Macula; DegenerationPhase 2NCT03197493

Extension, Carbidopa-levodopa in Neovascular Age-related Macular Degeneration (AMD)

A Phase 2 study testing carbidopa-levodopa 25-100 mg in people with Macula; Degeneration and Retina, run by Snyder, Robert W., M.D., Ph.D., P.C. at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

Who is it for?: Ages 50 to 85 years
Conditions the study is for: Macula; Degeneration, Retina
What is being tested?: carbidopa-levodopa 25-100 mg
Type of treatment: Pill or oral medicine
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 35 participants
Where: 1 siteUnited States
Study dates: 1 Aug 2017to 9 Jul 2020
Phase: Phase 2
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 50 to 85 years
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Completion of Protocol 002.
A diagnosis of AMd with choroidal neovascularization (CNV) in 1 eye.
Normal or Dry AMD of any grade in the second eye.
Age 50-85 years.
Willingness to maintain AREDS vitamin Supplements throughout the study, or remain off of these supplements for the duration of the study, if not taking them prior to the study.
Informed consent at visit 1, which is also Visit 5 of study 002.

Who cannot join

Any current use of L-DOPA containing medication or dopamine agonist medication, or any planned use of any of these agents, except for study medication, during the study;
Concurrent use of monoamine oxidase (MAO) inhibitors;
Any eye condition, disease, or history of trauma in either eye, which can impair vision, except cataract or cataract surgery;
BCVA worse than 20/60 in the better eye;
Wet AMD in the second eye;
Neurologic conditions which can impair vision;

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Parkinson's Disease;
Significant orthostatic hypotension, defined as a drop in systolic blood pressure, immediately upon changing from the supine to standing position, of >19 mmHg, or a symptomatic drop in systolic blood pressure, immediately upon changing from the supine to standing position;
Significant ECG abnormalities, as judged by the Investigator;
Estimated glomerular filtration rate (eGFR) <20 ml/min;
Liver enzymes >3 X the upper limit of normal;
HbA1C >9.0;
Any other significant lab abnormalities, as judged by the Investigator.
Women of childbearing potential;
Known retinal hemorrhage;
Subjects who are not fluent in English.

Trial locations and contacts

1 site in 1 country.

United States1 site

Robert W Snyder, MD, PhD, PC
Tucson, Arizona, 85712

Other trials in United States

About this study

Official title: Extension of Protocol 002, Carbidopa-levodopa in Neovascular Extension of Protocol 002, Carbidopa-levodopa in Neovascular AMD

This protocol is an extension of protocol 0002, Proof of Concept and Dose Ranging Study of carbidopa-levodopa in Neovascular AMD. that is a 3 month study of escalating doses of carbidopa-levodopa in neovascular AMD. This trial is a 9 month extension for patients who successfully complete protocol 0002 and wish to continue carbidopa-levodopa therapy. It will use the two higher dose regimens of protocol 0002. these will be assigned according to how well the higher dose was tolerated in protocol 0002.

Read the detailed description

This extension will employ the same medications, measurements, guidelines for anti-VEGF injections and safeguards as in protocol 0002. In combination with protocol 0002, it will provide a total of 12 months of therapy with carbidopa-levodopa.

Conditions: Macula; Degeneration, Retina
Being tested: carbidopa-levodopa 25-100 mg

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

carbidopa-levodopa 25-100 mgDrug
Also called Sinemet
High Dose: daily oral administration 2 tablets TID Intermediate Dose: daily oral administration 1 tablet TID

Study groups in NCT03197493
Study group	Role	What they receive
Carbidopa/levodopa high dose	Experimental	carbidopa-levodopa 25-100 mg 2 tablets TID Receives: Drug: carbidopa-levodopa 25-100 mg

What is being measured

The primary outcome is the main question the study is designed to answer.

Change in Best Corrected Visual Acuity by ETDRS Visual Scale Testing
This outcome is a measure of letters correctly identified using an Early Treatment Diabetic Retinopathy Study chart. The higher the number of letters identified, the better the participant's visual acuity.
Measured: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study (visit 12), a maximum of 9 months following a 3 month enrollment in NCT03023059.

