Fuzeon (FUSE ee on) is an experimental fusion inhibitor being developed by Trimeris and Hoffman-La Roche. It has not yet been evaluated by the U.S. Food and Drug Administration (FDA) for use by people living with HIV. It is expected that Fuzeon will be approved and available to HIV-positive people early next year (Winter 2003). Fuzeon is currently in Phase III clinical trials.

What is Fuzeon?

Fuzeon is an anti-HIV medication. It is in a category of medication known as fusion inhibitors or entry inhibitors. Entry inhibitors are a new class of anti-HIV drugs.

Fuzeon binds to a protein on HIV’s surface called gp41. Once it does this, HIV cannot successfully bind with the surface of T-cells, thus preventing the virus from infecting healthy cells. Fuzeon will not work alone so it will most likely need to be used in combination with other anti-HIV drugs.

Administration

Since Fuzeon is a peptide, it cannot be taken by mouth. It is currently being developed in an injectable form and will require two shots daily: one in the morning and one 12 hours later.

	Dosage Each shot contains 90 milligrams (mg) of Fuzeon. Anticipated daily dosing is 50 mg to 100 mg twice a day, self-administered subcutaneous injection. Adverse Effects Skin irritation (itchiness and swelling) at the site where Fuzeon is injected has been the most common side effect reported in studies thus far. Other side effects include fatigue, insomnia, diarrhea, fever, nausea, asthenia, and peripheral neuropathy. Contraindications It is not known whether Fuzeon passes into breast milk and what effect it may have on a nursing baby. It is recommended that HIV-positive mothers not breast-feed. Pharmacokinetics Fuzeon might interact with other medications, including those used to treat HIV. It is expected that Fuzeon, when combined with other anti-HIV drugs, will have strong activity against HIV in people who have never taken anti-HIV medications in the past. Fuzeon alone reduced viral load from anywhere between 30% to more than 90% in patients who had not taken any other anti-HIV drugs.  Hoffmann-La Roche and Trimeris have an expanded access program for Fuzeon for HIV-positive people with limited treatment options, a viral load above 10,000 and a T-cell count below 100. View information for physicians on the U.S. Early Access Program for Fuzeon.