DAPTA (D-ala-peptide T-amide) is a synthetic peptide that prevents HIV entry by blocking binding of HIV gp120 protein with CCR5 receptor. In a small clinical study of internasal formulation of DAPTA in long-term infected HIV patients, administration of DAPTA led to decrease in the amount of virus isolated from white blood cells, an increase in gamma-interferon secreting T-cells in the absense of drug-related toxicity. In another clinical study DAPTA in combination with antiretroviral therapy reduced the peripheral (plasma and serum) viral load, but did not reduce the CSF viral load.