What is BAY 50-4798?

• BAY 50-4798 is very similar to interleukin-2 (IL-2), a protein produced by T-cells.
   
• Unlike drugs currently used to treat HIV, BAY 50-4798 does not attack the virus. It boosts the production and activity of important immune system cells, most notably T4 cells. And unlike IL-2 (Proleukin®), BAY 50-4798 has a limited effect on other immune system cells, most notably natural killer (NK) cells. This should reduce the risk of side effects sometimes seen in people receiving IL-2 treatment.
   
• Researchers believe that BAY 50-4798 can be helpful to HIV-positive people in two ways: 1) to help protect the immune system from the damage caused by HIV, and 2) to help the immune system control HIV reproduction.

• A dose for BAY 50-4798 has not yet been determined. It is being studied in an injectable form. BAY 50-4798 will likely be "cycled." In one clinical trial, BAY 50-4798 is cycled every eight weeks. Patients are receiving twice-daily injections of BAY 50-4798 for a total of five days, every eight weeks. In other words, BAY 50-4798 injections are given for five days, followed by approximately seven weeks of no BAY 50-4798 injections. After the seven weeks of no injections, BAY 50-4798 is injected twice-daily for another five days and then stopped again.
   
• BAY 50-4798 will likely need to be used in combination with anti-HIV drugs. This is because it may cause viral load to increase in the absence of effective anti-HIV therapy (similar to IL-2 therapy).
   
• Phase II clinical trials involving HIV-positive people receiving various doses of the drug are currently under way.
   
•  Like other drugs, BAY 50-4798 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.

• The side effects of BAY 50-4798 have not yet been determined.

•  It is not known whether BAY 50-4798 will harm an unborn baby. It is very important to treat HIV/AIDS during pregnancy to reduce the risk of infecting your baby. Talk to your doctor about your treatment options.
   
•  It is not known whether BAY 50-4798 passes into breast milk and what effect it may have on a nursing baby. To prevent transmission of the virus to uninfected babies, it is recommended that HIV-positive mothers not breast-feed.