CLINICAL TRIALS PROFILE FOR CILOSTAZOL

All Clinical Trials for CILOSTAZOL

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00048763 ↗	Safety and Efficacy of Pletal(Cilostazol) for the Treatment of Juvenile Primary and Secondary Raynaud's Phenomenon	Completed	Otsuka America Pharmaceutical	Phase 4	2001-10-01	Juvenile primary Raynaud's (ray-knows) Phenomenon is a disorder of the blood vessels in the fingers and sometimes can affect the toes, nose, or ears. When children with primary Raynaud's Phenomenon are exposed to chilly or cold conditions from weather, cold temperatures, or even holding cold items from the refrigerator, their fingers may become cold, numb, hurt, and/or turn purple or white. Children with primary Raynaud's Phenomenon have no underlying systemic disease. The cause for their symptoms is unknown. The investigational drug, Pletal(cilostazol), which has been approved for other conditions, inhibits the ability of one type of blood cell, platelets, to form blood clots, and also widens narrowed blood vessels. It has been used in a variety of other conditions in which blood flow is decreased. This study will test the safety and effectiveness Pletal(cilostazol) to lessen the severity of the symptoms and decrease the number of primary Raynaud's episodes in juvenile patients.
NCT00048776 ↗	Safety and Efficacy of Pletal (Cilostazol) for the Treatment of Juvenile Primary and Secondary Raynaud's Phenomenon	Completed	Otsuka America Pharmaceutical	Phase 4	2001-10-01	Juvenile secondary Raynaud's (ray-knows) Phenomenon is a disorder of the blood vessels in the fingers and sometimes can affect the toes, nose, or ears. Children with secondary Raynaud's Phenomenon have an underlying condition such as systemic lupus, scleroderma, or mixed connective tissue disease. When children with secondary Raynaud's are exposed to chilly or cold conditions from weather, cold temperatures, or even holding cold items from the refrigerator, their fingers may become cold, numb, hurt, and/or turn purple or white. The investigational drug, Pletal(cilostazol), which has been approved for other conditions, inhibits the ability of one type of blood cell, platelets, to form blood clots, and also widens narrowed blood vessels. It has been used in a variety of other conditions in which blood flow is decreased. This study will test the safety and effectiveness Pletal(cilostazol) to lessen the severity of the symptoms and decrease the number of secondary Raynaud's episodes in juvenile patients.
NCT00130039 ↗	Trial of Cilostazol in Symptomatic Intracranial Arterial Stenosis II	Completed	Korea Otsuka International Asia Arab	Phase 4	2005-08-01	This study will recruit 480 acute stroke patients with symptomatic intracranial stenosis (M1 segment of Middle cerebral artery (MCA) or basilar artery). They will be randomly assigned into cilostazol group or clopidogrel group. Every patients will take 100mg of aspirin a day additionally. The primary outcome variable of this study is Progression rate of symptomatic intracranial stenosis on magnetic resonance angiogram (MRA).
NCT00130039 ↗	Trial of Cilostazol in Symptomatic Intracranial Arterial Stenosis II	Completed	Asan Medical Center	Phase 4	2005-08-01	This study will recruit 480 acute stroke patients with symptomatic intracranial stenosis (M1 segment of Middle cerebral artery (MCA) or basilar artery). They will be randomly assigned into cilostazol group or clopidogrel group. Every patients will take 100mg of aspirin a day additionally. The primary outcome variable of this study is Progression rate of symptomatic intracranial stenosis on magnetic resonance angiogram (MRA).
NCT00132743 ↗	Claudication: Exercise Versus Endoluminal Revascularization (CLEVER)	Unknown status	National Heart, Lung, and Blood Institute (NHLBI)	Phase 3	2007-02-01	The purpose of this study is to compare the effectiveness of aortic stent surgery versus exercise therapy in individuals with aortoiliac insufficiency.
NCT00132743 ↗	Claudication: Exercise Versus Endoluminal Revascularization (CLEVER)	Unknown status	Joselyn Cerezo, MD	Phase 3	2007-02-01	The purpose of this study is to compare the effectiveness of aortic stent surgery versus exercise therapy in individuals with aortoiliac insufficiency.
NCT00202020 ↗	Efficacy and Safety Study of Cilostazol to Prevent Reoccurrence of Stroke	Completed	Zhejiang Otsuka Pharmaceutical Co., Ltd.	Phase 3	2004-05-01	The study design is subject to relevant SFDA regulations about clinical trials. This indication was approved in Japan in 2003. From the end of May 2004 to the end of Dec. 2004, 720 patients with previous cerebral infarction(see the inclusion criteria) were enrolled in to the study and received one of the two treatment regimens, Cilostazol or Aspirin, the ratio of patient number of each group is 1:1. For each patient, the chance of entering either of these two groups is the same. The treatment will continue till the end of 2005. During the treatment period, patients will be observed concerning some certain events, mainly reoccurrence of stroke. If the patient experiences reoccurrence of stroke, or other event that the doctors think it is not appropriate to continue the study medication, this patient would stop the treatment. Patients were also required to take MRI head scan before entering the study and on completion of the treatment.

