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Panel Discussion: Considerations for Human Radiolabeled Mass Balance Studies - FDA Draft Guidance

This webinar will take the format of a panel question and answer session focused on the FDA draft guidance clinical pharmacology considerations for human radiolabeled mass balance studies.

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This will be a new interactive format which will comprise a brief presentation on the FDA guidance “Considerations for Human Radiolabeled Mass Balance Studies” (issued as draft in May 2022) followed by a dynamic question-and-answer session with the Pharmaron panel and Scott Obach from Pfizer. Opportunity to ask questions in advance and taken live from the audience via the chat function.

  • Overview of FDA Draft Guidance
  • Human Mass Balance Studies Perspective on FDA Draft Guidance 
  • Panel Discussion
    • Key Opinion Leader: Scott Obach, Ph.D. - Vice President, Scientific Research in the Pharmacokinetics, Dynamics and Drug Metabolism Department at Pfizer
    • Pharmaron Panel: Ray Cooke, Ph.D., MBA - Principal Scientist, Metabolism, Eleanor Barton, MChem - Team Leader, Programme Management, Stephen English - Director, C14 Bioanalysis and Marie Croft, Ph.D. - Scientific Director, Radiolabelled Sciences

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Moderated by: Scott Summerfield - Senior Director Pharmaceutical Metabolism at Pharmaron


Scott Obach, Ph.D. - Vice President, Scientific Research in the Pharmacokinetics, Dynamics and Drug Metabolism Department at Pfizer

Scott Obach is Vice President of Scientific Research in the Pharmacokinetics, Dynamics, and Drug Metabolism Department at Pfizer in Groton, CT.  He joined the company in 1992.  His main role in Pfizer’s early research is to aid medicinal chemists in designing new drugs that will have good exposure in the body, and his role in the later phase of drug development is to characterize how the body metabolizes and excretes individual drug candidates.  His research interests include application of in vitro approaches to study drug metabolism, prediction of human pharmacokinetics and drug interactions, mechanisms of chemical reactions of drug metabolism, and late stage lead diversification using enzymatic and chemical approaches.  Scott earned his Ph.D. in biochemistry from Brandeis University in 1990, followed by a post-doctoral fellowship in 1990-1992 at the New York State Department of Health Research Laboratories.  He is an author or coauthor on over 200 research publications, on the editorial boards of Drug Metabolism and Disposition and Xenobiotica, and is current president of the International Society for the Study of Xenobiotics.

Ray Cooke, Ph.D., MBA - Principal Scientist, Metabolism at Pharmaron

Ray is Principal Scientist at Pharmaron Radiolabelled Sciences (RLS) UK site. He has been involved in radiolabelled studies since his PhD (University of Manchester 1989) initially with tritiated peptides, then more exotic isotopes (Technetium-99m and Chromium-51) during his postdoctoral research into the pharmacokinetics of ADCs in Professor Malcolm Rowlands group at Manchester. Ray joined BioDynamics in its infancy in 1993 and stayed throughout the organisational transformations resulting in the acquisition of the radiolabelled ADME business by Pharmaron.  In this time, Ray has exclusively been involved with radiolabelled ADME.  His first radiolabelled clinical study was in 1999 and since then has supported over 200 radiolabelled clinical studies.  More recently Ray has been responsible for overseeing the non clinical metabolism support for Pharmaron’s integrated human metabolism programmes.

Eleanor Barton, MChem - Team Leader, Programme Management at Pharmaron

Eleanor has more than 20 years’ experience working in the pharmaceutical CRO industry, with the last 10 years specializing in human radiolabeled mass balance studies. She graduated from the University of York, UK in 2000 with a Master of Chemistry, during her degree she also spent a year in Germany at the University of Münster, working on her Master’s thesis. Eleanor began her career at BioDynamics (now Pharmaron UK), working in the bioanalysis group for 10 years, developing an in-depth knowledge of liquid-chromatography, tandem mass spectrometry (LC-MS/MS) and sample extraction technique. In 2013, she moved into the Pharmaron UK Metabolism department where she has since set up and developed the Programme Management team. This function is instrumental in aiding clients running complex drug development programmes across the Radiolabelled Sciences activities within Pharmaron.  Furthermore, Eleanor’s team are responsible for managing all clinical metabolite profiling and identification studies performed at Pharmaron UK, working closely with clients to ensure the metabolite identification objectives of a human mass balance study are met. 

Stephen English - Director, C14 Bioanalysis at Pharmaron

Stephen English joined Xceleron (later to be acquired by Pharmaron in 2017) in 2012. Prior to this, he spent 5 years in a GMP lab supporting the development of raw drug impurity assays via GC and LC. Since 2012, he has supported the execution of many AMS-enabled ADME and absolute bioavailability clinical studies as a lead scientist. He now oversees the 14C bioanalysis department in Germantown and collaborates with the Pharmaron CPC team in the execution of integrated radiolabeled clinical studies. He has co-authored a number of peer reviewed publications around the topic of AMS bioanalysis and presented at AAPS, EBF, IIS, and other conferences.

Marie Croft, Ph.D. - Scientific Director, Radiolabelled Sciences at Pharmaron

Marie Croft is Scientific Director, Radiolabelled Sciences at Pharmaron.  She has over 17 years of experience in bioanalytical applications of accelerator mass spectrometry (AMS). Following her graduation from De Montfort University in 2004, Marie started her career with Xceleron Ltd, obtaining hands on laboratory experience in AMS and LC+AMS analysis.  During this time, she conducted research into AMS microdosing, specifically cassette dosing in DDI studies, and combined use of AMS and PET after microdose administration.  She received her PhD in ‘Applications of human microdosing with accelerator mass spectrometry’ from the University of York in 2013. Marie works primarily with the 14C-bioanalysis team based at Pharmaron ABS, Germantown, and plays a key role in the design, review and execution of hADME studies.

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