US Patent 10,500,170: Scope, Claims, Expiration, Orange Book Status, and Gocovri Patent Landscape

US Patent 10,500,170 protects treatment of Parkinson's disease with a 258 mg amantadine free-base-equivalent regimen combining extended-release and immediate-release amantadine in an osmotic delivery system. The patent is directed to pharmacokinetic performance rather than merely to amantadine, an extended-release tablet, or an osmotic device in isolation.

The principal commercial product implicated by the claims is Gocovri, an amantadine hydrochloride extended-release capsule marketed by Supernus Pharmaceuticals. Gocovri is administered as 274 mg of amantadine hydrochloride, equivalent to approximately 258 mg of amantadine free base, typically as two 137 mg capsules taken once daily at bedtime.[1][2]

What does US Patent 10,500,170 protect?

The patent protects methods of treating Parkinson's disease using a specific amantadine regimen with defined formulation and pharmacokinetic characteristics.

Claim group	Independent claim	Primary limitation
Mean steady-state exposure	1	Mean steady-state Cavg at least 95% of an equivalent immediate-release regimen
Higher exposure threshold	2	Cavg at least 97% of the immediate-release comparator
Steady-state AUC	7	AUC0-24 at least 95% of the immediate-release comparator
Higher AUC threshold	8	AUC0-24 at least 97% of the immediate-release comparator
Steady-state Cmax	13	Cmax comparable to the immediate-release comparator
Time to steady-state	18	Steady-state achieved by about Day 6

The claims require all of the following core elements:

Treatment of a patient with Parkinson's disease.
Administration of a pharmaceutical composition containing amantadine or a pharmaceutically acceptable salt.
An extended-release component.
An immediate-release component.
An osmotic agent.
A total dose of 258 mg amantadine free-base equivalent.
One or more specified pharmacokinetic results.

The patent therefore has a narrow, performance-defined method-of-use scope. A product containing amantadine in an extended-release formulation would not necessarily infringe merely because it uses an osmotic mechanism. The accused product must also satisfy the dose, immediate-release/extended-release combination, Parkinson's treatment, and relevant pharmacokinetic limitations.

How should the independent claims be interpreted?

Claim 1: mean steady-state Cavg

Claim 1 requires the composition to produce a mean steady-state average plasma concentration, or Cavg, that is at least 95% of the Cavg produced by the same daily quantity of immediate-release amantadine.

Claim 2 narrows that threshold to at least 97%. Claim 6 further specifies a Cavg of about 947 ng/mL.

The comparator is important. The claim does not require a fixed absolute concentration alone. It requires a relative comparison against the same daily quantity of immediate-release amantadine. A generic manufacturer could face infringement risk even if its absolute Cavg differs from the commercial reference product, provided its formulation produces the claimed relationship to the immediate-release comparator.

Claim 7: AUC0-24

Claim 7 uses steady-state exposure over a 24-hour period. Claim 8 raises the required threshold to at least 97%, and claim 12 identifies an AUC0-24 of about 22,737 ng·h/mL.

AUC claims can be commercially significant because they may capture formulations with different release profiles but similar total exposure. A competing product might avoid a Cmax-based claim while still satisfying the AUC limitations.

Claim 13: Cmax comparability

Claim 13 requires a steady-state maximum plasma concentration comparable to that provided by the same daily quantity of immediate-release amantadine. Claim 17 identifies a Cmax of about 1,275 ng/mL.

"Comparable" is less numerically exact than the 95% and 97% thresholds in the Cavg and AUC claims. The specification and prosecution history would be central to determining the permissible range. The claim creates potential enforcement value because a formulation could be designed to reproduce immediate-release peak exposure while extending dosing intervals.

Claim 18: achievement of steady-state by about Day 6

Claim 18 focuses on accumulation kinetics. It requires steady-state to be achieved by about Day 6. Claim 19 adds a plasma concentration requirement of at least 85% of the concentration generated by the equivalent immediate-release regimen. Claim 23 identifies a concentration range of approximately 609 to 662 ng/mL.

This claim group may be particularly relevant to once-daily dosing. It links the product's release profile to the time required to reach stable systemic exposure.

What formulation technology is covered by the claims?

The claims cover a combination of immediate-release and extended-release amantadine, with the extended-release component associated with an osmotic agent. Dependent claims expressly identify an osmotic device and a semipermeable membrane.

Osmotic delivery system

The osmotic-device limitations indicate a system in which water enters through a semipermeable membrane and drives release of drug from the dosage form. The patent's relevant formulation concept includes:

An amantadine-containing extended-release compartment.
An immediate-release amantadine component.
An osmotic agent or osmogen.
A semipermeable membrane.
A release profile capable of providing sustained exposure without materially reducing daily systemic exposure.

