United States Patent 6,245,766: Claim Scope, Expiration, Orange Book Status, and Patent Landscape

U.S. Patent No. 6,245,766 is a broad method-of-treatment patent covering selected heteroaryl-substituted compounds for psychiatric disorders, dementia, dyskinesias, and behavioral disorders. The claim set reaches ziprasidone-related chemical space, including the 1,2-benzisothiazolyl-piperazine and oxindole combination associated with ziprasidone. The patent is no longer a live barrier to generic entry because its statutory patent term has ended. It remains relevant for historical Orange Book analysis, Paragraph IV litigation, patent-family review, and freedom-to-operate assessments involving older products.

What does U.S. Patent 6,245,766 protect?

The patent protects methods of administering compounds within a defined Markush genus to mammals, including humans, for specified psychiatric and neurological conditions.

The independent claim has five principal limitations:

Claim element	Scope
Patient	A mammal, expressly including a human
Administration	Administration of a pharmaceutically effective amount
Chemical subject matter	A compound of the claimed formula or a pharmaceutically acceptable acid-addition salt
Ar group	A broad list of fused and heteroaryl systems, including benzoisothiazolyl, quinolyl, isoquinolyl, quinazolyl, benzothiazolyl, indolyl, indazolyl and phthalazinyl systems
X/Y ring system	A second fused or spiro ring system attached through the phenyl ring, including quinolyl, benzothiazolyl, indazolyl, indolyl, oxindolyl, benzoxazolyl, benzoxazolonyl, benzothiazolonyl, benzimidazolonyl and benzotriazolyl systems

Claim 1 is drafted as a method claim rather than a compound or composition claim. A product would infringe only if the claimed compound were administered for one of the listed conditions and the other structural and dosage-related limitations were met.

The use of “comprising” makes the claim open-ended. Additional treatment steps, excipients, co-medications, dosage forms, or administration routes generally would not avoid the claim if the required elements were present.

How broad is claim 1?

Claim 1 is broad in both therapeutic indication and chemical structure.

Therapeutic breadth

The claim covers:

Dementia and dementia of the Alzheimer’s type
Bipolar disorders
Mood disorders with depressive, manic, or mixed features
Panic disorder, with or without agoraphobia
Agoraphobia without a history of panic disorder
Social phobia
Post-traumatic stress disorder
Acute stress disorder
Substance-induced anxiety and mood disorders
Anxiety disorder not otherwise specified
Dyskinesias
Behavioral manifestations of mental retardation
Conduct disorder
Autistic disorder

The claim does not require a particular DSM severity, disease stage, treatment duration, administration route, or dosage form. The dependent claims add diagnostic subcategories but do not materially narrow the independent claim’s basic mechanism.

Chemical breadth

The Ar definition alone covers numerous heteroaromatic systems. The X/Y definition adds a second extensive structural group. The claim therefore covers a large genus of compounds rather than a single active ingredient.

The scope is constrained by the requirement that the compound conform to the omitted formula and by the relationship among Ar, n, X, and Y. The formula is essential to claim construction. The textual claim excerpt identifies the permitted ring systems but does not reproduce the structural drawing or all substituent positions.

A pharmaceutical company assessing infringement would need to map:

The administered molecule against the complete formula.
The identity and substitution pattern of Ar.
The value of n.
The fused or spiro structure created by X and Y.
The indication for which the product is labeled, promoted, or administered.
Whether the compound is administered as an acid-addition salt.

What do claims 2 through 17 add?

The dependent claims divide into indication-specific and structure-specific limitations.

Claims	Subject matter
2-5	Dementia, including vascular dementia, HIV-related dementia, Alzheimer’s-type dementia, and specified onset and mood features
6-7	Bipolar I and II disorders, cyclothymic disorder, episode type, severity, and remission status
8-9	Drug-induced and neurodegenerative dyskinesias
10-13	Behavioral manifestations of mental retardation, conduct disorder, and autistic disorder
14	Benzoxazolonyl X/Y ring system
15	Benzoisothiazolyl Ar group with n = 1
16	Oxindole X/Y system with specified chloro, fluoro, or phenyl substitution
17	Naphthyl Ar group with n = 1

Claims 14 through 17 are particularly important for product-specific analysis because they move from a broad therapeutic genus toward narrower chemical embodiments.

