Intercompany Study to Evaluate the Robustness of Capillary Isoelectric Focusing Technology for the Analysis of Monoclonal Antibodies

Abstract

Interlaboratory comparisons are essential to bringing emerging technologies into biopharmaceutical industry practice and regulatory acceptance. As a result, an international team including 12 laboratories from 10 independent biopharmaceutical companies in the United States and Switzerland was formed to evaluate the precision and robustness of capillary isoelectric focusing (CIEF) to assess the charge heterogeneity of monoclonal antibodies. The different laboratories determined the apparent pI and the relative distribution of the charge isoforms of a representative monoclonal antibody (rMAb) sample using the same CIEF method. Statistical evaluation of the data was performed to determine within and between-laboratory consistencies and outlying information. The apparent pI data generated for each charge variant peak showed very good precision between laboratories with percentage of RSD values of B0.5%. Similarly, the percentage of RSD for the rMAb charge variants percent peak area values are B4.4% across different laboratories with different analysts using different lots of ampholytes and multiple instruments. Taken together, these results validate the appropriate use of CIEF in the biopharmaceutical industry in support of regulatory submissions.

Recent advances in the analysis of therapeutic proteins by capillary and microchip electrophoresis

“…The combined precision for the 12 labs was 0.8% RSD for the pI determination and 11% RSD for the percent peak area values for the charge variants of a therapeutic mAb. This study compared these values to those obtained using conventional CIEF, where the RSDs for pI and peak area were of 0.8% and 5.5%, respectively [129]. …”

Applications of capillary electrophoresis in characterizing recombinant protein therapeutics

“…Protein precipitation could lead to partial clogging of the capillary, chemical mobilization failure and/or irreproducibility of the analysis. To enhance protein solubility, urea, at various concentrations, is usually added to the sample mixture .…”

“…Arginine (p I 10.7) and iminodiacetic acid (p I 2.2) were chosen to be the ideal sacrificing agents (also called blockers or spacers) and the concentrations of these compounds are optimized. Many analyses on therapeutic proteins have incorporated sacrificial compounds and arginine and iminodiacetic acid do not have to be present at the same time.…”

Evaluation of capillary zone electrophoresis for charge heterogeneity testing of monoclonal antibodies

“…An international team of 11 laboratories from 9 independent companies/organizations in the US, Switzerland and Germany was formed to contribute to this study. As already demonstrated for capillary IEF [22] and imaged capillary IEF [23] the aim of the present CZE study was to show applicability in this context.…”