Alpha-type-1 Dendritic Cell-based Vaccines in Patients With Metastatic Colorectal Cancer

Dendritic cell (DC)-based vaccination, usually administered by a traditional intradermal route, is a new treatment option for cancer patients. While the previous DC-based vaccination trials have shown the safety of this approach and its ability to induce objective clinical responses, the overall efficacy of DC-based vaccines is still disappointing (Rosenberg et al., 2004). We hypothesize that the two likely causes of such limited clinical activity are: A) suboptimal type of DCs used as a vaccine and B) suboptimal modes of use of such vaccines that do not allow the vaccinated patients to fully benefit from DC biology. We will conduct a pilot evaluation of the therapeutic vaccination with DC1s loaded with autologous tumor material, in patients with metastatic colorectal cancer that have been resected to no or minimal evidence of disease.The proposed evaluation of the novel intralymphatic route of DC-based vaccination will allow us to administer the vaccine in a way that is more physiologic with respect to the kinetics of antigen appearance to the lymph nodes and is feasible to be performed in repetitive fashion, without damaging local lymph nodes.