(545d) Stability and Aggregation of Therapeutic Monoclonal Antibodies: Determination of Aggregation Kinetic Rates with Accelerated Studies

Monoclonal antibody (MAB) aggregation is gaining importance due to its pharmacological significance. Protein aggregation could cause immunogenicity as well as reducing the efficacy of the drug. Therefore, understanding the MAB stability and aggregation is very important for developing successful formulations. We investigated the stability and aggregation of several therapeutic IgGs with accelerated studies. Concentration dependency of the monomer and aggregates with time were studied with SEC-HPLC and protein conformational change and aggregate formation were followed with fluorescence spectroscopy. We also utilized light scattering methods for detecting molar masses and sizes. Results indicate that the protein aggregation is mainly via partially unfolded proteins and the aggregates consist of many sizes and shapes. In addition, we observed that considerable protein secondary structure is conserved within aggregates. Conformation of the protein within aggregates changes with aggregate size. Based on our experimental results, we also developed a protein aggregation mechanism, which could be used to analyze MAB aggregation kinetics. Lastly, we also discuss a method for connecting results from accelerated studies to those long-term results as well as a method for formulation ranking.