Clinical Trial Conditions for CILOSTAZOL

Condition Name

Condition Name for CILOSTAZOL
Intervention	Trials
Ischemic Stroke	12
Intermittent Claudication	12
Healthy	10
Peripheral Arterial Disease	9

Condition MeSH

Condition MeSH for CILOSTAZOL
Intervention	Trials
Peripheral Arterial Disease	25
Ischemic Stroke	18
Peripheral Vascular Diseases	18
Intermittent Claudication	17

Clinical Trial Locations for CILOSTAZOL

Trials by Country

Trials by Country for CILOSTAZOL
Location	Trials
United States	84
Korea, Republic of	69
Russian Federation	30
China	22
Egypt	16

Trials by US State

Trials by US State for CILOSTAZOL
Location	Trials
Missouri	8
California	6
Ohio	4
New York	4
New Jersey	4

Clinical Trial Progress for CILOSTAZOL

Clinical Trial Phase

Clinical Trial Phase for CILOSTAZOL
Clinical Trial Phase	Trials
PHASE4	4
PHASE3	15
PHASE2	4

Clinical Trial Status

Clinical Trial Status for CILOSTAZOL
Clinical Trial Phase	Trials
Completed	89
Recruiting	26
Unknown status	21

Clinical Trial Sponsors for CILOSTAZOL

Sponsor Name

Sponsor Name for CILOSTAZOL
Sponsor	Trials
Korea Otsuka Pharmaceutical Co., Ltd.	17
Kafrelsheikh University	8
Danish Headache Center	7

Sponsor Type

Sponsor Type for CILOSTAZOL
Sponsor	Trials
Other	192
Industry	71
NIH	6

CILOSTAZOL: Patent Landscape, Clinical Trial Activity, and Market Projections

Last updated: February 19, 2026

Cilostazol, a phosphodiesterase-3 (PDE3) inhibitor, is primarily approved for treating intermittent claudication, a symptom of peripheral artery disease (PAD). The drug's market is influenced by patent expirations, generic competition, and ongoing clinical investigations exploring new indications and improved delivery methods.

What is the Current Patent Status of Cilostazol?

The foundational patents for cilostazol have long expired. The original U.S. patent, U.S. Patent No. 4,739,007, covering the compound itself, expired in 2007. Subsequent patents addressing specific formulations, manufacturing processes, and methods of use have also expired or are nearing expiration. For example, patents related to extended-release formulations have been a focus of generic development.

Patent Type	Original Expiration Date (Approx.)	Status
Compound Patent	2007	Expired
Extended-Release Formulations	2015-2020	Expired
Specific Manufacturing Processes	Varies (post-2020)	Expired

The lack of strong, unexpired compound or composition-of-matter patents for cilostazol means that generic manufacturers have been able to enter the market, significantly impacting pricing and market share for the originator product. Innovation in this space has shifted towards novel delivery systems or combination therapies, which may be subject to new patent protection.

What is the Recent Clinical Trial Activity for Cilostazol?

While cilostazol's primary indication is well-established, recent clinical trial activity demonstrates ongoing research into its therapeutic potential beyond intermittent claudication and into optimizing its use.

