Abstract SY41-01: Selection of targeted neoantigens for personalized cancer vaccines

Abstract Neoantigen targeting personalized cancer vaccines (PCV) have the potential to revolutionize cancer treatment. These personalized vaccines rely on accurate epitope prediction and selection. We previously reported phase I trials of neoantigen targeting PCV in melanoma and glioblastoma multiforme (GBM). Recently we concluded a trial in renal cell carcinoma (RCC) where the neoantigen targeting PCV was immunogenic in all patients, targeted cancer drivers, and demonstrated in vitro reactivity to primary patient tumors. The neoantigen selection pipeline at DFCI supporting clinical trials utilizes immunopeptidome-trained epitope prediction algorithms to design synthetic long peptides as vaccine antigens containing predicted HLA Class I neoantigens. We also prioritize highly expressed neoantigens and neoantigens originating from cancer drivers as vaccine epitopes. For future iterations of this pipeline, we aspire to include novel classes of neoantigens originating from endogenous human retroviruses (ERV), fusion epitopes, novel or unannotated open reading frames (nuORFs), and immunopeptidome-identified neoantigens. The neoantigen selection pipeline is currently supporting multiple cancer vaccine trials at DFCI targeting melanoma, GBM, RCC, ovarian cancer, and chronic lymphocytic leukemia (CLL). Citation Format: Derin Keskin. Selection of targeted neoantigens for personalized cancer vaccines abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (7Suppl): Abstract nr SY41-01.