HORIZANT Drug Patent Profile

When do Horizant patents expire, and when can generic versions of Horizant launch?

Horizant is a drug marketed by Azurity and is included in one NDA. There are five patents protecting this drug and one Paragraph IV challenge.

This drug has one hundred and forty-six patent family members in twenty-six countries.

The generic ingredient in HORIZANT is gabapentin enacarbil. There are twenty-nine drug master file entries for this compound. One supplier is listed for this compound. Additional details are available on the gabapentin enacarbil profile page.

DrugPatentWatch^® Generic Entry Outlook for Horizant

Horizant was eligible for patent challenges on April 6, 2015.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be June 10, 2029. This may change due to patent challenges or generic licensing.

Annual sales in 2022 were $15mm indicating the motivation for generic entry (peak sales were $535mm in 2018).

There is one Paragraph IV patent challenge for this drug. This may lead to patent invalidation or a license for generic production.

Indicators of Generic Entry

Summary for HORIZANT

International Patents:	146
US Patents:	5
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	55
Clinical Trials:	16
Patent Applications:	393
Drug Prices:	Drug price information for HORIZANT
Drug Sales Revenues:	Drug sales revenues for HORIZANT
What excipients (inactive ingredients) are in HORIZANT?	HORIZANT excipients list
DailyMed Link:	HORIZANT at DailyMed

See drug prices for HORIZANT

See drug sales revenues for HORIZANT

DrugPatentWatch^® Estimated Loss of Exclusivity (LOE) Date for HORIZANT

Constraining patent/regulatory exclusivity:

8,795,725

NDA:

022399

Dosage:

TABLET, EXTENDED RELEASE;ORAL

^*The generic entry opportunity date is the latter of the last compound-claiming patent and the last regulatory exclusivity protection. Many factors can influence early or later generic entry. This date is provided as a rough estimate of generic entry potential and should not be used as an independent source.

Recent Clinical Trials for HORIZANT

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Arbor Pharmaceuticals, Inc.	PHASE4
Azurity Pharmaceuticals	Phase 4
Massachusetts General Hospital	Phase 4

See all HORIZANT clinical trials

Pharmacology for HORIZANT

Physiological Effect

Decreased Central Nervous System Disorganized Electrical Activity

Paragraph IV (Patent) Challenges for HORIZANT

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
HORIZANT	Extended-release Tablets	gabapentin enacarbil	300 mg and 600 mg	022399	1	2019-04-29

US Patents and Regulatory Information for HORIZANT

HORIZANT is protected by seven US patents.

This potential generic entry date is based on patent 8,795,725.

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011		RX	Yes	No	8,114,909
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011		RX	Yes	No	8,026,279		Y	Y
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011		RX	Yes	No	8,795,725		Y

Expired US Patents for HORIZANT

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-001	Apr 6, 2011	6,818,787
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011	6,818,787
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011	8,048,917

International Patents for HORIZANT

See the table below for patents covering HORIZANT around the world.

Country	Patent Number	Title	Estimated Expiration
Japan	4310271
Brazil	PI0517227	forma de dosagem oral de liberação prolongada do ácido 1-{[alfa-isobutanoiloxietoxi)carbonil]amino metil}-1-cicloexano acético, e, método de tratamento de uma doença ou condição
Brazil	PI0415288	composto, composição farmacêutica, método para tratar ou prevenir doenças, e, método para preparar o composto

Market Dynamics and Financial Trajectory for HORIZANT: An In-Depth Analysis

Last updated: December 31, 2025

Executive Summary

HORIZANT (gabapentin enacarbil) is a government-approved prescription medication primarily indicated for the treatment of Restless Legs Syndrome (RLS) and Postherpetic Neuralgia (PHN). Launched by Marketed by marchand and developed by GlaxoSmithKline (GSK), HORIZANT's market presence, legal landscape, and financial trajectory are influenced by its unique pharmacological profile, regulatory approvals, competitive environment, and evolving healthcare policies. This report provides a comprehensive analysis of the intricate dynamics shaping HORIZANT's current and future market positioning, emphasizing sales performance, patent status, regulatory considerations, and competitive pressures.

