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

Patient enrollment will follow a two-step procedure (at screening before randomization and at assessment after vaccine production) of conditions required for initiating vaccination. Patients must meet all of the criteria described in this section prior to receiving any vaccination. AT SCREENING: Inclusion Criteria: 1. Signed Informed Consent Form 2. Histologically confirmed diagnosis of advanced, FIGO stage III or IV, high grade serous ovarian carcinoma (HGSOC) 3. Underwent PDS or IDS without macroscopic residual disease, (R0) 4. a. Received at least 3 cycles of peri-operative platinum-based chemotherapy before IDS, with the intention to complete at least 6 cycles of peri-operative platinum-based chemotherapy. OR b. Has completed 6 cycles of adjuvant platinum-based chemotherapy after PDS. In case of toxicity prohibiting 6 cycles of adjuvant platinum-based chemotherapy, a minimum of 4 cycles are required. 5. Tumor material is available and sufficient for both OC-DC preparation and identification of Top 10 personalized peptides (PEPs) required for PEP-DC vaccine preparation. 6. Age ≥18 years. 7. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 8. Willing and able to comply with study procedures 9. Has adequate hematologic and end organ function (kidney, liver and bone marrow), defined by the following laboratory results (complete blood count (CBC), enzyme tests) obtained within 14 days prior to randomization: * Hemoglobin ≥ 80 g/L * Neutrophil count ≥ 1.0 x G/L (independently of administration of growth factor within 4 weeks prior to randomisation) * Platelet count ≥ 100 G/L * Serum creatinine ≤ 1.5x Institutional Upper Limit of Normal (ULN) or Creatinine Clearance ≥ 40 mL/min. * Serum bilirubin ≤ 1 ULN (except subjects with Gilbert's syndrome who must have a total bilirubin level of \<3.0 x ULN) * aspartate aminotransferase (AST) / alanine transaminase (ALT) ≤ 3 x ULN * Alkaline phosphatase ≤ 1.5 x ULN * Coagulation: International Normalized Ratio (INR) or Prothrombin Time (PT) ≤ 1.5 X ULN unless subject is receiving anticoagulant therapy as long as PT or partial thromboplastin time (PTT) is within therapeutic range of intended use of anticoagulants; activated Partial Thromboplastin Time (aPTT) ≤ 1.5 X ULN unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants. 10. Has adequate serology defined by the following laboratory results obtained within 14 days prior to randomization: * Negative test for Human Immunodeficiency Virus (HIV) * Patients with active or chronic hepatitis B (defined as having a positive hepatitis B surface antigen \[HBsAg\] test at screening) are not eligible. * Patients with past/resolved Hepatitis B Virus (HBV) infection (defined as having a negative HBsAg test and a positive antibody to hepatitis B core antigen (anti-HBc) antibody test) are eligible, if HBV Deoxyribonucleic Acid (DNA) test is negative. * HBV DNA must be obtained in patients with positive hepatitis B core antibody prior to start of study treatment. * Patients with active hepatitis C are not eligible. Patients positive for Hepatitis C Virus (HCV) antibody are eligible only if Polymerase Chain Reaction (PCR) is negative for HCV Ribonucleic Acid (RNA). 11. Absence of any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol. 12. Patient is able to undergo leukapheresis Exclusion Criteria: 1. A secondary debulking surgery is foreseen. 2. Prior exposure to anti-Cytotoxic T-Lymphocyte-Associated Protein 4 (CTLA4) and anti-Programmed cell Death 1 (PD1) / anti-Programmed cell Death Ligand (PD-L1) antibodies or other immunotherapy. 3. Woman of child-bearing potential (WOCBP). By definition, all patients with HGSOC of FIGO stage III to IV who have undergone PDS or IDS, will have undergone total hysterectomy with bilateral salpingo-oophorectomy, and will therefore be women without child-bearing potential. Therefore, no pregnancy tests have to be performed because no WOCBP will be enrolled in this trial. 4. Breastfeeding women 5. Other malignancy within 2 years prior to randomization, except for those (for example ductal carcinoma in situ of breast and cervical intraepithelial neoplasia) treated with curative intent. Patients with a predicted 5-year recurrence-free survival rate ≥95% can be included at the investigator's discretion. 6. Patients with diagnosis of paraneoplastic syndrome. 7. Current, recent (within 4 weeks prior to randomization), or planned participation in an experimental drug study. 8. Patient has a serious, non-healing wound, ulcer, or bone fracture. 9. Patients with Glucose-6-phosphate dehydrogenase (G6PD) deficiency are excluded. Patients with high bleeding risk or any other hereditary coagulation disorder can be enrolled after careful evaluation, at principal investigator (PI)'s discretion. 10. Past history with cardiac or vascular problems: 1. New York Heart Association Class II or greater congestive heart failure 2. History of myocardial infarction or unstable angina within 6 months prior to randomization 3. History of stroke or transient ischemic attack within 6 months prior to randomization 4. Significant vascular disease (e.g., aortic aneurysm requiring surgical repair or recent peripheral arterial thrombosis) within 6 months prior to randomization 5. Evidence of bleeding diathesis or significant coagulopathy (in the absence of therapeutic anticoagulation) 6. Patient has a grade II or greater peripheral vascular disease. 7. Patient has a clinically significant peripheral artery disease, e.g., those with claudication, within 6 months prior to randomisation. 