Abstract 3761: Specific and dynamic tumor antigen-specific immune responses were elicited in patients with hepatocellular carcinoma after cell-based immunotherapy

Abstract

Abstract Hepatocellular carcinoma (HCC) is one of the most common cancers in China and frequently occurs with chronic hepatitis B virus (HBV) infection. To investigate whether cell-based cancer immunotherapy induces tumor specific immune responses in patients with HCC and provides clinical benefits, as well as to elucidate the most immunogenic tumor associated antigens (TAAs), multiple antigen stimulating cellular therapy (MASCT) was applied in addition to standard of care. Mature dendritic cells (DCs) and activated T cells prepared for MASCT were generated from autologous peripheral blood mononuclear cells (PBMCs). DCs were loaded with a peptide pool of multiple HCC-related tumor antigens, and T cells were stimulated by these DCs. Thirteen patients with HCC received repeated MASCT after tumor resection during which their immune responses were examined. After three courses of MASCT, the frequency of regulatory T cells in the patients’ PBMCs significantly decreased (p < 0.001), while the antigen peptide pool-triggered T cell proliferation (p < 0.001) and IFNγ production (p = 0.001) were significantly enhanced. The specific T cell responses against each antigen in the pool were detected in eleven patients, but with individualized distinct patterns. The most immunogenic TAAs for HCC are survivin, CCND1, and RGS5. Moreover, the antigen-specific immune responses observed in tumor-free patients’ PBMCs were significantly stronger than that in the patients with recurrence (p = 0.037). Conclusion: Our study demonstrates that MASCT is well-tolerated by patients with HCC and elicits strong and dynamic immune responses specifically against multiple tumor associated antigens, which may correlate with clinical outcomes. Citation Format: Yanyan Han, Ye Wu, Chou Yang, Jing Huang, Yabing Guo, Li Liu, Ping Chen, Dongyun Wu, Junyun Liu, Jin Li, Xiangjun Zhou, Jinlin Hou. Specific and dynamic tumor antigen-specific immune responses were elicited in patients with hepatocellular carcinoma after cell-based immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3761. doi:10.1158/1538-7445.AM2017-3761