US Patent 8,618,130: Pimavanserin Psychosis-Method Claims, Scope, Expiration and Generic Risk

US Patent No. 8,618,130 is an Acadia Pharmaceuticals patent directed to treating psychosis with pimavanserin, including psychosis associated with neurodegenerative disease, dopaminergic therapy, L-dopa therapy and drug exposure. The patent is a method-of-treatment patent rather than a composition-of-matter patent. Its commercial relevance is tied to Nuplazid, whose active ingredient is pimavanserin tartrate.

The patent’s broadest claim covers administering a therapeutically effective amount of pimavanserin, or a pharmaceutically acceptable salt, to a patient suffering from psychosis or a symptom of psychosis. Dependent claims narrow the protection by combination therapy, salt form, dose, dosing frequency and specified causes of psychosis.

What drug does US Patent 8,618,130 protect?

The compound of formula (I) in the claims is pimavanserin, also known as ACP-103. The marketed product is Nuplazid, which contains pimavanserin tartrate.

Item	Information
Patent	US 8,618,130 B2
Title	Methods of treating psychosis
Patent holder and commercial sponsor	Acadia Pharmaceuticals Inc.
Active ingredient	Pimavanserin
Marketed product	Nuplazid
US approval	FDA approval in 2016
Approved indication	Hallucinations and delusions associated with Parkinson’s disease psychosis
Dosage form	Oral tablets and capsules, depending on product presentation
Patent category	Method of treatment
Principal regulatory issue	Orange Book-listed method-of-use protection
Small-molecule or biologic	Small molecule
Biosimilar pathway relevance	None; an ANDA, not a biosimilar application, is the expected generic pathway

Pimavanserin is a selective serotonin 5-HT2A inverse agonist and antagonist. Its commercial positioning differs from conventional antipsychotics because Nuplazid was approved for Parkinson’s disease psychosis without the dopamine D2 receptor antagonism associated with many antipsychotic products.[1]

What are the independent and dependent claims of US 8,618,130?

Claim 1 is the core claim. It covers:

A patient suffering from psychosis or a symptom of psychosis;
Administration of a therapeutically effective amount;
Pimavanserin or a pharmaceutically acceptable salt;
Treatment of the psychosis or symptom.

The claim does not require Parkinson’s disease psychosis. It is broader on its face and reaches psychosis generally, subject to the chemical limitations imposed by formula (I), statutory validity requirements and claim-construction principles.

The dependent claims create narrower positions:

Claims	Limitation
2	Combination with a specified antipsychotic agent
3	Tartrate salt
4	Hydrochloride salt
5	Dose of about 0.001 mg to about 50 mg
6	Dose of about 1 mg to about 10 mg
7	About 10 mg
8	About 25 mg
9	About 50 mg
10	Daily administration
11	Once-daily administration
12	Psychosis associated with a neurodegenerative disorder
13	Drug-induced psychosis
14	Psychosis associated with dopaminergic therapy
15	Psychosis associated with L-dopa therapy

Claims 12, 14 and 15 are particularly relevant to Nuplazid because Parkinson’s disease is a neurodegenerative disorder and Parkinson’s treatment commonly involves dopaminergic therapy, including levodopa.

How broad is claim 1 of US Patent 8,618,130?

Claim 1 is materially broader than the FDA-approved indication for Nuplazid. It is not limited expressly to:

Parkinson’s disease;
Parkinson’s disease psychosis;
elderly patients;
hallucinations and delusions;
a specific tablet strength;
pimavanserin tartrate;
once-daily dosing; or
monotherapy.

The claim covers psychosis and psychotic symptoms generally if the accused product and use satisfy the formula (I) limitation and the administration requirement.

Its practical scope is narrower than its text in several respects. The accused treatment must involve the claimed compound. A generic manufacturer does not infringe merely by making a chemically identical product. The principal infringement question is whether the generic label, prescribing information, marketing conduct or distribution supports an indication or use covered by the patent.

The claim is also subject to ordinary validity defenses, including lack of written description, enablement, anticipation, obviousness, indefiniteness and patent-term limitations. The patent’s method claims must be assessed against the prior art available at the relevant priority date.

What formulations and salts are protected by US 8,618,130?

The patent claims pimavanserin and pharmaceutically acceptable salts. Claim 3 specifically recites the tartrate salt, while claim 4 recites the hydrochloride salt.

