Viewing Study NCT03451500



Ignite Creation Date: 2024-05-06 @ 11:11 AM
Last Modification Date: 2024-10-26 @ 12:41 PM
Study NCT ID: NCT03451500
Status: TERMINATED
Last Update Posted: 2024-04-25
First Post: 2018-02-23

Brief Title: Carbidopa-Levodopa in Dry AMD With Geographic Atrophy
Sponsor: Snyder Robert W MD PhD PC
Organization: Snyder Robert W MD PhD PC

Study Overview

Official Title: Carbidopa-Levodopa in Dry Age Related Macular Degeneration With Geographic Atrophy
Status: TERMINATED
Status Verified Date: 2024-04
Last Known Status: None
Delayed Posting: No
If Stopped, Why?: Lack of funding required for enrollment to reach statistical significance
Has Expanded Access: False
If Expanded Access, NCT#: N/A
Has Expanded Access, NCT# Status: N/A
Acronym: None
Brief Summary: From 3 large patient databases patients diagnosed with AMD who have never taken levodopaL-DOPA containing medications have a mean age of diagnosis at 71 years

Patients who have been treated with L-DOPA containing medications have a mean age of diagnosis of AMD at 79 years L-DOPA binds to GPR143 in the retinal pigment epithelium and releases PEDF which protects the retina and downregulates VEGF which is the cause of neovascularization

The Investigators will evaluate the safety and tolerability of carbidopa-levodopa in patients with Neovascular AMD and measure the effects on visual acuity and retinal abnormalities due to wet neovascular AMD The Investigators will evaluate the safety and tolerability of carbidopa-levodopa in patients with Dry AMD and Geographic Atrophy and measure the effects on visual acuity area of geographic atrophy and other retinal abnormalities due to dry AMD
Detailed Description: Age-related macular degeneration AMD is the most common cause of blindness in individuals over the age of 50 in the developed world AMD becomes more common as people age and is more common in lightly pigmented individuals AMD appears more common in patients with Parkinsons Disease than in those without The AREDS nutritional supplements are effective in slowing the progress of intermediate AMD5

Most AMD is dry AMD which progresses relatively slowly and may impair vision but usually does not lead to legal blindness There are two forms of AMD wet AMD and geographic atrophy GA that can cause more profound vision loss In aggregate they occur in about 25 patients with AMD Wet AMD is due to new growth of abnormal blood vessels under the retina The new blood vessels are believed to be due to an excessive release of vascular endothelial growth factor VEGF by the retinal pigment epitheliumRPE cells Wet AMD is now effectively treated with intraocular injections of VEGF inhibitors Geographic Atrophy the other form of advanced AMD represents focal death of the RPE cells and overlying neurosensory retina There is no current treatment for GA It is suspected that GA is due in part to a localized inflammatory response damage to RPE cells and loss of RPE cell function It may also be speculated that stimulation of RPE cells to release a potent neurotrophic factor pigment epithelium derived factor PEDF may slow progression of GA In 2008 Dr Brian McKay identified a receptor G protein coupled receptor

143GPR143 on the surface of RPE cells and discovered that L-DOPA was the natural ligand or stimulator of GPR143 Dr McKay showed that treatment of RPE cells with exogenous L-DOPA resulted in the release of additional PEDF In subsequent work Dr McKays group also showed that L-DOPA stimulation of PEDF in RPE cells was also associated with a decrease in VEGF Thus Dr McKay hypothesized that exogenous LDOPA may prevent the onset of AMD or progression to wet AMD

In 2015 Dr McKay and his associates published a paper that showed that patients who had been treated with L-DOPA had a delay in the onset of AMD by 8 years compared to patients who had not been treated with L-DOPA In addition those who had AMD and went on to develop wet AMD did so 5 years later than those with no history of L-DOPA treatment L-DOPA is an intermediate in the pigmentation pathway Dr McKay and his associates suggested that the reason darkly pigmented races do not get AMD nearly as frequently as lighter pigmented races is that they produce more pigment and thus more L-DOPA to stimulate GPR143 on RPE cells According to this hypothesis the stimulated RPE cells release PEDF and decrease VEGF which together are responsible for the protective effect

