Drugs that once treated conditions such as type 2 diabetes, cancer, high cholesterol and dementia are now being evaluated in repurposed drug trials in Parkinson’s disease. To find out more, you can read our summary here.
What is a repurposed drug?
A repurposed drug is a drug that has been developed to treat one type of disease, but is being utilised in the treatment of another disease.
The benefits of repurposed drugs are that they have already gone through the expensive and time-consuming clinical trial process to get them to market. Therefore, they can be less costly to develop and more readily available than novel therapies.
Many repurposed drug trials are currently underway in Parkinson’s disease. Examples include:
- Exenatide – a drug currently used to treat type 2 diabetes, acts on the GLP-1 receptors in the pancreas and brain. Promising research from the UK has shown improvements in motor symptoms of PD in those participants receiving Exenatide, however more research is needed.
- Liraglutide and lixisenatide – are newer drugs that also treat type 2 diabetes. Initial rodent studies found these drugs were more effective at preventing brain cell death than Exenatide. Currently, there are two trials underway to investigate the effects of these drugs on PDin the US and France.
- Statins – are often prescribed to help lower cholesterol in people at risk of cardiovascular disease. Research in rodent models suggest statins have protective effects on PD progression, such as; reducing inflammation, oxidative stress damage, as well as reducing the build-up of alpha-synuclein proteins. Currently, a randomised control trial is underway in the UK to assess the effectiveness of a statin – Simvastatin on PD symptoms in 235 patients with mild PD symptoms.
- Ursodeoxycholic acid (UDCA) – a drug typically used to treat liver disease has been implicated in the restoration of mitochondrial cells (which fuel our cells) in a UK based study. Impairments in mitochondrial function are a key contributor to brain cell death in PD.
- Nilotinib – used traditionally to treat a form of leukaemia, however recent research has found Nilotinib reduces brain cell death by binding to specific proteins in the brain. A 2015 study found patients who took Nilotinib had a reduction in PD-related motor symptoms.
- Deferiprone – is used to treat people with excess iron, a common symptom of PD, thought to be due to excess iron found in dopamine-producing brain cells. Promising research from animal models has led to a current European-based trial with over 300 participants to investigate Deferiprone in slowing the progression of PD.
- Isradipine – is used to treat high blood pressure. It works by blocking the uptake of calcium into cells. Research has found Isradipine also works on dopamine-producing brain cells, leading to reduced calcium uptake and subsequent oxidative damage. A multi-centre clinical trial involving 336 newly diagnosed PD patients is currently underway across the US and Canada. The trial is expected to finish at the end of 2019.
- Ambroxol – typically used as a cough medication to help reduce the build-up of mucus, has had positive effects in the treatment of PD through increasing the activity of a protein called glucocerebrosidase (or GCase), which control alpha-synuclein levels – a key protein implicated in PD. Current research is underway in the UK and Canada to investigate Ambroxol in PD patients.
- Rivastigmine – is currently used to treat dementia but has shown promise in PD patients via its ability to increase acetylcholine levels, implicated in memory and concentration. A UK-based study recruiting 600 PD patients is currently underway to investigate the effect Rivastigmine has on PD symptoms.
Repurposed drug trials will soon be commencing in Australia through the Australian Parkinson’s Mission. See our next blog for further information.
The information provided in this article is of a general nature only and is not treatment advice. Recommendations regarding therapy can only be made on a case by case basis, discussed between a patient and their treating doctor/s.
The information in this article was current at December 2019.