Title: Development and Validation of Therapy for GM1 Gangliosidosis

PROJECT SUMMARY GM1 gangliosidosis is lysosomal storage disease in which a key hydrolase enzyme, known as beta- galactosidase is missing in the lysosome resulting in the toxic accumulation of complex sugars called gangliosides, in particular GM1 and GA1 principally in the central nervous system. There is currently no cure or effective treatment available. A primary approach for treating related types of disorders involves replacement of the missing enzyme by injection into the circulation. Although intravenous enzyme replacement therapy (ERT) resolves many aspects of the disease, unfortunately it does not resolve complications of the disease in the CNS. Although, ERT is not a cure for this disease it can have a marked effect on the patient’s development and thus quality of life. Intravenous ERT has been successfully commercialized for lysosomal mucopolysaccharidoses (MPS) disorders with approved drugs on the market, including (i) Laronidase for MPS I (Aldurazyme®, alpha-iduronidase, Hurler Syndrome), (ii) Idursulfatase for MPS II (Elaprase®, iduronate-2- sulfatase, Hunter Syndrome) and (iii) Vestronidase alfa for MPS VII (Mepsevii™, beta-glucuronidase, Sly Syndrome). Intracerebroventricular (ICV) ERT has also been successfully commercialized for a progressive neurodegenerative lysosomal disease called Batten disease. Cerliponase Alfa (Brineura®, tripeptidyl peptidase-1) is a lysosomal enzyme delivered via ICV infusion directly to the brain to replace the deficient enzyme. This therapy is the first safe and effective ICV ERT approved for direct delivery to the brain. A Phase II clinical trial is also underway using a modified lysosomal enzyme ICV-delivered directly to the brain. Together, the FDA and investors are familiar with ERT and its commercialization path forward, both of which are essential in reaching a clinical trial. This proposal focuses on the development of the ICV route of administration to perform ERT directly to the central nervous system and its application to treating GM1 gangliosidosis. GM1 gangliosidosis has severe neurodegenerative symptoms with no current therapies available due to poor transport across the blood-brain barrier. In our studies, we will engineer cells to produce sufficient quantities of recombinant human beta-galactosidase enzyme for testing in GM1 gangliosidosis knockout mice. These mice will be ICV-administered enzyme and analyzed for dose-dependent biodistribution of the enzyme and effects on biochemical and histological pathology will be evaluated. Efficacy and safety will be assessed in single intermittent dose; once a week for 8 weeks dosing study. The results will provide the preclinical information needed to proceed towards a novel treatment of the disease in humans.