What is IL-7?

• IL-7 is an immune-based therapy being developed by the French company Cytheris.
   
• IL-7 is a synthetic version of a naturally occurring immune messenger protein called a cytokine. IL-7 prompts the immune system to make more CD4 and CD8 cells.
   
• IL-7 is being studied as a treatment for HIV, viral hepatitis and cancer.
   
• IL-7 is currently being developed with the goal of enhancing a person’s immune response against HIV. More specifically, researchers hope it will boost CD4 cells counts, help reduce the levels of HIV in a person’s blood, and—in conjunction with other treatments—reduce or eradicate a reservoir of HIV-infected cells that typically escapes the immune system and common HIV medications.
   
• IL-7 is currently being studied for use in conjunction with ARV therapy and not as a permanent replacement.

• Cytheris has conducted several small trials to assess the safety and activity of IL-7, and more trials are ongoing.
   
• So far Cytheris has reported the results of a Phase I/II study of two doses of IL-7: either 10 micrograms per kilogram of body weight (µg/kg) or 20 ug/kg, once-weekly under the skin for three weeks, compared with a placebo.
   
• In the Phase I/II study, people receiving IL-7—along ARV therapy—had significant increases in CD4 and CD8 cells and the average CD4 count increased from 200 to over 500 within 14 days of treatment. Unlike an older cytokine studied in HIV called Proleukin, which predominantly expanded the numbers of existing CD4 and CD8 cells, IL-7 prompted the body to produce brand new naive T-cells: cells that can be taught to respond to any type of infection. This could mean that IL-7 can replenish the immune systems of people with advanced HIV disease.
   
• Thus far, it does not appear that the body produces antibodies against the Cytheris’s synthetic version of IL-7, which could not only blunt its effectiveness, but could also harm the immune system.
   
• Longer-term studies of repeated cycles of IL-7 are ongoing.
•  Researchers are also studying whether temporarily adding IL-7 to an intensified ARV treatment regimen could help reduce the reservoir of latent HIV-infected CD4 cells.
   
• Like other drugs, IL-7 might interact with other medications, including those used to treat HIV. It is important that your personal physician and/or the research nurse or study investigator be aware of all drugs you are taking, including those you buy without a prescription.

• Information regarding the long-term safety and possible side effects of IL-7 in HIV-positive people has not yet been reported.

• It is not known whether IL-7 will harm an unborn baby. It is very important to treat HIV during pregnancy to reduce the risk of infecting your baby. Talk to your provider about your treatment options.
   
• It is not known how IL-7 will affect babies who are breast-feeding when the mother while the mother is being treated. To prevent transmission of the virus to uninfected babies, it is recommended that HIV-positive mothers not breast feed.

• If you would like to find out if you are eligible for any clinical trials that include IL-7, visit ClinicalTrials.gov, a site run by the U.S. National Institutes of Health. The site has information about all HIV-related clinical studies in the United States. For more info, you can call their toll-free number at 1-800-HIV-0440 (1-800-448-0440) or email contactus@aidsinfo.nih.gov.