Immunogenicity Risk Assessment of Process-Related Impurities in An Engineered T Cell Receptor Cellular Product

Area of Science:

• Biotechnology
• Immunology
• Cell Therapy Manufacturing

Background:

• Genetically modified T cells offer promising treatments for hematologic cancers and other diseases.
• Process residuals from genetic modification, such as AAV6 and Cas9, can pose an immunogenicity risk in final cell therapy products.

Purpose of the Study:

• To establish a framework for qualifying an assay to assess the immunogenicity risk of AAV6 and Cas9 residuals in cell therapy products.
• To guide risk assessment and CMC strategy for cell therapy development.

Main Methods:

• Elucidation of theoretical risks associated with process residuals.
• Summary of analytical data from process development.
• Qualification of an in vitro human PBMC cytokine release assay.
• Identification of a multiplexed inflammatory cytokine panel with defined criteria and positive controls.

Main Results:

• A qualified in vitro assay was developed to assess immunogenicity risk from cellular product-associated process residuals.
• A multiplexed cytokine panel was identified for evaluating inflammatory responses.
• Challenges and solutions for establishing meaningful exposure thresholds were discussed.

Conclusions:

• The developed framework and assay are crucial for assessing the immunogenicity risk of process residuals like AAV6 and Cas9.
• This assessment aids in establishing safe exposure levels and informs CMC strategies for clinical trials.
• The methodology provides a robust approach for ensuring the safety of engineered T cell receptor (eTCR) cellular products.