Claim 15 and ziprasidone-related chemistry

Claim 15 specifies a benzoisothiazolyl Ar group and n = 1. This is significant because ziprasidone contains a 1,2-benzisothiazolyl-piperazine pharmacophore.

The supplied claim language does not identify ziprasidone by name, and the full formula is not reproduced. A definitive infringement conclusion therefore depends on the patent’s structural drawings and definitions. The claim nevertheless reaches the principal ziprasidone-related structural class more directly than the other dependent claims.

Claim 16 and oxindole embodiments

Claim 16 narrows the X/Y system to an oxindole structure optionally substituted by chloro, fluoro, or phenyl. Ziprasidone contains a chloro-substituted oxindole moiety. This makes claim 16 a key narrowing claim for assessing whether the marketed ziprasidone structure falls within the issued claims.

Claim 17 and internal dependency issue

The supplied text of claim 17 states that Ar is naphthyl and n is 1. The claim 1 excerpt, however, appears to describe naphthyl as an optional substituent in part of the Ar definition rather than as an independent Ar category. That creates a textual dependency issue if the excerpt exactly matches the issued claim.

For legal analysis, the certified patent document, prosecution history, claim amendments, and any judicial construction control. The claim should not be evaluated solely from an extracted text version that may contain OCR, formatting, or transcription errors.

When did U.S. Patent 6,245,766 lose exclusivity?

U.S. Patent 6,245,766 issued on June 12, 2001. Its effective expiration was governed by the 20-year patent term measured from the applicable earliest nonprovisional filing date, subject to patent-term adjustment and any terminal disclaimer. The patent term therefore ended before the current period of generic commercialization of ziprasidone.

The patent is treated as expired for commercial exclusivity analysis. It cannot presently block an ANDA applicant from launching a product solely because of the rights granted under Patent 6,245,766.

Patent-term timeline

Event	Date or period
Patent application and priority chain	Prior filings predating issuance
Patent issuance	June 12, 2001
FDA approval of Geodon capsules	2001
FDA approval of Geodon intramuscular injection	2002
End of ordinary 20-year patent term	Before current generic-market entry
Current status	Expired

The precise term date must be taken from the USPTO patent-term record rather than inferred from the issue date. Issuance in 2001 did not create a new 20-year term.

What is the Orange Book status of Patent 6,245,766?

Patent 6,245,766 was associated with the historical patent estate for Geodon, the Pfizer product containing ziprasidone. Orange Book listings for small-molecule products identify patents that a new drug applicant must address under the Hatch-Waxman framework. Listed patents can cover the active ingredient, formulation, method of use, or other approved-product attributes.[1]

The patent’s significance was primarily as a method-of-use listing. It did not function as a current composition-of-matter barrier after expiration.

Orange Book implications

For a generic ziprasidone applicant:

A Paragraph IV certification could challenge the patent before expiration.
A successful or uncontested Paragraph IV pathway could support earlier ANDA approval.
After expiration, the patent no longer creates a launch prohibition.
A generic applicant would still need to address any other unexpired listed patents, applicable regulatory exclusivity, and product-specific requirements.

FDA approval of generic ziprasidone products confirms that the historical patent estate did not prevent generic entry indefinitely.[2]

Which products and compounds are most closely related?

The patent landscape centers on ziprasidone and earlier benzisothiazole antipsychotic patents.

Product or patent area	Relevance
Ziprasidone	Closest commercial compound and likely principal product associated with the method claims
Geodon capsules	Oral ziprasidone hydrochloride product
Geodon injection	Intramuscular ziprasidone mesylate product
U.S. Patent 4,831,031	Earlier benzisothiazole derivative patent associated with ziprasidone chemistry
U.S. Patent 6,245,766	Broad psychiatric and neurological method-of-treatment patent
Generic ziprasidone	ANDA products entering after the relevant patent barriers expired or were resolved

The older compound patent and the later method patent protected different layers of the commercial estate. The compound patent targeted the chemical entity or closely related derivatives. Patent 6,245,766 targeted therapeutic use across a broad set of psychiatric and neurological indications.

How does Patent 6,245,766 compare with compound and formulation patents?

Compound patents

Compound-of-matter patents generally provide the strongest exclusionary position because they can cover manufacture, sale, importation, and use of the active ingredient regardless of the approved indication.

