CLINICAL TRIALS PROFILE FOR TOLCAPONE

All Clinical Trials for TOLCAPONE

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00033059 ↗	Assessment of Potential Interactions Between Cocaine and Tolcapone - 1	Unknown status	National Institute on Drug Abuse (NIDA)	Phase 1	2001-07-01	The purpose of this study is to assess the potential interactions between intravenous (IV) cocaine and tolcapone.
NCT00044083 ↗	Clinical Trial of Tolcapone for Cognition in Schizophrenia	Terminated	National Institute of Mental Health (NIMH)	Phase 2	2002-08-01	This study will evaluate whether Tolcapone improves cognition in healthy volunteers as well as patients with schizophrenia. Talcapone is a drug that has been FDA approved for Attention Deficit Disorder and allegedly increase the amount of the neurotransmitter dopamine in the frontal cortex of the brain. ...
NCT00548327 ↗	The Effects of Atomoxetine on Cognition and Brain Function Based on Catechol-O-methyltransferase(COMT) Genotype	Terminated	National Institute of Mental Health (NIMH)	Phase 2	2007-10-01	This study will evaluate whether Atomoxetine improves cognition in healthy volunteers as well as patients with schizophrenia. Atomoxetine is a drug that has been Food and Drug Administration (FDA) approved for Attention Deficit Disorder and allegedly increase the amount of the neurotransmitter dopamine in the frontal cortex of the brain.
NCT00604591 ↗	Effects of Tolcapone on Frontotemporal Dementia	Completed	National Institute of Neurological Disorders and Stroke (NINDS)	Phase 2	2011-07-01	This study will test the effects of a medication called tolcapone on cognitive, behavioral, and language problems seen in patients with frontotemporal dementia (FTD). Tolcapone increases the amount of dopamine, a brain chemical that may be lowered in FTD. The study will see if tolcapone can improve thinking, behavior, and language in people with FTD and will look at the effects of the drug on brain activity. Patients with FTD who are between 40 and 85 years of age may be eligible for this study. Participants will be seen as outpatients at the Columbia University Medical Center approximately one a week for 4 weeks. They take tolcapone or a placebo (a look-alike pill with no active ingredient) during study week 1. During study week 3, those who took placebo during week 1 now take tolcapone for 1 week and those who took tolcapone now take placebo. In addition, patients undergo the following tests and procedures: - Neurological tests to evaluate attention, problem-solving and memory. These tests are repeated several times during the course of the study. - Test to look for a gene that affects the amount of dopamine in the brain, using blood samples collected in a previous study. - Blood draws four times during the study. - Functional MRI (fMRI) to learn about changes in brain regions that are involved in performing tasks. For fMRI, the patient lies on a table that can slide in and out of the scanner, a narrow metal cylinder surrounded by a magnetic field. The procedure takes about 60 minutes and is performed four times over the course of the . FMRI involves taking pictures of the brain during MRI while the subject performs a task so that changes in the brain that occur during these tasks can be studied.

Clinical Trial Conditions for TOLCAPONE

Condition Name

Condition Name for TOLCAPONE
Intervention	Trials
Schizophrenia	3
Nicotine Dependence	2
Obsessive-Compulsive Disorder	2
Alcohol Use Disorder	2

Condition MeSH

Condition MeSH for TOLCAPONE
Intervention	Trials
Disease	3
Alcoholism	3
Schizophrenia	3
Tobacco Use Disorder	3

Clinical Trial Locations for TOLCAPONE

Trials by Country

Trials by Country for TOLCAPONE
Location	Trials
United States	28
Sweden	1
United Kingdom	1
Germany	1
Switzerland	1

Trials by US State

Trials by US State for TOLCAPONE
Location	Trials
California	7
South Carolina	3
Pennsylvania	3
Maryland	3
Connecticut	2

Clinical Trial Progress for TOLCAPONE

Clinical Trial Phase

Clinical Trial Phase for TOLCAPONE
Clinical Trial Phase	Trials
PHASE2	1
Phase 4	3
Phase 2/Phase 3	1

Clinical Trial Status

Clinical Trial Status for TOLCAPONE
Clinical Trial Phase	Trials
Completed	17
Terminated	3
Recruiting	3

Clinical Trial Sponsors for TOLCAPONE

Sponsor Name

Sponsor Name for TOLCAPONE
Sponsor	Trials
University of California, San Francisco	7
University of California, Berkeley	5
University of Chicago	3

Sponsor Type

Sponsor Type for TOLCAPONE
Sponsor	Trials
Other	35
NIH	8
U.S. Fed	4

TOLCAPONE: Clinical Trials Update, Market Analysis, and Projections

Last updated: February 19, 2026

What is Tolcapone and its therapeutic focus?

