Original-Kommentar auf englisch

Treatment interruptions (TI) in the lifelong use of the antiretroviral drugs to control HIV offer many potential benefits. Proponents argue that if an effective strategy for use can be developed TI will reduce the substantial cost of daily combination antiretroviral therapy, minimize drug toxicity, may improve patient compliance as well as possibly stimulate an enhanced immune response by exposure to the virus. Opponents argue that resistance may develop, some immunity be lost and a window opened for potentially serious and expensive HIV related adverse events to develop. The Staccato trial, conducted in Thailand, Switzerland and Australia, compared the safety efficacy and antiretroviral costs of 284 patients undergoing a CD4 directed TI to 146 on continuous therapy. In contrast to the much larger SMART study1 no major differences between the arms were seen. A higher CD4 threshold (350 cells /mm3) for restarting therapy might in part explain the differences, as may the heterogeneity of regimens between trials. Reassuringly little resistance was documented in either arm and the CD4 counts at the end of the 19 month trial were similar. Although a large (61%) difference in antiretroviral costs were documented no other direct costs e.g. lab tests, hospitalization or physicians costs were reported. The Staccato trial keeps the question open as to whether a safe TI strategy can be developed for widespread use.

Michel John Gill, Southern Alberta HIV Clinic; Calgary;Alberta; Canada

1 Gianotti N, Setti M, Manconi PE et al. Reverse transcriptase mutations in HIV-1 infected patients treated with two nucleoside analogues: the SMART study. Int J Immunopathol Pharmacol 2002 (Mai); 15: 129-139