Profile
General Information
Fuzeon (enfuvirtide) is an is an HIV-1 gp41 fusion inhibitor.
Fuzeon in combination with other antiretroviral agents is indicated for the treatment of HIV-1 infection in treatment-experienced patients with evidence of HIV-1 replication despite ongoing antiretroviral therapy.
Dosing/Administration
Fuzeon is available in a single-dose lyophilized powder for injection containing 108 mg enfuvirtide per vial.
Fuzeon is administered subcutaneously into the upper arm, anterior thigh or abdomen after reconstituting the lyophilized powder containing 108 mg enfuvirtide with 1 mL of sterile water.
The recommended dosage of Fuzeon is 90 mg (1 mL) twice daily injected subcutaneously into the upper arm, anterior thigh or abdomen
The recommended dosage of Fuzeon in pediatric patients weighing at least 11 kg is 2 mg per kg twice daily up to a maximum dose of 90 mg twice daily injected subcutaneously into the upper arm, anterior thigh or abdomen. Please see drug label for dosing recommendations based on body weight.
Mechanism of Action
Fuzeon blocks HIV’s ability to infect healthy CD4 cells. When used with other anti- HIV medicines, Fuzeon can reduce the amount of HIV in the blood and increase the number of CD4 cells. This may keep the immune system healthy, so it can help fight infection.
The active ingredient, enfuvirtide, interferes with the entry of HIV-1 into cells by inhibiting fusion of viral and cellular membranes. Enfuvirtide binds to the first heptad-repeat (HR1) in the gp41 subunit of the viral envelope glycoprotein and prevents the conformational changes required for the fusion of viral and cellular membranes.
Side Effects
Adverse events associated with the use of Fuzeon may include (but are not limited to) the following:
- Local injection site reaction
- Pain and discomfort
- Induration
- Erythema
- Nodules and cysts
- Pruritus
- Ecchymosis
- Diarrhea
- Conjunctivitis
- Pancreatitis
Clinical Results
FDA approval of Fuzeon was based on data from two 24-week phase III pivotal studies of approximately 1,000 subjects, TORO 1 (T20-301), conducted in North America and Brazil, and TORO 2 (T20-302), conducted in Europe and Australia. These studies showed that treatment-experienced subjects receiving Fuzeon as a part combination regimen of anti-HIV drugs, experienced greater immunologic improvements and were twice as likely to achieve undetectable plasma levels of HIV compared to subjects receiving a anti-HIV regimen alone. In addition, those subjects with two or more active drugs in their background regimen were more likely to achieve undetectable levels of HIV.
Studies T20-301 and T20-302 are ongoing, randomized, controlled, open label, multicenter trials in HIV-1 infected subjects. Subjects were required to have either (1) viremia despite 3 to 6 months prior therapy with a nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI), and protease inhibitor (PI) or (2) viremia and documented resistance or intolerance to at least one member in each of the NRTI, NNRTI, and PI classes.