A Phase I Safety Study of a Cancer Vaccine to Treat HLA-A2 Positive Advanced Stage Ovarian, Breast and Prostate Cancer

Epithelial ovarian cancer has a high mortality rate even among those who obtain complete remission after surgery and chemotherapy. In prostate cancer, hormonal therapies including androgen ablation may control the disease for variable lengths of time but progression will invariably occur. There is also a high rate of relapse in breast cancer patients who have four or more positive axillary lymph nodes and in cases of resected metastatic disease. Immune therapies such as therapeutic vaccination may prolong remissions in these cancers. Many different therapeutic vaccines have been evaluated in these diseases in phase 1, 2 and even phase 3 trials. Much has been learned about the principals of applying immune-based therapies and specifically the types of patients that may be most likely to mount an effective immune response. Cancer vaccines may have their greatest impact earlier in the disease course or in situations with minimal residual disease. Most recently an overall survival benefit was documented in prostate cancer patients with an immunotherapy based vaccine. ImmunoVaccine Technologies Inc. (IVT) is developing a therapeutic vaccine against various solid cancers based on a patented vaccine delivery and enhancement platform. The antigens included in DPX-0907 were identified using an innovative antigen discovery platform to identify proprietary signature antigens actually presented on the surface of tumor cells and therefore capable of stimulating a cellular immune response in the patient. One or more of the peptide antigens are expected to be expressed in the types of tumors included in this trial. The peptide antigens proposed for DPX-0907 have been previously included in a phase I study in a different vaccine formulation at Duke University. No vaccine-induced autoimmune events were reported. These encouraging results suggest that the autoimmune potential of these cancer-specific peptide antigens is limited. IVT's DepoVax™ (DPX) lipid-based formulation was designed to enhance the speed, strength and duration of the cellular immune response. This formulation in combination with tumor targeting antigens has produced favorable safety and cellular immune responses in preclinical studies. These parameters will be studied in this phase I trial.