Chabakshin Research Institute Independently Develops New mRNA Delivery System to Replace LNP

Cha Vaccine Institute announced on the 25th that it has developed 'Lipoplex,' a messenger ribonucleic acid (mRNA) delivery system using an independently developed immune adjuvant.

Cha Vaccine Institute CI [Photo by Cha Vaccine Institute]

Medicines utilizing mRNA have the advantage of being rapidly designed and produced as long as the genomic information of the target virus is known, which has drawn attention during the COVID-19 pandemic. Recently, research has expanded beyond COVID-19 vaccines and treatments to include various infectious diseases and cancer vaccines such as influenza and respiratory syncytial virus (RSV).

However, mRNA has the weakness of being easily modified and degraded by enzymes in the body. This is why a delivery system that can overcome this and safely reach the target is essential. Most currently available mRNA vaccines use lipid nanoparticles (LNPs) as this delivery system. However, LNPs are thermodynamically unstable, requiring ultra-low temperature storage for distribution, and tend to be delivered only to the liver, raising concerns about side effects due to hepatotoxicity. There are also concerns about excessive allergic reactions such as anaphylaxis caused by the instability of polyethylene glycol (PEG) components used in commercially available LNPs.

Lipoplex, developed as a liposome-based mRNA delivery system, was created to overcome these drawbacks of existing LNPs. Cha Vaccine Institute explained that they optimized the lipid formulation constituting the liposome and added an independently developed toll-like receptor (TLR) 2-based immune adjuvant to increase the expression efficiency of the target antigen and enhance mRNA delivery effectiveness. They also noted that Lipoplex does not use PEG, eliminating allergic reactions, and can be freeze-dried, allowing for conventional room temperature distribution and storage instead of cold chain systems requiring refrigeration or freezing.

The efficacy of mRNA vaccines using Lipoplex was also demonstrated in animal experiments. Cha Vaccine Institute confirmed that when the mRNA-Lipoplex vaccine formulation was injected into animals, the humoral immune response increased 50-fold and the cellular immune response increased 15-fold compared to mRNA alone. In a mouse model implanted with skin cancer, tumor growth was suppressed by 41% on day 21 after administration of the mRNA-Lipoplex vaccine compared to mRNA alone. No hepatotoxicity or other side effects observed with LNP use were detected. Cha Vaccine Institute presented these research results as a poster at the '11th International mRNA Conference' held recently in Berlin, Germany.

Yeom Jeong-seon, CEO of Cha Vaccine Institute, stated, “We will develop cancer vaccines utilizing Lipoplex’s stability, delivery capability, and immune-enhancing efficacy,” adding, “In the current situation where some global companies monopolize patents related to LNP, we will also contribute to protecting the sovereignty of mRNA vaccines.”