Publications by authors named "Bruce Stouffer"

The 13 GCC Closed Forum for Bioanalysis was held in New Orleans, Louisiana, USA on April 5, 2019. This GCC meeting was organized to discuss the contents of the 2019 ICH M10 Bioanalytical Method Validation Draft Guideline published in February 2019 and consolidate the feedback of the GCC members. In attendance were 63 senior-level participants from eight countries representing 44 bioanalytical CRO companies/sites.

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The 12th GCC Closed Forum was held in Philadelphia, PA, USA, on 9 April 2018. Representatives from international bioanalytical Contract Research Organizations were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The issues discussed at the meeting included: critical reagents; oligonucleotides; certificates of analysis; method transfer; high resolution mass spectrometry; flow cytometry; recent regulatory findings and case studies involving stability and nonclinical immunogenicity.

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Over the last decade, the use of biomarker data has become integral to drug development. Biomarkers are not only utilized for internal decision-making by sponsors; they are increasingly utilized to make critical decisions for drug safety and efficacy. As the regulatory agencies are routinely making decisions based on biomarker data, there has been significant scrutiny on the validation of biomarker methods.

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The 11th Global CRO Council Closed Forum was held in Universal City, CA, USA on 3 April 2017. Representatives from international CRO members offering bioanalytical services were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The second CRO-Pharma Scientific Interchange Meeting was held on 7 April 2017, which included Pharma representatives' sharing perspectives on the topics discussed earlier in the week with the CRO members.

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The 2017 11th Workshop on Recent Issues in Bioanalysis took place in Los Angeles/Universal City, California, on 3-7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, week-long event - a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule analysis involving LC-MS, hybrid ligand-binding assay (LBA)/LC-MS and LBA approaches.

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The 10th Global CRO Council (GCC) Closed Forum was held in Orlando, FL, USA on 18 April 2016. In attendance were decision makers from international CRO member companies offering bioanalytical services. The objective of this meeting was for GCC members to meet and discuss scientific and regulatory issues specific to bioanalysis.

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This article aims to address approaches to ensuring method changes for regulated ligand-binding assays of biologics drugs from old to newer formats and technology are properly understood, characterized and validated to meet current industry expectations and regulatory requirements. Sections in the chapter will include descriptions of different formats of ligand-binding assays, reasons that may drive updating of methods and procedures for qualifying method changes for immunoassays that are designed to support PK and immunogenicity analyses for clinical and nonclinical applications. Case studies from the authors' experience, as well as literature references will be provided as examples of challenges, as well as providing guidance of when and how to provide smooth transitions of older methods to newer, more robust or sensitive methods as reagents or technology are available.

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The 2015 9th Workshop on Recent Issues in Bioanalysis (9th WRIB) took place in Miami, Florida with participation of 600 professionals from pharmaceutical and biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5 day, week-long event - A Full Immersion Bioanalytical Week - specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS and LBA approaches, including the focus on biomarkers and immunogenicity.

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Dapagliflozin (Farxiga), alone, or in the fixed dose combination with metformin (Xigduo), is an orally active, highly selective, reversible inhibitor of sodium-glucose cotransporter type 2 (SGLT2) that is marketed in United States, Europe, and many other countries for the treatment of type 2 diabetes mellitus. Here we report a liquid chromatography-tandem mass spectrometry (LC-MS/MS) bioanalytical assay of dapagliflozin in human plasma. A lower limit of quantitation (LLOQ) at 0.

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Aim: The determination of drug-protein binding is important in the pharmaceutical development process because of the impact of protein binding on both the pharmacokinetics and pharmacodynamics of drugs. Equilibrium dialysis is the preferred method to measure the free drug fraction because it is considered to be more accurate. The throughput of equilibrium dialysis has recently been improved by implementing a 96-well format plate.

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The 2014 8th Workshop on Recent Issues in Bioanalysis (8th WRIB), a 5-day full immersion in the evolving field of bioanalysis, took place in Universal City, California, USA. Close to 500 professionals from pharmaceutical and biopharmaceutical companies, contract research organizations and regulatory agencies worldwide convened to share, review, discuss and agree on approaches to address current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches and immunogenicity.

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The paradigm shift of globalized research and conducting clinical studies at different geographic locations worldwide to access broader patient populations has resulted in increased need of correlating bioanalytical results generated in multiple laboratories, often across national borders. Cross-validations of bioanalytical methods are often implemented to assure the equivalency of the bioanalytical results is demonstrated. Regulatory agencies, such as the US FDA and European Medicines Agency, have included the requirement of cross-validations in their respective bioanalytical validation guidance and guidelines.

