Susceptibility to 3BNC117 and 10-1074 in ART suppressed chronically infected persons.

OBJECTIVE: The aim of this study was to assess the susceptibility of HIV to two HIV monoclonal antibodies (bnAbs), 3BNC117 and 10-1074, in individuals with chronically suppressed HIV infection.

DESIGN: The susceptibility of bnAbs was determined using the PhenoSense mAb Assay, which is a cell-based infectivity assay designed to assess the susceptibility of luciferase-reporter pseudovirions. This assay is the only CLIA/CAP compliant screening test specifically developed for evaluating bnAb susceptibility in people with HIV infection.

METHOD: The susceptibility of luciferase-reporter pseudovirions, derived from HIV-1 envelope proteins obtained from PBMCs of 61 ART-suppressed individuals, to 3BNC117 and 10-1074 bnAbs was assessed using the PhenoSense mAb assay. Susceptibility was defined as an IC90 of <2.0 μg/ml and 1.5 μg/ml for 3BNC117 and 10-1074, respectively.

RESULTS: About half of the individuals who were chronically infected and virologically suppressed were found to harbor virus with reduced susceptibility to one or both of the tested bnAbs.

CONCLUSIONS: The reduced combined susceptibility of 3BNC117 and 10-1074 highlights a potential limitation of using only two bnAbs for PREP or treatment. Further studies are needed to define and validate the clinical correlates of bnAb susceptibility.