Cambridge Healthtech Institute’s 9th Annual

Optimizing Bioassays for Biologics

Case Studies Demonstrating Successful Bioassay Development

October 21 - 22, 2021 ALL TIMES EDT

New therapeutic modalities, including cell & gene therapies, immunotherapies, and antibody therapies, continue to push the limit on bioassay development and implementation. New formats present challenges including determining what reference materials to use and how to validate the assay. Health authorities and USP have provided guidance for the design and validation of a bioassay; however, they are just starting to consider solutions to common problems springing from this revolution in technology. Cambridge Healthtech Insitute's Ninth Annual Optimizing Bioassays for Biologics will bring together leaders working in bioanalytical and bioassay development to present case studies and best practices for handling the most common issues in biological assay development, validation, transfer, and maintenance.

Thursday, October 21

12:00 pm Registration


12:45 pm

Chairperson's Opening Remarks

Sumona Sarkar, PhD, Biomedical Engineer, Biosystems and Biomaterials Division, Biomaterials Group, National Institute of Standards and Technology
12:50 pm

Standards and Measurement Infrastructures to Improve Confidence in the Characterization and Testing of Cellular Therapeutic Products

Sumona Sarkar, PhD, Biomedical Engineer, Biosystems and Biomaterials Division, Biomaterials Group, National Institute of Standards and Technology

Analytical methods are critical in the characterization and testing of cell and gene therapy products.  Analytical method development occurs in parallel to product development and is refined as knowledge is accumulated during the development program.  Here we consider approaches for streamlining analytical method development via well-coordinated product and analytical method development efforts. We further discuss the importance of establishing a robust measurement infrastructure including key aspects such as, measurement assurance strategies, implementation of relevant documentary standards and enabling tools and technologies to streamline and integrate various aspects of the measurement process.

1:20 pm

Case Studies in Bioassay Analysis Using USP <1034>

Steven Walfish, Principal Scientific Liaison, Global Science & Standards, USP

Relative potency is a measure obtained from the comparison of a test sample to a standard based on the capacity to produce the expected biological activity. USP <1034> presents several different models and suitability criteria to determine the reliability of the estimate. This talk will cover traditional linear and non-linear bioassay models and case studies showing how to apply the chapter.

1:50 pm

Harmonisation of Bioassay Data: International Standards “Step Up” to New Challenges

Sandra Prior, PhD, Senior Scientist, National Institute for Biological Standards and Control (NIBSC, a Centre of the MHRA)

Biotherapeutic monoclonal antibodies and their biosimilars open the door to new possibilities for accessible and targeted treatments of oncological, immunological and infectious diseases. Advances in the analytical methods and regulatory processes have provided manufacturers with robust frameworks for their approval and control. Yet, the rapid market expansion and their complexity, whilst better understood, demand additional considerations. International Standards have contributed to the harmonisation of biological medicines for over a century, and now rise to the challenges set by of new medicines like monoclonal antibodies. Understanding their role and correct use is essential to realizing their potential as key tools to support product consistency and traceability over the product life cycle.

Ralf Stegmann, Dr., CEO, Stegmann Systems

The development and verification of test systems for biological assays is a challenging task. Focus of this talk are principle considerations and a practical approach to develop and verify efficient test systems for biological assays using equivalence tests.

2:50 pm Exhibit Hall with Poster Viewing


3:30 pm

Phase-Appropriate Potency Assays for Gene Therapy Products

Arkadi Manukyan, PhD, Scientist, Bioassay Dev & Gene Therapy, Sanofi

Virus-based gene therapies require complex analytical methods to assess key quality attributes during process development, GMP release, and stability monitoring of clinical-grade products. Here we discuss phase-appropriate paradigms for analytical method development, qualification, and implementation into gene therapy programs as they transition from research into clinical stages. In this talk, we will concentrate on a functional potency assay which often requires a multiplex approach to determine the true biological activity of the drug products. We will use one of our case studies as an example to discuss MOA potency assay development strategy, challenges, and method qualification.

4:00 pm

Cell-Based Bioassays for Cell and Gene Therapy

Sofie Pattijn, Founder & CTO, ImmunXperts SA

The development of cellular bioassays for cell and gene therapy products can be quite challenging due to the complex mode of action of this type of product. As an example, the development of an MSC bioassay with primary cells will be discussed. 

