Innovative therapeutics


Tralesinidase alfa (BMN 250) for MPS IIIB (Sanfilippo Syndrome B)

Tralesinidase alfa for MPS IIIB is an enzyme replacement therapy being developed to treat Sanfilippo B Syndrome.

Mucopolysaccharidosis IIIB (MPS IIIB) or Sanfilippo Syndrome Type B is a lysosomal storage disease belonging to the group of mucopolysaccharidoses. MPS IIIB is caused by deficiency in the enzyme alpha-N-acetylglucosaminidase (NAGLU), one of the four enzymes required for heparan sulfate (HS) degradation in people.
MPS III is unique among the MPS disorders as it is predominantly a neurological disease. In patients with the MPS IIIB subtype, the first symptoms typically appear between the ages of two and six years old, with behavioral disorders, intellectual deterioration, disturbed sleep, and in some cases, very mild dysmorphism. The neurological involvement becomes more prominent with progressive loss of motor milestones and communication problems.  The prognosis is poor with death occurring in most cases of MPS IIIB in the late teens or early 20s.

Tralesinidase alfa for MPS IIIB (Sanfilippo Syndrome B) is an investigational enzyme replacement therapy using recombinant human alpha-N-acetyglucosaminidase (NAGLU) fused with a peptide derived from insulin-like growth factor 2 ( IGF2) or Glycosylation Independent Lysosomal Targeting (GILT) tag. Tralesinidase alfa for MPS IIIB (Sanfilippo Syndrome B) leverages BioMarin’s proprietary technology to deliver large proteins directly to the brain, which bypasses the blood brain barrier. This BioMarin technology, to be used for the treatment of Sanfilippo B patients, builds on the experience the company has gained using this approach to treat CLN2 disease, a form of Batten disease.

There are an estimated 1,000 – 2,000 patients in the developed world with MPS IIIB (Sanfilippo Syndrome Type B). 



Lysosomal Storage Disorders (MPS I, MPS IVA, MPS VI, CLN2 disease) PKU, LEMS



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