Study to Assess Safety and Tolerability of G17DT in Patients With Colorectal Adenocarcinoma.

Inclusion Criteria: * Histologically verified adenocarcinoma of the colon or rectum * Recurrent/ metastatic disease not amenable to curative surgery and/or radiotherapy * measurable/ evaluable lesions * Life expectancy \> 3 months * Karnofsky index \> 50% or WHO performance rating of 0-2 * Biochemical markers: * renal function \< 25% above upper limit of normal range (creatinine, 140 imol/1 unless malignant involvement proven) * liver function \< 25% above upper limit of normal range (bilirubin \~25 mcmol/1 unless malignant involvement proven) * Haematological status: * haemoglobin, 11 g/ dl * WBC, 4 X 109/1 * platelets, 100 x 109/l * Written consent Exclusion Criteria: * Other concomitant malignant disease except treated basal cell carcinoma of the skin or cancer of the uterine cervix stage 0-1 * H 2 receptor antagonist or proton pump inhibitor therapy * Previous gastric surgery (including vagotomy) * Active uncontrolled infection * Autoimmune disorders * Anticancer treatment within the last three months unless progression of the disease occurred in the interim * Women of child-bearing age * Patient is a poor medical risk because of non-malignant systemic disease * Previous radiotherapy to all measurable or evaluable lesions.