Comprehensive characterization of critical quality attributes of meplazumab for injection
YANG Tianyi
SONG Peiming
GUO Xiaobing
CHEN Xiaochun
TANG Hao
Abstract：Objective To comprehensively characterize the critical quality attributes of meplazumab for injection,including primary structure,post-translational modifications,disulfide bond linkages,purity,higher-order structure,and Fc region functionality,thereby providing a scientific basis for its quality control and clinical application.Methods Ultra-performance liquid chromatography-mass spectrometry was employed to determine the intact molecular weight,peptide mapping coverage,post-translational modifications,and disulfide bond linkages.Hydrophilic interaction chromatography coupled with fluorescence detection and mass spectrometry was used for N-glycan profiling.Size exclusion chromatography(SEC),capillary electrophoresis-sodium dodecyl sulfate(CE-SDS),and analytical ultracentrifugation(AUC)were applied to assess purity and aggregation status.Circular dichroism spectroscopy was utilized to analyze secondary structure,while differential scanning calorimetry(DSC)was performed to evaluate thermal stability.Surface plasmon resonance(SPR)technology was employed to determine the binding affinity of the Fc region to C1q,Fcγ receptors,and FcRn.Results The measured intact molecular weight of meplazumab was consistent with the theoretical value,and the amino acid sequence coverage reached 100％.Post-translational modification analysis revealed a C-terminal lysine truncation of 99.7％on the heavy chain,oxidation of methionine M274 in the Fc region at 11.9％,and isomerization of aspartic acid D102 near the heavy chain complementarity-determining region at 18.1％.A total of 18 disulfide bonds were identified,with linkage patterns consistent with the IgG2 subtype characteristics.The N-glycan profile was predominantly composed of GOF,G1F,and G2F glycoforms.SEC and CE-SDS demonstrated monomer purity exceeding 99.5％,while AUC under native conditions revealed a monomer content of 95.5％.The secondary structure was predominantly β-sheet,and DSC exhibited three characteristic melting temperatures.SPR analysis confirmed high binding affinity of meplazumab to FcRn(KD=3.35 × 10-8 mol/L).Conclusion This study systematically elucidates the critical quality attributes of meplazumab,confirming the correctness of its primary and higher-order structures.Oxidation of M274 and isomerization of D102 are identified as potential critical quality attributes requiring enhanced monitoring.These findings provide essential physicochemical evidence to support quality standard establishment and clinical translation of meplazumab,while also contributing valuable research experience for the in-depth characterization of IgG2 subtype antibody therapeutics.
Keywords：monoclonal antibodymeplazumabIgG2 subtypequality characterizationpost-translational modificationsdisulfide bondsglycosylationcritical quality attributes
Publication Date：2026-07-31
Online Publishing Date：2026-08-26(First online date of this platform, not the publication date of the document)
Pages：9( 969-977 )