THERAPEUTIC POTENTIAL OF ANTI-HIV IMMUNOTOXINS

In vitro analyses have shown anti-HIV immunotoxins to be among the mos t effective AIDS antivirals tested. Because HIV has been continually s elected by antibody, immunotoxins targeted to constant domains of vira l antigens may not elicit drug-resistant mutants. A clinical trial wit h CD4-PE40, a possibly flawed immunotoxin with nonspecific toxicity an d short serum half-life, has reduced interest in this form of therapy. It is proposed that the use of an immunotoxin directed against gp41 i n combination with a CD4-Ig chimera is more likely to have a therapeut ic effect than CD4-PE40. Clinical trials are also underway utilizing a n immunotoxin that eliminates activated T-cells, an important cellular locus of HIV-replication.