What is Fuzeon?
Fuzeon is available as a powder for solution for injection in a vial. 1 ml of reconstituted solution contains 90 mg of the active substance enfuvirtide.
What is Fuzeon used for?
Fuzeon is an antiviral drug, indicated in combination with other antiviral medicines for the treatment of HIV-1 infected patients (human immunodeficiency virus type 1), a virus that causes AIDS (acquired immunodeficiency syndrome). Fuzeon is used in patients who have not responded positively to other previous antiviral therapies or who are intolerant to these therapies. These therapies must contain at least one medicinal product belonging to each of the following classes of drugs used for the treatment of HIV infection: protease inhibitors, non-nucleoside reverse transcriptase inhibitors and nucleoside reverse transcriptase inhibitors.
Doctors should prescribe Fuzeon only after carefully considering the previous antiviral treatments taken by the patient and the possibility that the virus responds to the drug.
The medicine can only be obtained with a prescription.
How is Fuzeon used?
Fuzeon should be prescribed by physicians experienced in the treatment of HIV infection. In adults the recommended dose is 90 mg twice a day injected under the skin in the upper arm, thigh or abdomen. The dose in children aged between six and 16 years depends on body weight. Fuzeon is not recommended for use in children under six years of age.
The patient can self-administer Fuzeon or ask another person to do so, provided that the person performing the injection follows the instructions in the package leaflet. The injection should always be given at a different site than the previous injection.
How does Fuzeon work?
The active substance in Fuzeon, enfuvirtide, is a fusion inhibitor. Fuzeon binds to a protein found on the surface of the HIV virus. In this way it prevents the virus from fixing itself on the surface of human cells and infecting them. Because HIV can only reproduce itself inside cells, Fuzeon, taken in combination with another antiviral drug, reduces the amount of HIV in the blood, keeping it at a low level. Fuzeon does not cure HIV infection or AIDS, but it may delay the damage to the immune system and the development of infections and diseases associated with AIDS.
What studies have been carried out on Fuzeon?
The two main studies of Fuzeon involved 1 013 patients at least 16 years of age who had contracted HIV infection and who had taken or did not respond to other antiviral medicines. On average, patients had received 12 antiviral drugs over seven years. The two studies compared the effects of Fuzeon in association with so-called "optimized base therapy" (a combination of other antiviral drugs selected for each patient because they offered the best chance of reducing HIV levels in the blood) compared to basic therapy optimized without Fuzeon. The main measure of effectiveness was the change in HIV levels in the blood (viral load) 48 weeks after treatment. Fuzeon has also been studied in 39 children aged between three and 16 years. The studies were still ongoing at the time of the evaluation of the medicine.
What benefit has Fuzeon shown during the studies?
Treatment with Fuzeon in combination with optimized background therapy was more effective in reducing viral loads compared to optimized baseline therapy alone. In the first study, viral loads precipitated an average of 98% in patients treated with Fuzeon and 83% in subjects not treated with the drug. The values in the second study were 96% and 78%, respectively. The approved dose of Fuzeon in children produces similar concentrations of the active substance in the blood compared to the approved dose in adults.
What is the risk associated with Fuzeon?
The most frequently reported adverse reactions with Fuzeon (seen in more than 1 in 10 patients) are reactions at the injection site (pain and inflammation), peripheral neuropathy (injury to the nerves of the extremities, accompanied by tingling or numbness of the hands and feet ) and weight loss. In clinical studies, injection site reactions were reported by 98% of patients, mostly in the first week of treatment. These reactions were associated with mild to moderate pain or malaise, the severity of which did not increase during treatment. For the full list of all side effects reported with Fuzeon, see the Package Leaflet.
Fuzeon should not be used in people who may be hypersensitive (allergic) to enfuvirtide or any of the other substances.
As with all other anti-HIV drugs, patients receiving Fuzeon may be at risk of osteonecrosis (death of bone tissue) or immune reactivation syndrome (inflammatory signs and symptoms caused by reactivation of the immune system). Patients with liver problems may be at an increased risk of developing liver damage if they are treated for HIV infection.
Why was Fuzeon approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Fuzeon's benefits are greater than its risks in combination with other antiretroviral medicines for the treatment of HIV-1 infected patients who have been treated and have not responded positively to regimes containing at least one medicinal product belonging to each of the following classes of antiretrovirals: protease inhibitors, non-nucleoside reverse transcriptase inhibitors and nucleoside reverse transcriptase inhibitors, or which are intolerant to previous antiretroviral therapies. The Committee therefore recommended that Fuzeon be given marketing authorization.
Fuzeon was originally authorized in "exceptional circumstances" since, for scientific reasons, it was not possible to obtain complete information on the medicine. As the company provided the additional information requested, the condition referring to "exceptional circumstances" was removed on 8 July 2008. Fuzeon was authorized in "exceptional circumstances". This means that, for scientific reasons, it was not possible to obtain complete information on the medicine. The European Medicines Agency (EMEA) reviews the new information available every year and, if necessary, updates this summary.
More information on Fuzeon:
On May 27, 2003, the European Commission granted a marketing authorization for Fuzeon, valid throughout the European Union, to Roche Registration Limited. The marketing authorization was renewed on 27 May 2008.
The full EPAR for Fuzeon can be found here.
Last update of this summary: 07-2008.