Patent 6,245,766 is weaker than a compound patent for several reasons:

It requires administration to a mammal.
It requires treatment of a listed condition.
It depends on the claimed structural formula.
It may not reach off-label use without proof of the relevant use.
It does not necessarily prevent independent development of the molecule for an unclaimed use.

Formulation patents

A formulation patent may cover a specific capsule, tablet, injectable composition, salt form, particle size, excipient system, or release profile. Patent 6,245,766 does not appear, from the supplied claims, to require a particular formulation, dosage form, excipient, or route.

That gives the method patent broader theoretical therapeutic reach but less control over manufacturing and product design than a formulation patent.

Method-of-use patents

Patent 6,245,766 is strongest where:

The accused product contains a covered compound.
The label identifies a listed psychiatric or neurological condition.
The compound falls within the claimed Ar/X/Y genus.
The relevant use occurred before expiration.

The patent is less effective against a product with a narrow label that omits the claimed indications, although induced-infringement analysis can consider marketing, prescribing, instructions, and foreseeable use.

How strong was the patent estate?

The estate was commercially meaningful but legally narrower than the breadth of the Markush language suggests.

Strengths

Broad indication coverage
Claim 1 covers major psychiatric categories, dementia, dyskinesias, and behavioral disorders.
Large chemical genus
The Ar and X/Y definitions reach numerous heteroaryl and fused-ring combinations.
Dependent claims directed to ziprasidone-related structure
Claims 15 and 16 are more commercially relevant than the broad genus claims.
Method-of-use leverage against labeled products
A generic label that reproduced a claimed indication could create a clearer infringement case.

Weaknesses

Structural dependency on an omitted formula
The breadth cannot be reliably assessed without the complete chemical formula.
Enablement and written-description pressure
A large Markush genus covering many structures and indications can face support and enablement challenges, particularly if the specification contains limited examples or pharmacological data.
Treatment-method limitations
The claims do not directly cover making or selling the active ingredient in every context.
Prior-art exposure
Antipsychotic and benzisothiazole compounds, dopamine and serotonin receptor activity, and psychiatric treatment methods were crowded fields.
Expiration
Any historical strength no longer produces present-day exclusionary value.

Which companies challenged the Geodon patent estate?

Generic manufacturers pursued ANDA approvals for ziprasidone after the original Geodon exclusivity period. Public FDA records identify multiple generic manufacturers for ziprasidone capsules and injectable products over time.[2]

The Paragraph IV record for an individual patent must be tied to the specific ANDA, certification, litigation docket, and settlement agreement. Patent 6,245,766 should not be treated as the sole patent at issue in historical Geodon litigation because the product estate also included earlier compound patents and other listed rights.

Settlement agreements

Generic entry in the ziprasidone market followed the resolution or expiration of historical patent barriers. A commercial settlement may have permitted entry before the nominal expiration date of one or more patents, but the existence, terms, and scope of a settlement must be determined from the specific litigation record.

No current settlement restriction can preserve an expired patent’s exclusionary effect. Contractual provisions may survive separately, but they do not restore patent rights after expiration.

What generic entry risks exist today?

For ziprasidone, patent risk is materially lower than it was during the Geodon exclusivity period.

Risk category	Current assessment
Patent 6,245,766	Expired; no current blocking effect
Original compound patents	Expired
FDA small-molecule exclusivity	Expired
Paragraph IV risk	Historical rather than current for this patent
Biosimilar risk	Not applicable
Generic substitution	Established market pathway
New formulation risk	Depends on separate patents, if any
Manufacturing risk	Primarily regulatory, quality, and process-related rather than based on this patent

A company developing a new ziprasidone product should focus on current FDA requirements, ANDA or 505(b)(2) strategy, product-specific labeling, salt and polymorph control, manufacturing validation, and any later patent rights unrelated to Patent 6,245,766.

Does biosimilar law apply to ziprasidone?

No. Ziprasidone is a chemically synthesized small molecule. Generic versions proceed through the ANDA pathway under Section 505(j) of the Federal Food, Drug, and Cosmetic Act, not through the biosimilar pathway under the Public Health Service Act.[3]

The relevant competitive issues are generic bioequivalence, pharmaceutical equivalence, salt form, dosage form, injection compatibility, and labeling. Biosimilar interchangeability and biologic reference-product exclusivity do not apply.

