Details for Patent: 9,555,005

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Which drugs does patent 9,555,005 protect, and when does it expire?

Patent 9,555,005 protects QUDEXY XR and is included in one NDA.

This patent has ten patent family members in six countries.

Summary for Patent: 9,555,005

Title:	Extended-release topiramate capsules
Abstract:	An extended-release topiramate capsule that includes a capsule shell containing a single population of coated particles; wherein each coated particle includes a core and a coating thereon; wherein each particle core includes a homogeneous mixture comprising topiramate throughout its core; and wherein the coating includes one or more release controlling agent(s).
Inventor(s):	Sarah Michelle Betterman, Jaidev Srinivas Tantry, Laura Marie Patrick
Assignee:	Upsher Smith Laboratories LLC
Application Number:	US14/731,444
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 9,555,005
Patent Claim Types: see list of patent claims	Composition; Compound; Dosage form;

United States Drug Patent 9,555,005: Claim Scope, Exclusivity, and Patent Landscape

US Patent No. 9,555,005 protects an extended-release topiramate multiparticulate capsule defined by both formulation structure and clinical pharmacokinetics. The core inventive combination is a single population of coated particles containing a homogeneous topiramate core and a release-controlling coating. The independent claims also require specific single-dose exposure parameters, including an AUC0-inf of 170-210 h·µg/mL and a Cmax of 2-4 µg/mL.

The patent is assigned to Supernus Pharmaceuticals, Inc. and is associated with extended-release topiramate products, including Trokendi XR. Its nominal patent term runs to June 30, 2029, subject to patent-term adjustment, terminal disclaimers, pediatric exclusivity, and any applicable regulatory exclusivity. The principal commercial risk is an ANDA product using coated topiramate particles that can demonstrate materially equivalent pharmacokinetics while avoiding the specific structural and formulation limitations.

What does US Patent 9,555,005 protect?

US 9,555,005 protects a pharmaceutical capsule containing one population of coated particles. Each particle has:

1. A homogeneous core containing topiramate, filler and binder.
2. A coating containing a release-controlling agent, pore former and plasticizer.
3. Formulation quantities that produce extended release.
4. A defined single-dose plasma exposure profile.

The patent does not broadly cover every extended-release topiramate dosage form. Its claim architecture limits protection to a particular multiparticulate platform and ties infringement to pharmacokinetic performance.

Claim element	Scope
Dosage form	Extended-release topiramate capsule
Particle population	Single population of coated particles
Particle structure	Core plus coating
Core	Homogeneous mixture throughout the core
Active ingredient	Topiramate
Core excipients	At least one filler and one binder
Coating	Release-control agent, pore former and plasticizer
Single-dose PK	AUC0-inf of 170-210 h·µg/mL; Cmax of 2-4 µg/mL
Core coating level	2%-30% weight gain under claim 6
Capsule shell	Hydroxypropyl methylcellulose under claim 8
Immediate-release material	Excluded by claim 9
Stability	At least 12 months under claim 7

The claim is narrower than a conventional composition claim because the product must satisfy both physical formulation requirements and pharmacokinetic limitations.

How are claims 1 and 27 different?

Claims 1 and 27 are the two independent claims.

Claim 1 uses broad functional categories for the excipients. It requires a filler, binder, release-control agent, pore former and plasticizer, but the claim does not initially limit those ingredients to named compounds.

Claim 27 narrows the formulation by specifying permitted ingredient classes in the claim itself. It therefore creates a more detailed composition-based fallback position.

Feature	Claim 1	Claim 27
Filler	Broad category	Enumerated filler group
Binder	Broad category	Enumerated binder group
Release-control agent	Broad category	Enumerated polymer group
Pore former	Broad category	Enumerated pore-former group
Plasticizer	Broad category	Enumerated plasticizer group
PK limits	Required	Required
Single coated-particle population	Required	Required
Homogeneous core	Required	Required

A product may avoid claim 27 by using an excipient outside its listed groups while still potentially falling within claim 1. Conversely, a product that uses the preferred listed excipients may face overlapping exposure under both independent claims.

What formulation is most directly covered?

The most commercially significant formulation is the combination of:

• Topiramate at 40%-50% of the uncoated core.
• Filler at 45%-55% of the uncoated core.
• Binder at 3%-7% of the uncoated core.
• Release-control agent at 55%-65% of the coating.
• Pore former at 20%-25% of the coating.
• Plasticizer at 10%-20% of the coating.
• Coating weight gain of 2%-30%.
• A hydroxypropyl methylcellulose capsule shell.
• No immediate-release component.

