Phase I Study of Multiple Epitope Peptide Vaccination in Patients With Recurrent or Persistent Cervical Cancer

Cancer immunotherapy has now been established as a leading standard therapeutic option in a subset of patients with cancer. In this study, we conducted a phase I dose-escalation trial using a mixture of 5 peptides to vaccinate cervical cancer patients with HLA-A*2402. The primary endpoints were safety and determination of a recommended vaccine dose, and the secondary endpoints were evaluations of immunologic responses and clinical efficacy. All patients had recurrent or persistent disease and had failed to respond to or were intolerant to prior standard chemotherapy. Peptides derived from forkhead box protein M1 (FOXM1), maternal embryonic leucine zipper kinase (MELK), Holliday junction-recognition protein, and vascular endothelial growth factor receptors 1 and 2 were administered to 9 patients in a 3 patient-cohort design, with doses of 0.5, 1, or 2 mg of each of the individual peptides in a mixture with incomplete Freund's adjuvant. The major adverse events were anemia and injection site reactions, which were seen in 77.8% (7/9) and 66.7% (6/9) of patients, respectively. Grade 3 anemia was observed in 1 patient. No dose-limiting toxicity of the vaccine was observed. Seven (78%) patients achieved stable disease, and the median progression-free survival was 3.3 months (102 d). Interferon-γ enzyme-linked immunospot assays for each of the 5 antigens showed that 8 (89%) and 7 (78%) patients had high T-cell responses to FOXM1 and MELK, respectively. In conclusion, we demonstrated that this 5-peptide vaccine was tolerable, and that FOXM1 and MELK could be promising targets for immunotherapy in patients with cervical cancer.