Active Immunoprophylaxis With A Synthetic Dna-Encoded Monoclonal Anti-Respiratory Syncytial Virus Scfv-Fc Fusion Protein Confers Protection Against Infection And Durable Activity

Respiratory Syncytial virus (RSV) is a major threat to many vulnerable populations. There are currently no approved vaccines, and RSV remains a high unmet global medical need. Here we describe the employment of a novel synthetic DNA-encoded antibody technology platform to develop and deliver an engineered human DNA-encoded monoclonal antibody (dMAb(TM)) targeting the fusion protein (F) of RSV as a new approach to prevention or therapy of at risk populations. Inin vivomodels, a single administration of synthetic DNA-encoding the single-chain fragment variable-constant fragment (scFv-Fc) RSV-F dMAb resulted in robust and durable circulating levels of a functional antibody systemically and in mucosal tissue. In cotton rats, which are the gold-standard animals to model RSV infection, we observed sustained scFv-Fc RSV-F dMAb in the sera and lung-lavage samples, demonstrating the potential for both long-lasting immunity to RSV and effective biodistribution. The scFv-Fc RSV-F dMAb harbored in the sera exhibited RSV antigen-specific binding and potent viral neutralizing activity. Importantly,in vivodelivery of synthetic DNA-encoding, the scFv-Fc RSV-F dMAb protected animals against viral challenge. Our findings support the significance of dMAbs as a potential platform technology for durable protection against RSV disease.