Introduction

1. monocytes iDC GM-CSF + IL-4 Leukaferesis TNFa + IL-1b Semi-mature, WT1 electroporated DC Injection in Aldara-treated skin (groins) WT1 mRNA Immunological Response After WT1 mRNA Dendritic Cell Immunotherapy in Ovarian Carcinoma and Carcinosarcoma Published : Coosemans A et al. Anticancer Research 2013;33:3855-9 1Department of Gynecologic Oncology, 2Neuroscience, 3Imaging and Pathology and 4Microbiology and Immunology, KU Leuven, Belgium; 5Gynecology and Obstetrics, 6Pathology and 7Pediatrics, University Hospital Leuven, Belgium; 8Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute, University of Antwerp, Belgium A. Coosemans1,5, A. Vanderstraeten1, S. Tuyaerts1, T. Verschuere2, Ph. Moerman3,6, V. Van Tendeloo8, Z. Berneman8, I. Vergote1,5, F. Amant1,5, S.W. Van Gool4,7 Results: Clinical characteristics • Introduction • Ovarian cancer is the second most important type of pelvic tumor in women. Ovarian carcinomas are epithelial in origin in 90% of cases (EOC). The smallest group is that of the mesenchymal ovarian tumors (<1 to 2% of all ovarian cancers) with ovarian carcinosarcomas (OCS) being the most important representative. In general, both EOC and OCS metastasize throughout the abdomen before causing symptoms. Consequently, disease in 63% of patients is detected at stage III or IV, leading to a poor prognosis. In the case of OCS, prognosis at early stages is also poor, resulting in a median survival for all OCS estimated to be less than 18 months. • Wilms’ tumor gene 1 (WT1) has recently been ranked as the most important tumor antigen. It is overexpressed in the majority of EOC, but has barely been studied in OCS. Since 2004, clinical case reports and studies were published about WT1 immunotherapy. For EOC, 30 patients have been included in 2 studies, using modified WT1 peptide injection to elicit a WT1-specific T cell response. Vaccination with autologous dendritic cells (DCs) loaded with WT1 peptides is another mean to establish such a response. One of the obstacles for the use of synthetic peptides is that patient accrual is limited to patients with the specific HLA-type, for which the peptide is restricted. One way that would allow to apply WT1-targeted immunotherapy for patients regardless of their HLA-type, is transfection of WT1 mRNA into DCs to achieve transient expression and subsequent presentation of antigenic epitopes. The in vitro work of several laboratories has suggested that mRNA transfection is an effective, if not superior, method to generate immunostimulatory DCs. Our research groups developed the technique of DC immunotherapy in the context of high grade glioma patients patients, acute myeloid leukemia and endometrial carcinoma. • Case Reports • One patient with EOC and one with OCS received 4 intradermal vaccinations with DCm-WT1-RNA, once every week. The skin of the injection sit was pretreated with Imiquimod cream during 3 days. *On a scale ranging from 1 (very poor) to 7 (excellent), °Chronological order Results: Immunological characteristics # measured by flow cytometry (tetramer staining); * PBMC were incubated with an overlapping peptide mixture covering WT1. After 24 h incubation, cells were analyzed by flow cytometry using anti-CD4, anti-CD137 and anti-CD8. The culture supernatant was used for cytokine quantification HQLE: Health and Quality of Life Estimation, OCS: ovarian carcinosarcoma, SOC: serous epithelial ovarian cancer, PFS: progression-free survival, OS: overall survival, V3: vaccination 3, V4: vaccination 4, PD: progressive disease, CT: computed tomography, DCm-WT1-RNA: WT1-RNA loaded mature dendritic cells, WT1: Wilms’ tumor gene 1, NK: natural killer cell Conclusions We present the first 2 ovarian cancer patients ever treated withWT1 mRNA-loaded DC immunotherapy. The technique was feasible without signs of toxicity. The treatment itself resulted in an immunological response in both patients, who also both showed a remarkably longer overall survival