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Background: An absolute bioavailability study that utilized an intravenous [(14)C]microdose was conducted for saxagliptin (Onglyza(®)), a marketed drug product for the treatment of Type 2 diabetes mellitus. Concentrations of [(14)C]saxagliptin were determined by accelerator MS (AMS) after protein precipitation, chromatographic separation by UPLC and analyte fraction collection. A series of investigative experiments were conducted to maximize the release of the drug from high-affinity receptors and nonspecific adsorption, and to determine a suitable quantitation range.

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The effect of trough levels of a monoclonal antibody drug (drugB) on screening cut point (CP) determination for an anti-drug antibody (ADA) assay was scrutinized and the conclusions substantiated by data from a phase 3 cancer clinical study. The ADA assay utilized an acid dissociation step and either 0 or 100 μg/ml drugB was added to the samples prior to obtaining the signals used for CP calculations. Serum samples from three different drug-naive populations were tested (healthy individuals, cancer patients enrolled in the drugB clinical trial and cancer patients whose serum samples were available commercially).

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Carvedilol is widely prescribed for the treatment of hypertension, heart failure and left ventricular dysfunction following myocardial infarction. A sensitive and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed and validated to enable reliable and efficient bioanalysis of the (R)- and (S)-enantiomers of carvedilol and its pharmacologically active 4'-hydroxyphenyl metabolite in human plasma. Following plasma extraction using supported liquid extraction (SLE) in a 96-well plate format, extracted samples were derivatized with 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate (GITC).

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Background: Nulojix(®) is a fusion protein composed of the Fc portion of a human IgG1 linked to the extracellular modified domain of CTLA-4. Nulojix differs from another Bristol Myers Squibb product, Orencia(®) by two amino acids and was approved by the FDA on 15 June 2011 for the prophylaxis of organ rejection in adult patients receiving kidney transplant.

Results: A sandwich ELISA utilizing two monoclonal antibodies against CTLA-4 was employed for Nulojix quantification and pharmacokinetic analysis.

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A liquid chromatography and tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously determine the concentrations of saxagliptin (Onglyza™, BMS-477118) and its major active metabolite, 5-hydroxy saxagliptin to support pharmacokinetic analyses in clinical studies. The dynamic range of the assay was 0.1-50 ng/mL for saxagliptin and 0.

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Dasatinib (Sprycel) is a potent antitumor agent prescribed for patients with chronic myeloid leukemia (CML). To enable reliable quantification of dasatinib and its pharmacologically active metabolites in human plasma during clinical testing, a sensitive and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated. Samples were prepared using solid phase extraction on Oasis HLB 96-well plates.

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Aims: To investigate the influence of age and gender on the intravenous pharmacokinetics and pharmacodynamics of the plasminogen activator, lanoteplase.

Methods: Forty healthy subjects (10 each of young males, elderly males, young females and elderly females) received a single bolus 10 kU kg(-1) intravenous dose of lanoteplase. Plasma from blood serially collected for 24 h post-dose was analyzed for lanoteplase (antigen), fibrinogen, plasminogen and α2-antiplasmin concentrations, plasma plasminogen activation activity (PPAA) and rapid plasminogen activator inhibitor (PAI-1).

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A sensitive method was developed and validated for the measurement of ixabepilone (BMS-247550, Ixempra) using a demethylated analogue of ixabepilone (BMS-212188) as an internal standard. A 0.050 mL portion of each plasma sample was extracted with 0.

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Objective: Lanoteplase is a rationally designed variant of tissue plasminogen activator. The aim of this study was to examine the pharmacokinetics and functional activity of a single intravenous bolus dose of lanoteplase with those of a bolus plus two-step infusion of alteplase.

Design: Seven-centre substudy of the InTIME-I angiographic trial in patients presenting within 6 hours of onset of suspected acute myocardial infarction.

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The effect of delivery route on lung tissue response to oncostatin M (OM) was evaluated in isolated perfused rat lung (IPRL) and normal human bronchial epithelial cell line BEAS-2B in vitro models. In this study, the extent of induction of the cytokine IL-6 by OM was examined as evidence for local pharmacological activity in response to OM in lung tissue. OM stimulated dose-dependent release of IL-6 in both BEAS-2B cells and IPRL after exposure of either the apical (AP) or basolateral (BL) side of the epithelium.

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