A groundbreaking trial, led from Cambridge, has revealed that immunosuppressing medicines show promise for the treatment of Parkinson’s disease, according to results presented this weekend at the world’s most prestigious neurodegeneration conference AD/PD.
This trial is the first to show that broadly suppressing the immune system could have a beneficial impact in Parkinson’s disease.
Participants on the treatment reported an overall improvement in movement-related symptoms. This meant they found it easier to perform tasks such as moving around, writing, washing and dressing. These improvements were greater in female participants compared to males.
I’m five years on from diagnosis, I’m only on low dose medication, and I’m still able to work and enjoy time with my family.
Sarah Price, AZA-PD trial participant
Additionally, patients with faster-progressing Parkinson’s disease showed signs of improved memory and thinking skills.
Importantly, the trial did not reveal significant safety concerns around using immunosuppression treatments in Parkinson’s disease This will enable larger research studies of immune therapies for PD in the future.
Parkinson’s disease is the fastest growing neurological condition in the world, affecting over 10 million people. This is around 153,000 people in the UK. Although treatments exist to manage some symptoms, there are no cures and treatments do not slow disease progression.
The trial, called AZA-PD, included 66 people with early-stage Parkinson’s disease. It investigated the effects of the drug Azathioprine, which suppresses the immune system. Azathioprine is already widely used to treat conditions such as rheumatoid arthritis and inflammatory bowel disease.
Existing research has shown that the immune system is over-active in people with Parkinson’s disease. This trial indicates that targeting immune activation might be a useful strategy for the treatment of Parkinson’s and provides impetus for further research to confirm these results in larger groups of patients.
There are currently no therapies available to cure or slow the progression of Parkinson’s disease. We know that inflammation in the brain is a factor but this is the first time we’ve been able to show that we can address this by suppressing the immune system with the potential to deliver benefits for patients.
Dr Caroline Williams-Gray, AZA-PD lead researcher
Participants on the trial were treated with Azathioprine or a placebo for 12 months and were then followed up for another 6 months. Assessments looked at various movement and non-movement related symptoms of Parkinson’s disease as well as assessing safety of treatment.
One of the reasons Parkinson’s disease has proven so challenging to treat is because the brain is surrounded by a structure called the blood-brain barrier that protects against infections. Many drugs cannot cross the barrier.
During the trial, the effect of the drug on the immune system was measured in both the blood and brains of participants. It showed that, although Azathioprine cannot cross the blood-brain barrier, it acts indirectly to slow progression of inflammation in the brain, and this could explain its effects in Parkinson’s disease.
A lot of research has suggested that inflammation is an important biological process in Parkinson’s disease. Anti-inflammatory drugs are being investigated as therapeutic options for slowing down the progress of the condition. We are delighted to support Dr Caroline Williams-Gray and her team in this pioneering research, which helps to build a strong foundation for future research in this area.
Dr Simon Stott, Director of research at Cure Parkinson’s
The results were presented on Saturday (5 April) by Dr Julia Greenland, a neurology specialist trainee at Cambridge University Hospitals NHS Foundation Trust (CUH) and clinical research fellow at the University of Cambridge, at the International Conference on Alzheimer’s and Parkinson’s Disease and Related Neurological Disorders (AD/PD) held in Vienna, Austria.
The study is led by Dr Caroline Williams-Gray, honorary consultant neurologist at Cambridge University Hospitals NHS Foundation Trust (CUH) and principal research associate at the Department of Clinical Neurosciences, University of Cambridge.
Dr Williams-Gray is also leading the DAPA-PD study, which is expected to open recruitment soon. This trial aims to test whether dapansutrile, a drug which targets a more specific component of the immune system implicated in Parkinson’s, could also be a safe and effective way of treating the condition. Dapansutrile is a new drug recently developed by Olatec Therapeutics.
If you're interested in taking part in research, find out more with Love Research.
The AZA-PD trial has been funded the Cambridge Centre for Parkinson-Plus and Cure Parkinson’s with support from the National Institute for Health and Care Research (NIHR) Cambridge Biomedical Research Centre (BRC) (NIHR203312), NIHR Cambridge Clinical Research Facility (CRF) (opens in a new tab), the Cambridge Clinical Trials Unit (CCTU) Neuroscience Theme and the core CCTU.
Sarah's story
Sarah Price (aged 56) is a trained social worker who provides psychiatric care in hospices. She lives in Little Thetford with her husband and two teenage daughters.
In 2019, Sarah started physiotherapy sessions to help with stiffness in her legs, which she thought was due to arthritis. During one of her sessions, she described how she’d sometimes forget to keep pedalling on her exercise bike and her physiotherapist recommended a referral to a neurologist.
In early 2020, neurologists at Addenbrooke’s Hospital diagnosed Sarah with Parkinson’s disease.
It was a surprise because I didn’t have a tremor or any of the things people think of when you say Parkinson’s disease. I didn’t expect something like this so early in my life, you don’t think something like this will happen to you when you’re still working.
Sarah
Sarah started low-dose treatment and was surprised by the immediate improvements she saw.
“I hadn’t realised how much the disease was affecting me. The stiffness in my legs meant it felt like I was walking through cement. Sometimes I’d be walking and have this sudden feeling that I was going to fall. I’d also get random anxiety about nothing. All of that went away as soon as I started the treatment.”
Sarah is passionate about research and began participating in a wide range of research studies and, thanks to her neurologist, Sarah was offered the chance to join the AZA-PD trial led by Professor Williams-Gray.
Through my work, I see so many people that aren’t eligible for research. I knew I was an ideal candidate so I wanted to do as much as I could to help us learn more about Parkinson’s.
Sarah
During the trial, Sarah took azathioprine in addition to her regular Parkinson’s medications. She also had regular appointments with the trial team to monitor the effects of the treatment and assess her symptoms.
I’m glad I took part. It’s hard to know how I would have progressed if I wasn’t on the trial. But I’m five years on from diagnosis, I’m only on low dose medication, and I’m still able to work and enjoy time with my family. When they diagnosed me I thought I could be bedbound within 10 years, so I’m feeling pretty good.
Sarah
With support from her family and minor adaptations Sarah is continuing to work in an active job. She enjoys getting outside to visit National Trust sites and reading murder mysteries. She also enjoys going out for coffee and cake and regularly attends social gatherings as part of a local group for working-age people living with Parkinson’s disease.
“The group shows you how different everyone’s experience of Parkinson’s disease is, but it also reminds you that you’re not alone.”