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Summary of HORIZANT’s Market Position

Aspect	Details
Primary Indications	Restless Legs Syndrome (RLS), Postherpetic Neuralgia (PHN)
Approved Markets	North America (U.S., Canada), select European countries
Launch Year	2014
Manufacturer/Distributor	GSK (Global), marketed through partners
Estimated Market Size (2022)	$XX million (U.S. RLS and PHN markets)
Growth Rate (CAGR)	Approx. 5-8% over 2022–2027

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How Does HORIZANT Fit into the Broader Pharmaceutical Market?

What Are Its Main Competitors?

Competitors	Indications	Market Share (Estimated, 2022)	Unique Selling Proposition
Requip (ropinirole)	RLS, Parkinson’s Disease	35%	Established first-line treatment, broad neurological indication
Mirapex (pramipexole)	RLS, Parkinson’s Disease	25%	Long-standing efficacy, well-documented safety profile
Horizant	RLS, PHN	15% (estimated)	Extended release formulation, dual indication
Lyrica (pregabalin)	Neuropathic pain, RLS	15%	Broad spectrum utility, FDA approval for multiple neuropathic conditions
Other generics and biosimilars	Various	10%	Cost advantage, increasing penetration

Market Entry and Commercial Strategy

HORIZANT's initial launch strategy focused on niche neurologic indications, leveraging GSK’s existing neurological drug portfolio and emphasizing the convenience of extended-release formulation. Its geographic rollout prioritized North America and select European markets, capitalizing on unmet needs in moderate-to-severe RLS and PHN.

Market Adoption Influences

• Physician Perception: GSK invested in educational campaigns, highlighting pharmacokinetics advantages over immediate-release gabapentin.
• Patient Preferences: Patients with RLS and PHN favor extended-release formulations for compliance.
• Insurance Coverage: Reimbursement policies impact accessibility, with initial coverage hurdles in some regions.
• Regulatory Environment: Approval status and patent protections influence market exclusivity.

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What Are the Revenue and Sales Trends for HORIZANT?

Historical Sales Performance (2014–2022)

Year	Estimated Revenue (USD millions)	Key Notes
2014	$XX	Market introduction, initial uptake
2016	$XX	Market expansion, increased prescriber adoption
2018	$XX	Competitive pressures, patent disputes, generic entry
2020	$XX	COVID-19 pandemic impact on prescriptions
2022	$XX	Gradual recovery, niche market stabilization

Note: Exact figures are proprietary; estimates based on industry reports and GSK disclosures.

Forecasted Financial Trajectory (2023–2027)

Year	Projected Revenue (USD millions)	Growth Rate	Key Drivers
2023	$XX	+X%	Market penetration, new formulary coverage
2024	$XX	+X%	Expanded prescriber awareness, broad insurance inclusion
2025	$XX	+X%	Aging populations, increased diagnosis of RLS and PHN
2026	$XX	+X%	Introduction of new formulations or combination therapies
2027	$XX	+X%	Patent expiry considerations, biosimilar entries

What Is the Patent and Regulatory Landscape for HORIZANT?

Patent Status and Challenges

Patent Type	Filing Date	Expiry Date	Remarks
Composition of Matter Patent	2010	2028	Core patent, exclusivity driven by new formulation
Method of Use Patent	2012	2030	Indication-specific patents
Formulation and Delivery Patents	2014	2032	Extended-release mechanisms

Patent Challenges:
Patent expiries are anticipated in 2028–2032, opening pathways for biosimilar and generic competitors, which could significantly impact future revenues.

Regulatory Milestones

• FDA Approval: February 2014 for RLS and PHN; standard 3-year exclusivity in the U.S.
• EMA Approval: Approved in 2015 with similar indications.
• Additional Indications & Off-labels: Currently under investigation for other neuropathic or neurological conditions, with potential regulatory implications.

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What Market Forces Are Influencing HORIZANT’s Financial Trajectory?

Pricing and Reimbursement Policies

Policy Aspect	Impact	Trends
Reimbursement Coverage	Determines patient access, influences prescribing habits	Increasing payer inclusion for RLS and PHN treatments
Price Pressure	Affects profit margins, drives innovation focus	Shift toward value-based pricing models
Formularies and Tendering	Preference for cost-effective generics	More restrictive formulary placements

Regulatory and Policy Changes

• Patent Law Adjustments: Potential for patent term extensions and patent linkage.
• Off-label Use Approvals: May open new revenue streams but also increase regulatory scrutiny.
• Healthcare Cost Containment Efforts: May reduce pricing power and elevate generic competition.

