title: Continuing or adding IL-2 in patients treated with antiretroviral therapy (ACTG Protocol A5051, a rollover trial of ACTG Protocol A328).
abstract: BACKGROUND
  Effective antiretroviral therapy reduces HIV-1 RNA levels, improves CD4 T-cell counts, and lowers the risk of opportunistic infections and malignancies. Interleukin-2 (IL-2) has been shown to increase CD4 T-cell numbers mainly by expanding CD4 cells and by prolonging their half-lives. HIV-infected patients previously enrolled into A328 had been randomized to antiretroviral therapy (ART) alone or ART followed by IL-2. In A5051, 53 patients from A328 who had previously received IL-2 were allowed to continue IL-2 for an additional 80 weeks; 27 patients who had received ART alone received IL-2 for 80 weeks.
  
  
  RESULTS
  The patients previously receiving IL-2 continued to have elevated CD4 levels with extended use of IL-2. The prior ART-alone recipients had increases in CD4 levels to comparable levels as the prior IL-2 recipients (median 804 versus 847 cells/mm3 at week 72; 60% versus 9% had >50% increase in A5051 to week 72, p < 0.001). Those who had previously received IL-2 required fewer IL-2 cycles to maintain their CD4 T-cell counts compared to those newly initiating IL-2. The treatments were well tolerated with no significant differences in toxicity or discontinuations between those newly versus previously receiving IL-2. There were few clinical events observed.
  
  
  CONCLUSIONS
  Although sustained CD4 T-cell count increases were seen with IL-2 administration as in other studies, the absence of clinical benefit in two recent randomized trials has demonstrated no apparent role for IL-2 as a therapy in HIV disease.
  
  
  BACKGROUND
  A5051 ClinicalTrials.gov Identifier: NCT00000923.
authors.affiliation: Harvard School of Public Health, Boston MA, USA. rbosch@hsph.harvard.edu.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Bosch
authors.forename: Richard B
authors.initials: RB
authors.lastname: Pollard
authors.forename: Alan
authors.initials: A
authors.lastname: Landay
authors.forename: Evgenia
authors.initials: E
authors.lastname: Aga
authors.forename: Lawrence
authors.initials: L
authors.lastname: Fox
authors.forename: Ronald
authors.initials: R
authors.lastname: Mitsuyasu