Clinical Trial

Disease: Mucopolysaccharidosis II, MPS II, (NCT03041324)

Disease info:

Mucopolysaccharidosis type II (MPS II), also known as Hunter syndrome, is a condition that affects many different parts of the body and occurs almost exclusively in males. It is a progressively debilitating disorder; however, the rate of progression varies among affected individuals.

Individuals with this disorder often have a large head (macrocephaly), a buildup of fluid in the brain (hydrocephalus), an enlarged liver and spleen (hepatosplenomegaly), and a soft out-pouching around the belly-button (umbilical hernia) or lower abdomen (inguinal hernia).

There are two types of MPS II, called the severe and mild types. While both types affect many different organs and tissues as described above, people with severe MPS II also experience a decline in intellectual function and a more rapid disease progression.The life expectancy of these individuals is 10 to 20 years. Individuals with mild MPS II also have a shortened lifespan, but they typically live into adulthood and their intelligence is not affected. Heart disease and airway obstruction are major causes of death in people with both types of MPS II.

MPS II occurs in approximately 1 in 100,000 to 1 in 170,000 males.
Official title:
A Phase I / 2, Multicenter, Open-label, Single-dose, Dose-ranging Study to Assess the Safety and Tolerability of SB-913, a rAAV2/6-based Gene Transfer in Subjects With Mucopolysaccharidosis II (MPS II)

United States, California

UCSF Benioff Children's Hospital Oakland, Oakland, California, United States, 94609


United States, Illinois

Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, United States, 60611


United States, New York

NYU School of Medicine, Neurogenetics Division, New York, New York, United States, 10016


United States, North Carolina

University of North Carolina, Chapel Hill, North Carolina, United States, 27514


United States, Ohio

Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States, 45229


Study start:
May. 11, 2017
9 participants
Gene editing method:
ZFN-Zinc Finger Nucleases
Type of edit:
Gene insertion
Iduronate 2-sulfatase (IDS)
Delivery method:
Adeno-associated virus (AAV2/6) - In-vivo
All nine subjects dosed in the study have rolled over to the Long-Term Follow-up Study IVPRP-LT01 (NCT04628871)
IND Enabling Pre-clinical
Phase I Safety
Phase II Safety and Dosing
Phase III Safety and Efficacy

Status: Terminated


The purpose of the study is to evaluate the safety, tolerability and effect on leukocyte and plasma Iduronate 2-Sulfatase (IDS) enzyme activity of ascending doses of SB-913. SB-913 is an intravenously delivered Zinc Finger Nuclease (ZFN) Therapeutic for genome editing. It inserts a correct copy of the IDS gene into the Albumin locus in hepatocytes with the goal of lifelong therapeutic production of the IDS enzyme.

The objectives of the study are to provide long term expression of IDS and improve the current clinical outcome of enzyme replacement therapy (ERT) in subjects with MPS II, a recessive lysosomal storage disorder that results from mutations in the gene encoding IDS. SB-913 is a therapeutic for ZFN-mediated genome editing which will be delivered by adeno-associated virus (AAV)-derived vectors. SB-913 is intended to function by placement of the corrective copy of IDS transgene into the genome of the subject's own hepatocytes, under the control of the highly expressed endogenous albumin locus, and is expected to provide permanent, liver-specific expression of Iduronate 2-Sulfatase for the lifetime of an MPS II patient.

Last updated: Dec. 28, 2023
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