Abstract

The use of HAART with double or triple drug combinations has significantly improved the survival of AIDS patients. However, the emergence of virus-drug resistance and both short- and long-term drug-related side effects are among the main reasons for continuing the development of new classes of effective anti-HIV drugs that target the replicative cycle at different sites. In recent years, tremendous progress has been made in understanding HIV-1 entry, a multistep process that comprises viral attachment, coreceptor interactions and fusion. The mechanistic insight gained from these studies has enabled the design of specific agents that can inhibit each step in the HIV entry process. The successful results from clinical trials with enfuvirtide (T-20), the first approved entry inhibitor, indicate that targeting of HIV entry will soon be an important component of antiretroviral therapy and further encourage the development of effective entry inhibitors. In this article the recent developments of therapeutic agents endowed with inhibitory properties against the binding of the HIV envelope glycoprotein gp120 to the CD4 receptor (e.g., PRO 542, BMS-378806, TNX-355, PRO 2000 and CV-N) are briefly outlined. Major focus is placed on the anti-HIV activity of cyclotriazadisulfonamides (CADA), a novel class of compounds with a unique mode of action by down-modulating the CD4 receptor in lymphocytic and monocytic cells.

Keywords: hiv entry inhibitors, cd4 receptor, cada