Inflammation and Parkinson’s

What is inflammation?

Inflammation is a normal part of our body’s natural healing response. When our bodies detect something is wrong, either because of an injury, infection, virus or bacteria, our immune system kicks into action to try and fight it off.

Part of this process is inflammation, where immune cells in our bodies are called to the area that’s under attack. These cells rush to the site, where they then release chemicals that work on fixing the problem, including clearing up damaged cells, promoting more blood flow to the area, or killing the bacteria or virus that’s causing the issue. The immune system is vital to keeping our bodies healthy.

When can inflammation be harmful?

Whilst inflammation is important, prolonged inflammation or over active inflammation can actually have some negative effects on our bodies. Constant inflammation, or ‘chronic’ inflammation is when immune cells get stuck in ‘attack mode’, working even when there is no real threat to the body. This causes a knock on effect resulting in damage to healthy cells and tissues. Some medical conditions, such as diabetes, or even some cancers, have been linked to chronic inflammation. It is now thought that chronic inflammation in the brain may play a role in the development of some brain conditions, including Parkinson’s.

Previous studies have shown that people with Parkinson’s appear to have more inflammation in areas of the brain affected by the condition. Understanding the role that inflammation may play in the development and progression of Parkinson’s is an active area of research.

Could targeting inflammation help slow Parkinson’s?

In other conditions that affect the brain, such as multiple sclerosis and Alzheimer’s, using drugs that reduce inflammation to treat the condition has bought hope. 

Read more about what Director of Research, Professor David Dexter, has to say about treating brain conditions with anti-inflammatory drugs on our blog.

Researchers hope to understand whether reducing inflammation in the brain can provide hope for treatment for  Parkinson’s. By switching off or suppressing the inflammation, it might be possible to reduce the damage caused to dopamine-replacing cells, which could help to slow or even stop the progression of Parkinson’s.

Let’s look at some of the ongoing research:

Preventing the onset of inflammation

Stage of research: Preclinical - developing a new drug
Where: UK and USA

US company Neumora is working on an anti-inflammatory drug that can move easily from the bloodstream to the brain. The drug is designed to prevent the formation of the ‘inflammasome’ – a cluster of proteins that come together in the cell to kick start the inflammation process.

In 2024, we announced we’d be partnering with Neumora through the Parkinson’s Virtual Biotech, to accelerate the last phase of lab testing for this new drug. This will involve conducting studies in cells and animals to carry out testing that is legally required for all new medicines. These tests will investigate possible side effects, how the potential new drug may interact with other common medications, and how it is distributed and processed inside the body.

If these vital tests are successfully completed, the new drug should be ready to move forward towards testing in people in clinical trials.

Read the news story about Neumora and the Virtual Biotech.

Blocking inflammation

Stage of research: Phase 1 clinical trial in 48 people with Parkinson’s
Where: UK, USA and the Netherlands

Researchers based at the University of Exeter are aiming to understand whether a new drug, called selnoflast, is able to stop inflammation in the brain of people with Parkinson’s. In this small phase 1 study, 48 people with Parkinson’s will receive either the selnoflast drug or a placebo (dummy drug) in capsule form for 28 days. The main aim of this early research is to assess the safety of the drug, as well as explore whether it shows signs of being effective.

If the results of the study show that selnoflast is safe for people with Parkinson’s and can reduce inflammation in the brain, larger studies could take place to investigate the benefits of the drug further, potentially leading to new treatments. The study is currently ongoing and is currently predicted to share results in 2025.

Read more about the selnoflast trial in our research news story.

Suppressing the immune system

Trial name: AZA-PD
Stage of research: Phase 2 clinical trial in 60 people with Parkinson’s
Where: UK

Researchers at the University of Cambridge are running a study to understand whether suppressing the immune system of people with Parkinson’s could slow the progression of the condition. The idea is that making the immune system less sensitive could reduce the levels of inflammation in the body, including areas of the brain affected by Parkinson’s. In the AZA-PD trial, 60 people with Parkinson’s received either a drug to suppress the immune system, called azathioprine, or a placebo (dummy drug) once a day for 1 year.

This study has finished recruiting participants. Results are currently being collected and are due to be published in late 2024.

Read more about the AZA-PD study on the Cambridge Clinical Trials Unit website.

What does this research mean for people with Parkinson’s?

The potential of using drugs to reduce inflammation is exciting. Particularly because anti-inflammatory drugs are already bringing some hope in other similar conditions, such as multiple sclerosis. But a lot of the ongoing research studies are in the early stages and a long way from becoming an available treatment for people with Parkinson’s.

The AZA-PD study is one that could be a little closer to becoming a reality, as azathioprine is already an approved drug used for treating inflammation. This means that, if the results of the latest trial are positive, it could be much quicker to get the drug approved for treating Parkinson’s too. We look forward to seeing more research, and more evidence, of the potential of these drugs in the future.