Enzyme-linked immunosorbent assays for quantification of MMMAE-conjugated ADCs and total antibodies in cynomolgus monkey sera / 药物分析学报

Antibody-drug conjugates(ADCs)are commonly heterogeneous and require extensive assessment of exposure-efficacy and exposure-safety relationships in preclinical and clinical studies.In this study,we report the generation of a monoclonal antibody against monomethyl auristatin E(MMAE)and the development,validation,and application of sensitive and high-throughput enzyme-linked immunosor-bent assays(ELISA)to measure the concentrations of MMAE-conjugated ADCs and total antibodies(tAb,antibodies in ADC plus unconjugated antibodies)in cynomolgus monkey sera.These assays were suc-cessfully applied to in vitro plasma stability and pharmacokinetic(PK)studies of SMADC001,an MMAE-conjugated ADC against trophoblast cell surface antigen 2(TROP-2).The plasma stability of SMADC001 was better than that of similar ADCs coupled with PEG4-Val-Cit,Lys(m-dPEG24)-Cit,and Val-Cit linkers.The developed ELISA methods for the calibration standards of ADC and tAb revealed a correlation be-tween serum concentrations and the OD450 values,with R2 at 1.000,and the dynamic range was 0.3-35.0 ng/mL and 0.2-22.0 ng/mL,respectively;the intra-and inter-assay accuracy bias％ranged from-12.2％to-5.2％,precision ranged from-12.4％to-1.4％,and the relative standard deviation(RSD)was less than 6.6％and 8.7％,respectively.The total error was less than 20.4％.The development and validation steps of these two assays met the acceptance criteria for all addressed validation parameters,which suggested that these can be applied to quantify MMAE-conjugated ADCs,as well as in PK studies.Furthermore,these assays can be easily adopted for development of other similar immunoassays.

Content Comparison of Total Flavonoids in Cyperus Rotundus from Different Habitats / 中国药师

Objective:To establish the determination method for total flavonoids in Cyperus rotundus and investigate the total fla-vonoids content in Cyperus rotundus from different habitats. Methods:Total flavonoids in Cyperus rotundus from different habitats were detected by ultraviolet spectrophotometry with rutin as the standard substance. Results:The absorbance of rutin had a good linear cor-relation with the concentration within the range of 0.064 3-0.642 6 mg·ml-1(r =0.999 1). The average recovery was 99.74%(RSD=2. 16%,n=6). The order of total flavonoids content in Cyperus rotundus from different habitats was Henan province >Sichuan province> Guangdong province >Anhui province > Halnan province >Shandong province. Conclusion:The method is easy and ac-curate, which can be applied in the quality control of Cyperus rotundus. The total flavonoids content in Cyperus rotundus from Henan province is the highest.