The claims do not require every specific structural detail of Gocovri's commercial capsule unless those limitations appear in the relevant claim or are imported from the specification through claim construction. Claims 4, 5, 10, 11, 15, 16, 21, and 22 expressly narrow the scope to an osmotic device and, in the further dependent claims, a semipermeable membrane.

Amantadine hydrochloride

Claims 3, 9, 14, and 20 specify amantadine hydrochloride. The 258 mg free-base-equivalent limitation corresponds to approximately 274 mg of amantadine hydrochloride because the hydrochloride salt has a higher molecular weight than the free base.

The dose limitation is central. A formulation administered at 137 mg of amantadine hydrochloride per capsule would fall within the claimed total dose if two capsules are administered to provide approximately 258 mg of amantadine free base equivalent.

What are the strongest and weakest patent limitations?

Stronger limitations

The following limitations provide relatively concrete enforcement anchors:

Limitation	Enforcement significance
258 mg free-base equivalent	Narrows the claims to a commercially relevant daily dose
Amantadine plus pharmaceutically acceptable salt	Limits the active pharmaceutical ingredient
Combined immediate-release and extended-release forms	Excludes many conventional once-daily extended-release designs
At least 95% or 97% Cavg/AUC	Creates measurable exposure thresholds
About 947 ng/mL Cavg	Provides an absolute pharmacokinetic target
About 22,737 ng·h/mL AUC0-24	Provides an absolute exposure target
Osmotic device and semipermeable membrane	Narrows the formulation architecture

Weaker or more contestable limitations

Several terms create claim-construction and proof issues:

"Comparable" in the Cmax claims is not defined in the claim itself.
"About" permits some variation but requires interpretation based on the specification, examples, and prosecution record.
"Mean steady-state Cavg" and "steady-state AUC0-24" require an agreed sampling protocol and statistical methodology.
"Same daily quantity" requires identification of the immediate-release comparator and dosing schedule.
"Steady-state is achieved by about Day 6" depends on the definition of steady-state and the sampling interval.
The claim does not state every physical feature that may distinguish the commercial dosage form from alternative osmotic systems.

The patent is strongest against an ANDA product that uses the same dose, same disease indication, same osmotic architecture, and a release profile designed to match the claimed pharmacokinetic data. It is less certain against a product that changes the release mechanism, dosing schedule, total dose, or indication labeling.

When does US Patent 10,500,170 expire?

Public patent records identify March 14, 2034, as the nominal expiration date associated with the patent family, before any applicable patent-term adjustment or extension.[3]

Event	Date
Nonprovisional family filing associated with the patent	March 14, 2014
Patent grant	December 3, 2019
Nominal patent expiration	March 14, 2034
Commercial relevance	Gocovri extended-release amantadine

The effective enforceable expiration date should be taken from the current USPTO patent record and the FDA Orange Book listing because patent-term adjustment can alter the statutory date. Patent 10,500,170 is distinct from regulatory exclusivity. FDA exclusivity may expire before the patent, while an Orange Book-listed patent can delay approval of an ANDA through patent litigation or a statutory stay.

What is the Orange Book status of US Patent 10,500,170?

US Patent 10,500,170 is associated with the Gocovri regulatory patent estate and is listed in FDA Orange Book materials for the amantadine hydrochloride extended-release product.[1]

Regulatory significance

An ANDA applicant referencing Gocovri must address each listed patent through one of the statutory certifications:

Paragraph I: no patent information has been submitted.
Paragraph II: the patent has expired.
Paragraph III: the applicant will wait until patent expiration.
Paragraph IV: the patent is invalid, unenforceable, or will not be infringed.

A Paragraph IV certification can trigger patent litigation under the Hatch-Waxman Act. If suit is filed within the statutory period after notice, FDA approval may be subject to a 30-month stay, subject to statutory exceptions and court action.[4]

The Orange Book listing does not establish that every claim of the patent is valid or infringed. It establishes that the listed patent must be addressed by an ANDA applicant seeking approval before the listed expiration date.

Which companies own or commercialize the relevant rights?

Adamas Pharmaceuticals developed Gocovri and transferred control of the product portfolio to Supernus Pharmaceuticals through Supernus's acquisition of Adamas.[2]

Entity	Role
Adamas Pharmaceuticals	Original developer of Gocovri and related amantadine technology
Supernus Pharmaceuticals	Current commercial owner and marketer of Gocovri
FDA	Regulator for the NDA and Orange Book listings
Generic applicants	Potential ANDA sponsors required to address listed patents

The relevant commercial right is therefore concentrated in Supernus rather than split between an originator and a separate licensee based on the information publicly associated with the product's ownership history.

