GM1 ganglioside in Parkinson's disease: Results of a five year open study.

Previous work demonstrated that short-term (i.e., 16 weeks) use of GM1 ganglioside resulted in significant symptom reduction in Parkinson's disease (PD) patients. As GM1 use may have long-term benefit for PD patients, the present study was conducted to evaluate the long-term safety and efficacy of GM1 in PD patients. Twenty-six patients who concluded a previous randomized double blind placebo controlled trial of GM1 volunteered for this open-extension study. At the end of 5 years of GM1 use, patients generally had lower Unified Parkinson's Disease Rating Scale (UPDRS) motor scores (assessed during a practically defined "off" period) than at baseline prior to randomization into the original study. A similar result was found for UPDRS Activities of Daily Living scores. Performance of timed motor tests also remained mostly stable over the 5 year observation period. No consistent clinically significant changes in blood chemistry, hematologic indices or urine chemistry were noted over the course of this study. These results suggest that long-term GM1 use by PD patients is safe and may provide some clinical benefit for PD patients. Additional study is required to more completely assess the degree to which GM1 treatment may be a symptomatic and/or disease-modifying agent for treatment of PD.