CHA Vaccine Institute, a Kosdaq-listed vaccine development company, said Thursday that it has developed Lipoplex, a messenger ribonucleic acid (mRNA) delivery system using adjuvants.

Medicines utilizing mRNA have gained prominence since the Covid-19 pandemic. The advantage of mRNA vaccines and therapeutics is that they can be designed and produced quickly by understanding the genome of the target virus.

However, mRNA is susceptible to modification or degradation by enzymes in the body, necessitating a delivery vehicle to transport the mRNA to the target cells.

Currently, mRNA vaccines use lipid nanoparticles (LNPs) as carriers. However, LNPs are thermodynamically unstable and require extremely low temperatures for distribution.

In addition, they can only be delivered to the liver, creating a risk of side effects due to hepatotoxicity. Also, commercialized LNPs use polyethylene glycol (PEG), which is unstable and can cause excessive allergic reactions, including anaphylaxis.

Lipoplex is a liposome-based mRNA delivery vehicle. CHA Vaccine Institute optimized the formulation of lipids of liposomes, adding toll-like receptor 2 (TLR2)-based adjuvant developed by CHA Vaccine Institute. As a result, the expression efficiency of the target antigen increased with effective mRNA delivery.

Also, Lipoplex does not use PEG, which is added to LNPs, preventing allergic reactions such as anaphylaxis. In addition, liposomes can be lyophilized, enabling being stored and distributed at room temperature without the need for a separate cold chain.

CHA Vaccine Institute said animal studies of the mRNA-Lipoplex vaccine showed a 50-fold increase in humoral immune responses and a 15-fold increase in cellular immune responses compared to mRNA alone.

In mouse models implanted with skin cancer, the mRNA-Lipoplex vaccine prevented tumor formation more than mRNA alone, inhibiting tumor growth by 41 percent at day 21 compared to mRNA alone.

CHA Vaccine Institute presented these findings at the 11th International mRNA Health Conference in Berlin, Germany, last year, and confirmed the possibility of collaborative research to develop vaccines and therapeutics in business meetings with global companies.

"We plan to develop an anti-cancer vaccine by utilizing the stability and efficacy of Lipoplex," said Yum Jung-sun, CEO of CHA Vaccine Institute. "We will help protect the sovereignty of mRNA vaccines as some global companies currently monopolize LNP-related patents."