IL-2 Alone in Early Disease

This study explores a novel concept. It explores raising CD4s with Il-2 before initiating first-line HAART therapy. The investigators reported the IL-2 treatment did not raise viral load but CD4 increased from 440 to 660 (p=0.02). I assume the author's theory is that CD4s can be elevated with IL-2 while delaying initiation of HAART.

Randomized study of intermittent subcutaneous IL-2 therapy without antiretrovirals versus no treatment at all; from Mike Youle, Royal Free Hospital, London

This study was designed to evaluate the virologic and immunologic effects of IL-2 alone in antiretroviral naÔve subjects and CDs >350. This study is an open-label, randomized, parallel group study, comparing no treatment with IL-2--4.5 MIU or 7.5 MIU every 12 hours subcutaneously for 5 days every 8 weeks for 24 weeks. Subjects who received IL-2 could then continue cycles if they request. The primary endpoints for the study were mean area under the curve (AUC) change from baseline CD4 count and plasma HIV RNA.

36 subjects (1 female) were enrolled. The 3 arms were well matched at baseline, with median CD4 440 (nadir 399) and HIV-RNA of 4.3 log (20,000 copies/ml). Median follow-up was 9.8 months (range 0-16) and 31/36 subjects remained on study at week 24. Two patients randomized to receive IL-2 did not start, while 6 IL-2 and 1 control patients withdrew from study. Mean AUC change from baseline CD4 cell counts were significantly higher (p=0.001) in recipients of IL-2 (148 cells) compared to controls (25 cells) at week 24, and by week 48, the mean CD4 was 656 (+232) cells and 443 (+13) (p=0.02) respectively. Mean plasma HIV-RNA levels during follow-up and mean AUC change from baseline plasma HIV-RNA were not significantly different between treatment arms. Six endpoints occurred in the control group versus 2 in the IL-2 group.

Youle concluded that this study suggests that cyclical IL-2 therapy produces sustained and significant CD4 rises without sustained increases in HIV replication when given without antiretrovirals in individuals with CD4 counts >350.