Abstract 4115: Unleashing the power of MHC associated peptide proteomics: Immunogenicity assessment of oncology drugs

Abstract Bispecifics targeting multiple antigens or epitopes have been showing great promise for treatment of cancer. However, managing unwanted immunogenicity has become a challenge in the development cycle of these promising therapeutics as there is a trend towards higher unwanted immune responses compared with classical monoclonal antibodies. A thorough assessment of their immunogenic potential leads to safe biotherapeutics with high treatment efficacy. MAPPS assays (MHC associated peptide proteomics) enable the precise identification of all the regions of a protein that may evoke an immune response. This information is key for correct risk assessment and for modulating biotherapeutics. High-sensitive MAPPS workflow leads to higher numbers of identified peptides (self + non-self peptides) and gives the deepness of analysis required for confident immunogenicity derisking and modulation. We show the importance of peptides presented by HLA-DP and HLA-DQ (next to the standard HLA-DR presented peptides). Next, we also show the first ever comparison of presented peptides in true immune cells: dendritic cells (as compared to monocyte derived dendritic cells) and B cells. Citation Format: Sofie Pattyn. Unleashing the power of MHC associated peptide proteomics: Immunogenicity assessment of oncology drugs abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 4115.