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Gene therapy clinical trial for Parkinson’s disease

This clinical trial is focused on a specific type of Parkinson’s disease linked to a GBA1 genetic variant (also called a ‘mutation’).

The clinical trial will assess the safety, tolerability, and effectiveness of a gene therapy aimed at slowing the progression of Parkinson’s and its symptoms.

How do I take part?

To take part in this clinical trial, you need to have a specific genetic variant. You can get free genetic testing through the PD GENEration program to see if you qualify. For questions, email Jim Howley, Global Lead, Patient Advocacy and Engagement, at Prevail.Patients@lilly.com or speak to your healthcare team.

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Who can take part?GBA1 variants in Parkinson’s About the clinical trial Clinical trial processFind your nearest clinical trial center
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Who can take part?

To join the Parkinson’s gene therapy clinical trial, you need to meet these requirements:

  • Aged between 35 and 80 years old.
  • Be able to walk without using a walker or wheelchair.
  • Have a diagnosis of Parkinson’s.
  • Have at least one genetic variant in the GBA1 gene.
  • If you take medication for Parkinson’s, your dose should be stable for at least eight weeks.
  • Have a clinical trial partner – a family member or friend who can come to the clinical trial visits and share information about your experience.

Understanding GBA1 variants in Parkinson’s

  • Genetics is the field of science that looks at how traits are passed down, or inherited, from parents to children through genes.
  • Changes in your genes are mostly harmless, but in some cases, they can affect your risk of getting a disease.
  • Scientists have identified genetic variants in several genes associated with Parkinson’s.
  • Variants in the GBA1 gene are the most common genetic risk factor for Parkinson’s, affecting about 5–10% of people with Parkinson’s.
  • Having a GBA1 genetic variant doesn’t mean a person will definitely develop Parkinson’s, but it does mean they have a higher risk.
  • People with Parkinson’s and GBA1 genetic variants may have symptoms that start earlier and progress faster than in other forms of Parkinson’s.

Learn more about your genetic links to Parkinson’s

PD GENEration is an initiative offering free genetic testing and counseling for people with Parkinson’s.

The test, which requires only a simple blood draw, looks for changes in genes related to Parkinson’s. This information can help you and your doctor better understand your condition and may open the door to more clinical trial options.

Learn more about PD GENEration on the Parkinson’s Foundation website.

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About the clinical trial

Key questions and considerations

How is gene therapy different from other treatments?

This gene therapy aims to address the underlying cause of Parkinson’s with GBA1 genetic variants, offering a different approach from current treatments.

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What are the key facts about this clinical trial?

This clinical trial is testing a gene therapy for people with a type of Parkinson’s linked to a GBA1 genetic variant. Each participant will receive a one-time injection of the gene therapy into an area at the base of the skull, near the nape of the neck.

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What are the potential risks and benefits?

This gene therapy may help to slow the progression of Parkinson’s with GBA1 genetic variants, but this is not guaranteed and there are risks to consider.

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What will happen during the clinical trial?

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Screening

Up to 45 days before the clinical trial starts

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Clinical trial treatment

Day 1

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Monitoring

Day 2 to Month 18

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Follow-up

Month 18 to Month 60

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Find your nearest clinical trial center

To find your nearest center for our gene therapy clinical trial for Parkinson’s disease, please visit ClinicalTrials.gov. There, you can see detailed information about where the clinical trial is taking place.

Find a trial center

Considering a gene therapy clinical trial?

You can hear more about gene therapy and Parkinson’s from Travis Lewis, a member of the Prevail clinical team:

Listen to episode 081: Gene Therapy Explained on The Parkinson’s Experience podcast, hosted by 17 Branches

Listen Now

How is gene therapy different from other treatments?

This gene therapy aims to address the underlying cause of Parkinson’s with GBA1 genetic variants, offering a different approach from current treatments.

  • Current treatments: Current treatments focus on managing symptoms. While they can help some people with their symptoms, these medicines often lose effectiveness as the disease progresses and may cause side effects. They don’t target the root cause of Parkinson’s with GBA1 genetic variants or prevent neuron loss.
  • How gene therapy works: This gene therapy is designed to deliver a healthy copy of the GBA1 gene, which may help address the underlying cause of Parkinson’s with GBA1 genetic variants. Scientists hope it will provide long-term benefits beyond symptom management.

What are the key facts about this clinical trial?

This clinical trial is testing a gene therapy for people with a type of Parkinson’s linked to a GBA1 genetic variant. Each participant will receive a one-time injection of the gene therapy into an area at the base of the skull, near the nape of the neck.

  • The gene therapy is given only once through an injection into the cisterna magna, an area at the base of the skull, near the nape of the neck.
  • Participants will receive one of two possible dose levels of the gene therapy to help researchers find the safest and most effective dose.
  • The clinical trial will test each dose level in stages. Each participant’s dose will depend on when they join the clinical trial, and the clinical trial doctor will inform them of their assigned dose.
  • Participation in the clinical trial is voluntary, and you may leave at any time.

What are the potential risks and benefits?

