ProStorm® Whole Blood Based Cytokine Release Assay: Insights and Experiences

Innate immunogenicity assays using fresh whole blood have become a pivotal approach for assessing the immunogenicity risk of biological drugs due to their clinical relevance. These assays are crucial for regulatory filings, especially for generic peptide drugs, as they help identify risks tied to process- and product-related impurities. Unlike peripheral blood mononuclear cell (PBMC) assays, fresh whole blood assays represent all blood cell types without introducing bias from cell purification methods. To ensure that the data reliably inform immunogenicity risk, thorough assay validation is essential – covering sensitivity, drug tolerance, specificity, precision, robustness, and accuracy.

In this talk, I outline the comprehensive process followed at ProImmune to validate fresh whole blood assays. This includes establishing cytokine panels, generating standard curves, defining assay acceptance criteria (such as upper and lower limits of quantification), and confirming signal recovery and assay variability. I will also cover the selection of Innate Immune Response Modulating Impurity (IIRMI) controls, applied both alone and spiked into the drug product to determine assay sensitivity.

Additionally, I discuss the importance of confirming the viability of diverse antigen-presenting cell phenotypes, analyzed via flow cytometry, in the presence of the drug. This also includes the use of cell-death controls to ensure accuracy. Finally, I highlight critical considerations for study design, such as determining the highest drug product concentration that maintains cell viability, the range of drug batches to test, and the IIRMI spiking strategy.

As a leader in this field, ProImmune’s ProStorm Cytokine Release Assay is on file with the FDA as a Drug Master File (DMF), simplifying the reference process for your Abbreviated New Drug Application (ANDA).

Wen Zhe is an immunology sales specialist based in Singapore, responsible for the APAC region. He graduated from National University of Singapore with a major in Chemistry. He joined ProImmune in early 2023 and supported many academic and research institutes alike by facilitating in-depth discussions, sharing relevant case studies, and engaging in thought experiments to help ensure their projects are well-conceived.