Dendritic cell-based immunotherapy targeting Wilms' tumor 1 in patients with recurrent malignant glioma

Object Dendritic cell (DC)-based vaccination is considered a potentially effective therapy against advanced cancer. The authors conducted a Phase I study to investigate the safety and immunomonitoring of Wilms' tumor 1 (WT1)-pulsed DC vaccination therapy for patients with relapsed malignant glioma. Methods WT1-pulsed and/or autologous tumor lysate-pulsed DC vaccination therapy was performed in patients with relapsed malignant gliomas. Approximately 1 × 107 to 2 × 107 pulsed DCs loaded with WT1 peptide antigen and/or tumor lysate were intradermally injected into the axillary areas with OK-432, a streptococcal preparation, at 2-week intervals for at least 5-7 sessions (1 course) during an individual chemotherapy regimen. Results Ten patients (3 men, 7 women; age range 24-64 years [median 39 years]) with the following tumors were enrolled: glioblastoma (6), anaplastic astrocytoma (2), anaplastic oligoastrocytoma (1), and anaplastic oligodendroglioma (1). Modified WT1 peptide-pulsed DC vaccine was administered to 7 patients, tumor lysate-pulsed DC vaccine to 2 patients, and both tumor lysate-pulsed and WT1-pulsed DC vaccine to 1 patient. The clinical response was stable disease in 5 patients with WT1-pulsed DC vaccination. In 2 of 5 patients with stable disease, neurological findings improved, and MR images showed tumor shrinkage. No serious adverse events occurred except Grade 1-2 erythema at the injection sites. WT1 tetramer analysis detected WT1-reactive cytotoxic T cells after vaccination in patients treated with WT1-pulsed therapy. Positivity for skin reaction at the injection sites was 80% (8 of 10 patients) after the first session, and positivity remained for these 8 patients after the final session. Conclusions This study of WT1-pulsed DC vaccination therapy demonstrated safety, immunogenicity, and feasibility in the management of relapsed malignant gliomas.