A phase II clinical study of the long-term safety and antiviral activity of enfuvirtide-based antiretroviral therapy

Jacob P. Lalezari*, Joseph J. Eron, Margrit Carlson, Calvin Cohen, Edwin DeJesus, Roberto C. Arduino, Joel E. Gallant, Paul Volberding, Robert L. Murphy, Fred Valentine, Emily L. Nelson, Prakash R. Sista, Alex Dusek, J. Michael Kilby

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

143 Scopus citations


Objectives: The primary objective was to determine the long-term safety of the subcutaneous self-administration of enfuvirtide. Secondary objectives included the determination of enfuvirtide pharmacokinetics and antiviral activity and the immunological response to the enfuvirtide-containing regimen. Methods: A multicenter 48-week uncontrolled open-label rollover study was conducted on 71 HIV-infected adults recruited from previous enfuvirtide clinical trials. Patients with extensive previous use of protease and reverse transcriptase inhibitors received a twice-daily dose of 50 mg enfuvirtide subcutaneously (45 mg deliverable) combined with two or more antiretroviral drugs selected for each individual, guided by resistance testing and previous treatment history. Results: The mean baseline plasma HIV-RNA level was 4.81 log10 copies/ml and the mean CD4 cell count was 134.8 cells/μl. The majority (86.9%) of treatment-emergent adverse events were grade 2 or less in severity. Injection site reactions were common, but no patients discontinued treatment. A mean HIV-RNA change of -1.33 log10 was achieved within 14 days of treatment initiation. At week 48, approximately one-third of all patients in the intent-to-treat population maintained significant suppression of plasma HIV RNA, with either less than 400 copies/ml or more than a 1.0 log10 decline from baseline. The mean gain in absolute CD4 cell counts at 48 weeks was 84.9 cells/μl. Trough plasma concentrations of enfuvirtide were consistently higher than target concentrations. Conclusion: Self-administration of enfuvirtide is not associated with unexpected toxicities for up to one year, and combined with oral antiretroviral drugs was associated with a significant decrease in HIV RNA and an increase in CD4 cell counts.

Original languageEnglish (US)
Pages (from-to)691-698
Number of pages8
Issue number5
StatePublished - Mar 28 2003


  • Antiretroviral therapy
  • Enfuvirtide
  • Fusion inhibitor
  • T-20

ASJC Scopus subject areas

  • Infectious Diseases
  • Immunology and Allergy
  • Immunology


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