This study was designed to investigate the antibody response generated by a 500µg dose of G17DT in patients with gastric cancer.

Another study, GC2, initiated prior to the start of this study investigated the appropriate dose and dosing schedule for G17DT in patients with Stage I-III gastric cancer. The highest dose tested in the GC2 study was 250µg. This dose was well tolerated but was not considered sufficiently immunogenic. Since tolerability had not constrained dosing up to 250µg, the GC5 study was designed to investigate a 500µg dose administered as a regimen of 0, 2, and 6 weeks.

Inclusion Criteria:

• Patients with histologically confirmed UICC Stage I, II or III gastric adenocarcinoma.
• Patients 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 patients aged 18 years or older.
• Life expectancy of at least 3 months.
• WHO Performance Status of 0 to 1.
• Written informed consent

Exclusion Criteria:

• Gastric surgery within four weeks of baseline (Week 0, visit 2) or gastric surgery anticipated during the period of the study.
• History of other malignant disease within the previous five years, except nonmelanomatous skin cancer or in situ carcinoma of the uterine cervix.
• Previous use within the last four weeks, concomitant use of anticipated use in the period of study, of any anti-cancer therapies.
• Concomitant use of immunosuppressants, including systemic (i.e. oral or injected) corticosteroids.
• Females who were pregnant, planning to become pregnant or lactating.
• Patients taking part in another study involving an investigational or licensed drug or device in the three months preceding enrollment or during this study.
• Previous G17DT treatment.
• Haematologicial indicators:

Haemoglobin (Hb) < 10g/dL White blood cell count (WBC) < 4.0 x 10^9/L Platelets < 100 x 10^9/L