BioMarin presents interim Phase 1/2 BMN 250 study data at ICIEM 2017
BioMarin Pharmaceutical announced that it presented interim data from the dose escalation arm of a Phase 1/2 trial for BMN 250, an investigational enzyme replacement therapy using a novel fusion of recombinant human alpha-N-acetylglucosaminidase with a peptide derived from insulin-like growth factor 2, for the treatment of Sanfilippo B syndrome or mucopolysaccharidosis IIIB at the 13th International Congress of Inborn Errors of Metabolism 2017. Discovered by BioMarin, BMN 250 is being studied in a multicenter, international clinical trial evaluating safety and tolerability, as well as cognitive function of patients with Sanfilippo B receiving BMN 250. Designed to restore functional NAGLU activity in the brain, BMN 250 is administered via intracerebroventricular nfusion. In the completed dose escalation portion of the study (Part 1), which was primarily designed to determine safety and pharmacodynamic activity of BMN 250, three patients received escalating doses of BMN 250 over 9 to12 months. Cerebrospinal fluid heparan sulfate levels, which were markedly elevated at baseline, were reduced to the non-affected or normal range in all three patients, whether assessed as total or disease-specific HS. Sanfilippo B patients are missing one of four enzymes for HS degradation. In those same patients, abdominal MRI scans showed significantly enlarged liver size at baseline followed by rapid decreases in liver size into the normal range for age with BMN 250 treatment, suggesting that ICV-administered BMN 250 reaches the peripheral circulation and may have activity in somatic organs. In contrast, most Sanfilippo B patients enrolled in BioMarin's concurrently-running observational study had increased liver size at baseline and experienced further increases in liver size over time.