Swissmedic-informed preclinical PK study design for advanced therapy medicinal products (ATMPs)

PROVEN INTELLIGENCE ACCELERATING NEXT-GENERATION THERAPIES

Swissmedic-informed preclinical PK study design for advanced therapy medicinal products (ATMPs)

Preclinical Pharmacokinetics for ATMPs: Swissmedic Regulatory Alignment

CELL & GENE | RNA | BIOLOGICS

  • Navigating Complex Biodistribution for Advanced Therapies.*

This strategic framework outlines the design of preclinical pharmacokinetics (PK) and biodistribution studies for advanced therapy medicinal products (ATMPs) intended for Swissmedic submission. We detail the core bioanalytical and in vivo components required to characterize vector persistence, tissue tropism, and potential immunogenicity. The focus is on generating a robust data package that directly addresses regulatory expectations for gene and cell therapies, facilitating a clear path toward clinical trial authorization.

What are Swissmedic’s primary concerns for ATMP PK/biodistribution studies?

Swissmedic, consistent with other major regulatory bodies, prioritizes a comprehensive understanding of an ATMP’s in vivo behavior. Key areas of focus include the extent and duration of vector persistence in target and non-target tissues, the potential for germline transmission, and the kinetics of transgene expression. A well-defined non-target tissue biodistribution profile is fundamental to the safety assessment.

How does PK for an AAV gene therapy differ from a cell therapy product?

While both are ATMPs, their PK profiles are distinct. For AAV vectors, PK studies focus on quantifying vector DNA copies to track distribution and clearance. For cell therapies, studies measure the trafficking, persistence, and engraftment of the cellular product. The bioanalytical methods differ significantly: qPCR or ddPCR for AAVs versus flow cytometry, bioluminescence imaging, or cell-specific PCR for cell products.

What is the role of qPCR vs. ddPCR in quantifying vector biodistribution?

Both are used to quantify vector DNA in tissue samples. Quantitative PCR (qPCR) is a well-established method providing relative or absolute quantification. Droplet digital PCR (ddPCR) offers higher precision and sensitivity without reliance on a standard curve, making it particularly valuable for detecting low copy numbers in non-target tissues or during late-stage clearance phases. The choice depends on the specific study objectives and required limits of quantification.

How early should immunogenicity assays be integrated into the PK plan?

Immunogenicity assessment should be integrated from the earliest stages of the preclinical program. Anti-drug antibody (ADA) responses, including neutralizing antibodies (NAbs), can significantly impact an ATMP’s exposure, efficacy, and safety. Correlating immunogenicity data with PK and biodistribution profiles provides a mechanistic understanding of the product’s in vivo behavior and potential clinical outcomes.

Aligning ATMP PK/PD Strategy with Swissmedic Guidance

Designing a preclinical program for an ATMP requires a distinct approach. The persistence of the therapeutic agent, whether a viral vector or a modified cell, introduces unique safety and efficacy considerations. For Swissmedic, the preclinical data package must convincingly characterize the product’s biodistribution, duration of activity, and potential for non-target tissue effects.

Our approach focuses on building a dataset that prospectively answers key regulatory questions. This involves:

  • Selecting relevant species and designing studies that provide clear translational value.

  • Developing and validating sensitive, specific bioanalytical methods to track the ATMP and its products.

  • Integrating PK data with toxicology and efficacy endpoints to build a comprehensive safety narrative.

A digital rendering of a DNA double helix on a dark blue background with floating particles.

A stylized, 3D rendering of a DNA double helix in light blue and white, set against a soft-focus, light gray background.

Core Principles of a Regulatable Biodistribution Study

A successful ATMP biodistribution study provides a clear picture of where the product goes, how long it stays there, and what it does. The strategic value of evaluating a therapy’s safety and efficacy profile across multiple, relevant species cannot be overstated, as it builds a comprehensive dataset that de-risks subsequent clinical development (PMID: 35333110). This is particularly important for gene therapies, where long-term vector persistence is an intended outcome.

Key study components include:

  • Tissue Collection: A comprehensive panel of tissues is collected at multiple time points to characterize both the initial distribution phase and long-term persistence.

  • Vector Shedding: Analysis of excreta (urine, feces, saliva) is performed to assess the potential for transmission.

  • Bioanalytical Methods: Robust, GxP-compliant assays are a key component for accurately quantifying vector DNA or cell products in complex biological matrices.

In Vivo Study Conduct and Animal Welfare

All in vivo studies are conducted within our >100,000 sq ft facility, which is fully accredited by AAALAC International and registered with the USDA.

We adhere strictly to the 3Rs principles (Replacement, Reduction, and Refinement) to minimize animal use and improve welfare. This ethical framework ensures the generation of high-quality, reproducible data necessary for regulatory submission.

A marketing flyer for Franklin Biolabs detailing their immunogenicity services, including various assays and support for cell and gene therapy clinical trials.

Bioanalytical Strategy and Assay Validation

The quality of a PK study is defined by the quality of its bioanalytical data. We develop and validate custom assays tailored to each unique ATMP, ensuring the necessary sensitivity, specificity, and accuracy to meet regulatory standards. Our integrated approach allows for Accelerated PK Profiling for Rapid Dose Optimization. This rigorous process supports our clients’ programs, contributing to a typical 18-24 month IND timeline. Since the Franklin Biolabs brand launch in 2024, programs we have managed have maintained a 100% IND success rate, building on a legacy of success dating back to 2019.

Assay Type Application Key Considerations
ddPCR / qPCR Vector DNA quantification in tissues & fluids Primer/probe specificity, assay sensitivity (LLOQ)
RT-qPCR Transgene mRNA expression analysis RNA quality, normalization strategy, tissue-specific expression
ELISA / MSD Transgene protein quantification, immunogenicity (ADA) Antibody pair selection, matrix effects, NAb correlation
Flow Cytometry Cell therapy persistence, trafficking, & phenotype Panel design, compensation, gating strategy

Scientific Process Diagram

This content is for informational purposes. For guidance specific to your therapeutic program, please contact our team for a consultation.

Explore More Capabilities