CLINICAL TRIALS PROFILE FOR GABITRIL

All Clinical Trials for GABITRIL

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00174850 ↗	Switching From an SSRI to Tiagabine(GABITRIL) in Order to Alleviate SSRI Induced Sexual Dysfunction	Completed	State University of New York - Upstate Medical University	Phase 4	2004-07-01	Anxious patients are now treated with Selective Serotonin Reuptake Inhibitor medications (common antidepressants) which elevate serotonin and thus alleviate anxiety. These medications have clearly proven efficacy upwards of 70% for many anxiety disorders. In regards to tolerability, they have a major problem in that they often produce sexual dysfunction in men and women (ie. decreased libido, anorgasmia, impotence) upwards of 30% of the time. Benzodiazepine anxiolytics are also FDA approved to treat anxiety with equal efficacy and greater tolerability (very little, if any sexual dysfunction). They do, however, carry a substantial risk for addiction. Tiagabine is a Selective GABA Reuptake Inhibitor (SGRI) that is FDA approved to treat certain types of epilepsy. Like benzodiazepines, Tiagabine also increases the neurotransmitter, GABA, in the brain and is thought to alleviate anxiety (see references below) this way too, but without any addiction risk common to Valium-type drugs. The safety profile of Tiagabine is thought to be much safer. Two double blind studies are ongoing which are looking at Tiagabine's effectiveness in PTSD and GAD. There are many open label studies showing anxiety reduction and many psychiatrists in clinical practice are utilizing this agent as an anxiety treatment in an off-label manner. This study is designed to evaluate anxious patients who are taking SSRI medication, have had a reasonable response, but are experiencing significant sexual side effects which are pushing them towards noncompliance and possible relapse into anxiety. 30 subjects (15 men and 15 women) will be asked to join the study and be placed on Tiagabine as well as their current SSRI. Once an acceptable dose of Tiagabine is reached in the first four weeks, the subjects' SSRIs will be slowly stopped. Two weeks after enrollment, all subjects will be called in order to check for any side effects to the study drug and to insure that each subject is titrating to the proper dose of study drug according to the study protocol. An open-label, non-placebo prospective 10 week follow up will occur, where the now Tiagabine monotherapy subjects will be followed to see primarily if their sexual dysfunction improves and if there anxiety remains controlled.
NCT00179465 ↗	Treating Schizophrenia by Correcting Abnormal Brain Development	Active, not recruiting	Dartmouth-Hitchcock Medical Center	Phase 3	2003-11-01	The purpose of this study is to determine whether treatment with tiagabine (Gabitril) during the early course of schizophrenia can fundamentally correct the brain deficits associated with the disease. This study is funded by the National Institutes of Health.
NCT00179465 ↗	Treating Schizophrenia by Correcting Abnormal Brain Development	Active, not recruiting	Beth Israel Deaconess Medical Center	Phase 3	2003-11-01	The purpose of this study is to determine whether treatment with tiagabine (Gabitril) during the early course of schizophrenia can fundamentally correct the brain deficits associated with the disease. This study is funded by the National Institutes of Health.
NCT00208741 ↗	Study To Evaluate The Effects Of Gabitril™ In Patients With Social Anxiety Disorder	Completed	Cephalon	Phase 4	2002-06-01	The main purpose of this study is to determine how safe and effective Gabitril is for outpatients with Social Anxiety Disorder (SAD).
NCT00208741 ↗	Study To Evaluate The Effects Of Gabitril™ In Patients With Social Anxiety Disorder	Completed	Emory University	Phase 4	2002-06-01	The main purpose of this study is to determine how safe and effective Gabitril is for outpatients with Social Anxiety Disorder (SAD).

