Patient-individualized Peptide Vaccination Based on Tumor-specific Mutations in Children and Young Adults With Primary/Relapsed ALL

Inclusion Criteria: * Pediatric patients and young adults with ALL (T, B, pro-B, pre-B or c-ALL) ≥CR3 or with ≥1st relapse after stem cell transplantation (SCT); or patients in ≤CR2 who have received SCT without having reached a sufficient molecular remission prior to, or after SCT (defined as MRD ≥10\^-4); or patients with initially refractory disease to standard treatment who could proceed to stem cell transplantation with alternative treatment options. * Hematological remission has to be reached (\<5% blasts in bone marrow or detectable minimal residual disease (MRD) ≤5x10\^-2) after salvage chemotherapy and/or subsequent SCT. Exclusion Criteria: * Frank relapse (\>5% leukemic blasts). * Ejection fraction \<25%; Creatinine-clearance \<40ml/min; Bilirubin \>4mg/dl, Transaminases \>400 units/ml; severe infection (HIV, Hepatitis), acute GvHD III-IV or chronic GvHD. * Significant psychiatric disabilities, uncontrolled seizure disorders or severe peripheral neuropathy/ leukoencephalopathy. * Signs of autoimmune disease (i.e. idiopathic thrombocytopenic purpura, autoimmune hemolytic anemia). * Need for immunosuppressive drugs. * No tumor material available for exome sequencing.