BioPharmaceutical Emerging Best Practices Association

HCP Scientific Committee

Christina De Zafra
Christina De Zafra, Ph.D.

Director in the Nonclinical Sciences, Seagen

California, USA

Dr. Christina Zuch de Zafra received her PhD in Toxicology from the University of Rochester and conducted a post-doctoral research fellowship at the University of Colorado; her research utilized rodent models to study the impact of toxins (lead) or neurodegenerative disease (Parkinson’s disease) on dopaminergic pathways in the central nervous system. Christina has been a part of the nonclinical toxicology departments at Genentech and Amgen, supporting the development of multi-modality biotherapeutics (including mAbs, fusion proteins, ADCs, and oncolytic viruses), and is currently a Director in the Nonclinical Sciences department at Seagen (based in South San Francisco). She has specialized in oncology, and has experience in neuroscience-, ophthalmic- and infectious disease-focused drug development. Her other areas of focus include product quality risk assessments, nonclinical abuse liability assessment, and the 3Rs of ethical animal use. Christina is a member of the Society of Toxicology and is a Diplomate of the American Board of Toxicology. BEBPA HCP Scientific Committee Member since 2018.

Denise Krawitz
Denise Krawitz, Ph.D.

Dr. Krawitz, Principal Consultant at CMC Paradigms LLC, is based out of the San Francisco Bay Area. With over 20 years of strategic and technical CMC development experience, Denise provides consulting expertise to large and small biotechnology companies to move products from late-stage research to commercialization efficiently. Denise’s skill set is the product of working directly as a bench scientist, group, leader, project team leader, and project manager. She has broad process development experience, with an emphasis in analytical development and impurity analysis.

Prior to becoming a consultant, Denise served multiple technical and team leadership roles at Genentech, BioMarin, and Ambrx. At Genentech, she was the subject matter expert for host cell protein (HCP) strategy and testing. Denise led all R&D related to HCP strategy, including development of HCP ELISAs, characterization of HCP ELISA reagents, CHO and E. coli proteomics, and implementation of orthogonal techniques to monitor HCPs. Additionally, Denise was responsible for setting the strategic direction for HCP management across the Genentech pipeline, including setting acceptance criteria, risk assessments, and authoring all regulatory documents. Denise has authored several peer-reviewed publications in the HCP field, and been invited to give presentations at multiple international conferences.

Denise received her Doctor of Philosophy in Molecular and Cell Biology from the University of California, Berkeley. Her focus was establishment of chromatin structures that modulate gene expression. Additionally, she received a Fulbright fellowship to study protein folding in Regensburg, Germany.

Alexey Khrenov
Alexey Khrenov, Ph.D.

CMC reviewer, DPPT, OTAT, CBER/ FDA

Maryland, USA

Dr. Alexey Khrenov received his Ph.D. in Biochemistry from the Institute of Biochemical Physics of Russian Academy of Sciences in Moscow, Russia and is currently CMC reviewer in the Division of Plasma Protein Therapeutics (DPPT), in the Office of Tissues and Advanced Therapies (OTAT) in CBER/ FDA. His review responsibilities include review of CMC sections of marketing and investigational applications and supplements for plasma-derived and recombinant hemostatic products. Dr. Khrenov also participated in multiple pre-license and surveillance inspections of manufacturing facilities. Prior to joining the FDA Dr. Khrenov worked at the American Red Cross Holland Laboratory, United States Pharmacopeia and National Institutes of Health. He has been with the FDA since 2013. BEBPA HCP Scientific Committee Member since 2018.

Frieder Kröner
Frieder Kröner, Ph.D.

Group Head Bioanalytics, Novartis

Basel, Switzerland

Dr. Frieder Kröner works on the analytical development and characterization of new biological entities as the Group Head Bioanalytics at Novartis, Switzerland. He is heading a laboratory which develops analytical methods for biological impurities and potency.

From 2013-2015, Dr. Kröner was working as a postdoctoral researcher at Novartis establishing the use of a CHO platform HCP assay and establishing other additional characterization methods, e.g. as 2-D DIGE and LC-MS for host cell proteins. From 2015 on, Dr. Kröner became a functional lead in the late-phase analytics department including the role as expert for HCP impurities.

Dr. Kröner holds a doctoral degree in bioengineering with a focus on protein analytics and downstream process development from the Karlsruhe Institute of Technology in Germany.
BEBPA HCP Scientific Committee Member since 2019.

Catherine Shoemaker-Ramsey
Catherine Shoemaker-Ramsey, M.S.

Associate Director of Analytical Development, Biogen

Massachusetts, USA

Dr. Catherine Shoemaker-Ramsey is an Associate Director of Analytical Development at Biogen. She leads a group responsible for development and qualification of potency and residual impurity assays, including host cell protein measurement, for protein biologics and gene therapy clinical programs. She received her PhD in Biochemistry and Molecular Genetics from the University of Virginia. BEBPA HCP Scientific Committee Member since 2022.

