CLINICAL TRIALS PROFILE FOR SINEMET CR

505(b)(2) Clinical Trials for Sinemet Cr

This table shows clinical trials for potential 505(b)(2) applications. See the next table for all clinical trials

Trial Type	Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
New Formulation	NCT00363727 ↗	Onset Motor Complications Using REQUIP CR (Ropinirole Controlled-release) As Add-on Therapy To L-dopa In Parkinson's	Completed	GlaxoSmithKline	Phase 3	2003-12-01	This study evaluates how effective a new formulation of a marketed drug is in increasing the time to onset of dyskinesia (abnormal twisting, writhing movements) in patients with Parkinson's Disease who have been taking levodopa for less than 2 years.

All Clinical Trials for Sinemet Cr

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00004576 ↗	Study of LY300164 for the Treatment of Parkinson's Disease	Completed	National Institute of Neurological Disorders and Stroke (NINDS)	Phase 2	2000-02-01	This study will test the effectiveness of an experimental drug called LY300164 on improving Parkinson's disease symptoms, such as movement impairments and tremor, as well as involuntary movements produced by long-term treatment with levodopa. Patients with relatively advanced (Stage II to IV) Parkinson's disease between 30 and 75 years of age may be eligible for this 8-week study. Participants will have a complete medical history and physical examination, including blood tests and an electrocardiogram, and possibly brain magnetic resonance imaging (MRI), CT scan, and chest X-ray. Patients will stop taking all anti-parkinsonism medications except levodopa (Sinemet) and the experimental drug during the study. For the first 1 to 3 days, patients will be in the hospital for a levodopa "dose-finding" procedure. For this study, levodopa is infused through a vein for up to 8 hours, with symptoms monitored frequently to determine the doses that will produce two results: 1) the dose that is less than what is needed to relieve symptoms, and 2) the dose that relieves symptoms, but may produce dyskinesias. When these dose rates are determined, patients will begin treatment in one of two groups. One will take LY300164 3 times a day, along with levodopa, for 3 weeks. The second group will take placebo tablets (a look-alike tablet with no active ingredient) and levodopa on the same schedule as the LY300164 group. A brief medical examination and routine blood and urine tests will be done weekly. The drug dose will be increased every 3 to 4 days until significant side effects occur or the maximal dose is reached. Patients will be closely monitored for 4 hours after every increase. At the end of the 3 weeks, or when the maximal dose is reached, patients will be readmitted to the hospital for 2 to 3 days for a second levodopa dose-finding study, while continuing on LY300164 or placebo. After this test, patients will resume taking levodopa and the experimental drug or placebo as before for another 2 weeks. At the end of the 2-weeks, the entire procedure will be repeated in both groups, but the treatments will be switched-that is, the patients who were taking LY300164 will now take placebo, and the patients who took placebo will now take the drug. At the end of the second 3 weeks, the levodopa infusion procedure will be repeated once more. Throughout the study, parkinsonism symptoms and dyskinesias will be evaluated and blood samples will be drawn periodically to measure drug levels.
NCT00004733 ↗	Timing of Levodopa Treatment in Parkinson's Disease	Completed	National Institute of Neurological Disorders and Stroke (NINDS)	Phase 3	1998-01-01	The ELLDOPA study is a controlled clinical trial in patients with newly diagnosed PD to determine the optimal timing and dosing with levodopa (Sinemet or its generic equivalents).
NCT00006077 ↗	Effects of Monoamine Reuptake Inhibitor NS2330 in Parkinson's Disease	Completed	National Institute of Neurological Disorders and Stroke (NINDS)	Phase 2	2000-08-01	This study will evaluate the effects of an experimental drug called NS2330 on Parkinson's disease symptoms and on dyskinesias (involuntary movements) that develop as a result of long-term treatment with levodopa. This drug prevents the neurotransmitter dopamine from entering nerve cells. Patients between 18 and 75 years old who have moderately advanced Parkinson's disease and motor problems resulting from levodopa therapy may be eligible for this 5-week study. Candidates will have a complete medical history and physical examination with a detailed neurological evaluation. If needed, some patients will undergo a magnetic resonance imaging (MRI) or computerized tomography (CT) scan of the brain and a chest X-ray. All patients will have blood and urine tests and an electrocardiogram (EKG) and will take a written test for evaluation of depression. Patients enrolled in the study will, if possible, stop taking all antiparkinson medications except levodopa (Sinemet) for one month before the study begins and through its duration. For the first 1 to 3 days, patients will undergo a levodopa "dose-finding" procedure. For this study, patients will stop taking their usual oral levodopa medicine and instead will have levodopa infused through a vein for up to 12 hours. During the infusions, the drug dose will be increased slowly until either 1) parkinsonism symptoms improve, 2) dyskinesias appear, 3) unacceptable side effects occur, or 4) the maximum study dose is reached. When the patient's optimal dose is determined, treatment will begin. Patients will take three pills containing NS2330 or placebo (a look-alike pill with no active ingredient) 3 days a week for up to 5 weeks, in addition to their regular levodopa medication. All participants will receive placebo at some point in the study; some patients will receive only placebo throughout the entire 5 weeks. On treatment days, patients will have a brief medical examination before receiving the drug and will then be monitored for side effects for about 6 to 8 hours after taking the drug. At the beginning of weeks 2 and 5, the levodopa infusions will be repeated at the previously determined optimum rate. Throughout the study, parkinsonism symptoms, dyskinesias and depression will be evaluated. Blood and urine samples will be collected each week for standard safety tests, and blood will also be drawn periodically to measure NS2330 levels.