This gene therapy may help to slow the progression of Parkinson’s with GBA1 genetic variants, but this is not guaranteed and there are risks to consider.

Benefits: If effective, this gene therapy may slow the progression of Parkinson’s with GBA1 genetic variants. However, results cannot be guaranteed. If the effects wear off, participants may return to their previous treatments but will not be able to receive an additional dose of the gene therapy as part of this clinical trial. By participating, you will contribute valuable information that could help improve future treatment options for people with Parkinson’s with GBA1 genetic variants.

Risks: All clinical trials involve some level of risk, and individual risks may vary. People who participate in this clinical trial may not be eligible for other gene therapy clinical trials in the future. Researchers take every measure to ensure safety, but each clinical trial carries its own unique risks.

To learn more about the risks and benefits of participating, please email Jim Howley, Global Lead, Patient Advocacy and Engagement, at Prevail.Patients@lilly.com or talk to your healthcare team.
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Screening

Up to 45 days before the clinical trial starts

At your nearest clinical trial center we will:

This will take around 3 days, and we will ask participants and their clinical trial partners to stay at the clinical trial center for this time.

  • If accepted onto the clinical trial, you will receive immunosuppressants on the day before the gene therapy. Immunosuppressants are medicines that moderate the immune system, reducing the chance of the body attacking the inactivated virus that carries the gene therapy to the cells. This should reduce the risk of side effects.
  • The team will continue to give you immunosuppressants until Month 3 of the clinical trial.
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Clinical trial treatment

Day 1

Day 1 of the clinical trial

  • The gene therapy will be delivered as an injection into the cisterna magna, at the base of the skull.
  • The injection will be carried out under general anesthesia or deep sedation.
  • While under general anesthesia or deep sedation, the team will also collect a small sample of the CSF from around your brain with a needle.
  • Next, the team will monitor you closely while you recover. If your overall condition and health are good, you will be able to leave about 24 hours later.
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Monitoring

Day 2 to Month 18

Day 2 to Day 28 (Month 1)

  • We will ask participants and their clinical trial partners to visit the clinical trial center three times. This is so we can do things like blood and urine tests and check vital signs.

Month 2 to Month 18

  • We will ask participants and their clinical trial partners to come to the clinical trial center six times between Month 2 and Month 18 of the clinical trial. Each visit will take between 2 and 4 hours.
  • You will stop taking immunosuppressants at Month 3.
  • During the visits, we will:
    • Ask questions about your health and any possible side effects of the gene therapy.
    • Check your vital signs.
    • Perform tests, such as brain and bone scans, and blood, urine, and stool tests.
    • At three of these visits (Months 2, 6, and 12), the team will carry out a lumbar puncture.
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Follow-up

Month 18 to Month 60

Month 18 to Month 60

  • We will ask participants and their clinical trial partners to come to the clinical trial center once every 6 months for 4 years. Each visit will take between 2 and 4 hours.
  • During the visits we will:
    • Ask questions about your health and any possible side effects of the gene therapy.
    • Check your vital signs.
    • Perform tests, such as blood and urine tests.
  • At four of these visits (Month 18 and Years 2, 3, 4, and 5) we will ask you to have an optional lumbar puncture. These tests are designed to help us monitor your progress on the gene therapy.

Definitions

β-glucocerebrosidase (GCase)

An enzyme in the body. It helps break down fatty substances. These substances are recycled inside lysosomes, which are the recycling centers of cells. If GCase doesn’t work properly or is missing, fat builds up in lysosomes. This buildup happens in places like the spleen, liver, and bone marrow. It can cause health problems, such as Gaucher disease.

Cerebrospinal fluid (CSF)

A clear fluid that surrounds and cushions the brain and spinal cord, protecting them and helping transport nutrients and waste.

Cisterna magna

An area at the base of the skull where the brain and the spinal cord meet. This space is filled with cerebrospinal fluid and can be used by doctors to deliver treatments directly to the brain and spinal cord.

Clinical trials

Research studies that test new treatments or procedures in people to make sure they are safe and work well.

Dopamine transporter single-photon emission computed tomography (DaT-SPECT)

A scan that is used to diagnose neurodegenerative Parkinson’s disease from other types of Parkinson’s disease. For example, Parkinson’s disease caused by medicines or reduced blood supply to the brain.

Electrocardiogram (ECG)

A test that checks the heart’s rhythm and electrical activity using small sensors attached to the skin.

Enzyme replacement therapy (ERT)

A treatment that gives the body enzymes it’s missing or that aren’t working properly. For Gaucher disease, ERT provides a replacement for the GCase enzyme through an infusion. This helps reduce the buildup of fat in the body and manage symptoms.

Frontotemporal dementia (FTD)

A type of dementia that gets worse over time. It damages the brain’s frontal and temporal lobes. These areas control personality, behavior, language, and movement, which means FTD can lead to significant changes in how a person acts, communicates, and moves.

FTD with GRN genetic variants

FTD is a type of dementia that damages the brain’s frontal and temporal lobes, causing changes in personality, behavior, language, and movement.

