NEW DRUGS NEW DRUGS Fusion Inhibitor for HIV

NEW DRUGS Fusion Inhibitor for HIV The Food and Drug Administration (FDA) has announced the accelerated approval of enfuvir tide (FuzeonTM, Roche) for use with other anti-HIV medications in adults and children ages six years and older with advanced human immunodeficiency virus (HIV) infection. Enfuvirtide is the first in a new class of medications called fusion inhibitors, which interfere with the fusion of viral and cellular membranes, thus hindering the entry of HIV-1 into cells. The FDA’s approval was based on six months of data from two ongoing clinical studies involving approximately 1,000 patients. Adding enfuvirtide to other antiHIV drugs reduced the level of infection more than the anti-HIV drugs did alone. Because HIV is treated with a combination of medications, enfuvirtide can be used in patients with limited treatment options. However, the drug is expected to cost about $20,500 a year, or nearly three times the price of the next most expensive drug used to treat acquired immunodeficiency syndrome (AIDS). The cost, the manufacturer explains, is attributable in part to the complexity of the drug. The manufacturing process is the most complicated ever instituted on a large scale. It takes 106 steps, not the five or six that are needed to make most other AIDS drugs, and 45,000 kilograms of expensive raw materials are needed to make 1,000 kilograms of enfuvirtide. The drug, administered as a subcutaneous injection, should be used only in patients who have taken other anti-HIV drugs and in whom viral replication has persisted. The long-term effects are being evaluated. Although bacterial pneumonia was uncommon in study participants, bacterial infection developed in more patients receiving enfuvirtide than in patients not treated with this drug. Enfuvirtide can also cause serious systemic allergic reactions. Patients should be advised to contact their health care providers right away if they have difficulty in breathing or if they experience fever, skin rash, chills, vomiting, or dizziness. Local skin reactions at the site of injection are common and can be painful. Patients should be cautioned about signs and symptoms of infection at the site. (Sources: FDA News, March 13, 2003; www.medscape.com/viewarticle/ 451067.)