Clinical Trial Conditions for Sinemet Cr

Condition Name

Condition Name for Sinemet Cr
Intervention	Trials
Parkinson's Disease	32
Parkinson Disease	18
Stroke	5

Condition MeSH

Condition MeSH for Sinemet Cr
Intervention	Trials
Parkinson Disease	55
Dyskinesias	6
Depressive Disorder	4

Clinical Trial Locations for Sinemet Cr

Trials by Country

Trials by Country for Sinemet Cr
Location	Trials
United States	154
Canada	8
Spain	6
Italy	6
Finland	6

Trials by US State

Trials by US State for Sinemet Cr
Location	Trials
Maryland	12
California	11
Texas	10
Illinois	10
Georgia	10

Clinical Trial Progress for Sinemet Cr

Clinical Trial Phase

Clinical Trial Phase for Sinemet Cr
Clinical Trial Phase	Trials
PHASE1	2
Phase 4	12
Phase 3	5

Clinical Trial Status

Clinical Trial Status for Sinemet Cr
Clinical Trial Phase	Trials
Completed	62
Recruiting	10
Terminated	4

Clinical Trial Sponsors for Sinemet Cr

Sponsor Name

Sponsor Name for Sinemet Cr
Sponsor	Trials
National Institute of Neurological Disorders and Stroke (NINDS)	13
Bial - Portela C S.A.	7
Orion Corporation, Orion Pharma	7

Sponsor Type

Sponsor Type for Sinemet Cr
Sponsor	Trials
Other	64
Industry	46
NIH	28

Sinemet CR: Clinical Trials Update, Market Analysis, and Future Projections

Last updated: October 31, 2025

Introduction

Sinemet CR (carbidopa-levodopa controlled-release) remains a cornerstone in Parkinson's disease (PD) management, providing sustained symptom relief through its extended-release formulation. As PD prevalence escalates globally, pharmaceutical companies, healthcare providers, and investors closely monitor Sinemet CR’s clinical development, market trajectory, and growth potential. This report synthesizes recent clinical trial data, evaluates current market dynamics, and projects the drug’s future performance within the neurodegenerative therapeutics landscape.

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Clinical Trials Update for Sinemet CR

Recent Clinical Developments

Over the past two years, Sinemet CR has attracted renewed scientific interest, primarily concerning its efficacy in managing motor fluctuations characteristic of advanced PD. Multiple phase IV studies focus on optimizing dosing regimens, minimizing dyskinesia, and improving quality of life.

One significant trial (NCT05183587), initiated in late 2021, examined the long-term safety and tolerability of Sinemet CR versus immediate-release formulations. Preliminary data published in 2022 indicate that sustained-release formulations maintain comparable efficacy with potentially reduced peak-related dyskinesias [1]. Additionally, research explores combining Sinemet CR with adjunct therapies like COMT inhibitors to enhance therapeutic window duration.

Innovations and Formulation Enhancements

Recent innovations aim to improve plasma dopamine levels regulation, address non-motor symptoms, and reduce side effects. Notably, recent patent filings explore nanoparticle-based delivery systems for Sinemet CR, enhancing drug stability and bioavailability. These advancements could extend clinical benefits, especially for patients with fluctuating responses.

Regulatory and Market-Authorized Updates

While Sinemet CR's core formulation remains unchanged, regulatory agencies––including the FDA––are emphasizing post-marketing surveillance to assess long-term safety, especially in vulnerable populations like the elderly. The FDA approved marketing label updates in 2021, emphasizing dosing flexibility and safety considerations for extended therapy [2].

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Market Analysis of Sinemet CR

Global Market Size and Trends

The PD treatment market, valued at approximately USD 5.4 billion in 2022, is projected to grow at a CAGR of 7.8% through 2030, driven by rising global prevalence, aging populations, and increased diagnosis rates [3]. Sinemet CR, commanding a substantial share, benefits from its longstanding clinical reputation.

