RecruitingPHASE3INTERVENTIONAL

A Study to Evaluate the Efficacy and Safety of Intravenous (IV) Prasinezumab in Participants With Early-Stage Parkinson's Disease

This research study is investigating a new medication, prasinezumab, for people who have Parkinson's disease in its early stages. We aim to find out if prasinezumab is effective in managing symptoms and if it is safe to use, by comparing it to a placebo (a dummy drug). All participants will already be taking a stable dose of levodopa, which is a common medication for Parkinson's. The study will also look at how the body processes prasinezumab. We hope to understand if this new treatment could be a helpful option in the future for people living with early Parkinson's.

At a glance

Status

Recruiting

Phase

PHASE3

Sponsor

Hoffmann-La Roche

Enrolment target

900

Start

24 Nov 2025

Estimated completion

30 Jun 2031

Parkinson's Disease

What is this study about?

This study is about exploring a new medicine called prasinezumab for people who have been recently diagnosed with Parkinson's disease. We want to understand if this new drug can help with the symptoms of Parkinson's and if it is safe to use. Currently, people in the study will already be taking a medicine called levodopa, which is a common treatment for Parkinson's, and their dose will be kept steady during the study.

To see how well prasinezumab works, some people in the study will receive prasinezumab, while others will receive a 'placebo'. A placebo looks exactly like the study drug but doesn't contain any active medicine. This helps researchers compare the real drug's effects against having no new treatment. By doing this, we can get a clearer picture of whether prasinezumab is truly making a difference.

Finding new and effective treatments for Parkinson's disease is very important. This study aims to gather important information that could lead to new ways to help people manage their condition in the future. Your participation could help us learn more about this potential new medicine.

Key takeaways

Investigating a new drug, prasinezumab, for early Parkinson's.
Comparing prasinezumab to a placebo (dummy drug).
Participants will continue their current stable levodopa medicine.
Aims to check if prasinezumab is safe and helps with symptoms.
Study involves regular clinic visits for assessments.
Participation is voluntary, and you can withdraw at any time.

Who may be eligible?

To join this study, you need to be generally healthy, weigh between 40 and 110 kilograms (about 6 to 17 stone), and be between 50 and 85 years old. You must have been diagnosed with early-stage Parkinson's disease, and this should be your only significant neurological condition.

You should also be taking only one medication for your Parkinson's, and your doctor should agree that your condition isn’t causing you any troublesome involuntary movements at the moment. If you are a woman who could become pregnant, you'll need to agree to use effective birth control during the study.

You can't join if you are pregnant or breastfeeding, or if you plan to become pregnant. Also, if you have other types of Parkinson's-like conditions or serious uncontrolled high blood pressure, this study might not be suitable for you.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 50 and 85 years old?
Do you have early-stage Parkinson's disease?
Are you taking only one medication (monotherapy) for your Parkinson's?
Do you currently not experience troublesome involuntary movements (dyskinesia)?
Are you not pregnant, breastfeeding, or planning to become pregnant during the study?
Do you weigh between 40kg and 110kg (about 6 to 17 stone)?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you will be given either the new medicine, prasinezumab, or a placebo (a dummy drug), through a drip into your arm (this is called intravenous or IV). You won't know which one you are receiving, and neither will your study doctor.

Throughout the study, you will have regular visits to the clinic where you will undergo various checks. These check-ups might include physical examinations, blood tests, and assessments of your Parkinson's symptoms. The doctors will monitor your health closely to see how the treatment is affecting you.

Overall, the study will involve several visits over a period of time, and there will be follow-up appointments even after you stop taking the study medication. The total length of your involvement in the study will be explained to you by the study team.

Potential risks and benefits

Taking part in a clinical study means there's a chance you might experience some benefits, such as receiving a new and potentially effective treatment before it's widely available, or extra medical attention and monitoring. However, there are also potential risks, like experiencing side effects from the study medication, or the treatment not working for you. You will be fully informed about any known risks before you decide to join. Remember, your participation is completely voluntary, and you have the right to withdraw from the study at any time without giving a reason, and it won't affect your usual medical care.

Locations (160)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

University of Alabama at Birmingham
Verified postcode
Birmingham, United States· Recruiting
Barrow Neurological Institute
Verified postcode
Phoenix, United States· Recruiting
Neurology Center of North Orange County
Verified postcode
Fullerton, United States· Recruiting
Keck School of Medicine of USC
Verified postcode
Los Angeles, United States· Recruiting
UCLA Neurology Outpatient Clinic
Verified postcode
Los Angeles, United States· Recruiting
Parkinson?s Research Centers of America ? Palo Alto
Verified postcode
Palo Alto, United States· Recruiting
Profound Research LLC at The Neurology Center of Southern California
Verified postcode
Pasadena, United States· Recruiting
UCSF Weill Institute for Neurosciences
Verified postcode
San Francisco, United States· Recruiting
Rocky Mountain Movement Disorders
Verified postcode
Englewood, United States· Recruiting
Institute for Neurodegenerative Disorders
Verified postcode
New Haven, United States· Recruiting
Georgetown University
Verified postcode
Washington D.C., United States· Recruiting
JEM Research LLC
Verified postcode
Atlantis, United States· Recruiting

Common questions

What is prasinezumab?

Prasinezumab is a new medicine being tested to see if it can help people with early-stage Parkinson's disease.

What is a placebo?

A placebo is a 'dummy' treatment that looks like the real medicine but contains no active drug. It helps compare the new drug's effects.

Will I still take my regular Parkinson's medicine?

Yes, you will continue your usual stable dose of levodopa throughout the study.

How will I receive the study medicine?

The study medicine will be given to you through a drip into your arm.

Can I leave the study if I change my mind?

Yes, you can leave the study at any time without explanation, and it will not affect your medical care.

How to find out more

Reference Study ID Number: BN44715 https://forpatients.roche.com/

global-roche-genentech-trials@gene.com 888-662-6728 (U.S. and Canada) Official trial record

Always speak to your GP or specialist before deciding to take part in a study.