A Phase 1 interventional study of Levodopa in Parkinson's Disease, sponsored by Kevin J. Black, MD. Completed at 1 site in United States. Open to participants aged 40 Years to 79 Years. Per ClinicalTrials.gov, last updated 2022-10-14.
Sponsored by Kevin J. Black, MD · Phase 1, Interventional, and Other
The Measuring Parkinson's Disease Progression study aims to use MRI scans and a controlled dose of levodopa to find a biomarker (objective measurement) of Parkinson's disease (PD). Biomarkers would help determine the effectiveness of therapies in slowing or stopping PD progression, and accelerate the pace of research.
Early in the course of Parkinson's disease, a small dose of levodopa (L-DOPA) provides benefit for many hours. The body responds as if the levodopa in the plasma filled a reservoir and then slowly leaked out to produce benefit. With disease progression, even though the same amount of levodopa circulates in the blood, the benefit wears off much faster, as if the reservoir had become leakier. This wearing off of benefit can be characterized by a single number, the effect site rate constant Ke. On average, patients with more severe disease and longer disease duration have a larger ("leakier") Ke when the response to drug is measured using clinical features like tapping speed. Unfortunately, clinical measurements are influenced by confounding factors such as patient fatigue and comfort. A direct, objective brain measure of response to levodopa may improve the reliability of this measurement. Fortunately, we can assess the effect of levodopa on the brain directly, using an MRI machine to measure blood flow in different parts of the brain. For instance, the midbrain has a robust blood flow response to a single, clinically sensible dose of levodopa. This study's goal is to validate MRI measurement of Ke in the brain as an objective, quantitative measure of disease severity in PD. We will do this by comparing MRI-based Ke values from people with PD across a wide range of disease duration and severity. In a subgroup of participants, we will do this measurement twice, once before treatment and once after 6 weeks of treatment with carbidopa-levodopa (Sinemet® and other brand names).
4,487 studies on the registry are indexed under Parkinson Disease; 1,081 are open to participants now.
This study's enrollment of 31 is below the median of 40 across 3,293 interventional studies indexed under Parkinson Disease.
Browse Parkinson Disease studies →This is the only study on the registry with Kevin J. Black, MD as lead sponsor.
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Inclusion Criteria:
Exclusion Criteria: Key exclusion criteria:
A broad range of Parkinson's disease severity and disease duration. Some subjects will not be treated currently with levodopa, and thus likely will be early in the disease process.
Drug: Levodopa
At least 1 hour after 200mg carbidopa p.o., each subject will receive an intravenous solution of levodopa in saline at a rate based on age and body mass according to the "final dose" described in Black et al 2003.The total dose for a 70-year-old, 70kg subject will be approximately 65mg. Subjects with untreated PD will then take 6 ± 1 weeks of clinically dosed oral carbidopa-levodopa tablets for clinical purposes and then repeat the carbidopa plus intravenous levodopa dose as above.
Also known as: Carbidopa
Ke measured by phMRI
Effect site rate constant measured by serum levodopa concentrations and regional cerebral blood flow. Note, there are no outcome measures relevant to clinical care. This is not a placebo-controlled treatment study.
Time frame: 2 hours
Side effect ratings
Nausea/vomiting, sleepiness, dizziness or lightheadedness, and overall feeling poorly or well, are each measured on a horizontal visual analog scale before and at the end of the i.v. levodopa infusion
Time frame: 2 hours
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — We will publicly share a fully anonymized set of linked data from this study. No protected health information (PHI) will be shared.
Supporting information: Study protocol, Icf
This study is completed, as verified in Oct 2022. You cannot join it, but the record below documents what was studied.
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