mAb 3A6

**mAb 3A6** is a human monoclonal antibody isolated from an Ebola virus disease (EVD) survivor during the 2014-2016 West Africa outbreak. It targets a highly conserved epitope in the stalk-membrane proximal external region (MPER) of the Ebola virus (EBOV) glycoprotein GP1,2 (residues 626-640, specifically I627-G639), stabilizing GP1,2 in a "lifted" conformation elevated from the virion membrane to access its occluded binding site. This novel mechanism potently neutralizes EBOV in vitro (PRNT50 of 0.33 nM) by blocking conformational changes required for viral membrane fusion and cell entry. In preclinical models, mAb 3A6 demonstrated unprecedented monotherapy efficacy, providing complete post-exposure protection in guinea pigs and rhesus monkeys at advanced high-viremia stages (10^9–10^10 PFU/mL) using a low 25 mg/kg dose administered intravenously on days 4 and 7 post-exposure—half the dose of mAb114 and one-sixth of REGN-EB3. Developed collaboratively by La Jolla Institute for Immunology and NIAID, it shows promise for next-generation pan-orthoebolavirus therapeutics due to epitope conservation across species.[1][2][4][5][7]

Other names

9.6.3A6