United States Patent 8,137,993: Claim Scope, Expiration, Orange Book Status, and Patent Landscape

U.S. Patent No. 8,137,993 protects a biomarker-based method for selecting patients for dopamine agonist therapy, particularly bromocriptine, to treat metabolic disorders. The patent does not broadly claim bromocriptine, dopamine agonists, or treatment of diabetes. Its enforceable scope depends on proving both patient-selection criteria and, for the treatment claims, administration of dopamine agonist therapy.

The patent was issued to VeroScience LLC on March 20, 2012. Its earliest publicly identified priority date is October 21, 2005, producing an expected ordinary patent-term expiration in October 2026, subject to any patent-term adjustment or terminal disclaimer recorded in the USPTO file. The patent is principally relevant to Cycloset, the quick-release bromocriptine product approved by the FDA for Type 2 diabetes. [1-4]

What does U.S. Patent 8,137,993 claim?

The patent contains four claims directed to patient identification and treatment.

Claim	Core subject matter	Practical scope
1	Identifying patients for dopamine agonist therapy using blood or urine biomarkers	Diagnostic or selection step based on catecholamine, serotonin, dopamine, or triglyceride abnormalities
2	Claim 1 plus a specified metabolic or cardiovascular condition	Narrows the selected patient population
3	Identifying patients under claim 1 and treating them with dopamine agonist therapy	Main treatment-method claim
4	Claim 2 with a regimen comprising bromocriptine	Most product-specific claim, although its dependency language creates a claim-construction issue

The patent is a method patent. It does not claim a new chemical entity, a bromocriptine salt, a tablet composition, a release profile, or a manufacturing process.

How does claim 1 define the patient-selection test?

Claim 1 requires analysis of a plasma or urine sample for one or more of the following:

Norepinephrine, or NE
Norepinephrine metabolites
Dopamine
Dopamine metabolites
Serotonin
Serotonin metabolites
Fasting triglycerides

The claim then requires a specified abnormality. The abnormality can be:

One or more listed NE-related combinations exceeding approximately 30% over normal;
Dopamine or dopamine metabolites falling approximately 30% below normal;
Fasting triglycerides exceeding 150 mg/dL;
Hypertension.

The claim language creates several alternative pathways to infringement. A method may fall within claim 1 if it uses:

Elevated NE metabolites;
An elevated NE or NE-metabolite-to-dopamine or dopamine-metabolite relationship;
Elevated NE and serotonin;
Elevated NE or NE metabolites with serotonin;
Elevated NE with serotonin metabolites;
Elevated NE or NE metabolites with serotonin metabolites;
Elevated NE alone;
Reduced dopamine or dopamine metabolites;
Fasting triglycerides above 150 mg/dL; or
Hypertension, in the context of the claimed patient-identification method.

The phrase "about 30%" introduces a numerical claim-construction question. Courts generally assess "about" in view of the specification, prosecution history, measurement method, and technical context. A company using a rigid cutoff such as 30% may still face infringement risk if the patent specification and prosecution record support a range around that value.

What conditions are covered by claim 2?

Claim 2 limits the identified patient to one or more metabolic or cardiovascular conditions:

Cardiovascular disease
Type 2 diabetes
Pre-diabetes
Metabolic Syndrome
Obesity
Hyperglycemia
Glucose intolerance
Hyperinsulinemia
Insulin resistance
Elevated plasma lipid levels
Combinations of those conditions

This claim does not require bromocriptine. It covers the identification method regardless of which dopamine agonist is ultimately selected, provided the other limitations are met.

The condition list is broad. A method using the same biomarker screen in a patient with Type 2 diabetes, obesity, insulin resistance, and elevated triglycerides could satisfy multiple listed conditions simultaneously. The claim does not appear limited to a particular severity of disease, body-mass index, fasting glucose level, or insulin concentration.

What does claim 3 add?

Claim 3 is the principal treatment claim. It requires:

Identifying the patient according to claim 1;
Administering a pharmaceutically effective regimen of dopamine agonist therapy; and
Treating a patient suffering from one of the listed metabolic conditions.

The claim therefore requires more than a physician’s use of bromocriptine in a diabetic patient. The accused method must include the claimed identification step or a sufficiently equivalent step.

This limitation may reduce infringement exposure for ordinary prescribing. A physician who prescribes bromocriptine to all patients with Type 2 diabetes, without performing the specified biomarker or clinical-selection analysis, may not practice claim 3. By contrast, a diagnostic algorithm, clinical protocol, electronic health record rule, or sponsored treatment program that screens for the claimed criteria before prescribing creates greater risk.

What does claim 4 protect?

Claim 4 specifies that the pharmaceutically effective dopamine agonist regimen comprises bromocriptine. It is narrower than claim 3 in active ingredient but retains the patient-selection framework.

Bromocriptine is therefore the commercial center of gravity for claim 4. The claim does not appear to require:

A particular bromocriptine dose;
Bromocriptine mesylate rather than another pharmaceutically acceptable form;
A quick-release tablet;
Administration at awakening;
A specific titration schedule;
A particular treatment duration; or
Use with another antidiabetic drug.

