MUC1 peptide vaccination in patients with advanced pancreas or biliary tract cancer.

BACKGROUND: To evaluate the immunogenicity of MUC1 peptide vaccine in advanced pancreatic and bile duct cancers, a phase I clinical trial was conducted. MATERIALS AND METHODS: A 100-mer MUC1 peptide consisting of the extracellular tandem repeat domain and incomplete Freund's adjuvant were subcutaneously administered to 6 pancreatic and 3 bile duct cancer patients at weeks 1, 3 and 5 and doses ranging from 300 to 3000 microg. Circulating intracytoplasmic cytokine-positive CD4+ T cells and anti-MUC1 IgG antibodies were measured before and after vaccination. RESULTS: There were no adverse events, except for mild reddening and swelling at the vaccination site. In 8 patients eligible for clinical evaluation, 7 had progressive disease and 1 stable disease with a tendency for increased circulating anti-MUC1 IgG antibody after vaccination. CONCLUSION: This phase I clinical trial revealed the safety of a vaccine containing 100-mer MUC1 peptides and incomplete Freund's adjuvant.