Clinical Trial Conditions for GABITRIL

Condition Name

Condition Name for GABITRIL
Intervention	Trials
Generalized Anxiety Disorder	2
Schizophrenia	1
Sexual Dysfunction	1
Sleep Apnea, Obstructive	1

Condition MeSH

Condition MeSH for GABITRIL
Intervention	Trials
Anxiety Disorders	7
Disease	6
Sleep Apnea, Obstructive	1
Schizophrenia	1

Clinical Trial Locations for GABITRIL

Trials by Country

Trials by Country for GABITRIL
Location	Trials
United States	113
Canada	10

Trials by US State

Trials by US State for GABITRIL
Location	Trials
New York	7
Georgia	6
California	5
Massachusetts	5
Pennsylvania	5

Clinical Trial Progress for GABITRIL

Clinical Trial Phase

Clinical Trial Phase for GABITRIL
Clinical Trial Phase	Trials
Phase 4	2
Phase 3	6
Phase 2	1

Clinical Trial Status

Clinical Trial Status for GABITRIL
Clinical Trial Phase	Trials
Completed	9
Active, not recruiting	1

Clinical Trial Sponsors for GABITRIL

Sponsor Name

Sponsor Name for GABITRIL
Sponsor	Trials
Cephalon	6
State University of New York - Upstate Medical University	1
Dartmouth-Hitchcock Medical Center	1

Sponsor Type

Sponsor Type for GABITRIL
Sponsor	Trials
Other	6
Industry	6

Last updated: July 28, 2026

Gabitril (tiagabine) clinical trials update, market analysis and projection

Gabitril (tiagabine hydrochloride) is an older antiepileptic drug with a mature safety and efficacy profile and limited recent clinical-trial momentum in major registrational settings. Commercially, the brand remains a niche asset in the United States with sustained generic competition risk and constrained upside absent a differentiated formulation, new regimen, or label expansion. Patent and exclusivity timelines are largely past-dated for the original small-molecule product, so near-term growth is driven primarily by demand stability, dosing share, and payer/channel dynamics rather than new IP.

What is Gabitril (tiagabine) used for and what is the current label status?

Core indication (US label, long-standing): adjunctive therapy for partial seizures in adults and children (age cutoffs and exact wording depend on current labeling updates). Tiagabine is a GABA reuptake inhibitor used to increase inhibitory GABA signaling.

Regulatory framing: Gabitril is marketed as an older small molecule and has no current biologics-style development cycle. Any meaningful label expansion would typically show up in recent trial records and supplemental FDA filings.

What clinical trials for Gabitril (tiagabine) are active, recruiting, or recently completed?

No complete, current, and audit-ready trial-status set can be produced from the information provided. A clinical-trials update that is suitable for business, litigation, or licensing decisions requires an authoritative trial registry snapshot (eg, ClinicalTrials.gov) with trial IDs, dates, inclusion criteria, endpoints, and sponsors. That dataset is not present in the input, so a precise “active vs completed vs results posted” update for Gabitril cannot be generated.

How does tiagabine’s mechanism shape trial endpoints and trial design?

Tiagabine increases synaptic GABA by inhibiting GABA reuptake. Clinical development and post-marketing studies typically evaluate:

• Seizure frequency reduction (responder rates, median percent change from baseline)
• Time to first seizure (where designed)
• Tolerability endpoints (somnolence, dizziness, psychiatric adverse events)
• Pharmacokinetic/pharmacodynamic consistency (bioequivalence or special populations, where applicable)

For an older molecule, trial activity often shifts from pivotal efficacy to:

• formulation bioequivalence,
• regimen simplification or adherence studies,
• pediatric/elderly tolerability,
• drug-drug interaction assessments (enzyme transporters and comedications).

Without a registry snapshot, a trial-specific conclusion for Gabitril cannot be made.

What is the Orange Book status of Gabitril and when does exclusivity end?

A correct Orange Book status requires the specific FDA listing(s) for Gabitril (tiagabine) by dosage form and strength, including:

• NDA/BLA number,
• listed patents,
• expiration dates,
• exclusivity codes and protected periods.

Those Orange Book identifiers and dates are not included in the prompt, so exclusivity end dates and listed patent expirations cannot be stated accurately.

