The NOA-21/AMPLIFY-NEOVAC-Trial compares in a multicenter, open, randomized phase 1 design the safety and immunogenicity of the mutation-specific IDH1 peptide vaccine from the NOA-16 study in combination with checkpoint inhibition with avelumab with avelumab therapy alone and an IDH1 peptide vaccine alone in the first recurrence of diffuse glioma with IDH1-R132H mutation and an indication for resection.