Abstract 871: Quality control aspects of cell therapy products

Abstract Quality control of cell therapy products is critical to ensure safety and efficacy of these advanced therapeutics. Cell therapy products are characterized by their complexity and variability due to the use of patient-individual living cells as the primary therapeutic agent. Consequently, QC processes must address several unique challenges and parameters. The QC process typically involves a combination of in-process controls and final product testing. In-process controls are essential to monitor critical manufacturing steps and ensure that the process remains within predefined parameters. Final product testing is conducted to confirm that the cell therapy product meets all established quality specifications before release. Key QC criteria for a T cell product include cell number and viability, identity, potency, as well as endotoxin, mycoplasma and microbiological testing. Analytical QC methods need to be extensively validated before routine use. The application of pre-validated QC kits simplifies the validation process while at the same time ensuring fast in-house QC testing. For endotoxin testing we have established a cartridge based testing methodology, which has been validated with the final cell product enabling rapid pre-release testing. Mycoplasm testing can be performed using a Ph.Eur. compliant TaqMan-based real-time qPCR method, which ensures fast and sensitive mycoplasm detection including a DNA extraction step from the cellular product. Pre-tested freeze-dryed antibody cocktails combined with automatic gating strategies ensure robust identity testing by flow cytometry analysis. Additionally, cell counting and viability testing can be integrated into this analysis, thus omitting additional counting methods. Due to the short product shelf-life of living cells, microbiological testing poses a challenge with classical culture methods. Post-release final results might be acceptable taking into account the advantage of direct application of living cells without additional freezing steps. Novel rapid testing methods will be a promising alternative in the future. Potency of the cell product is another challenge, which is often assessed by surrogate markers such as cytokines. In case of known target antigens, killing assays or ELISpot assays are possible. Additionally, multimer staining can test for MHC-antigen recognition of the cell product. In summary, robust QC systems are indispensable for the development and clinical application of cell therapy products, safeguarding patient health and advancing the field of regenerative medicine. Citation Format: Bettina A. Meissburger, Julian S. Thimm, Stefan B. Eichmueller. Quality control aspects of cell therapy products [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 871.