An exhaustive pre-clinical study of a circRNA drug candidate (cmRNA1210) encoding IL-12sc for anti-tumor therapeutics.

e14569 Background: Circular RNA as emerging technology hasn't been approved of acceptance of any IND application. What’s the pharmacokinetics, pharmacodynamics and toxicity study of circular RNA drug candidate would be like is still unpublished. Here we provide an exhaustive pre-clinical study of a novel circular RNA drug candidate encoding IL-12sc, the immune stimulatory effector. Methods: Here, we performed an exhaustive pre-clinical study of a circular RNA drug candidate(cmRNA1210) encoding IL-12sc, including pharmacokinetics, pharmacodynamics, pharmacology and toxicology study. Meanwhile, we explored the bioactivity and cross reactivity of cmRNA1210 in vitro and the pharmacokinetics in vivo. Results: cmRNA1210 and its replace molecule exhibits robust therapeutic effect and good safety in syngeneic mouse tumor model and humanized human tumor mouse model. In situ administration of cmRNA1210 achieves abscopal effect and inhibits lung metastasis progression. Treatment with cmRNA1210 leads to cytokines change in plasma and tumor, cytotoxic immune cells accumulation in tumor and tumor tissue necrosis. Dynamic transcriptome profiling of tumor tissue post cmRNA1210 treatment. Combination with checkpoint inhibitor exhibits synergy effect and significantly decreases tumor relapse rate. Kaplan-Meier survival curve in TCGA dataset shows strong correlation of high IL-12A/B expression and long survival. Conclusions: The bioactivity and cross reactivity in rodents and primates of cmRNA1210 were validated in vitro. The advantage of pharmacokinetics of circular RNA was confirmed in vivo. cmRNA1210 exhibits robust anti-tumor effect in various tumor models, indicating its wild application situation in clinical. In situ treatment achieves abscopal effect and significantly inhibits lung metastasis progression. Systemic anti-tumor effect has been successfully initiated. The pharmacodynamics study reveals there are cytokine changes, immune cells activation or accumulation at tumor site and tumor tissue necrosis after cmRNA1210 treatment. cmRNA1210 as immune stimulatory effector works synergistically with checkpoint inhibitor. Kaplan-Meier survival analysis of IL-12 expression based on TCGA dataset shows there is a strong correlation of high expression and long survival. Overall, this pre-clinical study provides elaborate results of cmRNA1210 as anti-tumor therapeutics and demonstrates the great potential to enter clinical trial in the future.