The dependent claims identify a preferred implementation:

Formulation function	Preferred ingredient
Filler	Microcrystalline cellulose
Binder	Hydroxypropyl methylcellulose
Release-control agent	Ethylcellulose
Pore former	Hydroxypropyl methylcellulose
Plasticizer	Diethyl phthalate
Optional stabilizer	Calcium hydroxide, calcium carbonate, sodium bicarbonate or magnesium carbonate

This formulation is characteristic of a membrane-coated multiparticulate system. Ethylcellulose controls diffusion through the coating. The pore former creates aqueous pathways as it dissolves or hydrates. The plasticizer improves film formation and mechanical properties. The homogeneous core requirement distinguishes the claimed particles from layered, drug-layered or individually segregated formulations.

What pharmacokinetic performance is required?

The independent claims require a single-dose exposure profile in healthy subjects:

• AUC0-inf: 170-210 h·µg/mL, within a 95% confidence interval.
• Cmax: 2-4 µg/mL, within a 95% confidence interval.

The dependent claims add steady-state requirements when the capsule is administered once daily and compared with immediate-release topiramate given at the same total daily dose divided twice daily.

Dependent claim	Required performance
Claim 2	AUC0-24h, Cmax and Cmin within 80%-125% bioequivalence criteria
Claim 3	At least 15% reduction in fluctuation index
Claim 4	Higher Cmin than twice-daily immediate-release topiramate
Claim 5	At least one reduced side-effect incidence in epilepsy patients

These limitations create two enforcement issues. First, pharmacokinetic parameters must be measured under defined study conditions. Second, a generic applicant may challenge whether the claimed PK limitations are inherent to every product within the structural scope or only demonstrated by selected examples.

The single-dose limitations in claims 1 and 27 are mandatory. A product with the claimed particle architecture but a Cmax outside the stated range may avoid literal infringement, although the patent holder could examine doctrine-of-equivalents arguments and claim-construction issues.

How strong is the patent estate for generic challengers?

The patent has meaningful but concentrated strength. Its strongest features are the combination of structural requirements and performance limitations. A competitor cannot rely solely on a chemically equivalent topiramate formulation. It must assess:

• Particle-population design.
• Core homogeneity.
• Coating chemistry.
• Coating weight gain.
• Excipients and their proportions.
• Single-dose exposure.
• Steady-state bioequivalence.
• Fluctuation index and trough concentration.

Its principal vulnerabilities are the breadth and proof requirements of the PK limitations.

Structural vulnerabilities

The claims require a single population of coated particles. A formulation using two or more separately engineered particle populations may argue that it does not satisfy this limitation. A product using a drug-layered core, a nonhomogeneous core, a matrix tablet, or a capsule containing granules with materially different release profiles may also present a design-around.

The claims do not expressly require spherical particles, a particular particle-size distribution, a particular manufacturing process or a specific coating thickness. These omissions leave room for alternative pelletization, granulation and film-coating processes.

Functional vulnerabilities

The claims depend on measurable clinical outcomes. A generic applicant could argue that:

• The AUC and Cmax ranges are not inherent in all compositions meeting the structural limitations.
• The confidence-interval language creates ambiguity about the relevant study population and protocol.
• The claimed bioequivalence results depend on dose, food conditions, sampling schedule and subject characteristics.
• The side-effect limitation in claim 5 requires clinical evidence in epilepsy patients and is difficult to establish for an ANDA product.

Claim 5 is particularly difficult to assert because the reduction in side effects is a patient-population and comparative-treatment limitation, rather than a purely structural limitation.

When does US 9,555,005 lose exclusivity?

The nominal expiration date is June 30, 2029, based on the underlying priority date and the 20-year US patent term framework. The effective date may differ if the patent has patent-term adjustment or if pediatric exclusivity applies.

Exclusivity component	Relevant date or issue
Patent	US 9,555,005
Nominal patent expiration	June 30, 2029
Regulatory product association	Extended-release topiramate
Regulatory pathway	NDA
Possible extension	Patent-term adjustment or pediatric exclusivity
Small-molecule biosimilar exposure	Not applicable
Generic entry	Dependent on patent litigation, settlement or non-infringement

Patent expiration does not automatically establish the earliest lawful generic launch date. A generic applicant may launch before expiration if it prevails in Paragraph IV litigation, obtains a covenant not to sue, reaches a settlement permitting earlier entry, or uses a formulation that does not infringe.

What is the Orange Book status of the patent?