Kevin Van Cott
Kevin Van Cott, Ph.D.

Associate Professor, University of Nebraska-Lincoln

Nebraska, USA

Dr. Kevin Van Cott earned his B.S. in Chemical Engineering from Purdue University, and his Ph.D. in Chemical Engineering at Virginia Tech.

Kevin has been working with private companies since 2007 to characterize their proteins by LC-MS/MS and other methods. He has worked with over 40 companies and many more products, helping them characterize post-translational modifications and identify and quantify HCPs. In his first official HCP project, he was tasked with detecting and identifying immunogenic HCPs that had shut down a Phase III trial. Van Cott’s lab then worked with the process engineers who were revising the purification process to confirm those HCPs were getting removed, and the product was approved by the FDA. Since then, he has analyzed HCPs in recombinant enzymes, monoclonals, vaccines, oncolytic virus products, and highly engineered chimeric proteins that have been produced in bacterial, yeast, and mammalian expression systems. His specialty is developing fast, efficient, and sensitive workflows that could generate results quickly so that process engineers could make informed decisions about the next steps to take for their purification process.

He is currently an Associate Professor in the Department of Chemical & Biomolecular Engineering, College of Engineering at the University of Nebraska-Lincoln and works with startup companies that need help using LC-MS/MS methods to solve their development problems. From 2020-2024, Dr. Van Cott was a member of an Expert Panel within the United States Pharmacopeia that drafted the USP General Chapter <1132.1> Residual Host Cell Protein Measurement in Biopharmaceuticals by Mass Spectrometry. Kevin has been active in BEBPA HCP conferences since 2015 as a speaker and workshop leader, leading and facilitating several workshops on the use of LC-MS/MS in HCP analysis. He joined the BEBPA HCP Scientific Committee Member in 2018 and has been the chair since 2023; in 2024 he joined the BEBPA Board of Directors.

Fengqiang Wang
Fengqiang Wang, Ph.D.

Principal Scientist, Merck & Co.

New Jersey, USA

Dr. Fengqiang Wang is currently a Principal Scientist in Analytical Research & Development department of Merck Research Laboratories (MRL), Merck & Co., Inc., Kenilworth, NJ, USA (known as MSD outside the US and Canada). He started at MSD in 2011 as a senior scientist working on the biochemical characterization of biologics and biosimilars using a variety of analytical tools. Then a major part of his work focused on the development of process specific or platform HCP ELISA methods and their antibody reagents qualification by 2D Western blot coverage assessment to support residual HCP drug substance release and in-process testing for biologics development. Other than ELISA method development, he also worked on orthogonal characterization of HCPs using 1D/2D SDS-PAGE, 2D-DIGE, and 1D/2D-LC-MS/MS to assess the impact of process change on HCP expression and clearance during biologics early and late phase development. His work has contributed to the successful development of commercialized biologics including Keytruda, Zinplava, and Ilumya. In recent years, he has expanded his role to also cover HCP control strategy in small molecules drugs synthesized with biocatalysts and in live virus vaccines. Fengqiang has presented at many national and international conferences including BEBPA HCP Annual Conference, Bioprocessing Summit HCP Conference, and AAPS PharmSci360 annual meeting. He is an active contributor to the BioPhorum HCP Workstream since 2014 and an Expert Panel member of USP HCP Standard 2020-2025 Cycle. BEBPA HCP Scientific Committee Member since 2023.

Stefanie Wohlrab
Stefanie Wohlrab, Ph.D.

Senior Scientist, Roche

Penzberg, Germany

Dr. Stefanie Wohlrab is a senior scientist and group leader in the Analytical Development and Quality Control Department at Roche. Her group is responsible for method development and qualification for process related impurities in classical and novel biopharmaceuticals. From 2014-2016, Dr. Wohlrab was working as a postdoctoral researcher at Roche with focus on new approaches to characterize host cell proteins and on the development of high-throughput methods. She received her Ph.D. in biochemistry with a focus on protein analytics from the University of Bayreuth. BEBPA HCP Scientific Committee Member since 2018.

Ying Zhang, Ph.D.

Director, Sarepta Therapeutics

Massachusetts, USA

Dr. Ying Zhang is currently a Director in the Analytical Development and Quality Control (ADQC) department at Sarepta Therapeutics, where she leads the AD team to support product characterization, process development, analytical method validation and transfer, as well as regulatory filings for all products within Sarepta’s portfolio. Ying has specialized in mass spectrometry-based characterization, especially HCP analysis. Ying was previously an employee of Pfizer. She received her Ph.D. in chemistry from Washington University in St. Louis. BEBPA HCP Scientific Committee Member since 2022.