Development and validation of bioanalytical methods to support investigations of AZD9496 in the clinic.

Aim: AZD9496 is an oral nonsteroidal, potent and selective antagonist and degrader of ER-alpha. Two major active metabolites (M3 and M5 as diastereomers) were identified in humans. Methodology/results: Multianalyte, sensitive LC-MS/MS method in human plasma was developed and validated that overcame the challenges encountered. The method demonstrated acceptable precision, accuracy and selectivity for AZD9496 and two major metabolites. Incurred sample reanalysis was acceptable from evaluation in clinical studies, indicating adequate reproducibility. In addition, a urine method for AZD9496 was also developed and validated. Conclusion: Robust and sensitive LC-MS/MS assays for the quantitation of AZD9496 and two diastereomeric metabolites in human plasma and AZD9496 in human urine have been validated and successfully applied to clinical studies.