Secondary outcomes (3)

Number of Adverse Events Experienced
Adverse events elicited by nonspecific questioning
Measured: Monthly for 9 months
Change in Central Retinal (Macular) Thickness
Central retinal thickness (in microns) is measured by spectral domain-optical coherence tomography. An increase in retinal thickness is associated with disease progression. A negative value represents a decrease in retinal thickness and therefore a positive clinical outcome measure.
Measured: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study, a maximum of 9 months.
Percent Change in Retinal Fluid From Baseline
Retinal fluid changes on direct retinal examination on spectral domain - optical coherence tomography. Changes in retinal fluid were compared to baseline values. A negative percentage point represents a decrease in retinal fluid and therefore a positive clinical outcome.
Measured: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study, (visit 10), a maximum of 9 months.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

1 Aug 20179 Jul 2020

First posted23 Jun 2017
Study start1 Aug 2017
Primary completion9 Jul 2020
Study completion9 Jul 2020

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Macula; DegenerationStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 2
Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Model description: Patients who complete 3 months of escalation dose carbidopa-levodopa, will receive 9 additional months of therapy with the highest dose used in protocol 0002, carbidopa-levodopa 25-100 mg 2 tablets TID.
Masking: None (open label)
Enrolment: 35 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT03197493
Sponsor's protocol ID: 0003
Status last verified: Sep 2025
First submitted: 19 Jun 2017
Last updated: 12 Sep 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

RecruitingPhase 2
A Phase 2 Efficacy and Safety Study of GAL-101, 2% Ophthalmic Solution in Non-foveal Geographic Atrophy Secondary to Non-neovascular AMD
Geographic Atrophy of the Macula
Not yet recruitingObservational study
OCT Macula Biomarkers Before Silicone Oil Removal and Visual Outcome After Silicone Oil Removal
Retinal Detachment, Macular Edema
Recruiting
Acute Intra Ocular Pressure Monitoring After Aflibercept 8mg/0.07mL
Macular Diseases
Active, not recruitingObservational study
The SPECTRUM Study: An Observational Study to Learn More About How Well Aflibercept 8 mg Works in Treating Visual Impairment Due to Neovascular Age-related Macular Degeneration or Diabetic Macula Edema
Visual Impairment, Neovascular Age-related Macular Degeneration (nAMD)
Not yet recruiting
Effectiveness of Multidisciplinary Protocolised Interventions on IVT Non-adherence Rates
Diabetic Macular Edema, Neovascular (Wet) Age-Related Macular Degeneration

All Macula; Degeneration trials

Study at a glance

From the registry record, last updated by the sponsor on 12 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Extension of Protocol 002, Carbidopa-levodopa in Neovascular Extension of Protocol 002, Carbidopa-levodopa in Neovascular AMD
ClinicalTrials.gov ID: NCT03197493
Acronym / sponsor ID: 0003
Conditions: Macula; Degeneration, Retina
Phase: Phase 2
Study type: Interventional
Recruitment status: Completed
Enrolment: 35 participants (actual)
Lead sponsor: Snyder, Robert W., M.D., Ph.D., P.C.
Collaborators: Snyder Biomedical Corporation
Study start: 1 Aug 2017 (actual)
Primary completion: 9 Jul 2020 (actual)
Study completion: 9 Jul 2020 (actual)
First posted: 23 Jun 2017 (actual)
Results: Posted 12 Sep 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1
Model description: Patients who complete 3 months of escalation dose carbidopa-levodopa, will receive 9 additional months of therapy with the highest dose used in protocol 0002, carbidopa-levodopa 25-100 mg 2 tablets TID.

Arm	Type	Receives
Carbidopa/levodopa high dose	Experimental	Drug: carbidopa-levodopa 25-100 mgcarbidopa-levodopa 25-100 mg 2 tablets TID

Who may qualify

Ages: 50 to 85 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (6 listed)

Completion of Protocol 002.
A diagnosis of AMd with choroidal neovascularization (CNV) in 1 eye.
Normal or Dry AMD of any grade in the second eye.
Age 50-85 years.
Willingness to maintain AREDS vitamin Supplements throughout the study, or remain off of these supplements for the duration of the study, if not taking them prior to the study.

