Background: Dendritic cell (DC)-based immunotherapy is an emerging new treatment option in ovarian cancer, an important cause of cancer-related mortality.
Patients and methods: One patient with ovarian carcinosarcoma (OCS) and one with serous ovarian cancer (SOC) received four weekly vaccinations of autologous DCs electroporated with mRNA coding for the Wilms' tumor gene 1 (WT1). Safety, feasibility and immunogenicity were assessed.
Results: Vaccination was feasible without toxicity. In an ex vivo antigen re-stimulation assay of peripheral blood mononuclear cells, both patients showed increasing cluster of differentiation 137 (CD137+) antigen-specific T-cells and interleukin 10 (IL-10) production post-vaccination. Moreover, interleukin-2 (IL-2) production increased (OCS) as well as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) (SOC). Disease in patients progressed after four vaccines and patients continued with conventional therapies. After cessation of immunotherapy, they had an extended survival of 19 (OCS) and 12 (SOC) months.
Conclusion: To our knowledge, we report for the first time the feasibility and T-cell immunogenicity of WT1 mRNA-loaded DC immunotherapy in ovarian cancer.
Keywords: DC immunotherapy; WT1; carcinosarcoma; ovarian cancer.