Using qPCR and ddPCR to study biodistribution of cell therapy products: a multi-site evaluation

Area of Science:

• Regenerative Medicine
• Cell Therapy
• Pharmacokinetics

Background:

• Cell therapy products (CTPs) require robust biodistribution (BD) evaluation for clinical translation.
• Current methods for assessing CTP BD lack international standardization.
• Standardized BD assays are essential for predicting CTP efficacy and safety.

Purpose of the Study:

• To standardize biodistribution assay methods for cell therapy products.
• To validate quantitative polymerase chain reaction (qPCR) and droplet digital PCR (ddPCR) for CTP BD assessment.
• To evaluate the in vivo biodistribution of human mesenchymal stem cells (hMSCs) in immunodeficient mice.

Main Methods:

• In vitro validation of qPCR and ddPCR using primate-specific Alu gene.
• Preparation and analysis of quality control samples with known human cell numbers in mouse tissues.
• In vivo biodistribution studies involving intravenous administration of hMSCs to immunodeficient mice, with tissue collection at 1, 4, and 24 hours post-administration.

Main Results:

• Both qPCR and ddPCR methods showed acceptable accuracy (within ±50%) and precision (CV < 50%).
• No significant quantification differences were observed among participating study facilities.
• Consistent hMSC biodistribution profiles were found across facilities, with the lungs exhibiting the highest cell distribution.

Conclusions:

• Quantitative evaluation using qPCR and ddPCR with Alu sequences is adaptable for cell therapy product biodistribution assessment.
• The standardized method provides a reliable approach for non-clinical biodistribution studies.
• This standardization facilitates the prediction of clinical efficacy and safety for cell-based regenerative therapies.