Key exclusion criteria (16 listed)

Any current use of L-DOPA containing medication or dopamine agonist medication, or any planned use of any of these agents, except for study medication, during the study;
Concurrent use of monoamine oxidase (MAO) inhibitors;
Any eye condition, disease, or history of trauma in either eye, which can impair vision, except cataract or cataract surgery;
BCVA worse than 20/60 in the better eye;
Wet AMD in the second eye;

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
carbidopa-levodopa 25-100 mgAlso: SinemetHigh Dose: daily oral administration 2 tablets TID Intermediate Dose: daily oral administration 1 tablet TID	Drug	Carbidopa/levodopa high dose

Primary outcome

Change in Best Corrected Visual Acuity by ETDRS Visual Scale Testing
Time frame: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study (visit 12), a maximum of 9 months following a 3 month enrollment in NCT03023059.
This outcome is a measure of letters correctly identified using an Early Treatment Diabetic Retinopathy Study chart. The higher the number of letters identified, the better the participant's visual acuity.

3 secondary outcomes

Number of Adverse Events Experienced
Time frame: Monthly for 9 months
Change in Central Retinal (Macular) Thickness
Time frame: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study, a maximum of 9 months.
Percent Change in Retinal Fluid From Baseline
Time frame: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study, (visit 10), a maximum of 9 months.

Results and safety

Results posted to the registry on 12 Sep 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Carbidopa/Levodopa High Dose	35	30

Primary outcome: Change in Best Corrected Visual Acuity by ETDRS Visual Scale Testing

Time frame: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study (visit 12), a maximum of 9 months following a 3 month enrollment in NCT03023059.. Mean (Standard Error). Unit: Change in letters (BCVA)

Measure	High Dose n = 30
Value	2.7 (1.8)

Population analysed: This population includes participants who completed NCT03022318 (naive to anti-VEGF injections at the time of enrollment) and patients who did not complete NCT03022318 but had been exposed to anti-VEGF injections before study initiation.

3 secondary outcomes are reported in the full results.

Adverse events

Time frame: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study (visit 12), a maximum of 9 months following a 3 month enrollment in NCT03023059. A total of 9 months.. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
High Dose	0 of 30 (0%)	3 of 30 (10%)	0 of 30

Limitations and caveats (from the sponsor): The major limitations of our study include the small sample size and limited patient racial diversity.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 12 Sep 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

Related trials for Macula; Degeneration

RecruitingPhase 2
A Phase 2 Efficacy and Safety Study of GAL-101, 2% Ophthalmic Solution in Non-foveal Geographic Atrophy Secondary to Non-neovascular AMD
Geographic Atrophy of the Macula
Not yet recruitingObservational study
OCT Macula Biomarkers Before Silicone Oil Removal and Visual Outcome After Silicone Oil Removal
Retinal Detachment, Macular Edema
Recruiting
Acute Intra Ocular Pressure Monitoring After Aflibercept 8mg/0.07mL
Macular Diseases
Active, not recruitingObservational study
The SPECTRUM Study: An Observational Study to Learn More About How Well Aflibercept 8 mg Works in Treating Visual Impairment Due to Neovascular Age-related Macular Degeneration or Diabetic Macula Edema
Visual Impairment, Neovascular Age-related Macular Degeneration (nAMD)
Not yet recruiting
Effectiveness of Multidisciplinary Protocolised Interventions on IVT Non-adherence Rates
Diabetic Macular Edema, Neovascular (Wet) Age-Related Macular Degeneration

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Robert W Snyder, MD, PhD principal investigator

Robert W Snyder

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing carbidopa-levodopa 25-100 mg in people with Macula; Degeneration and Retina, run by Snyder, Robert W., M.D., Ph.D., P.C. at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 12 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 12 Sep 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Best Corrected Visual Acuity by ETDRS Visual Scale Testing (time frame: From the start of the study (Visit 1) to the last completed visit, whether due to patient withdrawal, patient death or the completion of the last visit of the study (visit 12), a maximum of 9 months following a 3 month enrollment in NCT03023059.). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03197493.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Sep 2025.