Michael Schwenkert, Chief Technology Officer, Svar Life Science

The efficacy of gene therapies using recombinant AAV can be limited by an antibody-mediated immunity against the virus. AAV infections, potentially occurring in early childhood, may result in a pre-existing immunity to one or more AAV serotypes. Here we present a novel two-component iLite® reporter cell system for the detection and quantification of neutralizing antibodies against AAV vectors. This assay allows for reliable assessment of anti-AAV antibodies in clinical applications

5:15 pm Recommended Evening Short Course*
SC6: Strategic Bioassay Design

*Separate registration required. See short course page for details.

Friday, October 22

7:30 am Registration and Morning Coffee


8:30 am

What Does It Take to Validate Potency and Which Data Do You Need?

Jan Amstrup, PhD, Specialist, Chemistry & Manufacturing & Controls BioAnalysis, Novo Nordisk AS

What does it take to calculate potency and which data do you need? Determination of potency is a critical quality attribute, playing a key role in the development and control of biological products. As there is an increasing need for potency determinations, either a high throughput approach or manning up has to be implemented. In this study we have investigated the use of reduced curves. It will be shown, that by omitting numbers of dilution of the sample investigated, we obtain the same results as if full curves were used, increasing samples analyzed per run.

9:00 am

Reducing Method Complexity in Potency Assay: Cell Free Competition Binding Assay

Uchechukwu Okorji-Obike, PhD, Associate Scientist II, Bioassay Development, AstraZeneca

Increasing complexity of biotherapeutics with novel mechanism of action (MoA) make development of potency assays a challenging task. There is a need for careful assay design for potency (a critical quality attribute), ensuring assays reflect the MoA, while minimizing complexity for a QC release assay. Here we report the design of a cell-free competition bioassay to illustrate reduction of method complexity whilst being MoA reflective and phase appropriate.


9:30 am Interactive Discussions

Interactive Discussions are informal, moderated discussions, allowing participants to exchange ideas and experiences and develop future collaborations around a focused topic. Each discussion will be led by a facilitator who keeps the discussion on track and the group engaged. For in-person events, the facilitator will lead from the front of the room while attendees remain seated to promote social distancing. For virtual attendees, the format will be in a Zoom room. To get the most out of this format, please come prepared to share examples from your work, be a part of a collective, problem-solving session, and participate in active idea sharing. Please visit the Interactive Discussion page for a complete listing of topics and descriptions.

IN-PERSON INTERACTIVE DISCUSSION: Successes and Pitfalls of Potency Assay Development and Delivery

Nancy Sajjadi, Independent Quality Consultant
  • Successes and Pitfalls of Potency Assay Development and Delivery
  • Early and late-stage development strategies
  • Best practices for data analysis and data use
  • Engaging with agencies
  • Success stories
  • What to avoid​


Kate Getliffe, PhD, Senior Scientist, CMC, PsiOxus Therapeutics
  • Uses and value of DoE, e.g., cell characterisation, assay development, robustness studies.
  • General approach to DoE, e.g., scoping, screening, optimisation, confirmation
  • Software and statistical advice
  • Success stories


10:10 am Exhibit & Last Chance for Poster Viewing


11:00 am

Optimization of Cell Handling Methods for the Development of Robust Bioassays

Kate Getliffe, PhD, Senior Scientist, CMC, PsiOxus Therapeutics

The cells are arguably the most critical reagent in any cell-based bioassay. Therefore, understanding the cells is essential to the development of a truly robust bioassay and can be invaluable during technical transfer and troubleshooting activities. This presentation will describe an approach for improving these bioassays by optimizing cell handling methods such as cell counting, culture media supplementation, cell dissociation from flasks, cryopreservation, cell thaw, recovery from thaw and cell banking overall.  A broad overview of these studies followed by a more detailed description of the cryopreservation, cell thaw and cell banking optimizations will be presented.

11:30 am

Challenges and Strategies for Outlier Detection and Management in Bioassay

David Lansky, PhD, President, Precision Bioassay, Inc.

Bioassays typically have non-constant variance and complex statistical designs; good outlier methods require complex models which yield lower rates for both false and failed outlier detection than simple methods. Multiple statistical detection methods can be helpful. There may be multiple outliers and outliers at different levels (e.g.; well and sample). Automatic outlier removal (usually favored by QA) is strongly discouraged by statistical and regulatory guidelines. Documenting the processes that lead to outlier removal is essential. Analyzing assays with and without suspect observations, then reporting results from the least favorable of these analyses is a good strategy. 