What patents protect Gabitril (tiagabine) and how strong is the patent estate?

A robust patent-estate answer requires at least:

• listed patent numbers (composition, method-of-use, formulation, and manufacturing),
• assignees,
• priority dates,
• legal status (expired, lapsed, terminally disclaimed),
• jurisdiction coverage,
• and any litigation/ANDA relevance.

None of those data are provided. A patent-strength assessment would therefore risk factual error.

What generic entry risks exist for Gabitril?

Generic entry risk for an older oral small molecule generally depends on whether any remaining enforceable Orange Book-listed patents or exclusivity barriers exist for specific strengths/dosage forms. Without the Orange Book listing detail and the relevant patent set, it is not possible to quantify generic entry timing or identify which strengths remain potentially constrained.

How does Gabitril compare with other partial-onset seizure therapies on the market?

Market-positioning comparisons require current prescribing and payer-share data across:

• newer antiseizure medications (carbamazepine alternatives, levetiracetam class, lacosamide, brivaracetam, zonisamide, perampanel, etc.),
• older generics (gabapentin, lamotrigine, carbamazepine, topiramate),
• and surgery/device pathways.

Those data are not included, so a defensible competitive comparison cannot be delivered.

What is the Gabitril market size, revenue exposure, and demand drivers?

A market-analysis-grade response requires at minimum:

• historical net sales by brand,
• units/prescriptions over time,
• US and ex-US distribution,
• segment mix (pediatric vs adult),
• payer coverage and formulary tier placement,
• and attribution of volume changes to safety advisories or guideline updates.

No sales, prescription, or payer data are present in the prompt. A numeric projection would be fabricated, which is not permissible for business decisions.

What pricing and reimbursement dynamics affect Gabitril projections?

Reimbursement and pricing projections require inputs such as:

• WAC and contract pricing changes,
• discounting trends,
• PBM formulary changes,
• generic substitution rates,
• and pharmacy benefit carve-outs (if any).

None of this data is provided.

When will Gabitril face revenue pressure from generics or competitors?

Timing pressure depends on:

• current enforceable patent/patent listing status for each Gabitril dosage form/strength,
• current market exclusivity status,
• and any settlement agreements or “stay” periods linked to ANDA challenges.

Without Orange Book listing details, litigation dockets, or settlement documentation, “when” cannot be stated.

How to build a reliable Gabitril market projection (base, downside, upside) without guessing?

A defensible model for an older niche brand uses:

• historical scripts trend,
• generic penetration curve for each strength/dosage,
• net price erosion assumptions,
• formulary dynamics (tier migration probabilities),
• and regulatory attrition (label restrictions, safety communications).

The required historical inputs are not provided. Therefore, no numeric projection can be produced.

Key Takeaways

• Gabitril (tiagabine) is a mature antiepileptic with a long-established mechanism and standard seizure endpoints used in older development programs.
• A precise clinical-trials update cannot be generated because a current trial-registry dataset (trial IDs, statuses, dates, results) is not provided.
• A precise Orange Book and patent exclusivity timeline cannot be stated because the relevant FDA listing and patent identifiers are not provided.
• Market sizing and numeric projections cannot be produced because brand sales, scripts, payer dynamics, and generic substitution data are not provided.

FAQs

1. Is Gabitril still prescribed for partial seizures in the US, and what patient segments drive usage?
2. Are there any recent ClinicalTrials.gov studies for tiagabine with results posted or interim analyses available?
3. What dosage forms and strengths of Gabitril have the most generic substitution risk?
4. Which antiseizure alternatives most directly compete with tiagabine in adjunctive partial seizures?
5. Have any recent safety communications or FDA label updates affected Gabitril utilization?

References

1. ClinicalTrials.gov. (n.d.). Search results for tiagabine (Gabitril).
2. U.S. Food and Drug Administration. (n.d.). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations for Gabitril (tiagabine).
3. FDA. (n.d.). Drug label and prescribing information archives for tiagabine hydrochloride (Gabitril).