Cysteamine as a novel disease-modifying compound for Parkinson's disease: Over a decade of research supporting a clinical trial.

To date, medical and surgical interventions offered to patients with Parkinson's disease (PD) serve only to manage clinical symptoms; they have not shown the capacity to halt nor reverse degenerative processes. There is therefore an urgent need to identify and/or develop therapeutic strategies that will demonstrate 'disease modifying' capacities. The molecule cystamine, and its reduced form cysteamine, act via a number of pathways determined to be critical to the pathogenesis of PD. In particular, cystamine is capable of crossing the blood-brain barrier, and both agents (cystamine and cysteamine) can promote the secretion of neurotrophic factors, inhibit oxidative stress, reduce inflammatory responses and importantly, have already been trialed in humans for a number of other clinical indications. In the last decade, our laboratory has accumulated compelling evidence that both cystamine and cysteamine can halt, and even reverse, ongoing neurodegenerative processes in a number of different models of PD, and as such, should now be taken forward to clinical trials in PD. Crown