Hunter syndrome, also called Mucopolysaccharidosis Type II (MPS II), is a rare, inherited genetic disorder that is x-linked, which means only males are typically affected. The disease is caused when an enzyme called iduronate-2-sulfatase (I2S) is missing or not working properly. As a result, patients with Hunter syndrome have problems with the body such as the heart, lungs, liver, spleen, bones, and joints. In addition to the physical problems, up to about two thirds (2/3) of patients with Hunter syndrome may also develop problems in the central nervous system (CNS, the brain and spinal cord). This is called the severe form of Hunter syndrome. Patients with the severe form of Hunter syndrome typically do not develop normal abilities with language, learning, and many of the normal tasks that are a part of growing up. Patients may also develop these abilities and then lose them as time goes on.

The study sponsor, Shire, has produced a purified human form of the I2S enzyme, called Elaprase®. Elaprase® is approved by the United States Food and Drug Administration (FDA), Health Canada, the European Medicines Agency (EMA) in Europe, and in over 40 countries world-wide for the treatment of patients with Hunter syndrome. MPS II patients receiving IV Elaprase®, such as your child, are not expected to have improvement in brain function, because Elaprase® has been shown not to cross the blood-brain barrier (enter the brain and spinal cord from blood) in sufficient quantities to be effective. One reason that IV Elaprase® does not cross the blood-brain barrier effectively is the large size of the enzyme.

Currently, there is no approved therapy for treating the brain in patients with the severe form of Hunter syndrome. The goal of this study is to give an investigational drug (study drug) called idursulfase-IT directly into the cerebrospinal fluid (CSF), the fluid surrounding the brain and spinal cord), also called an intrathecal (IT) administration. In this study, an intrathecal drug delivery device (IDDD) is being used to deliver study drug. The IDDD “device” has been surgically placed (implanted) under your child’s skin with a tube going into the spinal canal. This device will allow the study drug (idursulfase-IT) to be injected directly into the spinal fluid without having to stick a needle into the spinal canal (lumbar puncture, also called a spinal tap); each time idursulfase-IT is given. If injection through the device is not possible, the injection will be performed while under general anesthesia by a procedure called a lumbar puncture during which a small needle is inserted between the lower back vertebrae of the spine. The active ingredient in idursulfase-IT, recombinant human iduronate-2-sulfatase, is the same active ingredient in the commercially available drug Elaprase®. However, Elaprase® is specifically formulated for IV treatment and idursulfase-IT is specifically formulated for IT treatment. Idursulfase-IT is an investigational drug and has not been approved by any regulatory agency


Currently recruiting participants: Yes

Eligible gender: Male, Female, Transgender, Other

Inclusion criteria:

1. Patients must have completed Visit Week 52 assessments in Study HGT-HIT-094
2. The patient’s parent(s) or legally authorized guardian(s) must have voluntarily signed CHREB approved informed consent form after all relevant aspects of the study have been explained and discussed. Consent of the patient’s parent(s) or legally authorized guardian(s) and the patient’s assent, as relevant, must be obtained.
3. The patient has continued to receive Elaprase on a regular basis in Study


This study is not currently accepting expressions of interest via the website. Please see contact information below.

Additional information

Contact information

By referral only

Principal investigator:

Aneal Khan

Clinical trial: