Quality evaluation of anti-PD-1/CTLA-4 bispecific antibody / 中国生物制品学杂志

ABSTRACT

@#Objective Establish quality control methods for critical quality attribute of bispecific antibody against programmed cell death protein 1(PD-1)/cytotoxic T-lymphocyte-associated protein 4(CTLA-4).Methods The biological activity of PD-1 target was determined by reporter gene assay,and the competitive binding activity of CTLA-4 target was determined by flow cytometry;The antibody molecular size variants were controlled by reducing/non-reducing capillary electrophoresis-sodium dodecyl sulfonate(CE-SDS) and size exclusion chromatography-high performance liquid chromatography(SEC-HPLC);Charge heterogeneity was determined by imaging capillary isoelectric focusing electrophoresis(iCIEF);Bispecific anti-PD-1/CTLA-4 antibody was identified by peptide map analysis;Glycosylation was analysed by high performance liquid chromatography(HPLC)Results The concentration for 50% of maximal effect(EC_(50)) of PD-1target was(6.91±0.78) nmol/L,and the relative biological potency to the reference was(103.50±13.08)% with the RSD of 12.64%;The EC_(50) of CTLA-4 target activity was(0.35±0.28) nmol/L,and the relative biological potency was(99.30±9.15)% with the RSD of 8.32%.The percentage of peak area of light chain and heavy chain of reducing CE-SDS was(98.86±0.02)%.The main peak area percentage of non-reducing CE-SDS was(93.07±0.13)%,fragment percentage was(4.44±0.13)%,and polymer percentage was(2.49±0.15)%.The peak area percentage of SEC-HPLC monomer and polymer were(97.20±0.01)% and(2.68±0.01)%,respectively.The area percentage of peak A group,peak B group,peak C group and peak D group were(38.43±0.54)%,(43.26±0.32)%,(11.31±0.14)% and(7.00±0.17)%,respectively.Peptide mapping showed the specific spectrum of the bispecific anti-PD-1/CTLA-4 antibody,which could be adopted for identification test.The highest proportion of glycotype was GOF,with a content of(41.06±0.11)%,There were three types of glycan containing sialic acid,namely G2F+G1F-NANA,G2F-NANA and G2F-2NANA,with the content of(12.44±0.12)%,(12.00±0.05)% and(5.37±0.05)%,respectively.The total content of glycan containing sialic acid was(29.80±0.20)%.Conclusion The critical quality attributes of bispecific anti-PD-1/CTLA-4 antibody were studied and the corresponding quality control methods were established to ensure its safety,effectiveness and quality control,which provides a reference for the quality control methods and strategies of this type of monoclonal antibody products.