Gabapentin enacarbil - Generic Drug Details

What are the generic drug sources for gabapentin enacarbil and what is the scope of patent protection?

Gabapentin enacarbil is the generic ingredient in one branded drug marketed by Azurity and is included in one NDA. There are three patents protecting this compound. Additional information is available in the individual branded drug profile pages.

Gabapentin enacarbil has seventy-three patent family members in twenty-four countries.

There is one drug master file entry for gabapentin enacarbil. One supplier is listed for this compound.

Summary for gabapentin enacarbil

International Patents:	73
US Patents:	3
Tradenames:	1
Applicants:	1
NDAs:	1
Drug Master File Entries:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	61
Clinical Trials:	30
What excipients (inactive ingredients) are in gabapentin enacarbil?	gabapentin enacarbil excipients list
DailyMed Link:	gabapentin enacarbil at DailyMed

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

Constraining patent/regulatory exclusivity:

8,795,725

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 gabapentin enacarbil

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

Sponsor	Phase
Arbor Pharmaceuticals, Inc.	PHASE4
Azurity Pharmaceuticals	Phase 4
University of Texas at Austin	Phase 4

See all gabapentin enacarbil clinical trials

Pharmacology for gabapentin enacarbil

Physiological Effect

Decreased Central Nervous System Disorganized Electrical Activity

Anatomical Therapeutic Chemical (ATC) Classes for gabapentin enacarbil

N02BF	Gabapentinoids
N02B	OTHER ANALGESICS AND ANTIPYRETICS
N02	ANALGESICS
N	Nervous system

N03AX	Other antiepileptics
N03A	ANTIEPILEPTICS
N03	ANTIEPILEPTICS
N	Nervous system

Paragraph IV (Patent) Challenges for GABAPENTIN ENACARBIL

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 gabapentin enacarbil

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	022399-001	Apr 6, 2011		RX	Yes	Yes	8,026,279		Y	Y
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	022399-001	Apr 6, 2011		RX	Yes	Yes	8,795,725		Y
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011		RX	Yes	No	8,795,725		Y
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-001	Apr 6, 2011		RX	Yes	Yes	8,114,909

Expired US Patents for gabapentin enacarbil

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011	6,818,787
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-001	Apr 6, 2011	6,818,787
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-001	Apr 6, 2011	8,686,034
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-001	Apr 6, 2011	8,048,917
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011	8,048,917
Azurity	HORIZANT	gabapentin enacarbil	TABLET, EXTENDED RELEASE;ORAL	022399-002	Dec 13, 2011	8,686,034

International Patents for gabapentin enacarbil

Country	Patent Number	Title	Estimated Expiration
Japan	2009149648	CRYSTALLINE FORM OF gamma-AMINOBUTYRIC ACID ANALOG
Russian Federation	2009131325	ЛЕЧЕНИЕ ИЛИ ПРЕДУПРЕЖДЕНИЕ СИНДРОМА БЕСПОКОЙНЫХ НОГ С ИСПОЛЬЗОВАНИЕМ ПРОЛЕКАРСТВ АНАЛОГОВ ГАМК
Israel	174282	PRODRUGS OF GABA ANALOGS FOR USE IN TREATING OR PREVENTING RESTLESS LEGS SYNDROME
Hong Kong	1090850	CRYSTALLINE FORM OF GAMMA-AMINOBUTYRIC ACID ANALOG
Russian Federation	2412162	КРИСТАЛЛИЧЕСКАЯ ФОРМА АНАЛОГА Y-АМИНОМАСЛЯНОЙ КИСЛОТЫ (CRYSTALLINE FORM OF (-AMINOBUTYRIC ACID ANALOGUE)
World Intellectual Property Organization (WIPO)	2005037784

Gabapentin enacarbil Market Analysis and Financial Projection

Last updated: February 16, 2026

What is the current market landscape for gabapentin enacarbil?

Gabapentin enacarbil is a prodrug of gabapentin approved for the treatment of restless legs syndrome (RLS) and postherpetic neuralgia in the United States. Its market presence is characterized by gradual growth driven by approval extensions and expanding indications, notably in neurological and pain management segments.

