Synergistic Enteral Regimen for Treatment of the Gangliosidoses

The investigators hypothesize that a combination therapy using miglustat and the ketogenic diet for infantile and juvenile patients with gangliosidoses will create a synergy that 1) improves overall survival for patients with infantile or juvenile gangliosidoses, and 2) improves neurodevelopmental clinical outcomes of therapy, compared to data reported in previous natural history studies. The ketogenic diet is indicated for management of seizures in patients with seizure disorders. In this study, the ketogenic diet will be used to minimize or prevent gastrointestinal side-effects of miglustat. A Sandhoff disease mouse study has shown that the ketogenic diet may also improve central nervous system response to miglustat therapy (see Denny in "Citations" list below). Patients with infantile and juvenile gangliosidoses commonly suffer from seizure disorders, and use of the ketogenic diet in these patients may therefore also improve seizure management.

The infantile and juvenile forms of GM1 and GM2 gangliosidoses are neurodegenerative conditions that are lethal during childhood. There are no known effective therapies available for treatment of infantile and juvenile gangliosidoses. Studies of monotherapy with miglustat for treatment of these conditions have demonstrated safety, but have not demonstrated notable clinical improvement. To date, combination therapy for the infantile and juvenile gangliosidoses has not been explored. This study will evaluate a multi-targeted combination therapy for treatment of the gangliosidoses, using FDA approved therapies that have demonstrated safety in children. It is the aim of this study to learn if combination therapy using the "Syner-G" regimen (that is, synergistic enteral regimen for treatment of the gangliosidoses) will show improvement in overall survival and clinical benefits in neurodevelopmental abilities in children with gangliosidosis diseases. This study is planned as a 5-year longitudinal treatment study. Subjects will be started on the treatment regimen when they are enrolled in the study. Data will be collected during yearly evaluations and at completion of study. Investigators may choose to stop therapy at any time, as clinically indicated for individual patients. The Ketogenic Diet is a special diet that contains higher amounts of fat and lower amounts of carbohydrate compared to an average diet. The purpose of this is to help reduce food-miglustat interactions. The ketogenic diet may also help in management of seizures in these patients. (The ketogenic diet has been used as an anti-seizure treatment in a variety of medical conditions for many decades.) A study in Sandhoff disease mice has shown that the ketogenic diet may also help miglustat be more effective in the central nervous system (see Denny in "Citations" list below). Miglustat will be used to reduce the amount of ganglioside accumulation in the child's cells. Miglustat is not FDA approved for treatment of the gangliosidoses. It is FDA approved for a different inherited metabolic disease called Gaucher disease type I. This study has been issued Investigational New Drug (IND) # 127636 by the U.S. Food and Drug Administration (FDA).