Design and evaluation of bi- and trispecific antibodies targeting multiple filovirus glycoproteins

Abstract

Filoviruses (family Filoviridae) include five ebolaviruses and Marburg virus. These pathogens cause a rapidly progressing and severe viral disease with high mortality rates (generally 30-90%). Outbreaks of filovirus disease are sporadic and, until recently, were limited to less than 500 cases. However, the 2013-2016 epidemic in western Africa, caused by Ebola virus (EBOV), illustrated the potential of filovirus outbreaks to escalate to a much larger scale (over 28,000 suspected cases). mAbs against the envelope glycoprotein represent a promising therapeutic platform for managing filovirus infections. However, mAbs that exhibit neutralization or protective properties against multiple filoviruses are rare. Here we examined a panel of engineered bi- and trispecific antibodies, in which variable domains of mAbs that target epitopes from multiple filoviruses were combined, for their capacity to neutralize viral infection across filovirus species. We found that bispecific combinations targeting EBOV and Sudan virus (another ebolavirus), provide potent cross-neutralization and protection in mice. Furthermore, trispecific combinations, targeting EBOV, Sudan virus, and Marburg virus, exhibited strong neutralization potential against all three viruses. These results provide important insights into multispecific antibody engineering against filoviruses and will inform future immunotherapeutic discoveries.

Monoclonal Antibody Cocktail Protects Hamsters From Lethal Marburg Virus Infection

“…In general, the filovirus field is moving toward the development of pan-ebolavirus or even pan-filovirus mAb cocktails. Several studies have described mAbs with in vitro and in vivo efficacies against multiple ebolavirus species [10][11][12][13][14]. Human data have even shown that cross-protection for EBOV and MARV can be naturally achieved [15], further supporting the pan-filovirus therapeutic concept.…”

Two Distinct Lysosomal Targeting Strategies Afford Trojan Horse Antibodies With Pan-Filovirus Activity

“…Multispecific antibodies with enhanced antiviral breadth and cross-protective efficacy have also been engineered and evaluated in rodent models of filovirus challenge. nAbs specific for different ebolaviruses and MARV were successfully combined into broadly neutralizing bispecific and trispecific antibodies ( 63 , 64 ). In the distinct Trojan horse approach, bsAbs were generated by linking a pan-ebolavirus non-neutralizing mAb, FVM09, with either of two mAbs targeting cryptic endosomal epitopes at the GP CL :NPC1 interface ( 27 ).…”

Design and characterization of protective pan-ebolavirus and pan-filovirus bispecific antibodies

“…MAb therapies that target two or more epitopes are advantageous for viral immunotherapy, because they are less susceptible to viral escape by a single mutation. Such multi-epitope targeting can be accomplished either by mixing canonical mAbs together into cocktails (e.g., Inmazeb or MBP134) or by physically joining variable domains (Fvs) from two antibodies as bispecific (bsAbs) or multispecific (e.g., trispecific) antibodies [32,33]. We have previously reported the development of bsAbs against filoviruses, and Crimean-Congo hemorrhagic fever virus (CCHFV), and other groups have targeted SARS-CoV-2 and HIV-1 [32][33][34][35][36][37][38][39][40][41].…”