Randomized phase II trial of patient-specific dendritic cell vaccines loaded with autologous tumor antigens versus autologous monocytes in patients with primary advanced ovarian cancer.

TPS10 Background: With standard debulking surgery and combination chemotherapy (adjuvant ± neoadjuvant) the 5-year survival for women with newly diagnosed advanced epithelial ovarian cancer (stage III or IV) is less than 40%. After completion of primary therapy there is an opportunity to introduce an immunotherapy modality in an effort to improve long-term survival. In patients with metastatic melanoma, patient-specific vaccines consisting of autologous dendritic cells (DC) loaded with autologous tumor antigens (ATA) derived from a short-term autologous tumor cell line were associated with minimal toxicity and a 5-year survival of 50% in a single arm trial, and more than doubled median survival (43 vs. 20 months) in a randomized trial. Newly diagnosed patients with ovarian cancer might benefit from addition of such patient-specific therapeutic vaccines (DC-ATA) to standard therapy. Methods: This is a double-blind, 2:1 randomized trial comparing adjunctive treatment with DC-ATA to autologous monocytes (MC) in patients with newly diagnosed stage III or IV epithelial cancer of the ovary, fallopian tube, or peritoneum. Patients eligible for randomization are those who have completed or discontinued standard primary therapy, have a Karnofsky performance status ≥70, have an autologous tumor cell line, and have a monocyte product from which DC can be derived. The tumor cell line is derived from fresh tumor; MC are derived from leukapheresis, and MC are converted to DC by incubation with GM-CSF and IL-4. Patients are stratified by whether there is no evidence of disease at completion of primary therapy, and then are randomized, typically 6 to 7 months after tumor collection. Treatment can begin about 4 weeks from randomization. The trial has been open at a single site since mid-November 2017; the first tumor was collected in December. Appropriate tumor samples have been submitted from 11 patients and all 11 have resulted in cell lines. The first patient was randomized in May 2018. As of October 2018 four patients had been randomized and all four had started treatment. Additional clinical sites are being initiated. Clinical trial information: NCT02033616.