Immunopeptide therapy has provided significant clinical improvements in the treatment of several malignancies. The generation 1 personalized edited sequence (G1-PES) vaccine administered to 43 severe metastatic cancer patients (terminal stage), safely and effectively in Dr. Catanzaro's clinic in 2001 to 2014. These all patients were considered for 3 to 4 months life support with no hope. Patients were on G1-PES an 18-month therapy program with the objective of achieving remission and cancer free survival within 18 months. Typically, patients received 4 cycles every 12 weeks. The safety and efficacy were assessed through adverse events, progression-free survival (PFS), overall survival (OS) and other parameters. Patients that received G1-PES were free from any serious adverse effects (SAE's), while receiving and after therapy. Typical reactions included slight fever, flu-like symptoms for 1-2 days and rash at route of administration site that lasted for 2-3 days. All of these minor reactions were self-limiting. Patients had significantly improved quality of life within 1-3 weeks of receiving therapy, with diminishing symptoms associated with their cancer and clinical evidence of cancer regression (p<0.001). G1-PES vaccine was feasible and safe for patients with advanced metastatic cancer. G1-PES vaccine was designed based on T cell-mediated immune response targeting tumor neoantigens as antitumor efficacy.