Abstract CT218: Wilms′ tumor gene 1 (WT1) peptide-based cancer vaccine combined with gemcitabine for patients with advanced pancreatic cancer

Abstract

Abstract Wilms′ tumor gene 1 (WT1) protein is an attractive target for cancer immunotherapy. To investigate the feasibility of a combination therapy consisting of gemcitabine and WT1 peptide for patients with advanced pancreatic cancer, 32 HLA-A*24:02-positive patients were enrolled. HLA-A*24:02-restricted, modified 9-mer WT1 peptide (3 mg) emulsified with Montanide ISA51 adjuvant (WT1 vaccine) was injected intradermally biweekly. Moreover, gemcitabine (1,000 mg/m2) was administrated on days 1, 8, and 15 of a 28-day cycle. Median survival time and one-year survival rate were 8.1 months and 29%, respectively. The association between longer survival and positive delayed-type hypersensitivity (DTH) to WT1 peptide alone was statistically significant, and longer survivors featured a higher frequency of memory-phenotype WT1-specific cytotoxic T-lymphocytes (CTLs) before and during treatment. In conclusion, the combination therapy was well-tolerated and promising treatment for advanced pancreatic cancer. DTH-positivity to WT1 peptide alone and a higher frequency of memory-phenotype WT1-specific CTLs could be useful predictive markers for clinical efficacy. Citation Format: Shigeo Koido, Sumiyuki Nishida, Sadamu Homma, Yutaka Takeda, Hideo Komita, Satoshi Morita, Toshinori Ito, Soyoko Morimoto, Yoshihiro Oka, Satoru Yanagisawa, Yoichi Toyama, Masahiro Ikegami, Hiroaki Nagano, Toshifumi Ohkusa, Hisao Tajiri, Haruo Sugiyama. Wilms′ tumor gene 1 (WT1) peptide-based cancer vaccine combined with gemcitabine for patients with advanced pancreatic cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT218. doi:10.1158/1538-7445.AM2014-CT218