What patent landscape surrounds Gocovri and amantadine extended release?

Patent 10,500,170 is one component of a broader Gocovri estate. The surrounding portfolio has included patents directed to:

Extended-release amantadine formulations.
Osmotic dosage-form architecture.
Pharmacokinetic profiles.
Dosing regimens for Parkinson's disease.
Treatment of dyskinesia and "off" episodes.
Capsule compositions and release characteristics.
Methods of treating neurologic disorders with once-daily amantadine.

The estate should be analyzed by claim category rather than by patent count alone.

Protection category	Relevance to Gocovri	Generic design-around potential
Dose claims	High, because 258 mg free-base equivalent maps to the commercial regimen	Moderate through different dose or dosing schedule
Osmotic-device claims	High for products using an equivalent osmotic architecture	Moderate to high through non-osmotic release technology
PK claims	High if the generic reproduces exposure targets	Moderate, depending on formulation and comparator data
Method-of-use claims	High when Parkinson's treatment is included in labeling	Possible through label strategy, subject to induced-infringement risk
Manufacturing claims	Depends on whether the generic uses the same process	Often higher design-around potential
Capsule or excipient claims	Product-specific	Variable

The commercial barrier is not limited to one patent. A generic applicant must assess the full Orange Book listing, the scope of pending applications, prosecution history, and any later-granted continuation patents.

What generic entry risks exist for Gocovri?

A generic entrant faces four main risk vectors.

ANDA patent certification risk

The applicant must certify to each Orange Book-listed patent. A Paragraph IV filing creates litigation exposure and may result in a 30-month approval stay.

Formulation substitution risk

A non-osmotic extended-release formulation may avoid claims requiring an osmotic device or semipermeable membrane. That approach could still encounter broader claims directed to dose, release profile, or pharmacokinetic performance in other patents.

Method-of-use risk

The claims are method-of-treatment claims for Parkinson's disease. A generic applicant may attempt a section viii statement to omit patented indications from its labeling. That strategy depends on whether the remaining label promotes or necessarily supports the patented use. The commercial product's labeling and the scope of the patented indication are therefore important.

Pharmacokinetic testing risk

The Cavg, AUC, Cmax, and time-to-steady-state limitations are potentially testable through bioequivalence and pharmacokinetic studies. A generic applicant that matches Gocovri exposure may increase the risk of satisfying the patent's relative PK limitations. A product with materially different exposure may reduce infringement risk but create FDA equivalence or substitutability challenges.

Are biosimilars relevant to US Patent 10,500,170?

No. Gocovri is a small-molecule amantadine hydrochloride product, not a biologic. The relevant competitive pathway is an ANDA for a generic drug 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.

Biosimilar patent procedures, including the Biologics Price Competition and Innovation Act patent-exchange process, do not apply to this product.

What litigation and settlement issues affect the patent?

The supplied claim set does not establish a current Paragraph IV lawsuit, settlement, or licensed generic launch date. The operative legal questions for any challenger would be:

Whether the ANDA product contains the claimed 258 mg free-base-equivalent dose.
Whether it combines immediate-release and extended-release amantadine.
Whether its formulation uses an osmotic agent or semipermeable membrane.
Whether its pharmacokinetic profile satisfies the 95% or 97% thresholds.
Whether the proposed label includes treatment of Parkinson's disease.
Whether the patent claims are anticipated or obvious in view of prior amantadine formulations and pharmacokinetic data.
Whether the claims are definite and enabled, particularly for "comparable," "about," and steady-state limitations.

Potential invalidity arguments would likely focus on obviousness of combining immediate- and extended-release amantadine, predictability of osmotic delivery, prior disclosure of once-daily dosing, and whether the claimed PK results represent unexpected properties or routine optimization. Infringement and validity outcomes would depend heavily on the specification, prosecution history, cited prior art, and the actual ANDA formulation.

How strong is the patent estate for commercial protection?

Patent 10,500,170 has meaningful commercial value because it aligns multiple claim types with the marketed Gocovri regimen:

A defined amantadine dose.
A once-daily extended-release treatment concept.
An immediate-release component.
Osmotic delivery.
Parkinson's disease treatment.
Quantified systemic exposure.
A specified time to steady-state.

Its principal limitation is that the claims are narrower than a pure composition claim. A challenger may attempt to avoid infringement through a different delivery mechanism, dose, release profile, or labeling strategy. The wider Gocovri estate is therefore more important than Patent 10,500,170 standing alone.

