Assessment of biodistribution using mesenchymal stromal cells: Algorithm for study design and challenges in detection...

Area of Science:

• Preclinical drug development
• Cell-based therapeutics
• Regulatory science

Background:

• Biodistribution of cell-based therapeutics is crucial for preclinical safety evaluation.
• Designing and interpreting pharmacokinetic studies for these therapies presents challenges for developers and regulators.
• Regulatory authorities require robust biodistribution data for dossier approval.

Purpose of the Study:

• To design a decision tree for preclinical biodistribution studies of cell-based therapeutics.
• To standardize the approach for assessing the safety and pharmacokinetics of these novel therapies.
• To provide guidance for developers and regulators based on approved regulatory dossiers.

Main Methods:

• Evaluation of eight preclinical studies involving mesenchymal stromal cells (MSCs) in mouse, rat, and sheep models.
• Comparison of various administration routes (local/systemic), cell labeling techniques (chemical/genetic), and detection methods (PCR, IHC, bioimaging, MRI).
• Assessment of labeling and detection methodologies based on cost, throughput, speed, sensitivity, and specificity.

Main Results:

• A decision tree was established, differentiating between small immunodeficient animals for heterologous MSC biodistribution and large animals for homologous labeled products.
• The decision tree facilitates the collection of biodistribution and pharmacodynamic data.
• Polymerase chain reaction (PCR) was identified as a convenient detection method, with immunohistochemistry (IHC) recommended for spatial distribution analysis.

Conclusions:

• The developed decision tree aids in standardizing biodistribution study designs for cell-based therapeutics.
• Combining different animal models and detection techniques offers a cost-effective and timely strategy for safety assessment.
• Improved methods for biodistribution studies enhance the accurate evaluation of therapeutic safety.