A Study of DSP-7888 in Pediatric Patients With Relapsed or Refractory High Grade Gliomas

Inclusion Criteria: 1. Patients meeting any of the conditions a) to c) below: 1. Have a diagnosis of diffuse intrinsic pontine glioma on the basis of imaging findings on magnetic resonance imaging (MRI) and clinical course 2. Have histologically or cytologically confirmed glioblastoma 3. Not meeting a) and b) above, but have histologically or cytologically confirmed grade III or IV glioma 2. Patients who will be able to be hospitalized from the initial dose of DSP-7888 until the end of the post-initial dose observation (In Phase 1 part only, patients may be permitted to have a temporary overnight leave during the hospitalization.) 3. Patients aged \< 20 years at the time of informed consent 4. Patients for whom either the legally acceptable representative or the patient (if aged ≥ 16 years) have provided written voluntary consent to participation in this study after fully receiving and understanding the information about this study, including study objectives, contents, expected pharmacological actions and effects, and foreseeable risks 5. Patients for whom standard therapy failed or no standard therapy is established 6. Diffuse intrinsic pontine glioma patients must received radiotherapy-based treatment or chemotherapy (if radiotherapy is not indicated) at least one cycle and subsequently had tumor enlargement accompanied by tumor-related symptomatic worsening (except for worsening due to dose reduction of steroid therapy for brain edema) 7. Glioblastoma patients and grade III or IV glioma patients must had radiologically evident tumor re-enlargement or recurrence 8. Patients with an ECOG PS score of 0 to 2 at enrollment. Patients with a PS score of 3 or 4 due to neurological symptoms associated with the primary disease may be eligible if appropriate in the opinion of the investigator or subinvestigator. 9. Patients with a life expectancy of 2 months (60 days) 10. Patients with a HLA type of HLA-A\*24:02 or A\*02:01/06 11. Patients with adequate major organ functions meeting the following criteria on the basis of laboratory data within 28 days before enrollment: Neutrophil count: 1000/μL Platelet count: 5.0 ×104/μL Hemoglobin: 9.0 g/dL Serum creatinine: 2-fold the upper limit of the normal range of the study site (ULN) Total bilirubin: 2-fold the ULN AST, ALT: 3-fold the ULN 12. Female patients of childbearing potential must have a negative pregnancy test within 4 weeks (28 days) before enrollment 13. Female patients of childbearing potential and male patients with female partners of childbearing potential must agree to use appropriate contraception from the time of consent until 180 days after the last dose of the study drug to avoid pregnancy Exclusion Criteria: 1. Patients with grade 3 infection according to the CTCAE v4.0 2. Patients with a positive test result for HIV antibody, HBs antigen, or HCV antibody 3. Patients with multiple or disseminated primary lesions (Multiple nodules in the same tumor cavity will be acceptable.) 4. Patients with other malignancies 5. Patients with significant diseases at enrollment that may affect study treatment, such as New York Heart Association (NYHA) Functional Class III or IV heart disease, CTCAE v4.0 grade 3 arrhythmia, angina pectoris, abnormal electrocardiogram findings, interstitial pneumonia or pulmonary fibrosis 6. Patients with uncontrollable complications 7. Patients who underwent allogeneic hematopoietic stem cell transplant 8. Patients who received any of the following treatments within the specified period before enrollment * Nitrosoureas, mitomycin C: \<42 days * Chemotherapy (including molecular-targeted drugs), radiotherapy: \<21 days * Surgery, blood transfusion, erythropoiesis-stimulating drugs, endocrine therapy, immunotherapy (including biological response modifier \[BRM\] therapy): \<14 days 9. Pregnant or breastfeeding women 10. Patients with concurrent autoimmune disease or a history of chronic or recurrent autoimmune disease, or patients who require long-term systemic steroid therapy (excluding therapy given on a PRN basis). However, steroid therapy for brain edema (prednisolone-equivalent dose of 30 mg/m2) and steroid replacement therapy at a physiologic dose will be acceptable. 11. Patients with any ongoing CTCAE v4.0 grade 2 adverse effects of prior treatment (excluding alopecia and phlebitis) 12. Patients who received any other investigational product or post-marketing study drug within 4 weeks (28 days) before enrollment 13. Patients with a history of allergy to any oil-based agents 14. Patients who previously received DSP-7888-containing WT1 peptide, or WT1 immunotherapy 15. Patients who are inappropriate for participation in the study for other reasons in the opinion of the investigator or subinvestigator