This is an open-label, phase II study evaluating the safety and efficacy of PTK787/ZK222584 administered daily in subjects with neuroendocrine tumors that are experiencing progressive disease and/or whose tumor-related syndrome symptoms (flushing and diarrhea) are considered inadequately controlled despite optimal doses of octreotide therapy. Inadequate control is defined as a minimum of 2 flushing episodes or 6 bowel movements per day for 7 consecutive days. Subjects who meet all inclusion and exclusion criteria and have completed all baseline and screening testing will receive an initial dose of PTK787/ZK222584 1,250 mg once daily and subjects will also remain on the scheduled doses of Sandostatin LAR 30 mg every 4 weeks. Both drugs will be dosed on a flat schedule of mg, not by weight or body surface area. The PTK787/ZK222584 medication will be taken orally with daily dosing. Each tablet of PTK787/ZK 222584 is 250 mg. The subject will take five tablets of study medication per day 2 tabs am and 3 tabs pm. Subjects may continue to receive therapy as long as they do not experience unacceptable toxicities or evidence of disease progression as defined by RECIST criteria. Subjects will be evaluated with a daily log to assess the degree of symptom control (flushing and diarrhea) and subjects will be monitored every 2 weeks for 3 months then monthly for biochemical control and every three months for tumor response. Subjects will be monitored by the Investigator every two weeks for 3 months then monthly for safety and efficacy.