Pimavanserin tartrate

Pimavanserin tartrate is the salt used in Nuplazid. Claim 3 therefore maps directly onto the commercial active pharmaceutical ingredient when used in the claimed treatment method.

Pimavanserin hydrochloride

Claim 4 separately protects the hydrochloride salt. This claim is relevant to a generic developer that uses a different salt from the marketed tartrate. A change from tartrate to hydrochloride does not necessarily avoid the patent if the hydrochloride is within the claimed formula and the treatment method satisfies claim 4.

Dosage forms

The claims supplied do not expressly require a tablet, capsule, liquid, injectable preparation or other dosage form. The patent therefore operates primarily through the active compound, salt, dose and treatment method rather than a specific finished-product formulation.

A separate formulation patent could protect excipients, release characteristics, particle size, polymorphs or a particular dosage form. Those limitations are not present in claims 1 through 15 as provided.

What doses and dosing schedules are covered?

The dosing claims create overlapping ranges and point doses:

Claim 5 covers about 0.001 mg to about 50 mg.
Claim 6 covers about 1 mg to about 10 mg.
Claim 7 identifies about 10 mg.
Claim 8 identifies about 25 mg.
Claim 9 identifies about 50 mg.
Claim 10 requires daily administration.
Claim 11 requires once-daily administration.

The claim structure gives Acadia multiple infringement positions. A product using a 10 mg dose may fall within claims 5, 6 and 7, while a once-daily 10 mg regimen may also fall within claims 10 and 11, assuming all limitations of claim 1 are met.

Nuplazid’s approved commercial dose is 34 mg of pimavanserin once daily, administered as two 17 mg tablets. The supplied claims do not identify 34 mg as a specific dependent-claim amount. A 34 mg regimen may still implicate claim 1 and potentially the broader range in claim 5, subject to construction of “about” and the formula limitation.[1]

Does US Patent 8,618,130 cover Parkinson’s disease psychosis?

Yes, the patent covers treatment of Parkinson’s disease psychosis through the combination of claim 1 with claim 12 and, in relevant cases, claims 14 and 15.

The most direct claim pathways are:

Clinical scenario	Potential claim pathway
Psychosis in Parkinson’s disease	Claims 1 and 12
Psychosis associated with dopaminergic treatment	Claims 1 and 14
Psychosis associated with L-dopa treatment	Claims 1 and 15
Pimavanserin tartrate treatment	Claims 1 and 3
Once-daily administration	Claims 1, 10 and 11

The patent is not limited to Parkinson’s disease psychosis. Claims 12, 14 and 15 narrow the broader psychosis claim to particular clinical contexts.

What is the patent expiration date for US 8,618,130?

US Patent 8,618,130 is generally associated with an August 2027 expiration date based on the patent family’s priority and US patent-term framework. The operative date for commercial planning is the expiration date recorded by the USPTO and FDA, including any patent-term adjustment or terminal disclaimer.

The patent issued on December 31, 2013. Its term does not run for 20 years from issuance. For a modern US utility patent, the base term generally runs 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment and other statutory adjustments.[2]

Milestone	Date or status
Earliest relevant family priority	2006
US patent grant	December 31, 2013
Expected base-term endpoint	2027
Commercial relevance	Method-of-use protection for pimavanserin psychosis treatment
Post-expiration position	Generic entry depends on other valid listed patents, regulatory exclusivity and litigation outcomes

A complete launch analysis must distinguish this patent from later Nuplazid patents. Expiration of US 8,618,130 would not necessarily eliminate all patent barriers if later patents remain listed and enforceable.

What is the Orange Book status of US Patent 8,618,130?

US 8,618,130 has been associated with the Nuplazid patent estate and method-of-use protection. Orange Book relevance depends on the specific approved product, listed patent use code and the FDA’s current listing status.[3]

A listed method-of-use patent can support a Paragraph IV certification by an ANDA applicant. The generic applicant may seek approval for non-infringing uses through a section viii statement when the patented indication can be carved out of the proposed labeling.

The commercial effect depends on the use code. If the use code is broad enough to cover the principal approved indication, a generic applicant may need to litigate or obtain a settlement before launching the full-label product. If the patented use can be removed while retaining an unpatented indication, a skinny-label strategy may be available.

What Paragraph IV challenges affect Nuplazid?

