Week-12 response to therapy as a predictor of week 24, 48, and 96 outcome in patients receiving the HIV fusion inhibitor enfuvirtide in the T-20 versus Optimized Regimen Only (TORO) trials

Academic Article


  • Background. Early virological response to antiretroviral therapy is predictive of long-term treatment outcome in therapy-naive patients. In treatment-experienced patients, such correlations are less well defined, because initial responses may be less pronounced and transient because of accumulated cross-resistance to prior therapies. Our objectives were to explore how the virological and immunological status of treatment-experienced patients at an early time point (week 12) during enfuvirtide-based therapy predicted their responses at weeks 24, 48, and 96 in the T-20 versus Optimized Regimen Only (TORO) trials. Methods. Post hoc, modified, on-treatment and intent-to-treat analyses were performed to determine whether the relationship between virological and immunological outcomes at weeks 24, 48, and 96 were predicted by the patients' week-12 responses to therapy. Results. Using a modified on-treatment analysis for patients who, by week 12, achieved a decrease in their HIV-1 RNA load of ≥1 log10 copies/mL, 39.2% (95% CI, 33.6%-44.8%) and 59.5% (95% CI, 53.8%-65.1%) achieved a viral load of <50 copies/mL or <400 copies/mL at week 96, respectively, compared with 1.3% (95% CI, 0%-3.8%) and 2.6% (95% CI, 0%-6.1%) of patients, respectively, who did not achieve an early virological response. Using the same modified on-treatment analysis method for patients who, at week 12, achieved a CD4 cell count increase of ≥50 cells/mm3, 87.2% (95% CI, 82.6-91.8) maintained or improved this response through week 96, compared with 56.6% (95% CI, 47.5-65.8) of patients who did not achieve this early categorical immunological response. Conclusion. Enfuvirtide-based treatment regimens are associated with a rapid and durable response. Week-12 virological and immunological responses to treatment with enfuvirtide are predictive of subsequent outcomes in triple-class treatment-experienced patients. © 2006 by the Infectious Diseases Society of America. All rights reserved.
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    Digital Object Identifier (doi)

    Author List

  • Raffi F; Katlama C; Saag M; Wilkinson M; Chung J; Smiley L; Salgo M
  • Start Page

  • 870
  • End Page

  • 877
  • Volume

  • 42
  • Issue

  • 6