Validated extended multiplexed LC-MS/MS assay for the quantification of adagrasib and sotorasib in human plasma, together with four additional SMIs.

Recently, two small molecular inhibitors (SMIs) -adagrasib and sotorasib- have been introduced for targeting Kirsten rat sarcoma (KRAS) p.G12C mutations in patients with non-small cell lung cancer (NSCLC). In order to support pharmacokinetic research as well as clinical decision making, we developed and validated a simple and accurate liquid chromatography-tandem mass spectrometry method for the multiplexed quantification of adagrasib and sotorasib. This assay was co-validated with the quantification for brigatinib, lorlatinib, pralsetinib and selpercatinib. Methanol was used for single-step protein precipitation. Chromatographic separation was performed using an Acquity® HSS C18 UPLC column, with an elution gradient of ammonium formate 0.1 % / in water and acetonitrile. In K2-EDTA plasma, adagrasib was found to be stable for at least seven days at room temperature and 4 °C, and at least 3 months at -80 °C. Sotorasib was found to be stable for at least three days at room temperature, seven days at 4 °C and at least 3 months at -80 °C. The method was validated over a linear range of 80-4000 ng/mL for adagrasib and 25-2500 ng/mL for sotorasib. The assay is therefore well-equipped for determining plasma concentrations in clinical practice.