Mitigating the aggregation challenge in immunocytokine production: Strategies during cell line development and purification optimization

Abstract

The rapid growth of bispecific antibodies and antibody fusion molecules in biopharmaceuticals necessitates precise process development. The molecular design, the biophysical properties, such as protein hydrophobicity and charge-charge interactions, and the process development workflows are crucial to manage the critical quality attribute (CQA) of development candidates at the development and manufacturing stage. This study focuses on aggregation mitigation for an immunocytokine, HLX101, comprised of an engineered cytokine fused to the knob chain of a Knob-into-Hole IgG. Aggregation and other CQAs were monitored and controlled throughout cell line development (CLD), expression, and purification. Our study effectively identified HLX101 clone #10 as optimal for large-scale manufacturing by demonstrating stable expression and by balancing high yield with low aggregation. This was achieved by using purification process results to guide the selection of the final clone in the cell line development, integrating both processes to optimize overall outcomes in immunocytokine production. Thus, clone #10, with its favorable profile, emerged as more efficient, enhancing overall yield and quality. This underscores the importance of considering both upstream and downstream processes in immunocytokine production.