PEP-DC and OC-DC Vaccine in High Grade Serous Ovarian Carcinoma

This will be a single center, Phase I/II randomized, two-arm, open-label study to evaluate immunogenicity, safety, and feasibility of two different vaccination regimens combined with low-dose cyclophosphamide in patients with surgically resected, advanced HGSOC. Patients with HGSOC at International Federation of Gynecology and Obstetrics (FIGO) stage III or IV who completed either primary debulking surgery (PDS) or interval debulking surgery (IDS) without residual disease (R0) and who have received at least 6 cycles of adjuvant standard of care (SOC) platinum-based chemotherapy after PDS, or 3 cycles of platinum-based perioperative chemotherapy within an IDS will be eligible for this protocol. A total of 16 patients (8 patients in each arm) will be randomized 1:1 as follows: * In arm A, patients will receive PEP-DC1 vaccine comprising autologous dendritic cells pulsed with personalized peptides detected or predicted a priori (using our current integrated antigen identification methodologies). * In arm B, patients will receive first, the OC-DC vaccine, an autologous dendritic cell vaccine loaded with autologous oxidized tumor lysate. Then, tumor antigens specifically recognized by the patients' immune response induced by OC-DC vaccination will be identified/predicted using integrated methodologies to enable production of PEP-DC2 vaccine (autologous dendritic cells pulsed with the peptides detected or predicted after vaccination with OC-DC). Finally, patients will be vaccinated with the personalized PEP-DC2 to continue maintenance vaccination. In both arms, vaccines will be administered to the patients in combination with low dose cyclophosphamide the day before vaccination. Patients will be vaccinated in the adjuvant setting, with first vaccine injected no more than 18 weeks after the end of SOC platinum-based chemotherapy. Patients will be vaccinated until vaccine exhaustion (which may happen any time after dose 6), disease recurrence, major toxicity or patient withdrawal, whichever is earlier.