Therapeutic
cancer vaccines have the potential to generate a long lasting immune response that will destroy
tumor cells with specificity and safety, in contrast to many other current
cancer therapies. Clinical success to date has been limited by a number of factors including choice of immunogenic
cancer rejection
antigens, optimization of
vaccine platforms and immune adjuvants to effectively polarize the immune response, and incorporation of strategies to reverse
cancer mediated immune suppression by utilization of effective adjuvant/immune modulators. WT-1 (Wilms' tumor gene 1) is a
cancer antigen that is required for
tumorigenesis, expressed in a high percentage of
tumor cells and rarely expressed in adult normal cells. Moreover spontaneous immunity to WT-1 is seen in
cancer patients and can be augmented with various therapeutic
vaccine approaches.
IRX-2 is an immune modulator with demonstrated preclinical and clinical pleiotropic immune activities including enhancement of the immune response to potential
tumor antigens. This paper presents the rationale and preclinical data for utilizing the WT-1
tumor antigen in a novel
vaccine platform consisting of a synthetic long
peptide containing multiple class I and class II
epitopes in combination with the
IRX-2 immunomodulatory regimen to overcome immuno-suppressive pathways and enhance the anti-
tumor response.