Key Takeaways

US Patent 10,500,170 is a method-of-treatment patent centered on a 258 mg amantadine free-base-equivalent regimen.
The claims combine immediate-release and extended-release amantadine, with dependent claims directed to osmotic devices and semipermeable membranes.
The key pharmacokinetic thresholds include at least 95% and 97% of immediate-release Cavg or AUC, approximately 947 ng/mL Cavg, approximately 22,737 ng·h/mL AUC0-24, and approximately 1,275 ng/mL Cmax.
The patent is associated with Gocovri, marketed by Supernus Pharmaceuticals.
The nominal expiration date is March 14, 2034, before any applicable patent-term adjustment.
The product is subject to the Hatch-Waxman patent-certification framework, including potential Paragraph IV litigation.
Biosimilar competition is not relevant because amantadine is a small molecule.
Generic risk is highest for an ANDA product that copies the dose, osmotic architecture, Parkinson's indication, and claimed pharmacokinetic profile.
A non-osmotic product or a product with materially different PK may have stronger design-around arguments, but other patents in the Gocovri estate must also be assessed.

Frequently Asked Questions

Does Patent 10,500,170 claim Gocovri itself?

It does not claim the product by brand name. It claims methods of treating Parkinson's disease using a specified amantadine formulation, dose, delivery architecture, and pharmacokinetic profile that correspond closely to Gocovri.

Is 258 mg the same as 274 mg of amantadine hydrochloride?

Approximately. The claims express the dose as amantadine free-base equivalent. Approximately 274 mg of amantadine hydrochloride corresponds to about 258 mg of amantadine free base.

Can a generic avoid the patent by using a non-osmotic extended-release formulation?

Possibly for claims requiring an osmotic device or semipermeable membrane. That approach would not automatically avoid broader claims in related patents covering dose, pharmacokinetics, release characteristics, or treatment methods.

Does a Paragraph IV certification immediately permit generic launch?

No. The patent holder may file an infringement action. A timely action can trigger a 30-month FDA approval stay, subject to statutory exceptions, court decisions, and settlement terms.

Is Patent 10,500,170 the only patent protecting Gocovri?

No. Gocovri has been associated with a broader patent portfolio covering formulations, osmotic delivery, pharmacokinetic characteristics, dosing, and methods of treatment. A complete freedom-to-operate analysis must review all Orange Book-listed patents and relevant continuation patents.

References

U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
Supernus Pharmaceuticals, Inc. (2024). Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. U.S. Securities and Exchange Commission.
United States Patent and Trademark Office. (2019). U.S. Patent No. 10,500,170, amantadine formulations and methods of use thereof. https://patents.google.com/patent/US10500170B2
U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application submissions: Patent certification and exclusivity. https://www.fda.gov/drugs/abbreviated-new-drug-application-anda/approved-drug-products-patent-and-exclusivity-information

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Supernus Pharms	OSMOLEX ER	amantadine hydrochloride	TABLET, EXTENDED RELEASE;ORAL	209410-001	Feb 16, 2018		DISCN	Yes	No	10,500,170	⤷ Start Trial				A PROCESS FOR TREATING A PATIENT SUFFERING FROM PARKINSON'S SYNDROME AND IN NEED OF TREATMENT	⤷ Start Trial
Supernus Pharms	OSMOLEX ER	amantadine hydrochloride	TABLET, EXTENDED RELEASE;ORAL	209410-004	Apr 22, 2020		DISCN	Yes	No	10,500,170	⤷ Start Trial				A PROCESS FOR TREATING A PATIENT SUFFERING FROM PARKINSON'S SYNDROME AND IN NEED OF TREATMENT	⤷ Start Trial
Supernus Pharms	OSMOLEX ER	amantadine hydrochloride	TABLET, EXTENDED RELEASE;ORAL	209410-002	Feb 16, 2018		DISCN	Yes	No	10,500,170	⤷ Start Trial				A PROCESS FOR TREATING A PATIENT SUFFERING FROM PARKINSON'S SYNDROME AND IN NEED OF TREATMENT	⤷ Start Trial
Supernus Pharms	OSMOLEX ER	amantadine hydrochloride	TABLET, EXTENDED RELEASE;ORAL	209410-003	Feb 16, 2018		DISCN	Yes	No	10,500,170	⤷ Start Trial				A PROCESS FOR TREATING A PATIENT SUFFERING FROM PARKINSON'S SYNDROME AND IN NEED OF TREATMENT	⤷ 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: 10,500,170

Which drugs does patent 10,500,170 protect, and when does it expire?

Summary for Patent: 10,500,170