Pharmaceutical compositions and uses directed to lysosomal storage disorders

A method of treating a lysosomal storage disorder (LSD) or one or more symptoms associated with the LSD in a subject in need thereof comprising:

• administering a therapeutically effective amount of acetyl-leucine or a pharmaceutically acceptable salt thereof to the subject for a duration chosen from at least about 3 months, at least about 6 months, at least about 1 year, at least about 2 years, and at least about 5 years,
• wherein the LSD is chosen from Niemann-Pick type C disease, Tay-Sachs disease, the AB variant of Tay-Sachs disease, Sandhoff disease, Niemann-Pick type A disease, Niemann-Pick type B disease, Fabry disease, neuronal ceroid lipofuscinoses, Krabbe disease, Farber disease, Gaucher disease, metachromatic leukodystrophy, multiple sulphatase deficiency, mucolipidosis II, mucolipidosis III, MPS III, MPS VII, GM1 gangliosidosis, and aspartylglucosaminuria, and
• wherein the subject achieves an improved Scale for the Assessment and Rating of Ataxia (SARA) assessment compared to before administration.

A method of delaying progression of a lysosomal storage disorder (LSD) or more symptoms associated with the LSD over time as compared to typical disease progression in a subject in need thereof comprising:

• administering a therapeutically effective amount of acetyl-leucine or a pharmaceutically acceptable salt thereof to the subject for a duration chosen from at least about 3 months, at least about 6 months, at least about 1 year, at least about 2 years, and at least about 5 years, and
• wherein the subject achieves an improved Scale for the Assessment and Rating of Ataxia (SARA) assessment compared to before administration.

A method of reversing progression of a lysosomal storage disorder (LSD) or one or more symptoms associated with the LSD over time in a subject in need thereof comprising:

• administering a therapeutically effective amount of acetyl-leucine or a pharmaceutically acceptable salt thereof to the subject for a duration chosen from at least about 3 months, at least about 6 months, at least about 1 year, at least about 2 years, and at least about 5 years, and
• wherein the subject achieves an improved Scale for the Assessment and Rating of Ataxia (SARA) assessment compared to before administration.

The method according to claim 35, wherein the single enantiomeric form is the L-enantiomer.