Cross-Reactive Polyclonal Antibodies Raised Against GalNAc-Conjugated siRNA Recognize Mostly the GalNAc Moiety

• Published in: The AAPS journal Vol. 26; no. 3; p. 41
• Main Authors: Ballman, Kimberly K., Peek, Victoria L., Sloan, John H., Li, Jingling, Konrad, Robert J., Wen, Yi
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 03.04.2024; Springer
• Subjects: Acetylgalactosamine; Animals; Antibodies; Antibodies, Monoclonal; Antigenic determinants; B cells; Biochemistry; Biomedical and Life Sciences; Biomedicine; Biotechnology; Health aspects; Humans; Immune response; Oligonucleotides; Pharmacology/Toxicology; Pharmacy; Research Article; RNA, Small Interfering - genetics; Viral antibodies; positive control; siRNA; assay development; immunogenicity; GalNAc
• ISSN: 1550-7416; 1550-7416
• DOI: 10.1208/s12248-024-00914-w

Small interfering RNA (siRNA) is gaining momentum as a therapeutic modality with six approved products. Since siRNA has the potential to elicit undesired immune responses in patients, immunogenicity assessment is required during clinical development by regulatory authorities. In this study, anti-siRNA polyclonal antibodies were generated through animal immunization. These cross-reactive polyclonal antibodies recognized mostly the N-acetylgalactosamine (GalNAc) moiety with a small fraction against sequence-independent epitopes. We demonstrate that the polyclonal antibodies can be utilized as immunogenicity assay positive controls for the same class of GalNAc-conjugated siRNAs. In addition, anti-GalNAc mAbs showed desired sensitivity and drug tolerance, supporting their use as alternative surrogate positive controls. These findings can guide positive control selection and immunogenicity assay development for GalNAc-conjugated siRNAs and other oligonucleotide therapeutics. Graphical Abstract