Galnac Lipid 29 is from Prime Medicine Patent: WO2024220807. Compound 29 is a GalNAc-functionalized lipid featuring a tripartite structure: an N-acetylgalactosamine (GalNAc) targeting moiety for ASGPR-mediated liver uptake, a flexible PEG-based linker (e.g., ethylene glycol repeats), and dual C18 alkyl chains for lipid nanoparticle (LNP) integration. Its design includes stereospecific amide/urethane bonds (R/S configurations) to optimize stability and ligand orientation. Preclinical data demonstrate enhanced prime editing efficiency (>2-fold vs controls) in hepatocytes at low doses, attributed to improved endosomal escape and payload release. The compound enables liver-specific delivery of CRISPR systems while minimizing off-target accumulation, with <5% activity in non-hepatic cells.