Efficacy of intranodal neoantigen peptide-pulsed dendritic cell vaccine monotherapy in patients with advanced solid tumors: A retrospective analysis

Background/Aim: Neoantigens are tumor-specific antigens that emerge due to gene mutations in tumor cells, and are highly antigenic epitopes that escape central immune tolerance in the thymus, making cancer vaccine therapy a desirable option. Patients and Methods: Tumor neoantigens were predicted in 17 patients with advanced cancer. They were resistant to the standard treatment regime, and their synthetic peptides were pulsed to the patient's monocyte-derived dendritic cells (DCs), and administered to the patient's lymph nodes via ultrasound. Results: Some patients showed sustained tumor shrinkage after this treatment, while some did not respond, showing no ELISpot reaction. Although the number of mutations and the predicted neoantigen epitopes differed between patients, the clinical effect depended more on the presence or absence of an immune response after vaccination rather than the number of neoantigens. Conclusion: Intranodal neoantigen peptide-pulsed DC vaccine administration therapy has clinical and immunological efficacy and safety.