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Study on the Effects of Prasinezumab in Patients with Early Parkinson's Disease

Verified siteInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying Parkinson's disease, specifically in its early stages. The treatment being tested is called prasinezumab, which is also known by its code name RO7046015. Prasinezumab is a type of medication that is given through an intravenous infusion, meaning it is administered directly into the bloodstream through a vein. The purpose of this study is to evaluate how effective prasinezumab is in treating early Parkinson's disease over a period of 52 weeks.

Participants in the study will receive either prasinezumab or a placebo. The study is designed to be double-blind, which means neither the participants nor the researchers will know who is receiving the actual medication and who is receiving the placebo. This helps ensure that the results are not biased. The study will last for a total of 52 weeks, with an additional extension period where all participants will receive the treatment. During the study, participants will be monitored for changes in their symptoms and overall health.

Parkinson's disease is a condition that affects movement, causing symptoms such as tremors, stiffness, and difficulty with balance and coordination. The study aims to see if prasinezumab can help improve these symptoms in people who are in the early stages of the disease. Participants will be assessed using various scales and tests to measure changes in their condition. The study will also monitor for any side effects or adverse reactions to the treatment. This research is important for understanding how prasinezumab might benefit people with early Parkinson's disease and potentially improve their quality of life.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, eligibility is confirmed based on specific criteria, such as a diagnosis of early Parkinson's disease for two years or less and a stable condition without the need for dopaminergic medication within the next 52 weeks.

  2. Step 2

    Initial assessment

    An initial assessment is conducted to establish a baseline. This includes a brain scan and evaluation of symptoms using the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS).

  3. Step 3

    Treatment phase

    Participants receive either the study medication, prasinezumab (RO7046015), or a placebo. The medication is administered as an intravenous infusion.

    The treatment is given regularly over a period of 52 weeks.

  4. Step 4

    Monitoring and assessments

    Throughout the 52-week period, regular monitoring and assessments are conducted to evaluate changes in symptoms and overall health.

    Assessments include changes in the MDS-UPDRS score, cognitive function, and daily living activities.

  5. Step 5

    End of initial study phase

    At the end of the 52-week period, a final assessment is conducted to measure the efficacy of the treatment compared to the placebo.

    The primary focus is on the change in the MDS-UPDRS total score from the baseline.

  6. Step 6

    Extension phase

    Participants have the option to continue in a 6-year extension phase where all receive the treatment.

    This phase aims to gather long-term data on the treatment's effects.

Who can join the trial?

7 criteria

  • The patient must have a brain scan called **DaT-SPECT** that matches the pattern seen in Parkinson's disease.
  • The patient's condition should not need medication that increases dopamine levels, and it should not be expected to need such treatment within 52 weeks from the start of the study.
  • If the patient is currently taking medication for Parkinson's disease, they must be on a stable dose of a type of medication called **MAO-B inhibitor** (such as rasagiline or selegiline) for at least 90 days before starting the study, and this dose should not change during the study period.
  • The patient must have **idiopathic Parkinson's disease**, which means Parkinson's disease with no known cause, showing slowness of movement (**bradykinesia**) and at least one other main symptom like shaking at rest (**resting tremor**) or muscle stiffness (**rigidity**), without any other known or suspected cause.
  • The patient must have been diagnosed with Parkinson's disease for 2 years or less at the time of screening.
  • The patient must be in **Hoehn and Yahr Stage I or II**, which are early stages of Parkinson's disease.
  • Both male and female patients can participate.

Who cannot join the trial?

5 criteria

  • Patients who have a different type of Parkinson's disease other than Early Idiopathic Parkinson's disease cannot participate. This means the study is only for those with a specific early form of Parkinson's disease.
  • Patients who are in a more advanced stage of Parkinson's disease than H&Y Stages I-II are not eligible. H&Y stages refer to the Hoehn and Yahr scale, which measures the severity of Parkinson's disease.
  • Patients who are taking medications other than monoamine oxidase-B (MAO-B) inhibitors for Parkinson's disease are excluded. MAO-B inhibitors are a type of medication that helps manage symptoms of Parkinson's disease.
  • Patients who are not within the specified age range for the study cannot participate. The study has specific age requirements.
  • Patients who are part of a vulnerable population, which means they might need special protection or care, are not eligible for this study.
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Investigated drugs

RO7046015/Prasinezumab (PRX002) is an investigational medication being studied for its potential to treat early Parkinson's disease. It is administered intravenously and is designed to target and bind to a specific protein associated with Parkinson's disease. The goal of this medication is to slow down the progression of the disease by reducing the harmful effects of this protein in the brain. This study aims to evaluate how effective this medication is in improving symptoms of Parkinson's disease over a 52-week period.

What is already known about the treatment

Prasinezumab – Prasinezumab is administered intravenously and is currently being studied in clinical trials for its potential use in treating early Parkinson's disease. It is in the experimental phase, with ongoing research to determine its effectiveness and safety. The main therapeutic indication for Prasinezumab is early idiopathic Parkinson's disease. At the molecular level, Prasinezumab is designed to target and bind to alpha-synuclein, a protein that accumulates abnormally in the brains of Parkinson's patients, potentially slowing disease progression. It is classified as a monoclonal antibody in pharmacology.

Investigated diseases

Parkinson's Disease – Parkinson's disease is a progressive neurological disorder that affects movement. It typically begins with subtle symptoms such as a slight tremor in one hand, but over time, it can lead to more pronounced tremors, stiffness, and slowing of movement. As the disease progresses, individuals may experience difficulties with balance and coordination. Non-motor symptoms, such as changes in mood, sleep disturbances, and cognitive impairment, can also occur. The progression of symptoms varies from person to person, and the rate of progression can differ widely.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-504472-24-00Protocol codeBP39529Estimated enrolment452 patientsSponsorF. Hoffmann-La Roche AG

sourced from the EU Clinical Trials Register and site verification

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