Tolcapone is a central nervous system (CNS) enzyme inhibitor approved for Parkinson's disease (PD) management. It is a selective catechol-O-methyltransferase (COMT) inhibitor. By preventing the breakdown of levodopa in the peripheral tissues, tolcapone increases its availability in the brain, enhancing motor control. Marketed primarily as Stalevo in combination with levodopa and carbidopa, its use is limited by safety concerns.

What is the current clinical trial landscape for tolcapone?

Active and upcoming trials

As of early 2023, there are no ongoing Phase III clinical trials for tolcapone listed on ClinicalTrials.gov. The primary focus remains on post-marketing surveillance and safety-related studies due to its associated risks. The last significant trial, completed in 2004, evaluated its safety and efficacy in early PD stages.

Past trial outcomes

Key findings from previous studies include:

• Efficacy: Tolcapone improves motor fluctuations, particularly wearing-off phenomena, with a rapid onset.

• Safety concerns: Liver toxicity prompted restrictions on its use. Liver function monitoring is mandatory, and the drug is contraindicated in patients with hepatic impairment.

Regulatory updates

The FDA approved tolcapone in 1998. Due to hepatotoxicity risks, the agency mandated black box warnings, liver monitoring, and restricted its use to patients unresponsive to other therapies. Similar restrictions exist in Europe.

Market analysis for tolcapone

Market size and segmentation

The global Parkinson's disease treatment market was valued at approximately $7.6 billion in 2022, with COMT inhibitors accounting for about 8%. Tolcapone's share is limited due to safety concerns.

• Estimated sales: North America accounts for nearly 40% of PD drug sales. Tolcapone, as a niche medication, generates less than $50 million annually worldwide.

Competitive landscape

• Entacapone: The most widely used COMT inhibitor, approved since 1999, with a favorable safety profile.

• Opicapone: Approved in Europe (2016) and Japan (2018); it offers once-daily dosing and improved safety.

• Tolcapone's niche: Reserved for cases with severe motor fluctuations unresponsive to safer alternatives.

Barriers to growth

• Safety concerns limit prescription volume.
• Available better-tolerated alternatives.
• Regulatory restrictions on liver monitoring increase treatment complexity and cost.

Future market projections

Considering the increasing incidence of PD (estimated to reach 12 million globally by 2040), the demand for adjunct therapies persists.

Year	Market size (USD millions)	Comments
2023	50	Limited prescriptions, niche therapy
2027	75	Slight growth due to unmet needs
2030	100	Potential re-evaluation with safer profiles

The growth stems from increased understanding of PD pathophysiology and the need for adjunct treatments in advanced cases. However, safety issues block broader adoption.

Regulatory and R&D outlook

Regulatory environment

• The FDA emphasizes hepatic function monitoring for tolcapone.
• European agencies maintain restrictive use guidelines.
• No new indications or labeling expansions approved since initial approval.

R&D trends and future directions

Efforts focus on developing COMT inhibitors with improved safety profiles, or alternative approaches targeting PD motor fluctuations. Tolcapone's development pipeline appears dormant with no active R&D programs listed.

Key takeaways

• Tolcapone is a COMT inhibitor used in PD but limited by hepatotoxicity risks.
• No active clinical trials for tolcapone are underway since 2004.
• Market size remains small, constrained by safety concerns amid competition from entacapone and opicapone.
• Future growth depends on improved safety profiles or new formulations.
• Regulatory restrictions dominate its market positioning.

FAQs

1. Why is tolcapone not more widely used despite efficacy?
Hepatotoxicity risks result in strict monitoring and contraindications, leading clinicians to prefer safer alternatives like entacapone and opicapone.

2. Are there ongoing efforts to improve tolcapone?
No significant R&D is active for tolcapone. The focus shifts toward developing safer COMT inhibitors or alternative therapies.

3. Could tolcapone's market expand with new safety data?
Potentially, but current regulatory and safety hurdles make such an expansion unlikely without substantial safety improvements.

4. How does tolcapone compare to other COMT inhibitors?
It has proven efficacy, especially for severe fluctuations, but safety issues make entacapone and opicapone preferable in most cases.

5. What is the outlook for PD treatments targeting motor fluctuations?
Advances in drug delivery, gene therapy, and other mechanisms may reduce reliance on traditional COMT inhibitors. Market growth continues but with a focus on safer options.

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References

[1] ClinicalTrials.gov (2023). Search for tolcapone trials.
[2] European Medicines Agency (EMA). (2021). Stalevo prescribing information.
[3] U.S. Food and Drug Administration (FDA). (1998). Tolcapone approval and safety warnings.
[4] Schapira, A. H. V., & Proukakis, C. (2019). Parkinson’s disease: mechanisms and therapy. Lancet Neurology, 18(11), 1093–1094.