Targeted mRNA delivery with bispecific antibodies that tether LNPs to cell-surface markers

Efficient delivery of mRNA-LNPs to specific cell-types remains a major challenge in the widespread application of mRNA therapeutics. Conventional targeting approaches involve modifying the lipid composition or functionalising the surface of lipid nanoparticles (LNPs), which complicates manufacturing, alters nanoparticle size, charge and stealth, impacting their delivery and immunogenicity. Here we present a generalisable method for targeted mRNA-LNP delivery that uses bispecific antibodies (BsAbs) to form a bridge between LNPs and cell-surface markers. Instead of attaching the targeting agent to the nanocarrier, BsAbs are administered first, bind to surface proteins on target cells, and later retain unmodified LNPs in affected tissues. We demonstrate efficient and cell-type-specific delivery of mRNA-LNPs to epidermal growth factor receptor (EGFR), and folate hydrolase 1 (PSMA) positive cells in vitro and in vivo. The flexibility of this technology, achieved by substitution of the cell-targeting region of the BsAbs, enables rapid development of next-generation targeted mRNA drugs.