About 5–10% of FTD cases are linked to genetic variants in the GRN gene. The GRN gene provides instructions for making progranulin, a protein needed to keep brain cells healthy. Genetic variants in GRN lead to lower levels of progranulin, causing brain cell damage and faster disease progression. People with these genetic variants often experience more severe and rapidly worsening symptoms.

GBA1 genetic variant

The GBA1 gene gives cells the instructions to make the GCase enzyme. This enzyme helps break down fatty substances inside lysosomes, which are the cell’s recycling centers. A GBA1 genetic variant is a change in this gene. This change can stop the GCase enzyme from working properly. When this happens, fatty substances build up in the body. This buildup can cause Gaucher disease or increase the risk of Parkinson’s disease.

Gaucher disease (GD)

A rare condition passed down through families, caused by changes (genetic variants) in the GBA1 gene. These changes affect a specific enzyme called GCase, which is needed to break down certain fatty substances. When GCase doesn’t work properly, these substances build up in lysosomes, the recycling centers of cells. Over time, this buildup can affect organs like the spleen, liver, and bone marrow, causing symptoms such as fatigue, bone pain, and organ swelling.

Gene therapy

A type of treatment that uses genetic material, such as DNA or RNA, to fix or replace faulty genes in the body. This treats or prevents certain diseases by enabling the genes to work as they should.

Genetic variant

A genetic variant is a change in a gene that can affect how it works. Changes in genes are mostly harmless. But, in some cases, they can make the body work differently and increase the risk of certain diseases. Genetic variants were previously called ‘mutations’.

Immunosuppressants

Medicines that lower the activity of the immune system. In gene therapy, they are used to reduce the chances of the immune system reacting to the inactivated virus that delivers the gene therapy to cells.

Informed Consent Form (ICF)

A document that provides important details about a clinical trial. It explains the potential risks and what is required before, during, and after the clinical trial. It also outlines the rights of participants. Participants sign the form to show they understand the clinical trial and agree to take part.

Infusion

A way of delivering fluids, including medicine, directly into the bloodstream using a needle or small tube.

Intravenous / intravenously (IV)

A method of giving medicine or fluids directly into a vein.

Lumbar puncture

A medical procedure where a small sample of cerebrospinal fluid is taken from the lower back using a needle. It’s sometimes called a spinal tap.

Lysosomes

Small parts of cells that act as recycling centers. They break down and recycle waste materials, including fatty substances, to keep the cells healthy. When lysosomes don’t work properly, these substances can build up and cause health problems, such as in Gaucher disease.

Magnetic resonance imaging (MRI)

A medical scan that uses powerful magnets and radio waves to create detailed images of the inside of the body, like the brain or spine.

Parkinson’s disease (PD)

A brain condition that affects movement. It happens when certain brain cells that produce a chemical called dopamine stop working properly. Without enough dopamine, the brain cannot send proper signals to the body. This can cause symptoms like tremors, stiffness, slow movements, and trouble with balance.

Parkinson’s disease with GBA1 genetic variants

Parkinson’s disease is a brain condition that affects movement, caused by the loss of brain cells that produce dopamine. Without enough dopamine, symptoms like tremors, stiffness, and slow movements can occur.

Some cases of Parkinson’s are linked to genetic variants in a gene called GBA1, the most common genetic risk factor for the condition. These genetic variants increase the risk of developing Parkinson’s and can lead to earlier and faster-progressing symptoms.

Peripheral vein

A vein found in areas like the arms, hands, legs, or feet. These veins are closer to the surface of the body and are commonly used for giving medications or drawing blood.

Placebo-controlled

In a clinical trial where there are two groups of participants, one group receives the active treatment or intervention, while the other group receives an inactive treatment or intervention (the placebo). The placebo is administered in the same way as the active treatment but does not contain any medicine.

Small interfering RNA (siRNA)

A type of therapy that uses small pieces of RNA, a natural molecule in cells, to block specific genes from making harmful proteins. siRNA works by ‘silencing’ genes that may cause or worsen certain diseases. This therapy is different from traditional gene therapy, as it focuses on turning off harmful gene activity rather than replacing or fixing genes.

Substrate reduction therapy (SRT)

An oral treatment (tablet) used for Gaucher disease. It works by partially stopping the body from making fatty substances. These substances are usually broken down by an enzyme called GCase. When GCase doesn’t work properly, these substances build up in lysosomes, the recycling centers of cells. SRT helps reduce this buildup and manage symptoms caused by Gaucher disease, such as organ swelling, fatigue, and bone pain.

Type 1 Gaucher disease

Type 1 Gaucher disease is the most common form of Gaucher disease, a rare inherited condition caused by genetic variants in the GBA1 gene. These genetic variants affect an enzyme called GCase, leading to a buildup of fatty substances in lysosomes, the recycling centers of cells.

Type 1 Gaucher disease usually begins during adolescence but can start at any age. Symptoms include bone pain, fractures, enlarged organs, bruising, and fatigue. Unlike other types, Type 1 does not typically affect the brain or spinal cord.
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