The dependency language supplied for claim 4 refers to claim 2 rather than claim 3, even though claim 4 recites a treatment regimen. That wording can create a formal dependency and claim-scope issue under 35 U.S.C. §112(d). The legal effect depends on the issued patent text, prosecution history, and any correction or disclaimer affecting the claim. The treatment limitation should not be assumed to have the same scope as a clean dependency from claim 3.

When does U.S. Patent 8,137,993 lose exclusivity?

Event	Date or status
Earliest identified priority date	October 21, 2005
U.S. patent application filing	2010
Patent issued	March 20, 2012
Expected ordinary expiration	October 21, 2026
Patent-term adjustment	Must be confirmed from the USPTO patent record
Patent-term extension	No established extension should be assumed
Regulatory exclusivity for Cycloset	Separate from patent term and expired years earlier

The patent’s expected expiration is based on the earliest priority date and the twenty-year patent-term framework. The controlling date is the USPTO term calculation, not the grant date. A later-filed continuation does not ordinarily reset the patent term.

FDA regulatory exclusivity is separate. Cycloset received FDA approval in May 2009. Because bromocriptine was previously approved for other indications, the product was not protected as a new chemical entity. Any three-year exclusivity associated with new clinical investigations would have expired in 2012. [3,4]

What is the Orange Book status of Patent 8,137,993?

Patent 8,137,993 has been associated with Cycloset’s FDA-listed patent estate and is relevant to an abbreviated new drug application seeking bromocriptine for the covered indication. The Orange Book analysis must distinguish between:

Patent listing;
Patent expiration;
Regulatory exclusivity;
The specific NDA product and indication;
Whether a generic applicant submits a Paragraph IV certification; and
Whether an applicant removes or carves out the patented use.

A listed method-of-use patent does not automatically block every bromocriptine product. A generic applicant may pursue:

A Paragraph IV certification challenging validity, enforceability, or infringement;
A Section viii statement omitting the patented method from labeling;
A label limited to nonpatented uses;
A product that avoids the claimed patient-selection protocol.

The commercial effect depends on whether the generic label, promotional activity, or physician-use pattern induces performance of the claimed method.

What Paragraph IV challenges and litigation affect the patent?

A Paragraph IV certification against an Orange Book-listed patent can trigger patent litigation under the Hatch-Waxman Act. A timely suit by the NDA holder or patent owner can create a 30-month stay of FDA approval, subject to statutory exceptions and court rulings. [5]

No specific final judgment invalidating U.S. Patent 8,137,993 is established by the patent claims alone. The patent should therefore be treated as potentially enforceable until expiration or a contrary court determination. A complete diligence review should distinguish:

A Paragraph IV notice letter;
An actual district-court complaint;
A settlement;
A consent judgment;
An inter partes review;
A post-grant proceeding; and
Routine Orange Book listing activity.

The principal litigation vulnerability is claim construction. An accused company could argue that its assay, threshold, patient protocol, or treatment decision does not satisfy the claimed combination. It could also challenge written description, enablement, indefiniteness, anticipation, obviousness, or eligibility.

How strong is the patent estate for bromocriptine?

The patent estate is narrower than a composition-of-matter estate but potentially meaningful for a labeled treatment strategy.

Estate category	Relevance to U.S. Patent 8,137,993	Risk level
Composition of matter	Not claimed	Low under this patent
Bromocriptine molecule	Old active ingredient	Low
Quick-release formulation	Not claimed in the supplied claims	Separate analysis required
Manufacturing process	Not claimed	Low under this patent
Patient selection	Central claim category	High if protocol is followed
Biomarker testing	Central claim category	High if specified markers and thresholds are used
Metabolic disease treatment	Claimed only with selection step	Moderate to high
Broad dopamine agonist treatment	Not claimed without selection limitations	Moderate
Bromocriptine treatment	Claim 4 and potentially claim 3	High for covered protocols

The patent’s commercial leverage comes from the combination of diagnostic selection and treatment. The patent is less effective against an undifferentiated generic bromocriptine product than against a company selling a biomarker-guided prescribing program.

What formulation patents protect Cycloset?

The supplied claims do not protect a formulation. Cycloset is a quick-release bromocriptine product developed for treatment of Type 2 diabetes. Formulation, dosage-form, salt, release, tablet, and manufacturing claims must be reviewed separately in the FDA Orange Book and the relevant patent family.

A formulation patent can create a different infringement pathway from U.S. Patent 8,137,993. A generic could avoid a formulation patent while still encountering a method-of-use patent, or it could challenge the formulation patent while carving out the patented use.

The existence of a bromocriptine formulation patent would not expand claim 8,137,993. Each patent must be analyzed by its own claim language.

Are biosimilar risks relevant?

No. Bromocriptine is a small-molecule drug, not a biologic. The relevant competitive pathway is an ANDA under Section 505(j) of the Federal Food, Drug, and Cosmetic Act, not a biosimilar application under Section 351(k) of the Public Health Service Act.

