Imiglucerase

Current data using a screening ELISA followed by a confirmatory radioimmunoprecipitation assay, suggest that, during the first year of therapy, IgG antibodies to imiglucerase are formed in approximately 15% of the treated patients. It appears that patients who will develop IgG antibody are most likely to do so within 6 months of treatment and will rarely develop antibodies to imiglucerase after 12 months of therapy. It is suggested that patients suspected of a decreased response to the treatment be monitored periodically for IgG antibody formation to imiglucerase.

Patients with antibody to imiglucerase have a higher risk of hypersensitivity reactions. If a patient experiences a reaction suggestive of hypersensitivity, subsequent testing for imiglucerase antibodies is advised. As with any intravenous protein product, severe allergic-type hypersensitivity reactions are possible, but occur uncommonly. If these reactions occur, immediate discontinuation of the imiglucerase infusion is recommended and appropriate medical treatment should be initiated. The current medical standards for emergency treatment are to be observed.

Patients who have developed antibodies or symptoms of hypersensitivity to alglucerase should be treated with caution when administering imiglucerase.

Limited experience from 150 pregnancy outcomes (primarily based on spontaneous reporting and literature review) is available suggesting that use of imiglucerase is beneficial to control the underlying Gaucher disease in pregnancy. Furthermore, these data indicate no malformative toxicity for the foetus by imiglucerase, although the statistical evidence is low. Foetal demise has been reported rarely, although it is not clear whether this related to the use of imiglucerase or to the underlying Gaucher disease.

No animal studies have been carried out with respect to assessing the effects of imiglucerase on pregnancy, embryonal/foetal development, parturition and postnatal development. It is not known whether imiglucerase passes via the placenta to the developing foetus.

In pregnant Gaucher patients and those intending to become pregnant, a risk-benefit treatment assessment is required for each pregnancy. Patients who have Gaucher disease and become pregnant may experience a period of increased disease activity during pregnancy and the puerperium. This includes an increased risk of skeletal manifestations, exacerbation of cytopenia, haemorrhage, and an increased need for transfusion. Both pregnancy and lactation are known to stress maternal calcium homeostasis and to accelerate bone turnover. This may contribute to skeletal disease burden in Gaucher disease.

Treatment naïve women should be advised to consider commencing therapy prior to conception in order to attain optimal health. In women receiving imiglucerase treatment continuation throughout pregnancy should be considered. Close monitoring of the pregnancy and clinical manifestations of Gaucher disease is necessary for the individualization of dose according to the patient’s needs and therapeutic response.

It is not known whether this active substance is excreted in human milk, however, the enzyme is likely to be digested in the child’s gastrointestinal tract.

Imiglucerase has no or negligible influence on the ability to drive and use machines.

List of adverse reactions

Adverse reactions are listed by system organ class and frequency (common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100) and rare (≥1/10,000 to <1/1,000)) below. Within each frequency grouping, adverse reactions are presented in order of decreasing seriousness.

Nervous system disorders

Uncommon: Dizziness, headache, paraesthesia*

Cardiac disorders

Uncommon: Tachycardia*, cyanosis*

Vascular disorders

Uncommon: Flushing*, hypotension*

Respiratory, thoracic and mediastinal disorders

Common: Dyspnoea*, coughing*

Gastrointestinal disorders

Uncommon: Vomiting, nausea, abdominal cramping, diarrhoea

Immune system disorders

Common: Hypersensitivity reactions

Rare: Anaphylactoid reactions

Skin and subcutaneous tissue disorders

Common: Urticaria/angioedema*, pruritus*, rash*

Musculoskeletal and connective tissue disorders

Uncommon: Arthralgia, backache*

General disorders and administration site conditions

Uncommon: Infusion site discomfort, infusion site burning, infusion site swelling, injection site sterile abscess, chest discomfort*, fever, rigors, fatigue

Symptoms suggestive of hypersensitivity (* marked in the list above) have been noted, overall in approximately 3% of the patients. Onset of such symptoms has occurred during or shortly after infusions. These symptoms generally respond to treatment with antihistamines and/or corticosteroids. Patients should be advised to discontinue infusion of the product and contact their physician if these symptoms occur.