ILKN421H

**ILKN421H** is a next-generation, lipid-nanoparticle (LNP)-formulated mRNA therapy developed by iLeukon Therapeutics that encodes a non-α human serum albumin (HSA)–IL-2 variant (IL-2v) fusion protein. Designed to selectively expand stem-like PD1-negative CD8⁺ T cells and natural killer (NK) cells, it achieves preferential expression in lymphoid organs (e.g., spleen, lymph nodes) with minimal off-target expression (<5% in liver), overcoming the cytokine-sink effect of protein-based IL-2 therapies through sustained mRNA-mediated production. Administered intravenously every 3 weeks, it demonstrates a ~20-hour half-life, robust pharmacodynamic effects (up to 10-fold CD8⁺ T cell and 25-fold NK cell expansion), and a favorable safety profile with no dose-limiting toxicities, vascular leak syndrome, or hypotension observed in Phase I across 45 advanced solid tumor patients. In first-line NSCLC (n=20) combined with pembrolizumab, it achieved an 80% confirmed objective response rate regardless of PD-L1 status, with median PFS projected >12 months.[1][3][5]

Other names

IL2v mRNAIL-2v mRNAIL 2v mRNA