Liquid chromatography–mass spectrometric assay for the quantitation in human plasma of ABT-888, an orally available, small molecule inhibitor of poly(ADP-ribose) polymerase

ABT-888, a poly(ADP-ribose) polymerase (PARP) -inhibitor in clinical trials, potentiates DNA-damaging agents. We developed and validated, according to FDA guidelines, an LC–MS assay for sensitive, accurate and precise quantitation of ABT-888 and its metabolite M8 in 0.2 mL human plasma. After ethyl acetate extraction, separation is achieved with a hydro-Synergi column and a 0.1% formic acid in acetonitrile/water-gradient. Detection uses electrospray, positive-mode ionization mass spectrometry. Between 10 (LOQ) and 1000 ng/mL, accuracy was 95.5–98.5% for ABT-888 and 91.4–100.9% for M8, and precision was 0.1–4.9% for ABT-888 and 0–13.7% for M8. The assay is being applied to samples generated in several clinical trials.