Parkinson’s disease (PD) is a progressive neurodegenerative
condition affecting more than 145,000 people in the UK. No drug has been
shown to slow, stop or reverse the neurodegenerative process of PD.
Existing treatments act to relieve symptoms and can become less
effective as the disease progresses.
Simvastatin, a widely-used cholesterol-lowering drug, was
identified in 2012 as worthy of investigation as a potential protective
therapy in Parkinson’s by the Cure Parkinson’s Trust’s Linked Clinical
Trial Initiative. The initiative identifies compounds that have shown some potential to slow, stop or reverse PD to bring them into clinical trials.
The PD STAT trial was designed and led by staff at the
University of Plymouth and the Peninsula Clinical Trials Unit and has
been running since 2016. It was designed to formally assess whether
simvastatin has the potential to slow the progression of Parkinson’s
disease. The trial was funded by
the Jon Moulton Charity Trust (formerly the J P Moulton Charitable Foundation)
and The Cure Parkinson’s Trust, was sponsored by University Hospitals
Plymouth NHS Trust and was run with the support of the NIHR Clinical
Research Network.
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.