Generic UPLC-MS/MS and Gyrolab assays with blood microsampling for pharmacokinetic assessments of therapeutic antibodies in mice.

Serial blood sampling from one animal is useful to understand relationship between pharmacokinetics (PK) and pharmacological or toxicological events in individual animals. To assess its feasibility in mice, two therapeutic antibodies were used to evaluate impacts by different blood sampling methods, sampling sites, and assay platforms on PK. Denosumab and Panitumumab were intravenously administered to mice and only 0.05 mL of blood sample per point was collected from jugular vein or tail vein. Blood samples were collected serially from a mouse or collected by traditional composite sampling from each mouse. Plasma concentrations of the two drugs were assayed by a generic ligand binding assay using Gyrolab or by a generic ultra-performance liquid chromatography with tandem mass spectrometry. The two assay platforms showed acceptable accuracy and precision and gave comparable PK parameters of the drugs, suggesting that both assays were successfully applied to the PK assessments. Comparable results in the PK profiles were noted between serial and composite blood samplings and differences in the two sampling sites did not impact PK. These findings suggest that microsampling combined with generic assays is useful to assess PK profiles of therapeutic antibodies in mice.