Treatment of Sanfilippo syndrome type B by intrathecal administration of alpha-n-acetylglucosaminidase
Among other things, the present invention provides methods and compositions of treating Sanfilippo syndrome type B (Sanfilippo B) by, e.g., intrathecal (IT) administration of a Naglu protein. A suitable Naglu protein can be a recombinant, gene-activated or natural protein. In some embodiments, a suitable Naglu protein is a recombinant Naglu protein. In some embodiments, a recombinant Naglu protein is a fusion protein containing a Naglu domain and a lysosomal targeting moiety. In some embodiments, the lysosomal targeting domain is an IGF-II moiety.
1. A method of treating Sanfilippo syndrome type B (San B) disease comprising the steps of:
intrathecally administering to a subject in need of treating San B disease a pharmaceutical composition comprising a recombinant fusion protein,
wherein the recombinant fusion protein comprises a lysosomal targeting moiety, an alpha-N-acetylglucosaminidase (Naglu) domain, and a linker between the lysosomal targeting moiety and the Naglu domain,
wherein the lysosomal targeting moiety is a peptide that binds cation-independent mannose-6-phosphate receptor (CI-MPR) or bis-phosphorylated oligosaccharides,
wherein the Naglu domain has alpha-N-acetylglucosaminidase activity and comprises an amino acid sequence having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 1, and
wherein the linker comprises the amino acid sequence of GAPGGGGGAAAAAGGGGGGAPGGGGGGAAAAAGGGGGGAPGGGGGAAAAAGGGGG GAP, which is residues 721-777 of SEQ ID NO:6.
2. The method of claim 1 , wherein the lysosomal targeting moiety is fused via the linker to the C-terminus of the Naglu domain.
3. The method of claim 1 , wherein the lysosomal targeting moiety is fused via the linker to the N-terminus of the Naglu domain.
4. The method of claim 1 , wherein the recombinant fusion protein is produced and isolated from human cells.
5. The method of claim 1 , wherein the intrathecal administration results in delivery of the recombinant fusion protein in one or more target brain tissues.
6. The method of claim 5 , wherein the one or more target brain tissues are selected from the group consisting of tissues from gray matter, white matter, periventricular areas, pia-arachnoid, meninges, neocortex, cerebellum, deep tissues in cerebral cortex, molecular layer, caudate/putamen region, midbrain, deep regions of the pons or medulla, and combinations thereof.
7. The method of claim 5 , wherein the recombinant fusion protein is delivered to neurons, glial cells, perivascular cells and/or meningeal cells.
8. The method of claim 1 , wherein the recombinant fusion protein is delivered to neurons in the spinal cord.
9. The method of claim 1 , wherein the intrathecal administration results in systemic delivery of the recombinant fusion protein in peripheral target tissues.
10. The method of claim 1 , wherein the intrathecal administration results in lysosomal localization in brain target tissues, spinal cord neurons and/or peripheral target tissues.
11. The method of claim 10 , wherein the intrathecal administration results in reduction of lysosomal storage in the brain target tissues, spinal cord neurons and/or peripheral target tissues.
12. The method of claim 10 , wherein the intrathecal administration results in increased Naglu enzymatic activity in the brain target tissues, spinal cord neurons and/or peripheral target tissues.
13. The method of claim 1 , wherein the intrathecal administration is used in conjunction with intravenous administration.
14. The method of claim 1 , wherein the intrathecal administration is used in the absence of intravenous administration.
15. The method of claim 1 , wherein the intrathecal administration is used in the absence of concurrent immunosuppressive therapy.
16. The method of claim 1 , wherein said pharmaceutical composition comprises a surfactant.
17. The method of claim 16 , wherein said surfactant is present in the pharmaceutical composition at a concentration from 0.001-0.5%.
18. The method of claim 16 , wherein said surfactant is present in the pharmaceutical composition at a concentration of 0.2%.
19. The method of claim 16 , wherein said surfactant is a poloxamer.
20. The method of claim 19 , wherein the poloxamer is poloxamer 188.