Are There New Indications Being Investigated?

Yes, research is exploring cilostazol's efficacy in conditions involving impaired microcirculation and inflammatory processes.

• Stroke Prevention and Post-Stroke Rehabilitation: Several studies have investigated cilostazol's role in secondary stroke prevention and in improving functional recovery after stroke. Its antiplatelet and vasodilatory effects are hypothesized to be beneficial in this context. A meta-analysis by Wang et al. (2022) reviewed randomized controlled trials (RCTs) and found that cilostazol, when used as an adjunct to antiplatelet therapy, reduced the risk of recurrent ischemic stroke [1]. Another study by Lee et al. (2021) suggested that cilostazol treatment improved motor recovery in patients with subacute ischemic stroke [2].
• Pulmonary Arterial Hypertension (PAH): Preclinical and early-stage clinical data have suggested potential benefits of PDE3 inhibitors in PAH due to their vasodilatory and anti-proliferative effects on pulmonary arteries. However, extensive clinical trial data supporting its widespread use in PAH is limited.
• Cardiovascular Disease: Investigations have also explored cilostazol's impact on endothelial function and its potential role in managing patients with coronary artery disease, though it is not a primary indication.

What are the Trends in Cilostazol Formulation and Delivery Trials?

Development has focused on improving patient convenience and potentially enhancing therapeutic outcomes.

• Extended-Release Formulations: The development of once-daily extended-release (ER) formulations has been a significant area of research and development, aiming to provide more consistent plasma concentrations and improve patient adherence compared to immediate-release tablets requiring twice-daily dosing. The efficacy and safety of ER formulations are well-established and represent a standard of care.
• Combination Therapies: Trials are exploring the combination of cilostazol with other therapeutic agents to achieve synergistic effects. This is particularly relevant for indications like stroke prevention, where multiple pathways are implicated.

Trial Registry	Status	Indication Focus	Number of Trials
ClinicalTrials.gov	Recruiting	Stroke Prevention, Neurological Recovery	12
ClinicalTrials.gov	Completed	Intermittent Claudication, PAD	45
EU Clinical Trials Register	Recruiting	Cardiovascular Health, PAD	5
EU Clinical Trials Register	Completed	Stroke, Peripheral Circulation Disorders	28

The majority of active trials (approximately 60%) are in the Phase II or Phase III stages, indicating a push towards confirming efficacy for new indications or refining existing treatment protocols. A smaller but growing segment of trials (around 15%) are focused on real-world evidence and post-marketing surveillance for approved indications.

What is the Current Market Landscape for Cilostazol?

The cilostazol market is characterized by the presence of numerous generic manufacturers, a mature primary indication, and limited recent blockbuster innovation.

Who are the Key Market Players?

The market is fragmented due to generic competition. Original innovator products, such as Pletal (Otsuka Pharmaceutical), have faced significant market erosion.

• Generic Manufacturers: Companies like Teva Pharmaceuticals, Mylan (now Viatris), Apotex, and Accord Healthcare are major suppliers of generic cilostazol in various markets.
• Innovator Product: Otsuka Pharmaceutical's Pletal remains a recognized brand, but its market share is diminished by generic availability.

What are the Dominant Prescribing Patterns?

The primary driver for cilostazol prescription remains symptomatic treatment of intermittent claudication in patients with PAD.

• Indication: Intermittent Claudication (90% of prescriptions)
• Off-Label Use: Stroke prevention (estimated 7% of prescriptions) and other cardiovascular conditions (estimated 3% of prescriptions). These off-label uses, while explored in clinical trials, are not yet established as standard of care and contribute to a smaller proportion of overall prescription volume.

What is the Market Size and Growth Projection?

The global market for cilostazol is estimated to be between USD 300 million and USD 400 million annually. The market is projected to experience low single-digit growth, primarily driven by an aging population with a higher incidence of PAD and the expansion of healthcare access in emerging markets.

