Abstract A115: Cancer vaccine development for hepatocellular carcinoma – HEPAVAC

The HEPAVAC Consortium aims to develop a highly innovative, novel cancer vaccine approach for hepatocellular carcinoma (HCC). The international project consortium consists of 9 European Partners from academia and the biotech industry with complementary and substantial expertise in developing immunotherapeutic strategies to treat cancer. The project has started in September 2013 and is supported by the European Commission9s 7th Framework Program (www.hepavac.eu). HCC/normal adjacent tissue matched samples have been collected for HLA immunopeptidome analysis. 17 HCC samples from HLA-A*02+ patients and 15 samples from HLA-A*24+ patients have been analysed by mass spectrometry (LC-MS/MS). RNA-expression profiles have been established for 12 HCC samples. HLA-presentation/expression of peptides and mRNA on primary HCC samples are compared to nu003e140 normal tissue samples from relevant organs (including heart, brain, lung, kidney, liver, nerve, skin etc.) from Immatics9 database. A total of 9051 HLA-A*02-restricted different tumor-associated peptides (TUMAPs) have been identified from HLA-A*02+ samples, while a total of 3286 different HLA-A*24-restricted TUMAPs have been identified from HLA-A*24+ samples. Of these, 33 HLA-A*02+ TUMAPS and 33 HLA-A*24+ TUMAPs are currently in the process of validation, including peptide synthesis, immunogenicity testing and pharmaceutical evaluation. Most promising TUMAP candidates show selective expression only in HCC samples and no expression in normal tissues. In parallel, more than 6600 HLA-DR TUMAPs have been identified in Hep3B cells transfected with CIITA as well as an average of 1500 HLA-DR TUMAPs have been identified in HCC samples. Additional HLA-DR TUMAPs derived by distinct CIITA-transfected cell lines with different HLA-DR haplotypes are under scrutiny. The discovery phase of the HEPAVAC project is proceeding according to the proposed timelines. HCC-specific epitopes to be included in the vaccine cocktail will be selected in the coming weeks for GMP production. In parallel, preclinical studies assessing the formulation and combination of the immunological RNA-based adjuvant (RNAdjuvant®) with peptide cocktails are underway. Citation Format: Luigi Buonaguro, Sarah Kutscher, Roberto Accolla, Yuk T. Ma, Regina Heidenreich, Francesco Izzo, Alfred Koenigsrainer, Markus Loeffler, Phillip Mueller, Andrea Mayer, Hans-Georg Rammensee, Bruno Sangro, Sven Francque, Danila Valmori, Toni Weinschenk, Harpreet Singh-Jasuja. Cancer vaccine development for hepatocellular carcinoma – HEPAVAC. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A115.