A personalized peptide-based cancer vaccine comprised of one or two de novo synthesized patient-specific tumor-mutated peptides associated with glioblastoma (GB), with potential immunomodulating and antineoplastic activities. Vaccination with synthetic GB mutated tumor-specific peptides vaccine therapy APVAC2 stimulates the host immune system to mount a cytotoxic T-lymphocyte (CTL) response against tumor cells expressing the selected mutated tumor-associated peptides, which results in decreased GB growth. These peptides are specifically selected and synthesized based on the expression of the patient's own mutated tumor-associated antigens, which were detected during individual tumor genome sequencing.