Swedish Orphan Biovitrum AB (publ) (Sobi™) announced that the FDA has issued a Study may proceed letter for the first study in humans, thereby accepting the investigational new drug (IND) application for the drug candidate SOBI003. In addition, SOBI003 was granted Fast Track status by the FDA. SOBI003 is a chemically modified human recombinant sulfamidase for the treatment of mucopolysaccharidosis type IIIA (MPS IIIA), a rare metabolic disorder also known as Sanfilippo syndrome type A. The clinical study with SOBI003 is expected to start during 2018. MPS IIIA or Sanfilippo A syndrome is a progressive, life-threatening and rare inherited metabolic disorder affecting children already from a young age. MPS IIIA belongs to a group of diseases called Lysosomal Storage Disorders (LSDs). In MPS IIIA, the body is unable to break down long chains of sugar molecules called heparan sulfate, resulting in the accumulation of heparan sulfate in lysosomes. MPS IIIA mainly affects the central nervous system where it causes severe progressive degeneration. SOBI003 is a chemically modified variant of a recombinant human sulfamidase product candidate, using Sobi's proprietary glycan modification technology, intended as an enzyme replacement therapy to reduce heparan sulfate storage materials in affected cells. SOBI003 is taken up by cells and transported into the lysosomal compartment where heparan sulfate is degraded. The modification of the molecule results in an extended half-life. SOBI003 was granted orphan designation by the European Commission for MPS IIIA in October 2016 and by the FDA in June 2017.