A fixed-sequence, open-label study to determine the activity of SCH 717454 (robatumumab) as assessed by positron emission tomography in patients with relapsed or recurrent colorectal cancer.

3584 Background: This study was to evaluate the antitumor activity of SCH717454 (robatumumab) by positron emission tomography in patients with metastatic colorectal cancer. Methods: Eligible patients (n = 67) were those with metastatic colorectal cancer refractory to first-line chemotherapy and whose tumors were 3 cm or more in diameter with a tumor to background ratio of 3:1 on PET-CT scan. All patients were randomized 1:3 to receive either chemotherapy or robatumumab at 0.3 mg/kg biweekly in period 1 and all patients received robatumumab at 10 mg/kg biweekly in period 2. The primary endpoint of the study was to determine the proportion of subjects who had a SUVmax response (defined by >20% decrease) after the first cycle of SCH 717454 in period 2. It was hypothesized that higher doses of SCH 717454 would result in a greater SUVmax response. The chemotherapy arm served to validate change in SUVmax in this disease and timing setting as a potentially useful anti-tumor activity marker. Results: Seven out of...