Masterarbeit

Scientific and regulatory preclinical strategy for initiating a first-in-human clinical study with selectively expressed RNA

Dr. Lukas Lövenich (2026)

Summary

Following the success of Moderna’s and BioNTech/Pfizer’s mRNA-based Covid-19 vaccines during the 2021 pandemic, RNA-based therapeutic approaches experienced a novel boost. While several RNA modalities including small interfering RNAs (siRNAs), aptamers and antisense oligonucleotides (ASOs) resulted in authorized therapeutic drugs, thus far mRNA has only been established for prophylactic vaccinations. One major challenge of a mRNA-based therapeutic approach is its absence in specificity, which is now circumvented by the selectively expressed RNA (seRNA) platform technology. Since no mRNA-based therapeutic drug has been authorized yet, the regulatory requirements for mRNA and especially seRNA are challenging, lacking regulatory classification and guidance. 

This thesis presents a scientifically and regulatorily justified preclinical strategy to initiate the first clinical use of the seRNA encapsulated in lipid nanoparticles (LNPs). The seRNA/LNP has been classified as a gene therapy medicinal product (GTMP), following advanced therapy medicinal product (ATMP) guidance with special considerations of GTMP guidelines. The preclinical studies have been scientifically justified and adapted based on the novel mode of action of the seRNA and its intended clinical use in end-stage primary liver cancer/hepatocellular carcinoma (HCC) patients.

Due to the specific mode of action, the proof-of-concept (PoC) will be demonstrated alongside supportive data from a similar GTMP investigating biodistribution and proving selective expression. Depending on the results of the biodistribution studies, endpoints concerning the safety pharmacology core battery will be included in the general safety and toxicity studies. This will only be conducted if organs of the functional core battery are reached and if an off-target expression via the seRNA can be investigated, following the ATMP risk-based approach. Similarly, the need for conducting reproductive toxicology studies will be investigated and justified.

General safety and toxicity studies will follow the guidance of the non-clinical GTMP guideline, while considering the typical study design of repeated-dose toxicity studies. Since RNA molecules delivered by LNPs typically accumulate within liver tissue, hepatotoxicity will be investigated as an additional in vivo readout parameter. Furthermore, immunogenicity and immunotoxicity will be included in the GLP-compliant general toxicity studies to enable the intended repeated administration of the seRNA/LNP in the first clinical application.

The safe initial clinical starting dose, which should provide potential therapeutic benefits to the HCC patients, will be determined considering all results of the preclinical program. This includes especially a maximal tolerated dose (MTD) study in a humanized xenograft mouse model and toxicity and immunogenicity data in immunocompetent mice using different dose levels. The potential immunogenicity or general toxicity of the non-viral vector, using LNPs will be investigated using an additional control group consisting of the LNPs and an appropriate, non-therapeutic control mRNA. 

As a result of this thesis, the proposed preclinical strategy will be discussed with the German national competent authority (NCA) – the Paul-Ehrlich-Institute (PEI). The questions to be asked are included in the thesis, which proposes the scientifically and regulatory justified answers. 

Pages: 71 

Annexes: 8; Pages: 11