What manufacturing and geographic barriers remain?

Patent 6,245,766 does not create a current manufacturing barrier. Its claims are directed to treatment methods and do not expressly claim a manufacturing process.

Remaining barriers can include:

FDA chemistry, manufacturing, and controls requirements
Control of impurities and degradation products
Salt and polymorph characterization
Bioequivalence for oral capsules
Sterility and container-closure requirements for injection
Facility qualification and inspection
Foreign patent rights with different term dates
Regulatory exclusivity or patent rights covering later formulations

U.S. expiration does not establish expiration in every foreign jurisdiction. A multinational launch requires country-by-country review of corresponding national patents, supplementary protection certificates, patent-term extensions, and local litigation.

What is the commercial impact of the expired patent?

Geodon generated substantial commercial value during the protected period as an atypical antipsychotic for schizophrenia and bipolar mania. Generic entry materially reduced branded pricing power and shifted demand toward lower-cost ziprasidone products.

Patent 6,245,766 had greater revenue relevance when branded indications overlapped with its psychiatric-use claims. Its expiration removed a layer of control over labeled therapeutic use, but the primary commercial protection for the molecule historically came from the compound patent and regulatory exclusivity.

The patent has no current standalone revenue-exclusion value. Its remaining business relevance is analytical: it defines part of the historical protection strategy for ziprasidone and illustrates how compound, method-of-use, formulation, and regulatory rights were layered around Geodon.

Key Takeaways

U.S. Patent 6,245,766 is a broad method-of-treatment patent covering specified psychiatric, dementia, dyskinesia, and behavioral disorders.
Claim 1 uses a large Markush structure covering numerous heteroaryl and fused-ring compounds.
Claims 15 and 16 are the most relevant to ziprasidone-related chemistry.
The patent is distinct from a composition-of-matter patent because infringement requires administration for a covered use.
The patent expired before the current generic-market period and is no longer a blocking right.
Ziprasidone is regulated as a small molecule through the ANDA pathway, not as a biosimilar.
Historical Paragraph IV activity involved the broader Geodon patent estate, not necessarily Patent 6,245,766 alone.
The supplied claim text contains a potential dependency inconsistency in claim 17 concerning the naphthyl Ar definition.
Current commercial risk is concentrated in FDA compliance, manufacturing quality, later patents, and foreign rights rather than this expired U.S. patent.

FAQs About U.S. Patent 6,245,766

Is U.S. Patent 6,245,766 a ziprasidone patent?

It is closely associated with ziprasidone-related chemical and therapeutic subject matter, particularly through the benzoisothiazolyl and oxindole limitations. The claim language is broader than ziprasidone alone.

Can Patent 6,245,766 block a generic ziprasidone launch?

No. The patent has expired and cannot independently block a current generic launch.

Did Patent 6,245,766 cover Geodon injection?

The broad treatment claims could be relevant to administration of a covered compound, but the claims supplied do not require an injectable formulation or intramuscular route. Any historical relevance depended on the product’s compound, indication, and patent-listing status.

Does the patent cover all treatments for schizophrenia?

Not based on the supplied claims. Schizophrenia is not expressly listed in claim 1 as reproduced. Coverage depends on the exact issued claims and whether a specific compound and treatment use fall within the listed conditions.

Are foreign equivalents of Patent 6,245,766 still enforceable?

No conclusion can be drawn from the U.S. patent alone. Foreign counterparts have separate prosecution histories, patent terms, national claims, and possible supplementary protection rights.

References

U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations (Orange Book). FDA.
U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drug products, Geodon and generic ziprasidone records. FDA.
U.S. Food and Drug Administration. (2024). Generic drug facts and the abbreviated new drug application process. FDA.
United States Patent and Trademark Office. (2001). U.S. Patent No. 6,245,766, methods for treating psychiatric disorders. USPTO.
United States Patent and Trademark Office. (1989). U.S. Patent No. 4,831,031, benzisothiazole derivatives. USPTO.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	231394	⤷ Start Trial
Australia	739472	⤷ Start Trial
Australia	9717098	⤷ Start Trial
Canada	2256227	⤷ Start Trial
Germany	69810889	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 6,245,766

Summary for Patent: 6,245,766