13 January 2020

Results published today in The Journal of the American Medical Association (JAMA) Neurology

Cure Parkinson’s is delighted to announce the publication of the results of a phase 2 clinical trial evaluating ambroxol as a potential treatment to slow the progression of Parkinson’s. The study has shown ambroxol can effectively cross the blood-brain barrier and increase levels of glucocerebrosidase (GCase) in the brain cells of people with Parkinson’s. The protein GCase allows cells to remove waste more effectively, a function which evidence suggests is deficient in some people with Parkinson’s, so to increase levels of this protein may therefore indicate the potential to slow the progression of Parkinson’s. This study has been funded by CPT in partnership with Van Andel Institute (VAI) and the John Black Charitable Foundation.

Background to the study

Ambroxol is a commonly used medication in Europe, which promotes the clearance of mucus and eases coughing. It is used for the treatment for respiratory diseases, and also has anti-inflammatory properties.

Preclinical experiments suggest that ambroxol may help by bolstering cellular waste disposal systems. In Parkinson’s, there is evidence to suggest that abnormal proteins are accumulated in cells and are not being disposed of properly. In particular, researchers have found that ambroxol increases levels of a protein called GCase in cells. By increasing levels of GCase, ambroxol allows cells to remove waste more effectively. This would ideally keep cells healthier for longer and therefore slow down the progression of Parkinson’s.

As a result of these preclinical findings, in late 2014 ambroxol was prioritised for clinical trial through Cure Parkinson’s International Linked Clinical Trials programme, an initiative where new treatments, many of which are pre-existing drugs, are prioritised by a committee of world-leading experts to go to clinical trial for use in Parkinson’s.

Between January 2017 and April 2018 a phase 2 clinical trial was conducted by Professor Anthony Schapira and his research team at University College, London and the Royal Free Hospital.

The results

The study involved evaluating the safety and tolerability of ambroxol in 17 people with Parkinson’s over six months. The investigators also assessed how well the drug was getting into the brain, how much it increased GCase, and they conducted some basic clinical assessments of disease progression in the participants.

The results show that ambroxol was well tolerated (there were no reported serious adverse events during the study). The drug was also getting into the brain, and there was a 35% increase in GCase protein levels in the cerebrospinal fluid.

Clinical assessments of the participants suggest that treatment improved motor features associated with Parkinson’s, but given that study was not designed to test disease modification as it was very small and there was no placebo control group, the clinical outcomes should be interpreted with caution.

The next steps

In order for the medical regulators to approve this drug for clinical use in people with Parkinson’s, further longer and larger studies will be required to determine if ambroxol is having a disease-modifying impact. CPT, VAI and the John Black Charitable Foundation are now actively exploring the next steps in the clinical testing of ambroxol.

Professor Anthony Schapira, Head of the Department of Clinical Neurosciences at the UCL Institute of Neurology and Professor of Neurology at the Royal Free and National Hospital for Neurology and Neurosurgery said:

“The results of the AiM-PD study indicate that ambroxol is safe, well tolerated and able to increase GCase levels in the spinal fluid of people with Parkinson’s. This is an important step to now allow us to find out whether this drug can slow the progress of Parkinson’s. We are grateful to the patients who participated and to The Cure Parkinson’s Trust who supported the trial.”

Dr Simon Stott, Deputy Director of Research at Cure Parkinson’s, commented:

“The ambroxol study is important because there are no treatments available for Parkinson’s that slow, stop or reverse Parkinson’s. All of the current medications only deal with the symptoms of the condition – they do nothing to delay the progression of Parkinson’s. This study provides us with the ‘proof of concept’ that we can raise levels of GCase in humans with ambroxol, and that the drug is safe and well tolerated in people with Parkinson’s. If further study shows ambroxol can improve the health and function of cells, it may result in slower disease progression for people with Parkinson’s.”

Professor Patrik Brundin, Chair of the Linked Clinical Trials committee and Director of the Center for Neurodegenerative Science at Van Andel Institute said:

“These promising results could lay the groundwork for larger studies designed to evaluate ambroxol’s potential to impede the actual disease process, a development that would be a game-changer for people with Parkinson’s. We are proud to have supported this important effort though the Linked Clinical Trials initiative and look forward to the next steps.”


Notes to Editors:

For more information or press enquiries: rachel@cureparkinsons.org.uk or 01923 779555

Cure Parkinson’s has one bold aim to cure Parkinson’s. Cure Parkinson’s funds pioneering research around the world which is dedicated to finding new treatments that can slow, stop or reverse Parkinson’s. Further information at www.cureparkinsons.org.uk
The Cure Parkinson’s Trust is a registered charity in England and Wales (1111816) and Scotland (SCO44368).

Van Andel Institute (VAI) is committed to improving the health and enhancing the lives of current and future generations through cutting edge biomedical research and innovative educational offerings. Established in Grand Rapids, Michigan, in 1996 by the Van Andel family, VAI is now home to more than 400 scientists, educators and support staff, who work with a growing number of national and international collaborators to foster discovery. The Institute’s scientists study the origins of cancer, Parkinson’s and other diseases and translate their findings into breakthrough prevention and treatment strategies. Our educators develop inquiry-based approaches for K-12 education to help students and teachers become the next generation of problem-solvers, while our Graduate School offers a rigorous, research-intensive Ph.D. program in molecular and cellular biology. Learn more at vai.org.

The John Black Charitable Foundation was formed by the Will of the late John Black; The Foundation is committed to funding research into Prostate Cancer and Parkinson’s Disease.

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