title: A double antibody radioimmunoassay for the determination of XV459, the active hydrolysis metabolite of roxifiban, in human plasma.
abstract: A radioimmunoassay (RIA) was developed for the determination of XV459, the active hydrolysis metabolite of the oral prodrug roxifiban (DMP 754), in human plasma. XV459 is a potent antagonist of the glycoprotein IIb/IIIa receptor. The method utilizes a competitive double antibody format employing an 125I-labeled XV459 analogue tracer which competes with XV459 for antibody binding sites and a second antibody precipitation step to separate antibody bound analyte from free analyte. The method has a validated lower quantification limit of 0.35 ng/ml (0.81 nM) using 12.5 microl of plasma and with dilution can accommodate clinical plasma samples ranging up to 48.0 ng/ml (110.7 nM). Cross-validation to an existing quantitative liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method showed good correlation (r(2)=0.98). The RIA has been successfully used to assay over 10000 clinical samples with sensitivity and specificity comparable to the LC-MS/MS method, but with faster turn around time and at greatly reduced costs.
authors.affiliation: Bristol-Myers Squibb Pharma Company, Stine-Haskell Research Center, 1090 Elkton Road, Newark, DE 19711, USA. pieniahj@delanet.com
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Pieniaszek
authors.forename: Anna F
authors.initials: AF
authors.lastname: Davidson
authors.forename: Harry L
authors.initials: HL
authors.lastname: Walton
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Pinto
authors.forename: Richard E
authors.initials: RE
authors.lastname: Olson
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Reilly
authors.forename: Yu Chen
authors.initials: YC
authors.lastname: Barrett
mesh_terms: D000578:Amidines / Q000097:blood* / Q000737:chemistry; D000596:Amino Acids / Q000097:blood* / Q000737:chemistry; D000818:Animals; D000906:Antibodies / Q000097:blood*; D001665:Binding Sites / Q000502:physiology; D006801:Humans; D007555:Isoxazoles / Q000097:blood* / Q000737:chemistry; D016014:Linear Models; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods
chemical_list: D000578:Amidines; D000596:Amino Acids; D000906:Antibodies; D007555:Isoxazoles; C104284:XV 459; C118235:roxifiban