OliX Pharmaceuticals(226950) is expanding its business into next-generation circular messenger ribonucleic acid (mRNA) manufacturing technology. Through a U.S. patent filing, it moved to secure a platform technology that can be applied to various antigens and therapeutic proteins.
OliX Pharmaceuticals said on the 1st that it filed a U.S. patent for a circular mRNA manufacturing platform technology through its U.S. subsidiary, OliXUS.
The company said it has laid the groundwork to expand its RNA technology portfolio from existing RNAi-based gene expression suppression to the area of protein expression.
Circular mRNA, unlike typical linear mRNA, has a ring structure in which the two ends of the RNA are joined. Because it has no free ends, it is relatively resistant to RNases and can remain more stable inside cells. As a result, it may sustain protein expression longer than linear mRNA.
Leveraging these properties can broaden applications to cancer vaccines, therapeutic protein and enzyme supplementation, immune modulation, gene editing, and cell therapies.
To develop circular mRNA into an actual therapy, the key is to stably produce long RNA while securing high purity and yield. OliXUS developed a method that produces kilobase (kb)-scale long RNA precursors from the transcription stage and then directly ligates the two RNA ends enzymatically.
By reducing the post-transcriptional processing steps, the approach lowers the likelihood of unwanted residual sequences in the final circular mRNA or byproducts in which multiple RNAs are joined.
In initial process evaluations, the yield of long RNA precursors was about 30% higher by mass than that of a comparator mRNA under the same conditions. Analysis of RNA length and integrity also confirmed that precursors of the target length were the major component.
Immediately after circularization, anion-exchange high-performance liquid chromatography (HPLC) analysis showed the circular mRNA ratio was up to about 72%. After RNase R treatment to selectively remove linear RNA, the circular mRNA purity rose to about 94% even before separate chromatography purification steps. The process yield relative to the input precursor RNA was about 34%.
OliX Pharmaceuticals noted that, compared with disclosed studies on similar kilobase-scale circular mRNA, it is meaningful that both purity and yield were secured at the early process stage. However, it said simple numerical comparisons have limitations because each study uses different processes and analytical conditions.
In cell experiments, protein expression from circular mRNA persisted longer than that of the comparator mRNA. When the two mRNAs were delivered to cells at the same molar concentration and tracked for up to six days, the expression signal of circular mRNA declined more gradually. In circular mRNA with specific nucleotide modifications, cumulative protein expression was also higher than that of the comparator mRNA.
The company believes it has confirmed, at an initial level, the key steps in circular mRNA development—from long RNA precursor production and circularization to linear RNA removal and intracellular protein expression.
OliXUS plans to advance its circular mRNA purification process and evaluate persistence of protein expression, biodistribution, immune response, and safety through animal studies. It then aims to verify efficacy in disease models and expand applications to cancer vaccines and therapeutic proteins.