Cell Based Potency Assays: De-Risk Your Path To Patients With An Experienced CDMO

By Danny Rooney, QC Senior Manager

This whitepaper examines the increasing regulatory focus on potency testing for monoclonal antibody (mAb) therapeutics and biosimilars, emphasizing the importance of phase-appropriate, mechanism-relevant bioassays to ensure safety, efficacy, and product consistency. It explores ligand-binding techniques—such as ELISA and surface plasmon resonance (SPR)—for evaluating binding affinity and kinetics, alongside cell-based potency assays that capture key Fc-mediated effector functions, including ADCC, ADCP, CDC, as well as FcRn interactions and signaling-driven mechanisms.

The discussion compares traditional primary cell–based assays with genetically engineered reporter systems, highlighting how the latter can enhance reproducibility and are better suited for cGMP release and stability testing. It also addresses practical considerations such as cell sourcing, assay optimization, and the development of robust, sensitive readouts — challenges that often lead organizations to partner with specialized service providers.

FUJIFILM Biotechnologies’ Bioassay Department offers end-to-end CDMO support, including routine cGMP analytics, bespoke potency assay development and validation, analytical cell banking, and integration of orthogonal data (e.g., SPR) to deliver a comprehensive, functional understanding of mAb products.