Monoclonal Antibody Cocktail Protects Hamsters From Lethal Marburg Virus Infection

Marburg virus (MARV), family Filoviridae, causes Marburg hemorrhagic fever (MHF) in humans and nonhuman primates with case fatality rates of up to 90%. There is no approved therapeutic for MHF, yet several experimental approaches have been evaluated in preclinical studies including small interfering RNA and monoclonal antibody (mAb) treatment. In this study we attempted to improve the therapeutic efficacy of the neutralizing mAb M4 by combining treatment with 1 or 2 of blocking but nonneutralizing mAbs 126-15 and 127-8. We found that single-dose treatment early after infection with the neutralizing mAb M4 or any of the mAb combinations resulted in similar protection in the MARV hamster model. However, a single-dose treatment with the cocktail of all 3 mAbs provided the best protection in delayed treatment, with 67%-100% of the animals surviving a lethal challenge depending on the time of treatment. This study identified a new promising mAb cocktail as a therapeutic option for MHF.