Abstract 4753: Anti-tumor effect of dendritic cell-based immunotherapy in combination with chemotherapy in the patients with advanced colorectal cancer

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Background and objective: Tumor-specific cytotoxic T lymphocytes (CTLs) can be activated in vivo by dendritic cell (DC)-based vaccination. However, clinical responses to the immunotherapy with DC vaccination have only been observed in a minority of patients with solid cancer. Combination with other treatment modalities such as chemotherapy may overcome immunoresistance of cancer cells. In the current study, the clinical efficacy of the DC vaccine pulsed with the peptide derived from colorectal cancer-associated antigens in combination with chemotherapy has been evaluated in the patients with advanced, inoperable colorectal cancer. Patients and Methods: Thirty-two patients with advanced, inoperable colorectal cancer refractory to standard treatment were entered the study. DCs which were generated from CD14+ monocytes from leukapheresis by 6-day cultivation with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4, were matured by OK-432, a streptococcal agent, and were pulsed with the pancreatic cancer-associated antigens, such as WT1, MUC1. These DCs (1 × 107) were intradermally administered 5 times at 14-day intervals. Results: Of the 32 patients, complete response (CR) was observed in 0 (0%), partial response (PR) in 7 (21.9%), stable disease (SD) in 12 (37.5%), progressive disease (PD) in 13 (40.6%). Response rate was 21.9%. Tumor control rate was 59.4%. Survival rate, quality of life, performance status were markedly increased. Severe side effects of more than grade 3 which were assessed in accordance with NCI-Common Toxicity Criteria v.2.0, were not observed. Conclusions: It was strongly suggested that the DC vaccination pulsed with cancer associated-peptides in combination with chemotherapy was safety and effective in the patients with the inoperable colorectal cancer refractory to standard treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4753.