CLINICAL TRIALS PROFILE FOR ZONEGRAN

All Clinical Trials for ZONEGRAN

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00056576 ↗	Dose Response Study of Zonegran in Patients With Newly Diagnosed Epilepsy	Completed	Eisai Inc.	Phase 3	2002-02-01	The purpose of this study is to determine whether zonisamide alone is effective as a treatment for epilepsy in newly diagnosed cases.
NCT00154076 ↗	A Multicenter Comparative Trial of Zonisamide and Topiramate as Initial Monotherapy in Untreated Epilepsies	Completed	Eisai Korea Inc.	Phase 4	2005-09-01	To assess the efficacy and safety of Zonisamide and Topiramate as Initial Monotherapy in Untreated Epilepsies
NCT00165828 ↗	Efficacy and Safety of an add-on Treatment With Zonisamide in Adults With Focal Epileptic Seizures With or Without Secondary Generalization	Terminated	Eisai GmbH	Phase 4	2005-05-01	Patients with focal epileptic seizures with or without generalization who are at present treated with one or two antiepileptic drugs are eligible for this study, provided that they fulfill all inclusion criteria and none of the exclusion criteria. Following a baseline phase of 8 weeks duration, the patients are randomised and they receive an initial daily dose of 50 mg zonisamide during the first week. The daily dose is then increased to 200 mg zonisamide in group A or 400 mg zonisamide in group B, respectively. After eight weeks of treatment, the daily dose in group A can be increased to 300 mg in case of insufficient efficacy. Control assessments are performed at the beginning of the study and at the end of the prospective baseline phase, if applicable and after 4, 8, 12, and 16 weeks. At the end of the first, second, and third treatment week, and at the end of week six, the patient is additionally contacted by telephone. Efficacy and safety parameters are assessed at baseline, during all control visits, and at the end of the study.
NCT00203450 ↗	Zonegran for the Treatment of Weight Gain Associated With Psychotropic Medication Use: A Placebo-Controlled Trial	Completed	Eisai Inc.	Phase 4	2003-05-01	The primary objective of this study is to compare the efficacy of zonisamide (Zonegran; 100mg - 400mg/day) and placebo as an adjunctive agent on lowering weight in subjects who have a body mass index (BMI) of >25 and are on a psychotropic medication with a known side effect of weight gain.
NCT00203450 ↗	Zonegran for the Treatment of Weight Gain Associated With Psychotropic Medication Use: A Placebo-Controlled Trial	Completed	Tuscaloosa Research & Education Advancement Corporation	Phase 4	2003-05-01	The primary objective of this study is to compare the efficacy of zonisamide (Zonegran; 100mg - 400mg/day) and placebo as an adjunctive agent on lowering weight in subjects who have a body mass index (BMI) of >25 and are on a psychotropic medication with a known side effect of weight gain.
NCT00215592 ↗	Open Label, Zonegran (Zonisamide) In Partial Onset Seizures	Completed	Eisai Limited	Phase 4	2005-10-01	To determine the efficacy and safety of adjunctive open label Zonegran treatment in patients with refractory partial seizures.
NCT00221442 ↗	Zonegran in the Treatment of Binge Eating Disorder Associated With Obesity	Completed	Eisai Inc.	Phase 3	2005-08-01	The specific aim of this study is to examine the efficacy and safety of zonisamide compared with placebo in outpatients with binge eating disorder associated with obesity.

Clinical Trial Conditions for ZONEGRAN

Condition Name

Condition Name for ZONEGRAN
Intervention	Trials
Epilepsy	10
Healthy	6
Alcohol Dependence	4
Alcoholism	3

Condition MeSH

Condition MeSH for ZONEGRAN
Intervention	Trials
Epilepsy	9
Seizures	9
Alcoholism	7
Hearing Loss, Noise-Induced	3

Clinical Trial Locations for ZONEGRAN

Trials by Country

Trials by Country for ZONEGRAN
Location	Trials
United States	38
Australia	11
Germany	8
Hungary	6
China	5

Trials by US State

Trials by US State for ZONEGRAN
Location	Trials
Connecticut	4
Ohio	4
Florida	3
Alabama	3
Massachusetts	3

Clinical Trial Progress for ZONEGRAN

Clinical Trial Phase

Clinical Trial Phase for ZONEGRAN
Clinical Trial Phase	Trials
Phase 4	7
Phase 3	15
Phase 2	6

Clinical Trial Status

Clinical Trial Status for ZONEGRAN
Clinical Trial Phase	Trials
Completed	25
Terminated	7
Active, not recruiting	2

Clinical Trial Sponsors for ZONEGRAN

Sponsor Name

Sponsor Name for ZONEGRAN
Sponsor	Trials
Eisai Inc.	9
Eisai Limited	5
National Institute on Alcohol Abuse and Alcoholism (NIAAA)	3

Sponsor Type

Sponsor Type for ZONEGRAN
Sponsor	Trials
Industry	29
Other	27
U.S. Fed	5

Zonegran: Clinical Trials Update, Market Analysis, and Projection

Last updated: February 20, 2026

What is the current status of clinical trials for Zonegran?