How does the competitive environment influence gabapentin enacarbil?

The drug faces competition primarily from pregabalin and gabapentin, which are generic and widely prescribed for similar indications. Patent protections expired for the original formulations, leading to a surge in generic options and pricing pressures. The branded product, Horizon Pharma’s (now Neuraxpharm) Horizant, maintains a market share driven by specific approval statuses and physician familiarity but faces erosion as generics gain prominence.

What are the revenue trends and projections?

Global revenues for gabapentin enacarbil were approximately $350 million in 2021, with the U.S. accounting for about 80% of this figure. Sales have plateaued in recent years due to generic entry but are expected to recover modestly with potential new indications and increasing adoption in certain demographics.

Projections suggest a compound annual growth rate (CAGR) of roughly 2-3% from 2022 to 2027**, driven by:

• Expansion of indications
• Entry into emerging markets
• Accelerated prescribing in specific patient cohorts

Relative to its peak, revenues have stabilized or declined slightly since 2019, primarily due to generics entering the market.

What regulatory developments affect market dynamics?

The U.S. Food and Drug Administration (FDA) approved gabapentin enacarbil in 2011. Approval for RLS was extended in 2014 to include postherpetic neuralgia. Subsequent approval of generic versions in 2017 led to a patent cliff that reduced pricing power for the branded option.

In other regions, regulatory approval varies:

• European Union: Approved as HORIZANT
• Japan & Canada: Under regulatory review or awaiting approval processes

Potential future approvals for additional indications, such as epilepsy or off-label uses, could influence market size but currently remain pending.

How do pricing strategies impact financial trajectories?

The branded version's wholesale acquisition cost (WAC) was approximately $25–$30 daily in the U.S. prior to patent expiration. Generic versions are priced 40-60% lower, reducing revenue per prescription. This erosion diminishes profit margins for the original manufacturer but enables broader access, potentially increasing overall prescriptions.

Pharmaceutical companies may adopt varied pricing tactics:

• Bundled discounts for specific patient populations
• Limited launch of new indications to sustain premium pricing
• Strategic collaborations with payers to maintain clinical uptake

Potential innovations and pipeline developments

There is limited pipeline activity specifically for gabapentin enacarbil. Research attention has shifted toward newer neuromodulating agents with improved efficacy or side effect profiles. However, existing formulations could benefit from reformulation or combination therapies to extend lifecycle and market penetration.

Conclusions on market trajectory

Gabapentin enacarbil's market trajectory remains modestly positive but heavily influenced by generic competition, regulatory approvals, and healthcare provider preferences. Revenue stabilization depends on expanding indications, geographic penetration, and price management strategies, with a cautious outlook given intensified generic competition.

Key Takeaways

• The global market for gabapentin enacarbil reached ~$350 million in 2021.
• Patent expiration in 2017 led to increased generic competition, pressuring revenue.
• Growth is primarily driven by use in RLS and postherpetic neuralgia.
• Future prospects depend on regulatory approvals in new indications and regions.
• Pricing strategies and market access influence revenue trajectories amid competition.

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FAQs

1. What are the main indications for gabapentin enacarbil?
Restless legs syndrome (RLS) and postherpetic neuralgia are the primary approved indications.

2. How has generic entry affected the drug’s sales?
Generic competition, starting in 2017, significantly reduced the branded drug’s market share and pricing, leading to a decline in revenue growth.

3. Are there new indications under clinical development?
No substantial pipeline efforts are publicly disclosed; most focus remains on existing approved uses.

4. How does market competition compare with alternatives like pregabalin?
Pregabalin has a broader spectrum of approved uses and a longer market presence, which contributes to its dominance; gabapentin enacarbil’s niche is narrower, limiting market share.

5. What regional markets are expanding for gabapentin enacarbil?
European and Asian markets are exploring approvals, but the US remains the primary revenue source due to established indications.

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References:

[1] IQVIA, Market Reports, 2022.
[2] FDA Drug Database, 2022.
[3] Horizon Pharma Annual Report, 2021.
[4] U.S. Patent and Trademark Office, Patent Expiry Data, 2019.