This trial, run by Professor Tony Schapira of the UCL Clinical Trials Unit across up to a dozen centres in the UK, aims to confirm if Ambroxol can successfully slow the progression of Parkinson's disease. Parkinson's is generally associated with the build up of proteins inside cells and by boosting the cellular waste disposal system it is thought that this could slow the progression of Parkinson's by improving the function of neurons.

Ambroxol has been demonstrated to be effective at improving the clearance of waste products from cells. There is extensive safety data available for this drug, particularly at the dosage expected to be used in this trial.