Roundtable Discussion: Interpreting the New US Pharmacopoeia Guidance for Sterility & Microbial Testing in Cell Therapy

Ensuring the absence of adventitious microbial contamination is fundamental to the quality and safety of cell therapy products. As the industry adopts more advanced manufacturing platforms, modern microbiological methods (M3) offer scientifically robust alternatives to traditional compendial tests, enabling faster results, improved sensitivity, enhanced automation, and greater operational efficiency.

This roundtable explores the evolution of USP’s holistic approach to M3 and provides practical guidance for implementing rapid microbiological technologies across quality control laboratories. Attendees will gain an overview of the latest USP standards supporting sterility and microbiological testing, including strategies for selecting challenge microorganisms, designing low-level inoculation studies, and establishing appropriate growth media and incubation conditions. The session will also discuss effective collaboration with equipment suppliers, approaches to strengthening data integrity using USP General Chapters <72> and <73>, and implementation of robust and flexible mycoplasma nucleic acid amplification tests (NATs) under USP <77>.

Drawing on real-world case studies and lessons learned, the discussion will highlight common implementation pitfalls and practical solutions for successful method adoption. Finally, attendees will gain perspective on the current state of PCR- and rapid sterility-testing technologies, emerging trends, and future directions for advancing microbiological quality control through modern, science-based testing approaches.

The roundtable will provide an insight into the below topics:

• The evolution of USP’s holistic approach to modern microbiological methods (M3)

• Navigating the latest USP standards for sterility and microbiological testing. To name a few   USP <72>, <73>, <77>

• Selecting test microorganisms and designing low-level inoculation studies

• Best practices for growth media and incubation strategy selection

• Partnering effectively with equipment suppliers for successful implementation

• Enhancing QC data integrity with USP <72> and <73> methodologies

• Implementing robust and flexible mycoplasma NATs under USP <77>

• Implementation pitfalls, case studies, and lessons learned

• PCR and rapid sterility testing: where are we today and what lies ahead?

The panellist include

Dr. Huiping Tu, Senior Principal Scientist, Microbiology, Global Biologics United States Pharmacopeia (USP)

Dr. Huiping Tu is a Senior Principal Scientist at the U.S. Pharmacopeia (USP), where she manages the Microbiology Expert Committee and Statistics Expert Committee and spearheads the development of standards related to microbiology and bioassays. She is recognized as a thought leader in advancing microbiology and bioassay standards and fostering scientific collaboration across industry, academia, and regulatory communities. Through her leadership of Expert Committees activities and active external engagement, Dr. Tu helps shape standards that address emerging scientific challenges, promote innovation, and support product quality and patient safety. Previously, she served as Director of the Biologics Laboratory at USP, managing multidisciplinary teams in bioanalytical, bioassay, and microbiology disciplines. Before joining USP in 2012, Dr. Tu was a Senior Research Scientist at Merck, contributing to early-stage drug discovery within the Cardiovascular Diseases Franchise. Dr. Tu holds an M.S. in Organic Chemistry and a Ph.D. in Physiology. With more than 20 years of experience spanning the pharmaceutical industry, academia, and regulatory science, she brings expertise in microbiology, molecular and cell biology, biochemistry, analytical chemistry, and the development of USP–NF standards and pharmaceutical reference standards. She is the lead or co-author of numerous peer-reviewed publications such as Cell, The Journal of Clinical Investigation, and Neuron and holds several patents.

Dr. David Roesti, PhD. Microbiology Expert/Senior Technical Steward Manufacturing Science and Technology at Novartis Pharma AG

Dr. David Roesti holds a PhD in microbial ecology from the University of Neuchâtel, Switzerland, and has more than 25 years of experience in microbiology. He currently works in the Manufacturing Science & Technology department at Novartis Pharma AG in Stein, Switzerland, where he is responsible for defining the site microbial control strategy. He also serves as a global subject matter expert in microbiology for the Novartis Group. Prior to this role, he led the Rapid Microbiological Methods team at Novartis Pharma AG and served as laboratory supervisor for microbiological testing of non-sterile drug products at Novartis Pharma Stein AG. Dr. Roesti is an elected member of the General Chapters Microbiology Expert Committee of the United States Pharmacopeia for the 2025–2030 revision cycle. Under his leadership, the USP M3 Microbiology Subcommittee successfully developed and published the first general chapters on rapid microbiological methods in the USP. Dr. Roesti is also the lead author or co-author of numerous publications in peer-reviewed journals and book chapters and has regularly presented at scientific congresses and expert forums.

Dr. Friedrich von Wintzingerode, PhD. Director, ADQC Microbiological Sciences at Roche-Genentech

Friedrich is Director, ADQC Microbiological Sciences at Roche-Genentech. His team ensures the safety of critical materials, drug substance, and drug product for cell therapies and individualized therapies by focusing on adventitious agents control (viruses, parasites, mycoplasma, bacteria, and fungi). Friedrich joined Roche-Genentech after earning his PhD in Microbiology and has over 25 years of experience in Quality Control and Quality Assurance in the biopharmaceutical industry, working on various topics including microbiological testing, material qualification and specifications, environmental monitoring, cleaning analytics, and analytics for release. Friedrich has led several global technical teams (e.g. microbial identification, microbiological testing for ATMPs, endotoxin testing, Low Endotoxin Recovery/LER, and ATMP materials) at Roche-Genentech and PDA. Friedrich is past-chair of the PDA ATMP advisory board and co-chair of the 2025 – 2030 USP Microbiology Expert Committee.