An open label, dose-finding, schedule-changing, sequential, multiple dose, multi-center study in patients with Stage I-III gastric cancer. The first group of patients received a starting dose of 250 µg at weeks 0, 1, and 3. Thereafter, allocation to treatment with 100 µg or 500 µg was based on antibody response and dose tolerability.

Inclusion Criteria:

• Histologically confirmed UICC Stage I, II or III gastric adenocarcinoma. Must have had a macroscopically curative resection for gastric cancer with absence of metastatic disease at the time of entry to the trial
• Male or female and over 18 years of age
• Must have a life expectancy of at least three months
• World Health Organization Performance Status of 0 to 1
• Given written conformed consent

Exclusion Criteria:

• Gastric surgery within four weeks of baseline (week 0) or gastric surgery anticipated in the period of the study
• History of other malignant disease within the previous five years, except non-melanomatous skin cancer or in situ carcinoma of the uterine cervix
• Previous use within the last four weeks, concomitant use or anticipated use in the period of the study, of any anti-cancer therapies
• Concomitant use of immunosuppressants, including systemic (i.e. oral or injected) corticosteroids
• Females who pregnant, planning to become pregnant or lactating
• Taking part in another study involving an investigational or licensed drug or device in the three months preceding enrollment or during this study
• Previously received G17DT treatment
• Haemoglobin (Hb) < 10.0 g/dL White blood cell count (WBC) < 4.0 x 10^9/L Platelets < 100 x 10^9/L