Abstract CT189: Patient-specific dendritic cell vaccines with tumor antigens from self-renewing autologous tumor cells in the treatment of primary advanced ovarian cancer: A multi-institutional phase II clinical trial

Standard treatment of primary ovarian epithelial cancer has improved, but 5-year survival is only about 40% for the cohort of patients who present with stage 3 or 4 disease. Adjunctive therapy with patient-specific vaccines may improve outcomes by enhancing each patient's anti-cancer immune response. A multi-institutional, double- blinded randomized phase II clinical trial was designed with a primary objective of a 50% reduction in the risk of death compared to the control arm. Key eligibility criteria are: (1) primary diagnosis of stage 3 or 4 ovary epithelial cancer, (2) successful cell culture of ovarian cancer cells, (3) successful monocyte collection by leukapheresis, and (4) ECOG of 0 or 1 at the time of randomization. After completing primary systemic therapy, patients are stratified based on whether they have any residual evidence of disease and then randomized 2:1 to vaccine or control arms. Randomization occurs about 7 months after initial surgery. In the active arm IL-4 and GM-CSF are used to differentiate monocytes into dendritic cells (DC) which are incubated with the lysate of cultured ovary cancer cells as the source of autologous tumor antigens (ATA) to produce each patient-specific DC-ATA vaccine. Patients in the control arm receive cryopreserved autologous monocytes from their leukapheresis product. Each dose is admixed with 500 mcg GM-CSF at the time of subcutaneous injections at weeks 1, 2, 3, 8, 12, 16, 20 and 24. DC-ATA may be given alone or in combination with maintenance or salvage therapies. At the time of this analysis, cell line success rate is 35/35 (100%); monocyte collection success rate is 19/20 (95%), and 2 patients required a second apheresis to get a satisfactory product. 14 patients had primary ovarian, 2 fallopian tube, and 1 primary intraperitoneal cancer. 17 of a planned 99 have been randomized. At diagnosis 15 patients had stage 3 disease and two had stage 4; 15 had no evidence of disease at the time of randomization. Primary systemic therapy was adjuvant for 7 and neoadjuvant for 10. Ages of the randomized patients range from 39 to 80 years with a median of 61 years. ECOG status was 0 for 11 subjects, and 1 for 6 subjects. 13 patients have started treatment and received 92 injections; 9 have received all 8 doses and only 2 have stopped before 8 doses. No patient has discontinued treatment because of toxicity, but 1 patient was hospitalized after the 8th dose for refractory urticaria that resolved after high-dose cort