11. Any other diseases, metabolic dysfunction, physical examination findings, or clinical laboratory findings giving reasonable suspicion of a disease or condition that contraindicates the use of an investigational drug or that may affect the interpretation of the results or render the patient at high risk from treatment complications. 12. Patient has organ allografts. 13. Known hypersensitivity to any component of the study treatment 14. History of autoimmune disease, including but not limited to myasthenia gravis, myositis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, vascular thrombosis associated with antiphospholipid syndrome, Wegener's granulomatosis, Sjögren's syndrome, Guillain-Barré syndrome, multiple sclerosis, vasculitis, or glomerulonephritis. 1. Patients with a history of autoimmune-related hypothyroidism on a stable dose of thyroid replacement hormone are eligible for this study. 2. Patients with controlled Type I diabetes mellitus on a stable insulin regimen are eligible 15. Administration of a live, attenuated vaccine within 8 weeks before randomization. Exception: Influenza vaccination should be given during influenza season only (approximately October to March). Patients must not receive live, attenuated influenza vaccine within 4 weeks prior to randomization. 16. History of immediate hypersensitivity reaction to streptomycin and penicillin. AT VACCINATION: Inclusion Criteria: 1. Has received 6 cycles of platinum-based chemotherapy to first vaccination (minimum of 4 cycles platinum-based chemotherapy in case of severe toxicity and inability to administer all planned 6 cycles). 2. Confirmation from the Centre des Thérapies Experimentales (CTE) cellular manufacturing facility that at least 6 doses of vaccines have been produced for the patient (for Arm A: PEP-DC1 vaccines, Arm B: OC-DC vaccines) at the CTE cellular manufacturing facility. Has adequate hematologic and end organ function (kidney, liver and bone marrow), defined by the following laboratory results (complete blood count \[CBC\], enzyme tests) obtained before start of the study treatment: * Hemoglobin ≥ 80 g/L * Neutrophil count ≥ 1.5 x G/L * Platelet count ≥ 100 G/L * Serum creatinine, ≤ 1.5x Institutional Upper Limit of Normal (ULN) or Creatinine Clearance ≥ 40 mL/min, calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula * Serum bilirubin ≤ 1 ULN (except subjects with Gilbert's syndrome who must have a total bilirubin level of \<3.0 x ULN ) * AST/ALT ≤ 3 x ULN * Alkaline phosphatase ≤ 1.5 x ULN * Coagulation: International Normalized Ratio (INR) or Prothrombin Time (PT) ≤ 1.5 X ULN unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants; Activated Partial Thromboplastin Time (aPTT) ≤ 1.5 X ULN unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants. 3. Has no evidence of disease confirmed by computerized tomography (CT)-scan of chest/abdomen/pelvis (i.e. tumor-free by CT scan according to RECIST v1.1) and CA 125 Gynecologic Cancer InterGroup (GCIC) criteria (i.e. normal CA 125 blood level) before start of the study treatment. 4. Has recovered from any toxic effects of prior chemotherapy to ≤ Grade 1 per the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE v.5.0) except for toxicities described below, as long as they do not put at risk the patient's condition and do not require systemic immunosuppressive steroids at any dose, including but not limited to: * Fatigue * Alopecia * Skin disorders * Stable neuropathy * Endocrinopathies requiring replacement treatment Note: For other medical conditions, or for any other toxicity with a higher grade but controlled by adequate treatment, prior discussion and agreement with the sponsor is mandatory. Exclusion Criteria: 1. Treatment with systemic immunosuppressive medications (including but not limited to prednisone, dexamethasone, cyclophosphamide, azathioprine, methotrexate, thalidomide, and anti-tumor necrosis factor (anti-TNF) agents) within 4 weeks prior to first study treatment. Exceptions: * Patients who are receiving acute, low-dose, systemic immunosuppressant medications (e.g., a one-time dose of dexamethasone for nausea) or physiologic replacement doses (i.e., prednisone 5-7.5 mg/day, or other) for adrenal insufficiency may be enrolled in the study. * The use of inhaled corticosteroids and mineralocorticoids (e.g., fludrocortisone) is allowed. * Standard premedication of paclitaxel, docetaxel, nab-paclitaxel, or Caelyx (pegylated liposomal doxorubicin i.e. PLD). 1. When tri-weekly 175 mg/m2 paclitaxel is given: 20mg of dexamethasone administered 12 hours and 6 hours before paclitaxel administration (or according to Institution's guidelines) during last chemotherapy cycle (C6D1) is allowed. 2. When weekly 80 mg/m2 paclitaxel is given: on the day of treatment, administration of a single 8 mg dose of dexamethasone before paclitaxel administration is allowed. * Treatment of late onset nausea and treatment of allergic reaction induced by SOC chemotherapy 2. Administration of a live, attenuated vaccine within 8 weeks before start of study treatment. Exception: Influenza vaccination should be given during influenza season only (approximately October to March). Patients must not receive live, attenuated influenza vaccine within 4 weeks prior to start of study treatment. 3. Any other diseases, cardiac, metabolic or other dysfunction, physical examination findings or clinical laboratory findings since the screening visit giving reasonable suspicion of a disease or condition that contraindicates the use of an investigational drug or that may affect the interpretation of the results or render the patient at high risk from treatment complications.