regulatory. It documents a clinically important dosing protocol and may remain relevant to historical licensing, litigation, and patent-family analysis.

Key Takeaways

• US 7,601,758 is a method-of-use patent for reduced-dose colchicine during clarithromycin or erythromycin administration.
• The principal regimen is approximately 0.6 mg instead of approximately 1.8 mg, with no repeat colchicine for at least three days.
• Claims 1 and 10 are the two independent claims.
• The patent does not cover colchicine itself, a colchicine formulation, or a manufacturing process.
• The patent was listed for Colcrys and had a nominal Orange Book term extending to approximately October 2, 2028.
• The Federal Circuit affirmed an obviousness ruling against the asserted claims in Takeda v. West-Ward.
• Generic risk is based on ANDA and Paragraph IV activity, not biosimilar competition.
• Any current freedom-to-operate analysis must review the broader Colcrys patent estate, FDA labeling, ANDA certifications, and later litigation separately from the ’758 patent.

FAQs About US Patent 7,601,758

Does US 7,601,758 cover all colchicine use with antibiotics?

No. It is limited to gout-flare treatment with concomitant clarithromycin or erythromycin, specified dose reductions, and a minimum three-day period without repeat colchicine.

Does taking 0.6 mg of colchicine automatically infringe the patent?

No. Dose amount alone is insufficient. The other claim limitations, including acute gout flare, macrolide administration, timing, patient conditions, and no-repeat requirements, must also be satisfied.

Is clarithromycin more important than erythromycin under the patent?

Clarithromycin is commercially prominent because claim 7 singles it out and because it is a strong interaction concern for colchicine. Claim 1 and claim 10 cover both clarithromycin and erythromycin.

Can a generic colchicine label omit the patented dosing instruction?

That depends on FDA labeling requirements and the specific Orange Book and ANDA strategy. Omitting a use from labeling does not eliminate all inducement or infringement risk if the product is marketed in a way that encourages the claimed use.

Does the patent cover colchicine prophylaxis?

The cited claims are directed to treating a gout flare. They do not expressly cover chronic gout prophylaxis without the claimed acute-flare and macrolide-administration limitations.

References

1. Takeda Pharmaceuticals U.S.A., Inc. v. West-Ward Pharmaceutical Corp., 785 F.3d 625 (Fed. Cir. 2015).

2. U.S. Food and Drug Administration. (2009). Colcrys (colchicine) tablets prescribing information. NDA 022352.

3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. Entry for Colcrys and U.S. Patent No. 7,601,758.

4. United States Patent and Trademark Office. (2009). U.S. Patent No. 7,601,758 B2: Methods of using colchicine.

5. Takeda Pharmaceuticals North America, Inc. (2012). Takeda completes acquisition of URL Pharma, Inc. Company transaction announcement.