[Anti-apoptosis protein, survivin-2B-derived peptide vaccine therapy]

As advances in new therapeutic modalities are urgently needed, one of which is tumor-specific immunotherapy. We identified an HLA-A24-restricted antigenic peptide, survivin-2B80-88, and started a phase I clinical study of survivin-2B peptide vaccination in patients with advanced or recurrent colorectal cancer. Of 15 patients who finished receiving the vaccination schedule, three suffered slight toxicities. In 6 patients, tumor marker levels decreased transiently during the period of vaccination. Slight reduction in tumor volume was observed in one patient, which was considered a minor responder. Analysis of peripheral blood lymphocytes of one patient using HLA-A24/peptide tetramers revealed an increase in peptide-specific CTL after vaccination. This phase I clinical study revealed that administration of the survivin-2B peptide is safe. The vaccination with survivin-2B peptide alone was not enough to elicit clinical responses. Consequently, we have recently started the second clinical study of survivin-2B peptide vaccine in combination with various adjuvants.