Safety of Urate Elevation in Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disease for which there is no cure. Multiple lines of evidence have implicated oxidative stress in the pathophysiology of ALS. Urate (uric acid) is an endogenous antioxidant system, and urate may serve as a major defense against oxidative stress. Urate has emerged as a promising neuro-protectant and therapeutic target based on convergent epidemiological, laboratory, and clinical data in multiple neurodegenerative diseases, most notably Parkinson's disease (PD). In PD, urate elevation has been pursued as a potential therapy by administration of inosine, a urate precursor that is available as an over-the-counter supplement. Administration of inosine results in a predictable elevation of urate levels and has been shown to be safe and well tolerated in PD. Analysis of ALS databases revealed that higher urate levels are an independent predictor of slower progression and prolonged survival in ALS. However, whether elevating urate in people with ALS would result in better outcomes is unknown. The Principal Investigator has recently concluded a Pilot Study of Inosine in ALS, which was a short, open label, single center study involving 25 subjects \[NCT02288091\]. The study assessed safety and feasibility of urate elevation in patients with ALS. The Principal Investigator is now pursuing a multi-center Phase II trial to assess the findings of the open label study with longer exposure time.