PHASE-I STUDY OF SYNTHETIC MUC1 PEPTIDES IN BREAST-CANCER

Exposed peptides in the repeat (VNTR) protein core of human mucin 1 (M UC1) could be a target for immunotherapy, as it is highly immunogenic in mice and a human cytotoxic T lymphocytes to MUC1 recognise the pept ide. On this basis 13 patients were immunised with a MUC1 peptide - a 20 amino acids dimer conjugated with diphtheria toroid as carrier. In patients with established breast cancer increasing doses (0.15 mg, 0.2 5 mg, 0.5 mg, 1.0 mg) were used at 2 week intervals (3 injections). No toxicity was found, other than for DTH reaction to the diphtheria car rier; weak antibody and T cell proliferative responses were seen and w eak DTH reaction in proportion of patients. The MUC1 peptide appears t o be safe but in the form used was not highly immunogenic.