For doctors

What is it?

Elaprase is a concentrate that is made up into a solution for infusion (drip into a vein). It contains the active substance idursulfase.

What is it used for?

Elaprase is used to treat patients with Hunter syndrome. It is designed for long-term use. Hunter syndrome, which is also known as mucopolysaccharidosis II, is a rare, inherited disease that primarily affects male patients. Patients with Hunter syndrome do not produce an enzyme called iduronate-2-sulfatase. This enzyme is needed to break down substances in the body called glycosaminoglycans (GAGs). Since patients with Hunter syndrome cannot break these substances down, the GAGs gradually build up in most of the organs in the body and damage them. This causes a wide range of symptoms, particularly difficulty breathing and difficulty walking. Without treatment, these symptoms become more severe over time.
Because the number of patients with Hunter syndrome is low, the disease is considered ‘rare’, and Elaprase was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 11 December 2001.
The medicine can only be obtained with a prescription.

How is it used?

Elaprase treatment should be supervised by a doctor or other healthcare professional who has experience in the management of patients with Hunter syndrome or other inherited diseases affecting the metabolism.
Elaprase is given every week, as an infusion, at a dose of 0.5 mg per kilogram body weight. The infusion should last three hours. However, as long as the patient does not develop an infusion reaction (rash, itching, fever, headache, high blood pressure or flushing), the medicine can be infused more rapidly, by gradually reducing the duration of infusion to one hour.
Patients who tolerate the infusions well for several months in a clinic may be able to start having them at home. Home infusions must be done under the supervision of a doctor or nurse.

How does it work?

The active substance in Elaprase, idursulfase, is a copy of the human enzyme iduronate-2-sulfatase. It is produced by a method known as ‘recombinant DNA technology’: the enzyme is made by a human cell that has received a gene (DNA), which makes it able to produce the enzyme. Idursulfase replaces the enzyme that is missing or defective in patients with Hunter syndrome. By supplying the enzyme, the symptoms of the disease are improved or controlled.

How has it been studied?

The main study of Elaprase involved 96 male patients aged between five and 31 years, and compared it with placebo (a dummy treatment). The main measures of effectiveness were lung function (‘forced vital capacity’, the maximum amount of air the patient could breathe out), and the distance the patients could walk in six minutes, which measures the combined effects of the illness on the heart, lungs, joints and other organs. These measurements were taken before and after a year of treatment.

What benefits has it shown during the studies?

Elaprase improved lung function and the walking ability of the patients. At the start of the study, the patients could walk an average of around 395 metres in six minutes. After a year, the patients receiving Elaprase could walk a further 43 metres on average, and the patients receiving placebo could walk a further 8 metres. The medicine also produced an improvement in lung function, while the patients on placebo showed a slight worsening.

What is the risk associated?

The most common side effects with Elaprase (seen in more than 1 patient in 10) are related to the infusion, including skin reactions (rash or itching), pyrexia (fever), headache, hypertension (high blood pressure) and swelling at the site of the infusion. Other side effects seen in more than 1 patient in 10 are flushing (reddening of the skin), wheezing, dyspnoea (difficulty breathing), abdominal pain (stomach ache), nausea (feeling sick), dyspepsia (heartburn), diarrhoea and chest pain. Severe allergic reactions have been seen in some patients taking Elaprase. For the full list of all side effects reported with Elaprase, see the Package Leaflet.
Elaprase should not be used in people who may be allergic (hypersensitive) to idursulfase or any of the other ingredients.

Why has it been approved?

The Committee for Medicinal Products for Human Use (CHMP) concluded that the improvements shown in the study, even if limited, represent a clinical benefit in the treatment of Hunter syndrome. The Committee decided that Elaprase’s benefits are greater than its risks and recommended that it be given marketing authorisation.
Elaprase has been authorised under ‘Exceptional Circumstances’. This means that because Hunter syndrome is rare, it has not been possible to obtain complete information about Elaprase. Every year, the European Medicines Agency will review any new information that may become available and this summary will be updated as necessary.

How has it been studied?

The company that makes Elaprase will investigate the long-term effects of the medicine, and whether it stimulates the body to produce antibodies that could affect the medicine’s safety and effectiveness. The company will also study the medicine’s effectiveness in patients below five years of age, and investigate whether it has any effects on the lungs, the heart or the blood vessels.

Further information

The European Commission granted a marketing authorisation valid throughout the European Union for Elaprase to Shire Human Genetic Therapies AB on 8 January 2007. The marketing authorisation is valid for five years, after which it can be renewed.

The record of Elaprase’s designation as an orphan medicine is available here.

Name

Elaprase 2 mg/ml concentrate for solution for infusion

Composition

Each vial of 3 ml contains 6 mg of idursulfase. Each ml contains 2 mg of idursulfase.

Idursulfase is produced by recombinant DNA technology in a continuous human cell line.

For a full list of excipients, see section 6.1.

Pharmaceutical Form

Concentrate for solution for infusion.
A clear to slightly opalescent, colourless solution.