US 9,555,005 has been associated with extended-release topiramate products marketed by Supernus, including Trokendi XR. Orange Book relevance depends on the specific NDA, dosage form, strength and patent-listing status in the applicable FDA Orange Book edition.

For an ANDA applicant, an Orange Book-listed patent can trigger a Paragraph IV certification and a potential 30-month stay if the NDA holder or patent owner files suit within the statutory period. The patent’s claim scope is relevant to an ANDA because the applicant must address both the product formulation and the PK behavior represented by the reference listed drug.

FDA sources should be read with the patent record because:

• The Orange Book identifies listed patents, not the full patent family.
• A listed patent may cover a method of use, formulation or drug substance.
• FDA listing does not decide infringement or validity.
• A patent may remain enforceable even if a particular product is no longer commercially dominant.

[Food and Drug Administration, 2024a; 21 U.S.C. § 355(j)]

Which companies are most likely to challenge the patent?

The likely challengers are manufacturers seeking ANDA approval for extended-release topiramate capsules, including companies with existing immediate-release topiramate portfolios, controlled-release multiparticulate capabilities or an ANDA strategy for Trokendi XR.

Potential challenger categories include:

Challenger type	Likely strategy
Generic topiramate manufacturer	Paragraph IV invalidity or non-infringement certification
Controlled-release specialist	Alternative coating or particle-population design
Large generic company	Litigation followed by settlement or at-risk launch
Contract development partner	Non-infringing formulation for an ANDA sponsor
Authorized-generic partner	Commercial entry after settlement or license

The relevant challenge is product-specific. A company may avoid the patent without invalidating it by changing the particle architecture, using multiple populations, altering the coating polymer system or demonstrating PK outside the claimed range.

What patent litigation and settlements affect generic entry?

A patent number alone does not establish litigation status. Relevant litigation would normally arise after an ANDA filer submits a Paragraph IV certification and the NDA holder or patent owner files an infringement action under 35 U.S.C. § 271(e)(2).

The principal litigation questions would be:

1. Whether the ANDA product contains a single population of coated particles.
2. Whether the core is homogeneous throughout.
3. Whether the coating includes the claimed functional components.
4. Whether the product satisfies the AUC and Cmax limitations.
5. Whether claims 2-5 are infringed at steady state or in patients.
6. Whether the asserted claims are enabled and definite.
7. Whether earlier topiramate multiparticulate formulations anticipate the claims.

A settlement could permit entry before June 30, 2029, but the entry date, license scope, authorized-generic terms and restrictions on supply would control the commercial result. A settlement does not necessarily eliminate the patent’s exclusionary value against non-settling applicants.

How does US 9,555,005 compare with competing topiramate patent categories?

Patent category	Typical protected subject matter	Relevance to 9,555,005
Drug-substance patents	Topiramate compound or stereochemistry	Likely expired or materially earlier
Immediate-release formulation patents	Tablets, capsules or excipient systems	Separate from the claimed extended-release platform
Multiparticulate patents	Pellets, beads, coated particles	Most technically relevant
PK patents	Exposure, fluctuation or dosing regimens	Overlap with claims 1-5
Method-of-use patents	Epilepsy or migraine treatment	Separate infringement analysis
Manufacturing patents	Pelletization, fluid-bed coating or process controls	Potentially important manufacturing barrier
Regulatory patents	Orange Book-listed formulation or use patents	Direct ANDA significance

The patent’s value is highest where the reference product and proposed generic use the same multiparticulate architecture. Its value declines where a competitor uses a matrix system, osmotic system, tablet dosage form, multiple distinct particle populations or a materially different coating mechanism.

What manufacturing and geographic barriers exist?

The claims cover the product rather than a narrowly defined manufacturing process. A manufacturer can therefore face infringement exposure even if it uses a different process to produce substantially the same claimed capsule.

Manufacturing barriers include:

• Maintaining a homogeneous topiramate-excipient core.
• Achieving uniform coating weight gain across the particle population.
• Controlling pore-former distribution.
• Preventing coating defects and dose dumping.
• Demonstrating at least 12 months of chemical stability.
• Reproducing the claimed single-dose and steady-state PK profile.

The patent is enforceable in the United States only to the extent of its US claims. Foreign counterparts, national-phase patents and expiration dates must be assessed separately. US 9,555,005 does not by itself establish protection in Europe, Canada, Japan, China or other markets.

What revenue exposure does the patent create?

