Validation of a Flow Cytometric Assay to Detect Antibodies to a Novel Cell Therapy for Immunogenicity Assessment


Genetically engineered cell therapies, specifically CAR (chimeric antigen receptor)-based cell therapies, are successful treatments in immune oncology. Now, alternative engineered cell-surface proteins, including cytokines, immune-evasion proteins, and other immunologic complexes show therapeutic promise. Immunogenicity to these engineered proteins is a safety concern during clinical studies. Thus, it is important to develop robust assays for measuring potential immune responses to these novel therapeutics. Herein, a cell-based, flow cytometric assay was validated to assess humoral immunogenicity to the engineered cell-surface protein in human serum. A cell-based assay was warranted, as the engineered cell-surface protein could not be purified for use in a standard ligand binding assay.