Extension of Study HGT-SAN-055 Evaluating Administration of rhHNS in Patients With Sanfilippo Syndrome Type A (MPS IIIA)

Summary

Sanfilippo syndrome, or Mucopolysaccharidosis (MPS) III, is a rare lysosomal storage disease (LSD) caused by loss in activity of 1 of 9 enzymes necessary for degradation of the glycosaminoglycan (GAG) heparan sulfate (HS) in lysosomes. MPS IIIA results from deficiency of the enzyme heparan N-sulfatase (sulfamidase). In the absence of this enzyme, intermediates of the HS degradation process accumulate in the lysosomes of neurons and glial cells, with lesser accumulation outside the brain. MPS IIIA symptoms arise on average at 7 months of age, with the average age of diagnosis at 4.5 years for the majority of patients. Patients present a wide spectrum and severity of clinical symptoms. The central nervous system (CNS) is the most severely affected organ system in patients with MPS IIIA, evidenced by deficits in language development, motor skills, and intellectual development. In addition, there are abnormal behaviors including but not limited to aggression and excess motor activity/hyperactivity that contribute to disturbances in sleep.Overall, individuals with MPS IIIA have a marked developmental delay and significantly reduced lifespan to 15 years of age on average. The purpose of this study is to collect long term safety and tolerability data in patients with MPS IIIA who previously received rhHNS in study HGT-SAN-055 (NCT01155778).

Timeline

Start

2011-03-01

Primary completion

2019-04-12

Completion

2019-04-12

Outcome

Outcome not reported

Stopped: “Completion of follow-up period”

Publications

• Wijburg FA, Heap F, Rust S, de Ruijter J, Tump E, Marchal JP, Nestrasil I, Shapiro E, Jones SA, Alexanderian D. Long-term safety and clinical outcomes of intrathecal heparan-N-sulfatase in patients with Sanfilippo syndrome type A. Mol Genet Metab. 2021 Dec;134(4):317-322. doi: 10.1016/j.ymgme.2021.09.003. Epub 2021 Sep 14.
• King B, Marshall N, Beard H, Hassiotis S, Trim PJ, Snel MF, Rozaklis T, Jolly RD, Hopwood JJ, Hemsley KM. Evaluation of enzyme dose and dose-frequency in ameliorating substrate accumulation in MPS IIIA Huntaway dog brain. J Inherit Metab Dis. 2015 Mar;38(2):341-50. doi: 10.1007/s10545-014-9790-8. Epub 2014 Nov 25.
• Langford-Smith A, Wilkinson FL, Langford-Smith KJ, Holley RJ, Sergijenko A, Howe SJ, Bennett WR, Jones SA, Wraith J, Merry CL, Wynn RF, Bigger BW. Hematopoietic stem cell and gene therapy corrects primary neuropathology and behavior in mucopolysaccharidosis IIIA mice. Mol Ther. 2012 Aug;20(8):1610-21. doi: 10.1038/mt.2012.82. Epub 2012 May 1.

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Indications