The emergence of cell-based protein arrays to test for polyspecific off-target binding of antibody therapeutics

• Main Authors: Diana M. Norden (Author), Carmen T. Navia (Author), Jonathan T. Sullivan (Author), Benjamin J. Doranz (Author)
• Format: Book
• Published: Taylor & Francis Group, 2024-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.1080/19420862.2024.2393785; 1942-0870; 1942-0862
• Keywords: Antibody; cell-based protein array; cross-reactivity; membrane proteome array; off-target binding; polyspecificity; Therapeutics. Pharmacology; RM1-950; Immunologic diseases. Allergy; RC581-607
• Source: mAbs, Vol 16, Iss 1 (2024)

Specificity profiling is a requirement for monoclonal antibodies (mAbs) and antibody-directed biotherapeutics such as CAR-T cells prior to initiating human trials. However, traditional approaches to assess the specificity of mAbs, primarily tissue cross-reactivity studies, have been unreliable, leading to off-target binding going undetected. Here, we review the emergence of cell-based protein arrays as an alternative and improved assessment of mAb specificity. Cell-based protein arrays assess binding across the full human membrane proteome, ~6,000 membrane proteins each individually expressed in their native structural configuration within live or unfixed cells. Our own profiling indicates a surprisingly high off-target rate across the industry, with 33% of lead candidates displaying off-target binding. Moreover, about 20% of therapeutic mAbs in clinical development and currently on the market display off-target binding. Case studies and off-target rates at different phases of biotherapeutic drug approval suggest that off-target binding is likely a major cause of adverse events and drug attrition.