Validation and application of hybridization liquid chromatography-tandem mass spectrometry methods for quantitative bioanalysis of antisense oligonucleotides.

Antisense oligonucleotide (ASO), an emerging modality in drug research and development, demands accurate and sensitive bioanalysis to understand its pharmacokinetic and pharmacodynamic properties. By combining the advantages of both ligand binding and liquid chromatography-mass spectrometry/tandem mass (LC-MS/MS), hybridization LC-MS/MS methods were successfully developed and validated/qualified in a good lab practice (GLP) environment for the quantitation of an ASO drug candidate in monkey serum, cerebrospinal fluid (CSF) and tissues in the range of 0.5-500 ng/ml. Special treatment of CSF samples was employed to mitigate nonspecific binding, improve long-term storage stability and enable the usage of artificial CSF as a more accessible surrogate matrix. The method was also qualified and applied to ASO quantitation in various monkey tissue samples using a cocktail tissue homogenate as a surrogate matrix. This work was the first reported GLP validation and application of ASO bioanalysis using the hybridization LC-MS/MS platform.