Quantification of KRAS inhibitor sotorasib in mouse plasma and tissue homogenates using liquid chromatography-tandem
Irene A Retmana1, Nancy H C Loos2, Alfred H Schinkel2
1The Netherlands Cancer Institute, Division of Pharmacology, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands; Utrecht University, Faculty of Science, Department of Pharmaceutical Sciences, Division of Pharmacology, Universiteitsweg 99, 3584 CG Utrecht, the Netherlands.
Abstract:
Sotorasib is a KRAS inhibitor with promising anticancer activity in phase I clinical studies. This compound is currently under further clinical evaluation as monotherapy and combination therapy against solid tumors. In this study, a liquid chromatography-tandem mass spectrometric method to quantify sotorasib in mouse plasma and eight tissue-related matrices (brain, liver, spleen, kidney, small intestine, small intestine content, lung, and testis homogenates) was developed and validated. Protein precipitation using acetonitrile was utilized in 96-well format to extract sotorasib and erlotinib (internal standard) from mouse plasma and tissue homogenates. Separation of the analytes was performed on an Acquity UPLC® BEH C18 column by gradient elution of methanol and 0.1% formic acid in water at a flow rate of 0.6 ml/min. Sotorasib was detected by a triple quadrupole mass spectrometer with positive electrospray ionization in selected reaction monitoring mode. A linear calibration range of 2-2,000 ng/ml of sotorasib was achieved during the validation. Accuracy values were in the range of 90.7-111.4%, and precision values (intra- and interday) were between 1.7% and 9.2% for all tested levels in all investigated matrices. The method was successfully applied to investigate the plasma pharmacokinetics and tissue accumulation of sotorasib in female wild-type mice.
Insights
A new method quantifies sotorasib, a KRAS inhibitor, in mouse plasma and tissues. This validated assay enables pharmacokinetic and tissue distribution studies for this promising anticancer drug.
Area of Science:
- Pharmacology
- Analytical Chemistry
- Oncology
Background:
- Sotorasib is a KRAS inhibitor showing anticancer potential in early clinical trials.
- Further clinical evaluation of sotorasib is ongoing for solid tumors as monotherapy and combination treatment.
Purpose of the Study:
- To develop and validate a sensitive bioanalytical method for quantifying sotorasib.
- To measure sotorasib concentrations in mouse plasma and various tissue matrices.
Main Methods:
- Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for quantification.
- Acetonitrile protein precipitation was used for sample extraction from plasma and tissue homogenates.
- Analysis was performed using an Acquity UPLC® BEH C18 column with gradient elution.
Main Results:
- The validated method demonstrated a linear calibration range of 2-2,000 ng/ml for sotorasib.
- Accuracy ranged from 90.7-111.4%, and precision (intra- and interday) was 1.7-9.2% across matrices.
- The method successfully analyzed sotorasib pharmacokinetics and tissue distribution in mice.
Conclusions:
- A robust and validated LC-MS/MS method for sotorasib quantification in biological matrices was established.
- This assay is suitable for preclinical pharmacokinetic and tissue distribution studies of sotorasib.
- The developed method supports the clinical development of sotorasib as an anticancer therapeutic.
