young doctor with digital tablet. Image courtesy of GettyImages

Parkinson’s is characterised by the lack of the chemical dopamine, which is used by the brain to send messages to help control movement. In people with Parkinson’s, dopamine-producing or dopaminergic neurons in the substantia nigra part of the brain stop working and are lost over time, resulting in a drop of dopamine being produced.

Chief Investigator, Dr Camille Caroll led the PD-STAT clinical trial, investigating the use of simvastatin – a statin typically used as a cholesterol lowering drug – as a neuroprotective treatment that could alleviate symptoms and slow the progression of Parkinson’s.

Funded by University of Plymouth the JP Moulton Trust and The Cure Parkinson’s Trust, the trial was run out of the Peninsula Clinical Trials Unit at University of Plymouth with the support of the NIHR Clinical Research Network for the South West Peninsula.

Innovations in the treatment for Parkinson’s

Part of The Cure Parkinson’s Trust Linked Clinical Trials Programme, this trial followed the successful pre-clinical work in multiple sclerosis investigating the effect of simvastatin on alpha-synuclein clumping, which is a common feature of Parkinson’s. 

Taking this treatment with its proven safety records in people to treat other conditions, like Parkinson’s, allows for innovations in the treatment of Parkinson’s over a much shorter timescale.

Double-blind placebo controlled study

The double-blind placebo controlled study involved 235 participants from 23 participating hospitals across the UK, including University Hospitals Plymouth NHS Trust. Started in 2016, patients who have Parkinson’s disease and had not previously taken statins were randomly allocated simvastatin capsules or a placebo to be taken orally. Information was then gathered from participants using a variety of questionnaires and practical tests during eight PD-TAT clinic visits over two years. 

Study findings

PD STAT was conducted at 23 hospitals across England and recruited 235 participants, who attended up to eight study visits at their local hospital over 26 months, interspersed with regular telephone calls from research nurses. 
The participants were randomly allocated to receive either simvastatin or a placebo (dummy drug) for 24 months, followed by a final study visit at 26 months.
The study clearly showed that simvastatin, in comparison with placebo, is unlikely to slow the rate of progression of Parkinson’s disease, and further trials of simvastatin as a protective therapy in Parkinson’s should not be recommended. There were no safety concerns with the use of simvastatin.
Although the results of the PD-STAT trial did not show that simvastatin has promise as a protective therapy in Parkinson’s, it is a great achievement to have a definitive answer to this important question. 
The main study results were presented to an international group of Movement Disorder Clinicians at the Movement Disorders Society Virtual Congress on Friday 11 September 2020.
There are many positives to emerge from this study, particularly the extent to which we were able to involve participants across the country and the very positive feedback received from them and staff in the hospitals involved.
PD-STAT has taught us a huge amount about how to improve the way we design and deliver clinical trials in Parkinson’s and this knowledge will be very useful in designing future trials.

Research sites

  • Derriford Hospital, Plymouth - Dr Camille Carroll
  • Royal Cornwall Hospital, Truro - Dr Christine Schofield
  • Royal Devon & Exeter Hospital - Dr Ray Sheridan
  • Musgrove Park Hospital, Taunton - Dr Anita Goff
  • Yeovil District Hospital - Dr Rani Sophia
  • Christchurch Hospital - Dr Khaled Amar
  • Royal United Hospital, Bath - Dr Veronica Lyell
  • St Peter's Hospital, Chertsey - Dr Jan Coebergh
  • Charing Cross Hospital, London - Dr Sophie Molloy
  • Royal Free Hospital, London - Prof Huw Morris
  • Queen's Hospital, Romford - Dr Anjum Misbahuddin
  • John Radcliffe Hospital, Oxford - Dr Sudhir Singh
  • Luton and Dunstable Hospital - Prof Anette Schrag
  • Addenbrookes Hospital - Dr Paul Worth
  • Salford Royal Hospital - Dr Christopher Kobylecki
  • Fairfield General Hospital, Bury - Dr Jason Raw
  • Royal Preston Hospital - Dr Omesh Kulkarni
  • Leeds General Infirmary - Dr Jane Alty
  • Clinical Ageing Research Unit, Newcastle - Professor Nicola Pavese
  • Kings College Hospital, London - Prof Ray Chaudhuri
  • Royal Hallamshire Hospital, Sheffield - Prof Oliver Bandmann
  • Norfolk and Norwich University Hospital - Dr Godwin Mamutse
  • Rotherham General Hospital - Dr Ahmed Hafiz

Associated publications

Carroll C, Webb D, Stevens KN, Vickery J, Eyre V, Ball S, Wyse R, Webber M, Foggo A & Zajicek J 2019 'Simvastatin as a neuroprotective treatment for Parkinson’s disease (PD STAT): protocol for a double-blind, randomised, placebo-controlled futility study' BMJ Open , DOI PEARL

Carroll CB, Wyse RKH & Grosset DG 2019 'Statins and Parkinson's: A complex interaction' Movement Disorders 34, (7) 934-935 , DOI PEARL

Carroll CB & Wyse RKH 2017 'Simvastatin as a Potential Disease-Modifying Therapy for Patients with Parkinson’s Disease: Rationale for Clinical Trial, and Current Progress' Journal of Parkinson's Disease , DOI PEARL


Why get involved in clinical trials?

Parkinson’s Disease does not define Michael Broad – he’s been a keen photographer, climber and cyclist, and has enrolled in many online courses to improve his knowledge of the condition. And since being diagnosed in 2013 he has taken part in a number of clinical trials to help find ways of alleviating symptoms and slowing the progression of Parkinson’s, most recently PD-STAT led by the University of Plymouth.

Read Michael’s story

Michael Broad PD-STAT trial
Patient with Parkinson's. At home care giver

Applied Parkinson’s Research Group

Dr Camille Carroll leads the Applied Parkinson’s Research Group that focuses on clinical trials of neuroprotective interventions in Parkinson’s, digital innovation for care and research, and genetic aspects of Parkinson’s.

Intrinsic to their work is the person-centred care approach. Dr Carroll and her team collaborate with an engaged and eternally optimistic community of Parkinson’s patients. Engaging with them from the very beginning, they provide research and health interventions that challenge the ‘status quo’ bio-medical approach to treating the illness and place as much control and influence over decisions on health and care in the hands of patients, care partners and the community. These co-designed pathways provide choices to patients and treatments that are sustainable in the long-run.

Find out more about the Applied Parkinson’s Disease Research Group.