Enfuvirtide (Fuzeon, T-20) has been lifesaving for many treatment-experienced individuals, yet substantial numbers of patients have bothersome injection site reactions (ISRs). In many instances, these adverse events demoralize patients and contribute to diminished ART adherence. Until recently, there was no alternative to enfuvirtide for most patients, but the availability of new antiretroviral (ARV) medications is rapidly changing that situation. Raltegravir is particularly attractive as a substitute for enfuvirtide in virologically suppressed individuals. It has no cross-resistance with agents from other ARV classes, is potent, and is very tolerable. The results of a small nonrandomized study presented at the 15th Conference on Retroviruses and Opportunistic Infections offer reassurance that a raltegravir substitution strategy is likely to be successful for appropriate patients.
Raltegravir (400 mg twice daily) was substituted for enfuvirtide in 35 patients with stable virologic suppression (HIV RNA of <50 copies/mL on enfuvirtide for a median of 24 months) who had significant ISRs on enfuvirtide-containing regimens. The patients continued their other ARV medications. After a median of 7 months (range 1-13 months), 34 patients continued to have HIV RNA <50 copies/mL, and 1 had a viral load of 60 copies/mL after 2 previous measurements of <50 copies/mL. All patients had resolution of ISRs, and none had adverse events attributable to raltegravir.
Although additional data may be required to determine the efficacy of this treatment strategy, it appears that substitution of raltegravir for enfuvirtide in patients with virologic suppression is effective and safe in the short term; and the study results reinforce a strategy that many clinicians have been pursuing empirically.
- Harris M, Larsen G, Montaner J. Outcomes of patients switched from enfuvirtide to raltegravir within a virologically suppressive regimen. In: Program and abstracts of the 15th Conference on Retroviruses and Opportunistic Infections; February 3-6, 2008; Boston. Abstract 799.