Patient population Phase I portion: Metastatic colorectal cancer. A total of 3 patients on each cohort. Additional 3 patients on the tolerable cohort. Total patient number: Minimum 6, Maximum: 12 Phase II portion: Metastatic colorectal cancer: A total of 33 patients will be treated in this portion. This will include the patients treated on the tolerable dose level from the phase I trial. The statistical justification is indicated in the Statistics section 7.