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Phase I/II Study of Retroviral-Mediated Transfer of Iduronate-2-Sulfatase Gene Into Lymphocytes of Patients With Mucopolysaccharidosis II (Mild Hunter Syndrome)

This study has been completed.
University of Minnesota - Clinical and Translational Science Institute
Information provided by:
Office of Rare Diseases (ORD) Identifier:
First received: October 18, 1999
Last updated: June 23, 2005
Last verified: October 2003

OBJECTIVES: I. Evaluate the safety and feasibility of treating mucopolysaccharidosis II (mild Hunter syndrome) by lymphocyte gene therapy.

II. Determine the levels of iduronate-2-sulfatase enzyme in these patients attained by infusing increasing doses of lymphocytes transduced with a retroviral vector designed for insertion and expression of this iduronate-2-sulfatase gene (L2SN).

III. Determine the duration of survival of these transduced cells in these patients.

IV. Determine whether monthly infusion of L2SN-transduced lymphocytes accomplishes metabolic correction (as measured by glycosaminoglycan excretion), decrease in liver or spleen volume, any therapeutic effect upon cardiac and pulmonary dysfunction, or any other effects from treatment.

Condition Intervention Phase
Mucopolysaccharidosis II Genetic: lymphocyte gene therapy Phase 1 Phase 2

Study Type: Interventional
Study Design: Primary Purpose: Treatment

Resource links provided by NLM:

Further study details as provided by Office of Rare Diseases (ORD):

Estimated Enrollment: 2
Study Start Date: October 1996
Detailed Description:

PROTOCOL OUTLINE: Peripheral blood lymphocytes are harvested from patient by apheresis, stimulated to initiate the growth of T-lymphocytes, transduced with retrovirus L2SN containing iduronate-2-sulfatase, and reinfused into the patient.

Patients receive 12 monthly infusions of these retroviral-mediated gene transduced lymphocytes with the first three infusions in a dose escalation format.

Patients are monitored for at least 2 hours after completion of each infusion. Patients are followed at 1 year after treatment, and then until death.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


--Disease Characteristics--

Mucopolysaccharidosis II (mild Hunter syndrome) as defined by the following:

  • Characteristic coarse facial features, hepatosplenomegaly, and radiographic evidence of dysostosis multiplex
  • Elevated urinary excretion of glycosaminoglycans in 3 urine specimens
  • Deficient iduronate-2-sulfatase enzyme activity as measured in plasma and leukocytes
  • Mutation consistent with mild Hunter syndrome must have either: A single base substitution of the coding sequence not previously associated with severe Hunter syndrome phenotype OR An exon-skipping mutation that would allow for occasional production of (minimal amounts of) normal protein

--Patient Characteristics--

Cardiovascular: No severe cardiac disease

Pulmonary: No severe respiratory disease


  • Must have IQ score of 80 or higher
  • Effective contraception required of all fertile patients
  Contacts and Locations
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Please refer to this study by its identifier: NCT00004454

United States, Minnesota
University of Minnesota Medical School
Minneapolis, Minnesota, United States, 55455
Sponsors and Collaborators
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
University of Minnesota - Clinical and Translational Science Institute
Study Chair: Chester B. Whitley University of Minnesota - Clinical and Translational Science Institute
  More Information Identifier: NCT00004454     History of Changes
Other Study ID Numbers: 199/13577
Study First Received: October 18, 1999
Last Updated: June 23, 2005

Keywords provided by Office of Rare Diseases (ORD):
inborn errors of metabolism
mucopolysaccharidosis II
rare disease

Additional relevant MeSH terms:
Mucopolysaccharidosis II
Carbohydrate Metabolism, Inborn Errors
Metabolism, Inborn Errors
Genetic Diseases, Inborn
Lysosomal Storage Diseases
Connective Tissue Diseases
Metabolic Diseases
Mental Retardation, X-Linked
Intellectual Disability
Neurobehavioral Manifestations
Neurologic Manifestations
Nervous System Diseases
Genetic Diseases, X-Linked
Heredodegenerative Disorders, Nervous System processed this record on September 25, 2017