NEOadjuvant Dendritic Cell Vaccination for Ovarian Cancer

Epithelial ovarian cancer (EOC) is the deadliest gynecological malignancy worldwide. Despite intensified treatment, 5-year overall survival rates only improved modestly over the last 20 years and remain low at around 30% for patients with advanced disease in the Netherlands. To this day, results from trials with the checkpoint inhibitors, that have revolutionized treatment in other cancer types, have been disappointing in EOC. Therefore, novel effective therapies are long awaited. Recently, naturally circulating blood -derived dendritic cells (nDC) were shown to be potent in inducing cytotoxic immune responses and tumor regression in cancer patients. An even more specialized DC subset, referred to as cDC1 (conventional Dendritic Cells type 1) or XP-DC (specialized cross presenting DC) have shown their superiority in preclinical models. They are better at inducing cytotoxic T-cell responses against tumors after uptake of necrotic tumor cell material, a phenomenon called cross-presentation. This capability in cross-presentation makes XP-DC an ideal DC type in combination with tumor lysate-loading to induce immune responses against the scarce neoantigens present in EOC tumors. The objective of this exploratory trial is to investigate the immunological efficacy as well as safety and feasibility of tumor-lysate loaded XP-DC in EOC patients undergoing (neo-)adjuvant chemotherapy. To this end 10 patients with stage III ovarian cancer will be included and offered a combined approach with DC vaccination in addition to standard-of-care chemotherapy and surgery. Extensive monitoring of the immune system throughout the course of the trial will be performed.