A Paragraph IV challenge to a listed Nuplazid patent requires the ANDA applicant to notify Acadia and the patent owner or holder of an infringement claim. Acadia may then bring an action under 35 U.S.C. §271(e)(2). A timely suit can trigger a 30-month stay of FDA approval, subject to statutory exceptions.[4]

The key litigation questions are:

Whether the ANDA label induces use covered by claim 1 or a dependent claim;
Whether the listed patent is valid and enforceable;
Whether the generic can use a section viii statement;
Whether the proposed salt, dose or regimen falls within the claims;
Whether a settlement sets a licensed launch date; and
Whether later Nuplazid patents create a separate injunction or damages risk.

Public generic activity around pimavanserin has involved challenges to parts of Acadia’s patent estate. The principal risk is not limited to US 8,618,130 because Nuplazid has been protected by multiple patents directed to the active ingredient, formulations, dosing and methods of use.

Which companies are challenging the Nuplazid patent estate?

Potential ANDA challengers are expected to include major generic companies with capacity in central nervous system products and complex oral small molecules. Public litigation and FDA records should be reviewed patent by patent because a company may challenge one listed patent while retaining validity or infringement positions against others.

The relevant competitive groups are:

Group	Strategic position
Acadia	Originator, NDA holder and patent-estate manager
Large generic manufacturers	Likely ANDA filers and Paragraph IV challengers
Specialty generics	Potential entrants if formulation and supply barriers are limited
Authorized or licensed entrants	May launch under settlement or license terms
CNS competitors	Compete clinically but do not necessarily create patent infringement risk

The existence of an ANDA filing does not establish an imminent launch. Approval, litigation disposition, settlement restrictions, court orders and remaining patents determine the actual entry date.

How strong is the patent estate for pimavanserin?

US 8,618,130 is strongest as a use patent when the accused label expressly directs treatment of Parkinson’s disease psychosis, psychosis associated with dopaminergic therapy or another claimed psychosis category.

Its main strengths are:

Broad claim 1 language covering psychosis generally;
Direct relevance to the approved Parkinson’s disease psychosis product;
Dependent claims covering tartrate and hydrochloride salts;
Overlapping dose and administration claims;
Specific claims directed to neurodegenerative and dopaminergic-treatment psychosis.

Its principal vulnerabilities are typical of method-of-treatment patents:

Design-around through labeling and use restrictions;
Section viii carve-out arguments;
Prior-art attacks directed to the compound and psychosis treatment;
Questions over the scope of “about” for dose limitations;
Divided-infringement issues where prescribers, patients and manufacturers perform different claim steps;
Reduced leverage if later patents expire later but do not cover the proposed generic use.

The estate should be evaluated as a portfolio, not through this patent alone. A generic may avoid one claim while still facing other Orange Book-listed patents.

What patent litigation and settlement issues affect generic launch?

A settlement can establish a confidential or public launch date before patent expiration. It may also include:

A license to manufacture and sell;
A delayed entry date;
Restrictions on product labeling;
Supply arrangements;
Authorized-generic provisions;
Covenants not to sue;
Acceleration clauses if another generic enters;
Allocation of patent challenges between parties.

Without the operative settlement terms and current court docket, no reliable launch date should be inferred solely from US 8,618,130’s expiration. A settlement involving another Nuplazid patent may control entry even if this patent is invalidated or expires.

Is there biosimilar risk for pimavanserin?

No. Pimavanserin is a small-molecule drug, not a biologic. The relevant competitive pathway is an abbreviated new drug application under section 505(j) of the Federal Food, Drug, and Cosmetic Act, not a biosimilar application under the Biologics Price Competition and Innovation Act.

The principal entry risks are:

Paragraph IV litigation;
Patent-term adjustment;
Other Orange Book-listed patents;
Formulation or salt patents;
Manufacturing capacity;
FDA approval timing;
Settlement restrictions;
Labeling carve-outs.

How does US 8,618,130 compare with composition and formulation patents?

Patent type	What it protects	Relevance to pimavanserin
Composition-of-matter patent	The chemical compound itself	Usually the strongest early barrier; likely expired or materially earlier than later method patents
Salt patent	A specific salt or crystal form	Can affect tartrate, hydrochloride or alternative-salt products
Formulation patent	Dosage form, excipients or release profile	Relevant if the generic copies a protected product design
Method-of-treatment patent	Use of the drug in a disease or patient population	US 8,618,130’s principal category
Manufacturing patent	Process, intermediates or purification	Can constrain production without necessarily blocking sale of a non-infringing product
Labeling patent	Approved indication or dosing regimen	Often central to ANDA Paragraph IV and section viii disputes

US 8,618,130 does not, on the claims supplied, create a standalone monopoly over every pimavanserin product. It protects specified treatment methods using the claimed compound or salt.

