Dendritic cell vaccination with MAGE peptide is a novel therapeutic approach for gastrointestinal carcinomas

The MAGE gene is selectively expressed in cancer tissues such as melanoma o r gastrointestinal carcinomas, whereas no expression is observed in normal tissues except testis. There are several reports of successful induction of HLA class I-restricted antitumor CTLs using MAGE peptides, and some clinic al trials with these immunogenic peptides were reported as effective for so me patients with malignant melanoma. However, there are no similar studies in gastrointestinal carcinomas, which are important neoplasms. Autologous d endritic cells (DCs) were generated ex vivo and were pulsed with MAGE-3 pep tide, depending on the patient's HLA haplotype (HLA-A2 or A24). Patients we re immunized with DC pulsed with MAGE-3 peptide every 3 weeks at four times . Twelve patients with advanced gastrointestinal carcinoma (six stomach, th ree esophagus, and three colon) were treated, and no toxic side effects wer e observed. Peptide-specific CTL responses after vaccination were observed in four of eight patients. Improvement in performance status was recognized in four patients. Tumor markers decreased in seven patients. In addition, minor tumor regressions evidenced by imaging studies were seen in three pat ients. These results suggested that DC vaccination with MAGE-3 peptide is a safe and promising approach in the treatment of gastrointestinal carcinoma s.