for people ages 5 years and up (full criteria)
at Oakland, California and other locations
study started
estimated completion



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.

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)


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.


Mucopolysaccharidosis II MPS II MPS ll Hunter syndrome Gene Editing Gene therapy Zinc Finger ZFN SB-913 Rare Genetic DNA Sangamo Genome editing Champions Hunter Gene Specific Targeted Insertion Mucopolysaccharidoses


You can join if…

Open to people ages 5 years and up

  • Male or female ≥ 5 years of age
  • Clinical diagnosis of MPS II (based on evidence of hepatosplenomegaly, dysostosis multiplex by X-ray, valvular heart disease, or obstructive airway disease) IDS deficiency confirmed by gene sequencing.

You CAN'T join if...

  • Known to be unresponsive to ERT
  • Neutralizing antibodies to AAV 2/6
  • Serious intercurrent illness or clinically significant organic disease (unless secondary to MPS II)
  • Receiving antiviral therapy for hepatitis B or C, or with active hepatitis B or hepatitis C or HIV 1/2
  • Lack of tolerance to idursulfase treatment with significant IARs or occurrence of anaphylaxis
  • Markers of hepatic dysfunction
  • Creatinine ≥ 1.5 mg/dL
  • Contraindication to the use of corticosteroids for immunosuppression
  • Current treatment with systemic (IV or oral) immunomodulatory agent or steroid use (topical treatment allowed)
  • Participation in prior investigational drug or medical device study within the previous 3 months
  • Prior treatment with a gene therapy product
  • Elevated or abnormal circulating α-fetoprotein (AFP)
  • Weight < 20 kg at Screening Visit


  • UCSF Benioff Children's Hospital Oakland
    Oakland California 94609 United States
  • Ann & Robert H. Lurie Children's Hospital of Chicago
    Chicago Illinois 60611 United States


in progress, not accepting new patients
Start Date
Completion Date
Sangamo Therapeutics
Phase 1/2
Study Type
Last Updated