What generic launch scenarios exist for Nuplazid?

Full-label launch after litigation

The generic applicant challenges the listed patents, wins or obtains a court ruling that the proposed product does not infringe. FDA approval can proceed subject to any remaining patents.

Launch after settlement

Acadia grants a license for a negotiated date. The agreement may resolve litigation without a final validity judgment.

Skinny-label launch

The generic removes patented indications or dosing instructions. This strategy depends on whether the remaining label avoids inducement of the patented method.

Delayed launch after patent expiry

The generic accepts the listed patents and launches after the relevant expiration dates, including any later patents that remain enforceable.

Authorized-generic or licensed supply

Acadia or a partner supplies an authorized generic or licenses a third party. This can reduce the commercial value of an independent ANDA launch even after approval.

What is the commercial exposure from US 8,618,130?

Nuplazid is the commercial product most directly exposed to this patent. The product’s revenue depends on continued treatment of Parkinson’s disease psychosis, label expansion, payer coverage and competition from generic pimavanserin.

The patent’s economic value is higher than a narrow indication patent because claim 1 reaches psychosis broadly and dependent claims map onto clinically relevant dosing and patient categories. Its value is lower than a valid composition patent because a generic can potentially challenge the treatment claims, carve out patented uses or rely on non-infringing labeling.

The principal revenue risk arrives when a generic obtains approval with a label that supports treatment of Parkinson’s disease psychosis or when a court finds that the relevant claims are invalid or not infringed.

Key Takeaways

US 8,618,130 protects methods of treating psychosis with pimavanserin or its pharmaceutically acceptable salts.
The patent is closely tied to Nuplazid and Parkinson’s disease psychosis.
Claim 1 is broad and is not expressly limited to Parkinson’s disease.
Claims 3 and 4 cover pimavanserin tartrate and hydrochloride, respectively.
Claims 5 through 9 cover specified dose ranges and dose amounts.
Claims 10 and 11 cover daily and once-daily administration.
Claims 12, 14 and 15 target neurodegenerative, dopaminergic-therapy and L-dopa-associated psychosis.
The patent is generally associated with an August 2027 US expiration date, subject to the official patent-term record.
Generic risk is based on ANDA Paragraph IV litigation, section viii carve-outs, settlement terms and later Nuplazid patents.
Biosimilar risk does not apply because pimavanserin is a small molecule.
The patent should be analyzed with the full Orange Book and patent-family record rather than in isolation.

FAQs

Can a generic sell pimavanserin before US Patent 8,618,130 expires?

It may be able to launch under a settlement, after a successful non-infringement or invalidity decision, or with a section viii label carve-out that avoids the patented uses.

Does changing pimavanserin tartrate to pimavanserin hydrochloride avoid the patent?

No. Claim 4 expressly recites the hydrochloride salt. A salt change must be analyzed against the complete claim set and other patents.

Does a 34 mg Nuplazid dose fall within the patent claims?

It may implicate the broad dose-range claim if the court construes “about” to encompass the administered amount. The 34 mg commercial regimen is not separately identified in the supplied dependent claims.

Can a generic avoid infringement by omitting Parkinson’s disease psychosis from its label?

A label carve-out can reduce induced-infringement risk, but omission alone does not resolve all infringement issues. Marketing, prescribing information, distribution and remaining labeled uses also matter.

Does expiration of US 8,618,130 guarantee immediate generic Nuplazid competition?

No. Later Orange Book-listed patents, regulatory exclusivity, litigation outcomes, settlements and manufacturing constraints can delay or limit entry.

References

U.S. Food and Drug Administration. (2016). FDA approves Nuplazid to treat hallucinations and delusions associated with Parkinson’s disease psychosis. https://www.fda.gov
United States Patent and Trademark Office. (n.d.). Patent term adjustment and patent term provisions. https://www.uspto.gov
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov
U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application: Paragraph IV certifications and 30-month stay provisions. https://www.fda.gov
United States Patent and Trademark Office. (2013). U.S. Patent No. 8,618,130: Methods of treating psychosis.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	407117	⤷ Start Trial
Austria	512136	⤷ Start Trial
Australia	2004206886	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,618,130

Summary for Patent: 8,618,130