A LC–MS/MS method for therapeutic drug monitoring of sorafenib, regorafenib and their active metabolites in patients with hepatocellular carcinoma

A liquid chromatography-tandem mass spectrometry (LC–MS/MS) method was developed and validated for the simultaneous quantification of sorafenib (SORA), its N-oxide active metabolite and of regorafenib (REGO) and its two active metabolites regorafenib N-oxide and N-desmethyl regorafenib N-oxide in hepatocellular carcinoma patients’ plasma. A proper analytes’ separation was obtained with Synergi Fusion RP column (4 μm, 80 Å, 50 × 2.0 mm) using a...