The main risks are:

Generic bromocriptine approval;
Paragraph IV litigation;
Section viii labeling;
Induced-infringement allegations;
Substitution at the pharmacy level; and
Prescriber adoption of a nonpatented indication or protocol.

Which companies are challenging the patent?

The patent document itself identifies the patent owner and inventors but does not establish a current generic challenger, a filed Paragraph IV lawsuit, or a settlement. A definitive challenger analysis requires the current FDA Orange Book, Paragraph IV correspondence, PACER docket records, PTAB records, and corporate disclosures.

No challenger, settlement, license, or litigation outcome should be inferred solely from the existence of an Orange Book listing.

What generic launch scenarios exist?

Scenario 1: Label carve-out

A generic applicant removes the patented metabolic-treatment use from its labeling. This is the most direct strategy against a method-of-use patent, although it does not eliminate all inducement risk.

Scenario 2: Paragraph IV challenge

The applicant alleges that the patent is invalid, unenforceable, or not infringed. Potential arguments include:

Prior art disclosed dopamine agonist treatment for metabolic disease;
The biomarker thresholds were predictable or obvious;
The claims lack adequate written description;
"About 30%" is indefinite in context;
The assay or treatment protocol does not meet every limitation;
Claim 4 has a dependency defect; or
The patent does not cover the proposed label.

Scenario 3: Delayed launch after patent expiration

The applicant accepts the patent and launches after the expected October 2026 expiration, assuming no enforceable term adjustment or separate blocking patent remains.

Scenario 4: Commercial launch without the claimed selection protocol

A generic may market bromocriptine for an approved nonpatented use or with labeling that omits the claimed patient-selection method. Actual physician conduct remains relevant to induced-infringement exposure.

What geographic coverage does the patent provide?

U.S. Patent 8,137,993 provides rights only in the United States. It does not establish protection in Europe, Canada, Japan, China, or other markets. Foreign counterpart patents require separate family review because:

Filing dates may differ;
Claims may have been narrowed;
Some jurisdictions may have rejected diagnostic or treatment claims;
Patent terms may vary; and
National litigation outcomes may not carry over.

The U.S. patent also does not block manufacture abroad unless the statutory requirements for importation, supply, or inducement into the United States are met.

Key Takeaways

U.S. Patent 8,137,993 is a method patent owned by VeroScience LLC and issued on March 20, 2012.
Its core innovation is selecting patients for dopamine agonist therapy using NE, dopamine, serotonin, metabolite, triglyceride, and hypertension criteria.
Claim 3 adds treatment with a dopamine agonist; claim 4 specifically identifies bromocriptine.
The patent does not broadly protect bromocriptine, Cycloset’s formulation, or manufacturing.
The expected ordinary expiration is October 21, 2026, subject to the official USPTO term calculation.
Cycloset’s FDA regulatory exclusivity expired well before the expected patent expiration.
Generic risk centers on Paragraph IV challenges, label carve-outs, and inducement theories.
The patent is strongest against a biomarker-guided bromocriptine treatment protocol and weaker against an undifferentiated generic product.
Biosimilar rules do not apply because bromocriptine is a small molecule.
Formulation, manufacturing, and foreign patent rights require separate patent-family analysis.

FAQs

Does Patent 8,137,993 cover all bromocriptine prescriptions?

No. The claims require patient-selection limitations involving specified biomarkers, triglycerides, hypertension, or related criteria. A routine bromocriptine prescription without that selection step may fall outside the claims.

Can a generic bromocriptine applicant omit the patented indication?

Potentially. A Section viii statement or label carve-out may allow approval without the patented use, subject to FDA requirements and the risk that marketing or labeling induces infringement.

Is the 150 mg/dL triglyceride threshold independently important?

Yes. Claim 1 expressly identifies fasting triglycerides above 150 mg/dL as one route into the claimed patient-selection method. The testing protocol and patient-identification decision remain essential.

Does the patent cover dopamine agonists other than bromocriptine?

Claims 1 through 3 are not limited to bromocriptine. Claim 3 refers generally to dopamine agonist therapy. Claim 4 narrows the regimen to one comprising bromocriptine.

Can a foreign manufacturer avoid the patent by making bromocriptine outside the United States?

Foreign manufacture alone does not resolve U.S. liability. Importation, sale, offer for sale, supply of components, and inducement into the United States can create separate exposure under U.S. patent law.

References

United States Patent and Trademark Office. (2012). U.S. Patent No. 8,137,993, Methods for identifying patients for treatment with dopamine agonists.
United States Patent and Trademark Office. (2024). Patent term adjustment and patent term information.
U.S. Food and Drug Administration. (2009). Cycloset (bromocriptine mesylate) prescribing information.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
U.S. Code, 21 U.S.C. § 355(j). (2024). Abbreviated applications for new drugs.

Details for Patent: 8,137,993

Summary for Patent: 8,137,993