Circular RNA Steps Into the Nucleic Acid Drug Spotlight as Capital Interest Presses for Clinical Answers

The race in nucleic acid drugs is shifting from “whether information can be delivered into cells” to “how long it can be expressed after delivery, whether it is controllable, and whether it can be safely used repeatedly.” On this question, circular RNA has recently been pushed to the forefront. BioSpectrum Asia reported on June 22 that these molecules are attracting attention from investors, pharma companies and gene therapy developers, not only because the technical term is new, but because they may fill a gap between existing mRNA and some gene therapies.

The core feature of circular RNA is that the molecule’s ends are joined to form a ring, without the termini that make traditional linear RNA more easily recognized by cellular nucleases. In theory, this could make it more stable inside cells and extend the duration of protein expression. For drug developers, this means fewer doses, a longer window of action, or, in areas such as immune cell engineering, protein replacement, vaccines and regenerative medicine, the ability to design a therapeutic rhythm different from that of linear mRNA.

But this wave of interest should still be understood in the context of an early platform technology. Existing public information does not provide specific transaction amounts, clinical data or individual product milestones; it more reflects the industry’s positioning around next-generation nucleic acid carriers. For circular RNA to move from a platform narrative to a drug, it must prove that its translation efficiency, immune response, manufacturing consistency and in vivo distribution can be stably controlled across different disease settings.

Background Context

mRNA vaccines helped the market understand the manufacturing speed and designability of nucleic acid drugs, but therapeutic uses are more demanding than vaccines: if protein expression is too short, efficacy may be insufficient; if expression lasts too long or tissue distribution is imprecise, safety risks will rise. Circular RNA is therefore seen as a compromise tool that may offer more durable expression than traditional mRNA, without the long-term irreversible concerns associated with viral vectors or integrating gene therapies.

This also explains why it has entered the field of view of gene therapy and cell therapy developers. If circular RNA can be paired with delivery systems such as lipid nanoparticles, polymers or non-viral DNA vectors, it may in the future be used to transiently express therapeutic proteins in vivo, reprogram immune cells, or reduce the complexity of ex vivo manufacturing for certain cell therapies. However, most of these applications remain in technical validation and early development stages, and are still some distance from clinical approaches that can be widely adopted.

The other side of industry enthusiasm is that regulatory issues will emerge more quickly. Circular RNA is not simply “more stable mRNA”; its structure, impurity profile, translation mechanism and immune-stimulatory properties may all affect quality standards and clinical risk assessment. For investors, the key in the next stage will not merely be who first claims platform success, but who can produce a reproducible process, a clear pharmacodynamic relationship, and human data sufficient to persuade regulators.