In vivo mRNA expression of a multi-mechanistic mAb combination protects against Staphylococcus aureus infection

Mol Ther. 2024 Aug 7;32(8):2505-2518. doi: 10.1016/j.ymthe.2024.05.036. Epub 2024 May 31.

Abstract

Single monoclonal antibodies (mAbs) can be expressed in vivo through gene delivery of their mRNA formulated with lipid nanoparticles (LNPs). However, delivery of a mAb combination could be challenging due to the risk of heavy and light variable chain mispairing. We evaluated the pharmacokinetics of a three mAb combination against Staphylococcus aureus first in single chain variable fragment scFv-Fc and then in immunoglobulin G 1 (IgG1) format in mice. Intravenous delivery of each mRNA/LNP or the trio (1 mg/kg each) induced functional antibody expression after 24 h (10-100 μg/mL) with 64%-78% cognate-chain paired IgG expression after 3 days, and an absence of non-cognate chain pairing for scFv-Fc. We did not observe reduced neutralizing activity for each mAb compared with the level of expression of chain-paired mAbs. Delivery of the trio mRNA protected mice in an S. aureus-induced dermonecrosis model. Intravenous administration of the three mRNA in non-human primates achieved peak serum IgG levels ranging between 2.9 and 13.7 μg/mL with a half-life of 11.8-15.4 days. These results suggest nucleic acid delivery of mAb combinations holds promise and may be a viable option to streamline the development of therapeutic antibodies.

Keywords: Staphylococcus aureus; alpha toxin; bacteria pathogenesis; clumping factor A; immunotherapy; in vivo expressed monoclonal antibodies; mRNA/LNP; monoclonal antibody combination; mouse disease models; scFv-Fc.

MeSH terms

  • Animals
  • Antibodies, Monoclonal*
  • Disease Models, Animal
  • Female
  • Humans
  • Immunoglobulin G* / immunology
  • Liposomes
  • Mice
  • Nanoparticles / chemistry
  • RNA, Messenger* / genetics
  • Single-Chain Antibodies / genetics
  • Staphylococcal Infections* / prevention & control
  • Staphylococcus aureus* / immunology

Substances

  • RNA, Messenger
  • Antibodies, Monoclonal
  • Immunoglobulin G
  • Lipid Nanoparticles
  • Single-Chain Antibodies
  • Liposomes