A novel autologous oxidized whole-tumor antigen vaccine therapy for recurrent ovarian cancer.

Abstract

5023 Background: Despite surgical and chemotherapeutic advances, the death rate from ovarian cancer has not changed. We report here an enhanced dendritic cell vaccine platform developed for clinical testing. Furthermore we report the application of this novel platform comprising of dendritic cell (DC)-based autologous whole tumor antigen vaccination in a pilot study of patients with recurrent ovarian cancer. Methods: To determine the optimal tumor lysate preparation for loading DCs, ovarian tumor lines were prepared by HOCl-oxidation, UVB-irradiation or freeze and thaw. Normal donor DCs were evaluated for tumor lysate uptake, cytokine and chemokine productions and phenotype. The optimal lysate preparation, was used in a phase I study where five patients with recurrent ovarian cancer with available tumor lysate from secondary debulking surgery underwent intranodal vaccination with OC-DC, an autologous DC preparation pulsed with HOCL oxidized autologous tumor cells. Feasibility, safety, and biological and clinical efficacy were evaluated. Results: Normal donor DCs pulsed with HOCl-oxidized tumor lines demonstrated the highest tumor lysate uptake, matured efficiently after LPS and IFN-gamma stimulation, and produced higher levels of proinflammatory cytokines and chemokines. In vitro, these lysates loaded DCs primed T cell responses against ovarian tumor associated antigens and effectively expanded against tumor specific T cells from donors and patients. Therapy was feasible and well tolerated in all subjects. Vaccination with OC-DC produced limited grade 1 toxicities and elicited tumor-specific T cell responses. Moreover specific HLA-A2-restricted responses were documented following vaccination and HER-2/neu specific T cells were expanded following 10 days of in vitro culture. Patients exhibiting immune response demonstrated clinical benefit including two patients who demonstrated remission inversion on vaccine maintenance. Conclusions: We developed a DC-HOCl oxidized whole tumor lysate vaccine which was safe and well-tolerated by patients. The vaccine was highly proinflammatory and elicited cellular and humoral anti-tumor responses establishing a platform for immune-combinatorial therapy.