Pharmacology of L-DOPA and carbidopa

L-DOPA is formed by 3-hydroxylation of tyrosine by tyrosine-3-monooxygenase tyrosinase18 The primary metabolic pathway of L-DOPA is decarboxylation by amino acid decarboxylase to dopamine which is responsible for most but not all of its pharmacologic effects and toxicity When carbidopa is administered with LDOPA systemic levels of L-DOPA double and central nervous system CNS L-DOPA increases from about 1 of the administered dose to about 4 Levodopa freely passes from the systemic circulation into the retina and brain but dopamine and carbidopa do not Adverse events are markedly decreased when carbidopa is administered with L-DOPA because systemic levels of the toxic metabolite of L-DOPA dopamine are markedly reduced In most patients 25 mg of carbidopa is sufficient to control side effects of 100 mg of L-DOPA primarily nausea by 90 L-DOPA is the natural ligand for GPR143 in the RPE cells The Investigators intent is to increase the L-DOPA available to RPE surface receptors GPR 143 while minimizing peripheral toxicity This concept is unique because all other uses of L-DOPA rely on CNS conversion of L-DOPA to dopamine in order to produce the desired effect

Since there are no established animal models for AMD and L-DOPA has a good safety profile in healthy volunteers and patients with Parkinsons disease the Investigators propose a prospective experiment to determine the safety and tolerability of L-DOPA in a population of patients with AMD The participants will be made aware of potential side effects of L-DOPA which are listed in the Informed Consent during the consent process Adverse events will be elicited by questioning the participants at each visit

The participants will also be advised to call the site if they have any medical problem between visits

The Investigators will also use this study to examine whether L-DOPA has a positive effect on visual acuity and pathologic retinal changes of dry AMD with geographic atrophy

The parameters to be evaluated are best corrected ETDRS visual acuity area of geographic atrophy by Fundus AutoFluorescence FAF macular thickness by spectral domain optical coherence tomography SD OCT new blood hemorrhage by direct retinal examination and subjective decrease in vision

Treatments

Study participants will receive randomly assigned single blind commercially available carbidopa-levodopa 25-100 mg two tablets once daily hs or two tablets dosed TID three times daily in the morning with supper and hs for one month or placebo two tablets dosed three times daily in the morning with supper and hs 200-600 mg of levodopa daily This is the equivalent of low to moderate doses of carbidopa-levodopa in patients with Parkinsons disease daily dose of levodopa 200-800 mg If a study participant experiences non-serious but bothersome adverse effects while taking the study medication the dose may be reduced to 1 tablet hs or 1 tablet TID

Number of subjects 154 randomized

Duration 12 months of treatment with visits at Baseline 1 week 1 month 3 months 6 months 9 months and 12 months

Primary Endpoint A statistically significant difference in progression of area of geographic atrophy with carbidopa-levodopa treatment compared to treatment with placebo

Measurements and Activities

1 Informed Consent at Baseline
2 Ophthalmic history and comprehensive eye examination including visual acuity with best optical correction using an EDTRS chart in both eyes prior to randomization ophthalmoscopic examination a subjective vision questionnaire and SD OCT with FAF
3 Repeat assessment of visual acuity using an EDTRS chart subjective vision questionnaire ophthalmoscopic examination and SD OCT at 1 3 6 9 and 12 month visits
4 Demographics at Baseline
5 Medical History Vital Signs and Physical Examination at Baseline
6 ECG CBC Chem 20 and HbA1C at Baseline
7 Dispense study medication at visits 2 3 4 5 6 and 7
8 Pill count at visits 3 4 5 6 and 7
9 Non-directed assessment of adverse events at each visit including classification as to severity seriousness and body system
10 Concomitant medications at each visit

Statistics Statistics will be generated for at a minimum area of geographic atrophty ETDRS visual acuity central retinal thickness and presence of hemorrhage Within patient trajectories for these outcomes will be plotted incorporating information on dose and duration Analysis of Variance may be conducted to relate logarithm of dose and duration of treatment to the outcomes listed above

Study Oversight

Has Oversight DMC: None
Is a FDA Regulated Drug?: True
Is a FDA Regulated Device?: False
Is an Unapproved Device?: None
Is a PPSD?: None
Is a US Export?: None
Is an FDA AA801 Violation?: None