Senior Advisor Eli Lilly and Company Indianapolis, Indiana
Oxidation is a significant post-translational modification for antibodies, impacting their safety, efficacy, clearance, and immunogenicity. Sub-unit Reversed Phase HPLC is commonly used to measure oxidation, but its performance can be compromised due to sample oxidation during analysis, leading to increased variability and reduced sample throughput. Herein we will discuss a case study where the drug substance batches of a range of monoclonal antibodies with variable physicochemical characteristics showed up to 50% increase in subunit oxidation levels over 48 hours, thereby introducing complexity for method validation. To minimize oxidation, the sample preparation technique was modified using metal chelators, with Ethylene Glycol-bis(β-aminoethyl ether)-N,N,N′,N′-Tetraacetic Acid Tetrasodium Salt (EGTA) showing the most significant stabilizing effect. The ability of the chelators to stabilize oxidation was found to be correlated to their effectiveness to mitigate polysorbate degradation. Overall, this case study provides understanding on increasing throughput, reducing method variability and enhancing cost-effectiveness for antibody oxidation assays.
Learning Objectives:
Upon completion, participant will be able to understand the limitations of a commonly used method for analysis of mAb oxidation. The learnings can be applied to solve the limitations and potentially offer new ways of designing stable mAb formulations.
