Differentiation and quantification of endogenous and recombinant-methionyl human leptin in clinical plasma samples by immunocapture/mass spectrometry

An LC-MS/MS method was developed for unambiguous differentiation of r-metHu-Leptin from endogenous leptin in human plasma. Using this method, specific quantitative information was obtained for pharmacokinetic studies in a clinical trial. The method should prove useful in quantifying this investigational drug against endo-leptin background in future clinical studies.