A UHPLC-MS/MS bioanalytical assay for the determination of BMS-911543, a JAK2 inhibitor, in human plasma.

Herein we report a rapid, accurate and robust UHPLC-MS/MS assay for the quantitation of BMS-911453, a Janus kinase 2 inhibitor under clinical development for the treatment of myeloproliferative disorders, in human plasma. A systematic method development approach was used to optimize the mass spectrometry, chromatography, and sample extraction conditions, and to minimize potential bioanalytical risks. The validated method utilizes stable-isotope labeled (13)C4-BMS-911543 as the internal standard. Liquid-liquid extraction was used for sample preparation. Chromatographic separation was achieved within 2min on a Zorbax Extend-C18 column with an isocratic elution. BMS-911543 and its internal standard were detected by positive ion electrospray tandem mass spectrometry. The assay range was from 1 to 500ng/mL, and the standard curve was fitted with 1/x(2) weighted linear regression. The intra-assay precision was within 5.0% CV and the inter-assay precision was within 2.6% CV. The inter-assay mean accuracy, expressed as percents of theoretical, was between 99.8% and 102.3%. The assay has high recovery (∼80%) and minimal matrix effect (0.95-1.00). BMS-911543 was stable in human plasma for at least 24h at room temperature, 90 days at -20°C, and following three freeze-thaw cycles. The validated method was successfully applied to sample analysis in clinical studies.