Validation of an LC-MS/MS method for simultaneous quantification of abiraterone, enzalutamide and darolutamide in human plasma

•We describe the first LC-MS/MS method for the simultaneous analysis of abiraterone, enzalutamide and darolutamide in human plasma.•We recommend a fast and cooled sample preparation and storage method for abiraterone, as abiraterone was found to be highly unstable in human whole blood and plasma at ambient temperature.•Clinical applicability of the assay was demonstrated, and the assay is currently used in clinical practice. Currently, several oral androgen receptor signalling inhibitors are available for the treatment of advanced prostate cancer. Quantification of plasma concentrations of these drugs is highly relevant for various purposes, such as Therapeutic Drug Monitoring (TDM) in oncology. Here, we report a liquid chromatography/tandem mass spectrometric (LC–MS/MS) method for the simultaneous quantification of abiraterone, enzalutamide, and darolutamide. The validation was performed according to the requirements of the U.S. Food and Drug Administration and European Medicine Agency. We also demonstrate the clinical applicability of the quantification of enzalutamide and darolutamide in patients with metastatic castration-resistant prostate cancer.