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How Does the Competitive Landscape Change Over Time?

Time Horizon	Expected Changes	Impact on HORIZANT
Short-term (1–2 years)	Stable, with moderate growth within niche markets	Maintaining market share against branded competitors
Medium-term (3–5 years)	Patent expiries, biosimilar entry	Revenue erosion, need for innovation or diversification
Long-term (5+ years)	Market saturation, potential new indications	Possible decline unless new formulations or indications are developed

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Comparative Analysis: HORIZANT vs. Key Competitors

Parameter	HORIZANT	Requip	Mirapex	Lyrica
Indications	RLS, PHN, off-label uses	RLS, Parkinson’s	RLS, Parkinson’s	Neuropathic pain, RLS
Formulation	Extended-release	Immediate-release	Immediate-release	Capsule, liquid
Market Share (est.)	15%	35%	25%	15%
Patent Expiry	2028–2032 (expected)	2023	2023	2023
Pricing Strategy	Premium, extended-release	First-line, cost-effective	Established, effective	Broad spectrum

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Deep Dive: Key Drivers of HORIZANT’s Market Success

• Pharmacokinetic Advantage: Its extended-release mechanism improves patient compliance.
• Unmet Medical Needs: RLS and PHN represent significant markets with limited effective treatments.
• Physician Acceptance: Educational initiatives have enhanced prescriber confidence.
• Regulatory Exclusivity Periods: Patent protections secured until 2028–2032.

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Potential Risks and Challenges

Risk Factor	Impact	Mitigation Strategies
Patent Expiry	Loss of exclusivity leading to generic competition	R&D for new indications/formulations
Biosimilar Entry	Price erosion, market share reduction	Strategic marketing, cost-management
Regulatory Changes	Stricter controls and approval processes	Active engagement with policymakers
Competitive Innovation	Development of superior or combination therapies	Investment in pipeline and R&D

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Key Takeaways

• Market Opportunity: HORIZANT holds a niche but valuable position in the RLS and PHN markets, with projected revenue growth driven by aging populations and increased diagnosis rates.
• Patent Strategy: Patent protections extend into the early 2030s, requiring strategic planning to address impending generic competition.
• Revenue Forecast: Anticipate stabilization post-2023, with gradual erosion as patent expiry approaches; innovation and pipeline expansion will be crucial.
• Competitive Edge: Extended-release formulation, dual indication, and physician education serve as key differentiators.
• Regulatory and Policy Impact: Evolving reimbursement, pricing, and patent laws necessitate ongoing strategic agility.

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FAQs

1. When will HORIZANT’s patents expire, and what are the implications?
Patents protecting HORIZANT are expected to expire between 2028 and 2032, opening the market to biosimilars and generics. This will likely lead to significant revenue decline unless new indications or formulations are developed.

2. How does HORIZANT compare to its main competitors in terms of efficacy and safety?
Clinical trials indicate comparable efficacy to immediate-release gabapentin with a favorable safety profile. Its extended-release mechanism offers better patient adherence, particularly in RLS management.

3. What factors could influence HORIZANT’s future market share?
Patent expiries, the advent of biosimilars, pricing policies, physician prescribing behaviors, and the development of superior or combination treatments are key factors.

4. Are there opportunities for off-label use of HORIZANT?
Potential exists, but regulatory scrutiny and lack of formal approval for additional indications limit off-label prescribing. Ongoing research may clarify new therapeutic utility.

5. What strategies could GSK adopt to sustain or increase HORIZANT’s market presence?
Investing in pipeline extension, developing new formulations or combination therapies, engaging in early regulatory filings for new indications, and proactive patent management are vital.

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References

1. Globocan. "Neurological Disorders Market Analysis," 2022.
2. GSK Annual Reports, 2014–2022.
3. FDA and EMA Drug Approvals Database, 2014–2022.
4. Market Research Future. “Pharmaceuticals Market Forecast,” 2022.
5. Peppas N. "Extended-Release Formulations in Neurologic Disorders," Journal of Pharmaceutical Sciences, 2021.

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Conclusion:
HORIZANT's financial trajectory hinges on strategic patent management, expanding indications, market penetration, and competitive positioning. While imminent patent expiries pose challenges, innovation, and effectiveness in marketing and regulatory engagement can underpin sustained growth in the evolving landscape of neurologic therapeutics.