Quantification of oligonucleotides by LC-MS/MS: the challenges of quantifying a phosphorothioate oligonucleotide and multiple metabolites

Background: LC–MS/MS allows quantification of therapeutic oligonucleotides in biological fluids at low ng/ml concentrations. Achieving selectivity between metabolites and parent molecules in a single assay is one of the biggest challenges when developing a method. We present a strategy that allows quantification of an 18-mer antisense therapeutic, trabedersen, and six metabolites in human plasma. Results/Methodology: The method utilizes phenol-chloroform and SPE with UHPLC–MS/MS to independently quantify trabedersen and the 5´n-1, 5´n-2, 5´n-3, 3´n-1, 3´n-2 and 3´n-3 metabolites in a single assay. The qualification data indicate that if the method was validated it would meet regulatory expectations for precision, accuracy and...

To view this content, please register now for access

It's completely free