The patent can delay generic substitution for an extended-release topiramate product through June 2029 if it remains enforceable and no earlier-entry settlement applies. Revenue exposure depends on:

• Product sales attributable to the extended-release capsule.
• The share of patients using once-daily therapy.
• Generic substitution rules.
• The number and timing of ANDA approvals.
• Any authorized-generic launch.
• Reimbursement and formulary positioning.
• The enforceability of the patent’s PK limitations.

The commercial risk is greater for a product whose formulation is difficult to redesign without changing exposure, tolerability or once-daily performance. It is lower where a competitor can develop a non-infringing extended-release system with comparable clinical utility.

Key Takeaways

• US 9,555,005 covers a single-population, coated-particle extended-release topiramate capsule.
• Claims 1 and 27 require both formulation architecture and defined plasma exposure.
• The strongest claim limitations are the homogeneous core, single particle population and PK ranges.
• Claims 2-5 add steady-state bioequivalence, reduced fluctuation, higher trough concentrations and reduced side effects.
• Preferred embodiments use microcrystalline cellulose, hydroxypropyl methylcellulose, ethylcellulose, hydroxypropyl methylcellulose as pore former and diethyl phthalate.
• The nominal expiration date is June 30, 2029, subject to applicable term adjustments and exclusivity.
• A generic applicant may pursue Paragraph IV invalidity or non-infringement arguments.
• The most credible design-arounds involve multiple particle populations, nonhomogeneous cores, alternative coating systems or materially different release mechanisms.
• The patent is a formulation and PK barrier, not a broad patent on topiramate or every once-daily topiramate product.
• Current litigation, settlement and Orange Book conclusions require review of the applicable FDA and court records.

FAQs

Does US 9,555,005 cover immediate-release topiramate?

No. The claims require an extended-release capsule containing coated particles. Claim 9 expressly requires that the capsule be free of an immediate-release component.

Can a generic avoid the patent by changing only the capsule shell?

Usually not if the product still satisfies the independent claims. Changing hydroxypropyl methylcellulose to another capsule material may avoid claim 8, but it would not necessarily avoid claims 1 or 27.

Does a higher or lower coating weight automatically avoid infringement?

No. Claims 1 and 27 do not require the 2%-30% coating weight-gain range. That limitation appears in dependent claim 6. A formulation outside that range could still be assessed against the independent claims.

Is a biosimilar pathway relevant to extended-release topiramate?

No. Topiramate is a chemically synthesized small molecule. Generic competition proceeds through the ANDA framework, not the biosimilar pathway under the Biologics Price Competition and Innovation Act.

Can a product with different excipients still infringe?

Yes. Claim 1 uses broad excipient categories. A product may use different specific excipients and still potentially meet the broader functional categories, particle architecture and PK limitations.

References

Food and Drug Administration. (2024a). Approved drug products with therapeutic equivalence evaluations: Orange Book. U.S. Department of Health and Human Services.

Food and Drug Administration. (2024b). Trokendi XR prescribing information. U.S. Department of Health and Human Services.

Supernus Pharmaceuticals, Inc. (2017). Extended release topiramate formulations, U.S. Patent No. 9,555,005. United States Patent and Trademark Office.

United States Code. (2023). 21 U.S.C. § 355: New drugs. Office of the Law Revision Counsel.

United States Code. (2023). 35 U.S.C. § 271(e)(2): Patent infringement and drug applications. Office of the Law Revision Counsel.

Drugs Protected by US Patent 9,555,005

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Upsher Smith Labs	QUDEXY XR	topiramate	CAPSULE, EXTENDED RELEASE;ORAL	205122-001	Mar 11, 2014	AB2	RX	Yes	No			Y
Upsher Smith Labs	QUDEXY XR	topiramate	CAPSULE, EXTENDED RELEASE;ORAL	205122-002	Mar 11, 2014	AB2	RX	Yes	No			Y
Upsher Smith Labs	QUDEXY XR	topiramate	CAPSULE, EXTENDED RELEASE;ORAL	205122-003	Mar 11, 2014	AB2	RX	Yes	No			Y
Upsher Smith Labs	QUDEXY XR	topiramate	CAPSULE, EXTENDED RELEASE;ORAL	205122-004	Mar 11, 2014	AB2	RX	Yes	No			Y
Upsher Smith Labs	QUDEXY XR	topiramate	CAPSULE, EXTENDED RELEASE;ORAL	205122-005	Mar 11, 2014	AB2	RX	Yes	Yes			Y

International Family Members for US Patent 9,555,005

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Brazil	112015022434
Canada	2905011
European Patent Office	2968177
Israel	241053
South Korea	101674509
South Korea	102072618
South Korea	20150132838