Results from a new study justify scientists’ continuing interest in interleukin-2 (IL-2) therapy for HIV. The French study, published in the September issue of AIDS, found that CD4 cell increases from the immune-based therapy were robust and long lasting, regardless of the potency of antiviral combination with which it was paired.
Yves Levy, MD, PhD, and his colleagues conducted a long-term follow-up of two earlier IL-2 studies in France—one, ANRS048, which paired IL-2 with the two nucleoside analogues, Retrovir (zidovudine) and Videx (didanosine), and a second study, ANRS079, which paired IL-2 with triple combination therapy including a protease inhibitor. A total of 131 people from both studies were ultimately treated with an average of 10 cycles of IL-2—each cycle involved a series of injections spaced eight weeks apart—and have been followed for at least three and a quarter years.
The results were quite promising. After 170 weeks on treatment, patients’ CD4s averaged 791 cells—an approximate 428-cell increase since entering the trials. One surprising finding was that, regardless of the antiviral regimen they initiated at the start of the studies, participants experienced sharp and sustained increases in their CD4s. Those who initiated the study with an antiviral regimen containing a protease inhibitor did maintain better control of virus, however, than those who initiated with just two nucleoside analogues.
Although IL-2 is available in the United States, it is not currently approved for use in HIV disease. A large international study is currently ongoing and will help determine whether the CD4 increases associated with IL-2 therapy actually result in improved health and survival for people with HIV.