New Adjuvant Vaccine in Glioblastoma, a Phase 1/2a Study

This phase I/II trial evaluates the safety and the immunological efficacy of a cancer vaccine against 2 glioma-associated antigens in newly-diagnosed glioblastomas. The objectives of this study are as follows: Primary objective * phase 1: * to assess the maximum tolerated dose (MTD) and select the recommend Phase 2a dose * phase 2a: * to assess anti- TERT specific T cell responses at 2 months at the selected dose level Secondary objectives: * To assess Short and long-time immunological safety * To assess Evolution of anti-PTPRZ1 and anti-TERT immune T cell responses over time * To assess Progression free survival (RANO 2.0 criteria) * To assess Overall survival * To assess Quality of life by EORTC QLQ30 and BN20 questionnaires as well as objective of ancillary study: to determine the mechanism of action of potential tumour escape in GBM (T-cell lymphocyte phenotype; antigen expression and checkpoint inhibitors on tumour cells at relapse, if available), analysis of circulating antibodies against TERT epitope and/or melanin, and identification of predictive biomarkers of response. Ultimately, this trial together will lead to the implementation of future phase III trial in GBM. All patients enrolled in the study will receive standard treatment consisting of surgical resection of the tumor followed by radio-chemotherapy. Immunotherapy will begin 4 weeks after the completion of radiotherapy.

This therapeutic vaccine targeting 2 identified glioma-associated antigens (TERT and PTPRZ1) is based on a new formulation that contains synthetic melanin and a TLR9 agonist, which is caable to induce strong cellular immune responses. One month after glioblastoma patients have completed the initial phase of treatment with concurrent radiochemotherapy, patients will be immunized during the adjuvant phase of monthly temozolomide. Immunizations will follow the standard schedule of a priming phase (D0, W2, W4, and W6) followed by a boost phase with one immunization every 2 months for a total of 12 months. Phase 1: subcutaneous injections at one of 3 pre-specified dose levels of peptides Phase 2a: subcutaneous injections at the dose selected in the phase 1 part. Safety will be evaluated clinically and with blood samples at each treatment visit. Efficacy will be assessed with anti-PTPRZ1 and anti-TERT specific T cell responses in peripheral blood, and with cerebral MRI every other months