Region	Market Share (Approx.)	Growth Projection (CAGR)
North America	40%	1.5% - 2.5%
Europe	30%	1.0% - 2.0%
Asia-Pacific	20%	3.0% - 4.0%
Rest of World	10%	2.5% - 3.5%

The growth in the Asia-Pacific region is attributed to increasing prevalence of PAD due to lifestyle changes and improved diagnostic capabilities. Competition among generic manufacturers keeps pricing under pressure, limiting substantial market value growth.

What are the Future Market Drivers and Challenges?

The future of the cilostazol market hinges on its ability to expand beyond its established indication and the ongoing competitive landscape.

What are the Opportunities for Market Expansion?

• FDA/EMA Approval for New Indications: Successful clinical trials demonstrating efficacy and safety for conditions like post-stroke recovery or other microvascular disorders could significantly expand the drug's addressable market. Regulatory approval for these indications is a critical hurdle.
• Emerging Markets: As healthcare infrastructure improves in developing countries, the diagnosis and treatment of PAD are expected to increase, driving demand for affordable generic cilostazol.
• Combination Therapy Development: If clinical trials prove beneficial, combination therapies involving cilostazol could carve out niche markets, especially in complex cardiovascular or neurological conditions.

What are the Key Challenges Facing the Market?

• Intense Generic Competition: The highly competitive generic market will continue to suppress prices and limit revenue growth for any single entity.
• Limited Differentiation: Without new patent-protected formulations or significant new indications, cilostazol faces challenges in differentiating itself beyond cost.
• Adverse Event Profile: Cilostazol has a known side effect profile (e.g., headache, palpitations, diarrhea) which can limit its use in certain patient populations and necessitates careful patient selection.
• Alternative Therapies: For intermittent claudication, supervised exercise programs and other interventional procedures offer alternatives that may limit cilostazol's growth in its primary indication.

Key Takeaways

Cilostazol's patent exclusivity has ended, leading to a market dominated by generic competition. While its primary indication for intermittent claudication remains stable, ongoing clinical trials are exploring its potential in stroke prevention and recovery, which could represent future growth opportunities if regulatory approvals are secured. The market size is modest, with low single-digit growth projected, largely driven by demographic trends and expansion in emerging markets. Intense generic competition and the need for proven efficacy in new indications are the primary challenges and opportunities shaping the drug's future.

FAQs

1. Has the patent for cilostazol expired globally? The foundational compound patent expired in 2007. However, specific formulation or method-of-use patents may have had later expiration dates in different jurisdictions, but these are largely expired or nearing expiration, allowing for broad generic market entry worldwide.

2. What are the most promising new indications for cilostazol based on recent clinical trials? The most promising areas based on recent clinical trial activity are secondary stroke prevention and the improvement of functional recovery post-stroke, leveraging cilostazol's vasodilatory and antiplatelet properties.

3. Are there any new delivery systems for cilostazol in development? While extended-release formulations are established, research into novel drug delivery systems is less prominent compared to other therapeutic areas. The focus has shifted more towards exploring new therapeutic indications rather than entirely new delivery platforms for cilostazol.

4. How does the price of generic cilostazol compare to the original branded product? Generic cilostazol is significantly less expensive than the original branded product (Pletal). Price differences can range from 50% to over 80% depending on the region and the specific generic manufacturer, reflecting the competitive landscape.

5. What is the primary regulatory pathway for cilostazol to be approved for new indications like stroke recovery? Cilostazol would require new New Drug Applications (NDAs) or supplemental NDAs, depending on the jurisdiction (e.g., FDA in the U.S., EMA in Europe). This necessitates the completion of rigorous Phase II and Phase III clinical trials to demonstrate safety and efficacy for the new indication, followed by a comprehensive regulatory review process.

Citations

[1] Wang, C. C., Chen, S. Y., Lee, Y. C., Chen, C. C., & Li, P. L. (2022). Cilostazol in secondary prevention of ischemic stroke: A meta-analysis of randomized controlled trials. Journal of Stroke and Cerebrovascular Diseases, 31(8), 106648.

[2] Lee, K. H., Choi, Y. C., & Kim, J. H. (2021). Effects of cilostazol on motor recovery in patients with subacute ischemic stroke: A randomized controlled trial. Neurorehabilitation and Neural Repair, 35(4), 345-354.