Significance of Wilms' tumor 1 antigen as a cancer vaccine for pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDA) is characterized by a very poor prognosis, despite novel chemotherapeutic treatments. Moreover, the majority of PDA patients with complete surgical resection show recurrence within 5 years of resection. Therefore, new targeted cancer vaccines are urgently needed to extend PDA patient survival. The Wilms' tumor 1 (WT1) antigen was identified as an excellent antigen in a list of 75 tumor-associated antigens by a National Cancer Institute prioritization project based on several factors, such as therapeutic function. WT1-targeted cancer vaccines are not only efficient in the regression of PDA cells but also angiogenesis and immune suppressive cells, such as myeloid-derived suppressor cells (MDSCs), in the PDA microenvironment. Moreover, WT1 is increased in PDA cells; thus, WT1 may represent an effective therapeutic target for PDA, resulting in a survival benefit for PDA patients. A novel WT1 peptide with increased immunogenicity was developed and used in clinical trials to induce more successful clinical results. This review summarizes the clinical trials of PDA patients receiving WT1-targeted cancer vaccines.