Executive Summary

To support Investigational New Drug (IND) applications for lipid nanoparticle (LNP) delivered mRNA therapeutics, regulatory agencies require robust data on payload persistence, biodistribution, and potential shedding. We have established GxP-compliant, highly sensitive reverse transcription quantitative PCR (RT-qPCR) assays specifically optimized for swine models. These assays provide precise quantification of mRNA construct levels in a comprehensive matrix of biological samples, including blood, urine, feces, and tissues. This data directly informs the Environmental Risk Assessment (ERA) and overall safety profile, supporting a key component of the preclinical data package.

The Regulatory Requirement for Shedding Data in LNP-mRNA Programs

Characterizing the shedding profile of an LNP-delivered mRNA therapeutic is a mandatory regulatory requirement. Unlike some traditional biologics, RNA-based platforms require specialized bioanalytical methods to track the distribution and clearance of the active payload. Regulators need to understand the persistence of the mRNA at the site of administration and in distal tissues, as well as the route and rate of its elimination from the body.

This analysis serves two primary functions:

• Safety Assessment: It defines the non-target tissue biodistribution and clearance kinetics, informing the overall safety profile.

• Environmental Risk Assessment (ERA): It provides quantitative data on the potential for the therapeutic agent to be released into the environment via excreta.

A well-designed study using a translationally relevant large animal model, such as swine, generates the defensible data package needed to satisfy these regulatory expectations.

RT-qPCR Methodologies for Swine Models

Our approach to quantifying mRNA persistence and shedding is built on highly sensitive and specific RT-qPCR assays. The workflow is optimized for the unique challenges presented by diverse biological matrices collected from swine.

The process involves:

• Sample Collection: A systematic collection schedule for blood, urine, feces, saliva, and relevant tissues is established based on the therapeutic’s expected pharmacokinetic profile.

• RNA Extraction: Validated extraction protocols are employed for each matrix to ensure high recovery rates and purity of the target mRNA, removing potential PCR inhibitors.

• Assay Validation: The RT-qPCR assay is developed and validated under GxP guidelines, establishing key performance characteristics such as specificity, sensitivity, linearity, accuracy, and precision.

This rigorous, quality-controlled process ensures that the data generated is reliable and suitable for inclusion in regulatory filings.

Correlating Persistence with Therapeutic Efficacy

Beyond safety and regulatory compliance, quantifying mRNA persistence provides valuable insights into the therapeutic’s mechanism of action and durability. Understanding how long the mRNA remains translationally active in target tissues helps establish a clear pharmacokinetic/pharmacodynamic (PK/PD) relationship. This is particularly relevant for therapies aiming for a sustained effect, as seen in strategies for mutation-independent treatments (PMID: 39001827).

The efficiency of LNP formulation and production directly impacts in vivo delivery and, consequently, the persistence and shedding profile. Advances in scalable manufacturing, such as parallelized microfluidic devices, can produce LNPs with superior delivery characteristics, enhancing potency and potentially altering clearance kinetics (PMID: 34189917). Our bioanalytical methods can precisely measure these downstream effects of manufacturing improvements.