An electrochemiluminescence assay for quantification of Denileukin Diftitox and its anti-drug antibodies in rat serum

Nonclinical immunogenicity assessment of E3112, a recombinant human hepatocyte growth factor, and its impact on pharmacokinetics in rats and monkeys

E3112 is a recombinant human hepatocyte growth factor currently in development for the treatment of acute liver failure. The assessment of immunogenicity is crucial in the development of biotherapeutics. Consequently, a semi-quantitative assay of anti-drug antibody (ADA) was developed in rat and monkey serum using a ligand binding assay with electrochemiluminescence detection. A standard tiered approach was employed for the immunogenicity assessment, comprising a screening assay and a subsequent confirmatory assay. In the assay validation studies, selectivity, sensitivity, prozone effects, reproducibility, drug tolerance, and stability were evaluated. These assessments were conducted using a surrogate positive control of ADA. The accuracy and precision of the surrogate ADA were within ± 20 % and 20 %, respectively. The stability of ADA was also confirmed under a variety of conditions. The developed assays were successfully employed for the assessment of immunogenicity in rats and monkeys following the administration of a repeated dose of E3112. The administration of E3112 resulted in an increase in ADA levels, with higher levels observed in rats than in monkeys. Systemic exposures of E3112 in rats with higher ADA levels were lower than those with lower ADA, confirming the utility of nonclinical immunogenicity in interpreting pharmacokinetics and its inter-individual variability.

Development and validation of bioanalytical methods to support clinical study of disitamab vedotin

Disitamab vedotin (RC48), a humanized anti-HER2 antibody conjugated with monomethyl auristatin E (MMAE), is the first antibody-drug conjugate in China with an approved biological license application. A bioanalytical method was established for three analytes (total antibody, conjugate antibody and free payload) to help characterize their pharmacokinetic behavior in clinical settings. The bioanalytical methods were validated according to M10 guidance. Electrochemiluminescence assay methods were used for the quantitative measurement of total antibody and conjugated antibody in human serum. A LC-MS/MS method was used to quantify the concentration of MMAE in human serum. The method had high specificity and sensitivity with a quantitative range of 19.531-1250.000 ng/ml (total antibody), 39.063-5000.000 ng/ml (conjugated antibody) and 0.04-10.0 ng/ml (MMAE), respectively.