Pharmaxis Ltd. announced update on Phase 2 study of the Pharmaxis drug discovery PXS4728. Parkinson's UK, will provide £2.9 million to fund a Phase 2 study of the Pharmaxis drug discovery PXS4728, with the aim of tackling Parkinson's disease at the earliest possible time. Previous research has identified that the development of isolated Rapid Eye Movement Sleep Behaviour Disorder (iRBD), where otherwise healthy people start acting out their dreams, is the strongest predictor for the development of Parkinson's disease and dementia with Lewy Bodies.

A recent multicentre study found that over 70% of iRBD patients transitioned to a neurodegenerative disease. The study will examine whether targeting inflammation in the brain of people with iRBD might provide a viable neuroprotective strategy to prevent the disease. Working in collaboration, experts from the University of Sydney and the University of Oxford will recruit 40 patients with iRBD to participate in a placebocontrolled Phase 2 trial to evaluate whether PXS4728 can reduce neuroinflammation as measured by nuclear scanning techniques.

PXS4728 is a potent inhibitor of the inflammatory enzyme SSAO (semicarbazidesensitive amine oxidase) that was discovered by the Pharmaxis research team at the company's Frenchs Forest laboratories in Sydney, Australia. The drug was licenced in 2015 by Boehringer Ingelheim and extensively studied in 11 clinical trials including the inflammatory diseases of NASH and diabetic retinopathy. Despite promising results, Boehringer returned the drug to Pharmaxis due to an off target effect on an additional inflammatory enzyme in the brain, MAOB (monoamine oxidase B).

The study in iRBD is seeking to reduce inflammation by inhibiting both SSAO and MAOB, a concept supported by preclinical models in neuroinflammation and published literature in Parkinson's disease. PXS4728 has passed all long term toxicity studies and has been well tolerated in all clinical studies including two Phase 2 studies. It is therefore an ideal candidate for long term studies in neurodegenerative diseases like Parkinson's, Alzheimer's and Huntington's Disease where neuroinflammation plays a significant role in disease progression.