May 18, 2004
Unveiled in 2002, Fuzeon, a fusion inhibitor with the pharmaceutical name enfuvirtide, is a synthetic peptide that attempts to block HIV from initially entering the cell. During its trials, patients whose immune systems were no longer responding to protease inhibitors saw their CD4 cell counts surge and their viral loads fall. The study results indicated that patients on Fuzeon were twice as likely to achieve undetectable levels of HIV and have double the CD4 counts compared to patients on other drug regimens. Fuzeon is made by the Swiss drug company Roche and U.S.-based Trimeris Inc.
In their recommendations, the nine-member panel placed significant emphasis on training health-care workers and patients on correctly using the drug, which must be injected under the skin. The panel said patients should be fully trained in how to measure the right dose and how to properly self-inject, beginning with demonstrations and assessments for the first two weeks and follow-up every three to four months.
The guidelines also included indicators about when to put a patient on Fuzeon. Physicians are advised to prescribe Fuzeon when the CD4 count is still relatively high, at 100 cells per cubic millimeter of blood, rather than wait for the CD4 count to hit bottom. The drug also works best when a patient is still responsive to "at least" two other antiretrovirals, the guidelines noted. "For early-stage patients, the objective of therapy is for the patient to achieve an undetectable level of HIV. For later-stage patients, however, the focus should shift towards achieving a boosted immune system (CD4 count) rather than focusing exclusively on a drop in HIV levels," said the panel's press release.
The guidelines, "Clinical Management of Treatment-Experienced, HIV-Infected Patients with the Fusion Inhibitor Enfuvirtide: Consensus Recommendations", were published in the journal AIDS (2004;18(8):1137-1146).