Our study shows that post-translational modifications—specifically cysteinylation of a free thiol and sialylation of glycans—significantly affect the potency of a dual-receptor Fc-fusion therapeutic. Process-dependent differences in cysteinylation correlated with lower potency between batches, while chemical removal of sialic acids increased potency, highlighting the need for detailed product characterization to identify critical quality attributes during manufacturing optimization.

Potency assays are critical for the development of biological drug products, and a potency assurance strategy is required. A case study will be presented on the development and qualification of bioassays for a bispecific antibody drug product. The potency assurance strategy for an early phase bispecific antibody drug product will also be presented.

The development of mRNA-based medicines requires robust potency assays to assess both translatability and biological activity. These assays can be either cell-free or cell-based assays; each provide a different assessment but are complementary to each other. As such, we will discuss various strategies for assessing mRNA DS and DP potency evaluation and the advantages and disadvantages between cell-free and cell-based assays.

Anti‑drug antibody (ADA) monitoring traditionally relies on a three‑tier assay format, but the titration step is labor‑intensive and only semi‑quantitative. We evaluated a streamlined two‑tier approach that replaces endpoint titers with signal‑to‑noise (S/N) ratios. Using data from four clinical studies and spiked samples generated across multiple CROs, the S/N method demonstrated strong inter‑laboratory correlation and enabled consistent, quantitative patient classification. This approach reduced turnaround time and reagent consumption while maintaining assay performance and scientific rigor.

Various autoimmune diseases are driven by autoreactive T cells that damage organs, tissues, or transplants. We developed a PBMC assay platform using artificial antigen-presenting cells and primary target cells to model tissue-specific T cell responses ex vivo. The system enables integrated measurement of T cell activation, proliferation, and target-cell killing. This assay provides a functional framework to interrogate autoreactive T cell behavior and evaluate candidate biologics therapeutic interventions modulate these pathogenic responses.

The development of immunostimulatory agents can be utilized towards several objectives, including as treatments and as novel vaccine adjuvants. The objective of the work described here was to develop an in vitro methodology to evaluate the immune stimulatory response for a compound in development (referred to as Compound A).  Our aim is to connect in vitro activity assay results with in vivo effects or activity. We have selected a monocyte cell line, and stimulatory conditions were optimized for the secretion of a select panel of chemokines. We have demonstrated utility of the assay as being indicative of decreased chemokine production associated with process and stability (stress) conditions for Compound A.  We believe this cell-based assay can be expanded to other therapeutic compounds, peptides, or biologics to assess their immunostimulatory responses.

This presentation evaluates the robustness of an in-house BrdU-based T cell proliferation assay, analyzing the impact of experimental variables across more than 300 donor samples. Using bococizumab as a case study, we demonstrate that assay precision remains highly consistent when normalized to a negative control like bevacizumab. Additionally, we will explore how T cell responses correlate with specific HLA-DRB1 genotypes, revealing critical HLA-associated immunogenicity patterns relevant to therapeutic development.

Immunogenicity is a critical factor in biologics development, and proactive mitigation at the preclinical stage improves safety, efficacy, and reduces clinical attrition. We established an in vitro immunogenicity risk assessment platform within CMC to address risks associated with product-related attributes, including physical and chemical properties, and post-translational modifications. We will present case studies demonstrating the application of this platform to assess immunogenicity risk across different modalities.

Potency assays are essential for demonstrating the quality and biological activity of therapeutic products; however, even well-established methods can exhibit unacceptable failure rates or high variability. This talk presents case studies on the remediation of ELISA and cell-based potency assays for biologics, emphasizing root cause identification, targeted corrective actions, and restoration of method suitability for routine use. Through practical examples, the session presents a structured approach to improving assay reliability, reducing the risk of false out-of-specification results, and strengthening lifecycle assay management in alignment with current regulatory expectations.

Cell-based assays are essential for evaluating biological activity of biotherapeutics. The development of cell-based assays and the statistical processing of biological data present scientific and regulatory challenges. Key challenges include biological complexity, variability and reproducibility. To overcome these, choose suitable cell line to reflect MoA, implement rigorous experimental design and establish acceptance criteria.  Statistical considerations involve robust statistical methods and continuous monitoring of assay performance. Automation enhances consistency across studies.

The use of cells in bioprocessing and therapeutic products requires high-quality, robust, and validated analytical methods for cell characterization. Here I will describe recent developments in analytical method standardization, including NIST laboratory programs that support documentary standard and reference material development, and public-private partnerships to support the development of critical analytical methods. A key aspect of analytical development is the need for a fit-for-purpose approach.