Cancer Drug May Prove Effective Against HIV by Targeting Infected CD4+ T Cells

The cancer drug motexafin gadolinium (Gd-Tex) may prove effective against HIV by targeting and destroying infected CD4+ T cells, BBC News reports (BBC News, 2/19). Gd-Tex worked in laboratory tests by "selectively kill[ing]" only HIV-infected CD4+ T cells, immune system cells that coordinate the body's immune repsonse against foreign invaders. Leonard Herzenberg, a professor emeritus of genetics at Stanford University Medical Center and senior author of a Gd-Tex study that appeared in the Feb. 19 issue of the Proceedings of the National Academy of Sciences, said that his research team was "surprise[d]" because the drug killed only cells that had already been infected with HIV. The researchers theorized that other CD4+ T cells were able to survive low doses of the drug because they were not "as compromised" as the HIV-infected cells (Stanford University release, 2/19). Although researchers are encouraged by the in vitro results, they caution that the drug may not be as effective in humans because it may prove more difficult to "produce a precise level of Gd-Tex in the body than in the test tube." They are also concerned that the rapid breakdown of CD4+ T cells could release harmful toxins into the body. However, they hope to begin human trials in the United States "within the next few months." A spokesperson for the Terrence Higgins Trust, a British HIV/AIDS group, called the study results "exciting and interesting," adding, "Clearly, more work with Gd-Tex is necessary, but in our battle to stay one step ahead of the ever-mutating [HIV], different treatment options are vital" (BBC News, 2/19).