Determination of osimertinib in human plasma, urine and cerebrospinal fluid.

Aim: Osimertinib (Tagrisso, AZD9291) has been approved for the treatment of patients with metastatic EGFRm T790M non-small-cell lung cancer. Results: Rapid and sensitive LC-MC/MS methods were developed for osimertinib and its metabolites, AZ13597550 and AZ13575104, in human plasma (low- and high-range), urine and cerebrospinal fluid. We discuss the challenges of these multi-analyte and multiple matrix assays. The methods have been successfully validated and used for the analysis of over 20,000 clinical samples, with successful incurred sample reproducibility. Conclusion: The assays have been shown to be selective, accurate and robust, providing high-throughput analysis during the clinical development of osimertinib.