Geographic Market Penetration

North America remains the dominant market due to established prescribing protocols and high awareness among neurologists. The U.S. constitutes over 50% of PD drug sales globally, with a sizable segment dedicated to Sinemet formulations. Europe follows, supported by comparable healthcare infrastructure, while Asia-Pacific presents emerging opportunities owing to increasing PD incidence and expanding healthcare access.

Competitive Landscape

Sinemet CR faces competition from newer formulations, including dopamine agonists, MAO-B inhibitors, and novel gene therapies. Notably, the emergence of Istradefylline and safinamide offers adjunct or alternative options but has yet to significantly erode Sinemet’s market dominance. Moreover, ongoing clinical trials of experimental therapies (e.g., gene delivery systems) pose potential future competition.

Pricing and Reimbursement Dynamics

Pricing strategies vary across regions, influenced by healthcare policies and patent statuses. In the U.S., Sinemet CR’s list price averages around USD 300–400 per month, with reimbursements largely through Medicare and private insurers. Patent expiries are looming, with the original formulation patent having expired in 2012, but extended protections via formulation patents have sustained market exclusivity until approximately 2025. Biogeneric entries pending approval could prompt price competition.

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Future Projections

Market Growth Drivers

• Aging Demographics: The global population aged over 65 is projected to reach 1.5 billion by 2030, intensifying PD prevalence.
• Early Diagnosis & Treatment: Advances in diagnostic tools facilitate earlier intervention, potentially expanding Sinemet CR’s use.
• Patient Preference for Extended-Release Formulations: Growing demand for drugs with less fluctuation in motor control sustains Sinemet CR's relevance.
• Regulatory Support: Continued approval of new formulations and combination therapies may bolster market share.

Potential Challenges

• Patent Expiry and Generics: Loss of exclusivity could lead to significant volume erosion and price reductions.
• Emergence of Novel Therapies: Gene therapy and cell replacement approaches may redefine PD management, threatening traditional drug markets.
• Side Effect Management: Persistent issues like dyskinesia and motor fluctuations necessitate adjunct therapies, influencing prescribing patterns.

Forecast for 2025-2030

By 2030, the market for Sinemet CR may grow modestly, reaching USD 2.5–3 billion globally, contingent on regulatory developments, patent protections, and competitive pressures. The drug is expected to retain a significant share in the standard-of-care arsenal, particularly in developed markets, but face steady erosion from biosimilars and advanced therapies.

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Key Takeaways

• Clinical Data Reinforces Efficacy: Recent studies support Sinemet CR’s role in managing motor fluctuations, with innovations aimed at enhancing safety and bioavailability.
• Market Valuation & Growth: The global PD therapeutics market is expanding, with Sinemet CR benefiting from longstanding clinical trust and patient preference for extended-release products.
• Competitive Landscape & Patent Environment: Patent expiries and the rise of biosimilars could challenge pricing power; however, ongoing formulation and patent protections delay generic competition.
• Regulatory & Future Outlook: Innovations in delivery systems and combination treatments may extend Sinemet CR’s lifecycle, but disruptive gene therapies pose an emerging threat.
• Strategic Focus for Stakeholders: Companies should monitor clinical innovations, prepare for biosimilar entries, and explore combination therapies to sustain market position.

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FAQs

1. What recent clinical trials have been conducted on Sinemet CR?
Recent phase IV studies focus on long-term safety, bioavailability, and side effect mitigation, including nanoparticle delivery systems and combination therapies, with preliminary results suggesting maintained efficacy and safety improvements [1].

2. How does Sinemet CR compare to other Parkinson’s treatments?
Sinemet CR provides sustained motor symptom control, particularly beneficial for patients with motor fluctuations. While newer therapies (e.g., dopamine agonists, gene therapy) are emerging, Sinemet CR remains a first-line, cost-effective option for many patients.

3. What is the patent outlook for Sinemet CR?
The original formulation's patent expired in 2012. Extended formulation patents and delivery innovations have extended exclusivity until approximately 2025, after which biosimilar versions are expected to enter markets.

4. How is the market for Sinemet CR expected to evolve over the next decade?
While overall market growth is positive, patent expiries and competition from emerging therapies may lead to price adjustments and market share redistribution, but Sinemet CR is projected to maintain a substantial role in PD management.

5. Are there ongoing efforts to improve Sinemet CR formulations?
Yes, pharmaceutical research focuses on embedding nanotechnology, bioavailability enhancements, and combination formulations aimed at improving therapeutic index and reducing side effects, potentially extending Sardamit CR’s clinical utility.

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Sources

[1] ClinicalTrials.gov, "Long-term Safety and Efficacy of Sinemet CR," NCT05183587, 2022.
[2] U.S. Food and Drug Administration, "Labeling Updates for Levodopa Preparations," 2021.
[3] MarketsandMarkets, "Parkinson's Disease Therapeutics Market," 2023.