3. Phase 1a: must have a histologically or cytologically confirmed advanced malignant solid tumor of epithelial origin and must have failed on previous chemotherapy. Phase 1b: must have a histologically or cytologically confirmed, recurrent, locally advanced or metastatic gastric cancer with measurable disease; must be chemo-naïve or must have failed on previous chemotherapy; must not have received an oxaliplatin-based chemotherapeutic regimen or monoclonal antibody therapy.