Lyophilized monoclonal antibody (mAb) encoded mRNA—lipid nanoparticles (LNPs) lead to stable in vivo expression of mAb after room temperature storage

Abstract The recent success of mRNA COVID-19 vaccines using lipid nanoparticles (LNPs) underscores the potential of this technology for delivering gene-encoded biologics in humans. Passive immunization by in vivo expression of monoclonal antibodies (mAbs) could provide advantages over traditional vaccines due to its immediate protection and broader applicability. The use of mRNA allows for rapid development and easily scalable production, while in vivo expression of biologics (IVEB) reduces the complexity and cost associated with traditional mAb manufacturing by leveraging the body as a bioreactor. However, the requirement of cold chain storage and transportation remains a critical challenge for the distribution of mRNA-LNP formulations. Lyophilization of the mRNA-LNP formulations to produce dry powder offers a potential solution to this issue. In this study, we have investigated several lyophilization conditions for mRNA-LNP and evaluated their efficacy both in vitro and in vivo . Further physical stability and structure characterization provided insights into the structure-efficacy relationship. We successfully identified the lyophilization condition using 5 mM Tris buffer at pH 8 with 10% sucrose, which retained LNP particle size within an acceptable range, preserved mRNA encapsulation efficiency, and maintained consistent level of in vivo expressed mAbs after being stored at room temperature for a month.