EVALUATION OF MONOCLONAL-ANTIBODIES TO HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 PRIMARY ISOLATES BY NEUTRALIZATION ASSAYS - PERFORMANCE CRITERIAFOR SELECTING CANDIDATE ANTIBODIES FOR CLINICAL-TRIALS

A collaborative study was organized to identify monoclonal antibodies (MAbs) that may be broadly and potently neutralizing for a panel of hu man immunodeficiency virus type 1 (HIV-1) low-passaged adult and pedia tric primary isolates in peripheral blood mononuclear cells, Five labo ratories evaluated a coded panel of seven human MAbs to HIV-1 subtype B envelope V3, CD4 binding region, gp41, and other conformationally se nsitive determinants. Each laboratory measured neutralizing activity o f the MAbs against tile laboratory isolate HIVMN and a panel of 9 subt ype B primary isolates. Antibodies were classified as suitable candida tes for future clinical studies if they could neutralize at least half of the 9 primary isolates at a concentration of less than or equal to 25 mu g/mL for 90% viral inhibition. The study identified three MAbs that met stated performance criteria: IgG1b12, 2G12, and 2F5. These re sults may provide a rationale for examining the clinical efficacy, eit her singly or in combination, of the three MAbs.