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Abstract

C-terminal lysine microheterogeneity and deamidation of Asn141 in the heavy chain and Asn161 in the light chain are the major causes of MMA383 charge heterogeneity. Identification of the two deamidation sites will allow replacement of these amino acids in order to create a product less susceptible to degradation.

Comparison of methionine oxidation in thermal stability and chemically stressed samples of a fully human monoclonal antibody

“…Retention time shift can also be caused by the indirect effect of Met oxidation. It has been shown that separation of antibody variants by ion exchange chromatography is not only based on charge or overall charge of the molecule [29,30]. Instead, separation of recombinant monoclonal antibody variants may be more dependent on local charge differences of the molecules.…”

Analysis of lysine clipping of a humanized Lewis-Y specific IgG antibody and its relation to Fc-mediated effector function

“…This is of particular relevance for the lysine present at the carboxyl-terminus of the two heavy chains [6] which can be clipped by carboxypeptidases during the fermentation process-a phenomenon commonly observed for therapeutic proteins [6,7]. According to the amino acid sequence of the IGN311 heavy chain, a maximum of two carboxy-terminal lysines per Ab are expected.…”

“…The removal of the carboxy-terminal lysine from the heavy chains is routinely observed upon the characterization of monoclonal antibodies [7,8] and is caused by intracellular enzymes [9]. From a regulatory aspect, this 'lysine clipping' is not regarded as critical under the condition that a potency assay is available that proofs the quality of the mAb [1].…”

Phase I Dose Escalation Study with the Lewis Y Carbohydrate Specific Humanized Antibody IGN311

“…Additional blood samples were taken on days 29 and 43. Concentrations of IGN311 in the serum were measured using a specific sandwich ELISA with the anti-idiotypic mAb MMA383 specifically recognizing the idiotype of IGN311 [32]. Pharmacokinetic parameters were calcu-lated [33] separately for each of the two infusions: The area under the concentration-time curve (AUC 0-t) was calculated from the original data using the trapezoidal rule.…”