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What is mRNA?
mRNA, also known as messenger RNA, is the information carrier in the process of gene expression: DNA containing human genetic information is transcribed in the nucleus to produce mRNA, which is then translated in the cytoplasm to produce proteins with various physiological functions.
Mechanism of mRNA-based medicines
The LPP delivery platform delivers in vitro transcribed-mRNA to specific cells in human body, and then mRNA is translated into protein or polypeptide used for immunotherapy, thus achieving treatment or prevention of diseases. Different from DNA, mRNA does not need to be expressed in the nucleus, thereby reducing technical difficulty and risk of changing the cell genome.
Compared with in vitro synthesis of antibody, the cost of in vitro transcription is lower and the development and production cycles are shorter. Therefore, mRNA represents an promising new direction for novel therapeutics.
Challenges for development of mRNA medicines
Since mRNA is easily degraded by RNase in human body, it needs to be protected by a package on its way entering the target cells in human body. In addition, mRNA needs to be delivered to specific antigen presenting cells to achieve the efficacy of immunotherapy.
mRNA needs to be expressed as proteins or polypeptides to achieve the therapeutic effect. Since the amount of protein expressed and therapeutic effect are usually positively related, the efficiency of mRNA translation is important. In order to be efficiently expressed in vivo, the mRNA synthesized in vitro needs to resemble the structure of natural mRNA as much as possible and even be further optimized to achieve an ideal level of translation.
Since different diseases involve different biological pathways and targets, mRNA needs to be delivered to specific tissues and cells to stimulate the correct immune response in order to treat diseases.
The industrial-level manufacturing of mRNA is still in an early stage in China and lacks reliable supply. In response to this challenge, Stemirna has built two technology platforms, mRNA synthesis platform and LPP delivery platform, and focuses on the development of mRNA-based medicines for various indications.