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.

Alternative strategies for mass spectrometer-based sample dilution of bioanalytical samples, with particular reference to DBS and plasma analysis.

BACKGROUND: The analysis of bioanalytical samples has required a physical dilution of high-concentration samples to bring concentrations into the validated calibration range of an assay. RESULTS: A reversed phase ultra-high performance liquid chromatography-tandem mass spectrometry method for the quantitative analysis of pioglitazone in dried blood spots has been used to partially validate two novel techniques to analyze sample concentrations that lie above a particular calibration range. The first of the two techniques is mass spectrometer signal dilution, which consists of lowering the signal that reaches the detector. The second technique designated isotope signal ratio monitoring looks at [M+2]+1 ions (caused by naturally occurring isotopes) for samples above the upper limit of quantification. CONCLUSIONS: The newly developed methods have the potential to simplify the analysis of bioanalytical samples for which previously a physical dilution of the sample was required to bring analytes within the calibration range of an assay.

Validation of a bioanalytical method for the quantification of a therapeutic peptide, ramoplanin, in human dried blood spots using LC-MS/MS.

A method has been developed and validated for the quantification of ramoplanin, a 2554 Da peptide antibiotic, in human dried blood spots using high-performance liquid chromatography with tandem mass spectrometric detection. The validation data meet FDA acceptance criteria for bioanalytical assays and cover the quantification of ramoplanin over the range 10-5000 ng/mL. The assay determines ramoplanin at the same lower limit of quantification as conventional liquid sample methods. Dried blood spot analysis provides an approach for quantification of peptide therapeutics and delivers significant benefits for sample collection and handling and also sample cleanup over conventional plasma and serum assays.

Application of the DBS methodology to a toxicokinetic study in rats and transferability of analysis between bioanalytical laboratories.

BACKGROUND: There are little published data on either the comparison of liquid blood and dried blood spots (DBS) analyses or the ability to generate comparable DBS data at different analytical laboratories. We assess the comparative results of samples stored as liquid blood and DBS. We also determine the transferability of DBS samples by comparing the analysis at two laboratories. RESULTS: Bioanalytical methods for the analysis of pioglitazone in DBS and liquid blood samples were validated to US FDA guidelines. Pharmacokinetic data generated from DBS and liquid blood samples demonstrated area under the time-concentration profile (0-24 h) values within 3% of each other and maximum plasma concentration values within 7% of each other. Comparing DBS sample results at different laboratories showed more than 99% of results agreeing within 20%. CONCLUSIONS: The results indicate that comparable concentration results are obtained from DBS and whole blood samples within the same laboratory, indicating that changing between the two matrices is viable. The comparable results of DBS samples analyzed at two laboratories using different analytical methodologies demonstrate that the technique is robust and transferable.