12:00 pm

They're Not Getting Older, They're Getting Better! Cell Line Characterization Reveals Changes in Expression of a Key Antigen

Kelli Matthies, MS, Senior Scientist, Process Development, Amgen

Cell lines are an important element when developing cell-based bioassays. Those cell lines that are used in current Good Manufacturing Practice (cGMP) lot release and stability testing require extensive characterization to understand their growth and performance characteristics. During characterization of the target cell line used in the potency assay for one of Amgen’s Bispecific T cell Engager (BiTE®) molecules, an increase in the cell surface and intracellular expression of the target protein was observed when cells from early passage to later passage were evaluated. The change in cell surface antigen expression had a positive impact on a key method performance parameter and resulted in an increase in the assay signal window. This presentation will describe our findings regarding this cell line in the context of its performance in a T cell dependent cellular cytotoxicity assay.

Travis Harrison, PhD, VICE PRESIDENT, BIOASSAY SOLUTIONS, Precision for Medicine

As a result of recent regulatory guidance, there is increasing demand for diagnostic immunogenicity assays, particularly in gene therapy.  Early planning is essential when designing an assay that may ultimately be used as a diagnostic.  In addition to requirements for documentation and performance verification, diagnostics also have specific needs for critical reagents and controls.  This presentation will describe the regulatory landscape and discuss considerations for design and performance verification of diagnostic NAb bioassays for gene therapies.

1:00 pm Enjoy Lunch on Your Own


2:15 pm

Moderators' Opening Remarks

Steven Walfish, Principal Scientific Liaison, Global Science & Standards, USP
Nancy Sajjadi, Independent Quality Consultant
2:20 pm

Bioassay Standard Curve Basics

Janice Callahan, Consulting Statistician

For bioassays with a continuous read out variable, visualization of the dose response curve often suggests a four-parameter logistic model is appropriate. Common challenges in achieving an optimal standard curve include an ability to reach an asymptote and heterogeneity of variance. Truncation of a 4 PL to a linear fit is a practical solution to asymptote issues but often overlooked, and is the utility of log transforming raw readout data to achieve constant variance and normality of residuals. An example data set will be used to highlight these important statistical assumptions and issues with the 5 PL model.

2:40 pm

Reference Material Bridging for Bioassay Lifecycle Management

Saipraveen Srinivasan, Senior Scientist, Analytical Research & Development, Pfizer Inc.

Reference materials play a crucial role in calibrating and confirming the suitability of bioassays that assess product quality. The assignment of an initial reference material and nomination of successors are important activities, the latter of which requires bridging studies to safeguard against potential drift in analytical results. While there are general guidelines for bridging, industry-wide best practices are not clearly established. A statistical approach to assess equivalency between an existing and new reference material is proposed.

3:00 pm

The Lifecycle of Potency Specifications

JoAnn Coleman, CMC Statistics Lead, Spark Therapeutics

Specification setting exercises for quantitative assays begin with a well-qualified, robust, precise, accurate, easy-to-implement assay. For each new lot of material generated, data is gathered measuring some defined attribute important to product quality. Potency, however, is an assay fraught with challenges limiting product knowledge early in the life cycle and beyond. This talk will focus on how to set specifications with limited data and adjust as knowledge grows.

3:20 pm

Use of Equivalence Bounds for Curve Parallelism Assessment: A Practical Case

Pierre Pirot, PhD, Sr Scientist, Bioassay Development, UCB

Demonstration of parallelism between reference standard and test sample dose-response curves is a prerequisite for relevant relative potency determination. USP 1032 advises the use of a residual sum of squares (RSSE) based single composite measure approach to assess the parallelism of four-parameters logistic model. This presentation will focus on a practical case of equivalence bounds definition and implementation for the RSSE based single composite measure of parallelism.


Statistics & Bioassays, from FAQs to Facts

Panel Moderators:
Steven Walfish, Principal Scientific Liaison, Global Science & Standards, USP
Nancy Sajjadi, Independent Quality Consultant


As both consultants and participants in the development of the USP Bioassay chapters, the two panel moderators are frequently asked questions about the numerous challenges encountered during design, development and validation of relative potency assays. Some of the questions asked stem from a lack of training or knowledge in biostatistics concepts on the part of bench scientists while other questions reflect the absence of clear communication on the appropriate statistical approaches due to apparent lack of consensus on the part of statisticians.  The aim of this session is to catalyze conversations that will lead to greater understanding of the statistical framework associated with bioassay data and implementation of better statistical practices in the industry. Speakers' topics will be chosen to introduce central concepts and participants will be invited to share any current challenges and ask for guidance.


JoAnn Coleman, CMC Statistics Lead, Spark Therapeutics
Saipraveen Srinivasan, Senior Scientist, Analytical Research & Development, Pfizer Inc.
Janice Callahan, Consulting Statistician
Pierre Pirot, PhD, Sr Scientist, Bioassay Development, UCB
4:20 pm Close of Summit