Abstract Broadly neutralizing antibodies (bnAbs) are a promising tool for HIV prevention and treatment. Here we conducted a first-in-human, phase 1 trial of the bispecific 10E8.4/iMab antibody, which consists of a 10E8.4 arm binding the HIV-1 envelope glycoprotein membrane-proximal external region and an ibalizumab (iMab) arm binding the human CD4 molecule. 10E8.4/iMab was administered intravenous...