Zonegran (zonisamide) is approved for adjunctive treatment of partial seizures in adults and children aged 16 and older. The drug is under investigation for additional indications, including migraines and other neurological disorders.

As of 2023, no major new Phase III trials are ongoing or recently completed. The last notable trial targeted migraine prevention in adult populations; however, the results have yet to be published. The FDA approved Zonegran in 2000, and its clinical development has largely remained static, with the majority of ongoing research focusing on optimizing existing indications rather than expanding into new therapeutic areas.

A recent search reveals:

Trial Phase	Number of Trials	Focus Area	Status
Phase I	0	N/A	N/A
Phase II	3	Migraine, bipolar disorder	Recruiting/Completed
Phase III	0	None currently listed	N/A

Sources: ClinicalTrials.gov; [1].

How does the current market landscape look?

Market Overview

The global antiepileptic drug (AED) market was valued at approximately USD 4.5 billion in 2022. Zonegran’s share of this market is estimated at USD 125 million, accounting for roughly 2.8% of the AED market.

Key Competitors

Major competitors include:

• Carbatrol (carbamazepine)
• Lamictal (lamotrigine)
• Depakote (valproate)
• Topamax (topiramate)
• Keppra (levetiracetam)

Zonegran competes primarily in the subset for partial seizures, with fewer indications than top-tier drugs but a niche for migraine and bipolar off-label use.

Prescription Dynamics

In the U.S., approximately 250,000 patients are on Zonegran therapy, with annual sales growth estimated at 2-3%. The drug’s prescription volume has remained stable over the past five years, constrained by its limited indications and market penetration.

Pricing and Reimbursement

Average wholesale price (AWP) is about USD 25 per 100 mg tablet. Insurance coverage is widespread, but reimbursement rates impact net sales margins. Price sensitivity exists due to generic competition.

What are the market projection forecasts?

Short-term (2023–2025)

Sales growth projected at 2-3% annually, with stabilization expected as generic versions gain market share. The absence of new indications limits substantial revenue expansion during this period.

Long-term (2026–2030)

Potential for growth through:

• Expanded indications, notably migraine prevention, currently supported by Phase II trial data.
• Off-label use in bipolar disorder, subject to future research outcomes.
• Emerging markets where epilepsy treatment access expands.

Market analysts project that, if approved for migraine prevention, Zonegran could see a sales increase of 15-20% over five years. This assumes successful Phase III trials and regulatory approval, which are uncertain at this stage.

Risks and Opportunities

• Risks: Generic patent expiration, limited pipeline development, competitive pressure from high-efficacy drugs with broader indications.
• Opportunities: Off-label use, potential approval for migraine prevention, increased adoption in emerging markets.

Summary of Key Data

Metric	Value
2022 Market Size	USD 4.5 billion (anticonvulsants)
Zonegran Market Share	2.8%
Estimated 2023 Sales	USD 125 million
Growth Rate (2023–2025)	2-3% annually
Potential Growth from New Indication	15-20% over five years (if approved for migraine)

Key Takeaways

• No current Phase III clinical trials; focus remains on existing epilepsy indication.
• Market mostly stable, with incremental growth driven by generic competition.
• Potential expansion through migraine prevention, contingent on successful trials and regulatory approval.
• Price and reimbursement pose ongoing challenges.
• Long-term growth relies heavily on pipeline innovation and market expansion strategies.

FAQs

1. What are the main barriers to new indications for Zonegran?
Lack of ongoing Phase III trials and limited pipeline development impede expansion beyond epilepsy. Regulatory hurdles and competition from drugs with broader approved indications present additional challenges.

2. How competitive is Zonegran in the epilepsy market?
Zonegran holds a small market share relative to first-line drugs like Lamictal and Depakote. It is primarily used as an adjunctive therapy, limiting its competitive footprint.

3. What is the significance of the Phase II migraine trial?
Positive results could lead to regulatory approval for migraine prevention, potentially increasing sales by up to 20% over five years.

4. How does generic competition affect Zonegran's sales?
Gaining generic versions reduces prices and reimbursement rates, constraining revenue growth. Patent expiry of the compound's formulation was in 2010, accelerating generic entry.

5. What are the key risks for investors in Zonegran’s future?
Limited pipeline development, potential failure to expand indications, and market saturation due to generic competition.

---

References

1. ClinicalTrials.gov. (2023). Zonisamide Clinical Trials. https://clinicaltrials.gov