A Study to Determine the Activity of Robatumumab (SCH 717454, MK-7454) in Participants With Relapsed or Recurrent Colorectal Cancer (P04721, MK-7454-003)

FDG-PET was used in this study to detect the biological activity of modulation of the target within the tumor. Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0 was used to select the target lesion. All measurable lesions up to a maximum of 5 lesions per organ and 10 lesions in total, representative of all involved organs were identified as target lesions and recorded and measured at Baseline. The changes in SUVmax were calculated using the formula: (endpoint SUVmax - baseline SUVmax)/baseline SUVmax as a percentage. If multiple lesions had been measured at a visit, percentages calculated for all target lesions were averaged to find the decrease during the treatment period per participant. FDG SUVmax responder was defined as participants with >20% decrease in SUVmax after the first cycle of robatumumab in Period 2.

An AE is any untoward medical occurrence in a participant administered study drug which does not necessarily have a causal relationship with the study drug. AEs may include the onset of new illness and the exacerbation of pre-existing conditions.

Tumor response was assessed by computed tomography (CT) or magnetic resonance imaging (MRI) scans using RECIST v 1.0 criteria at Screening, at every 8 weeks of robatumumab treatment during Period 2 and at post study. A sum of the longest diameter (LD) for all target lesions was calculated and reported as the baseline sum LD. Overall tumor responses were defined as: Complete Response (CR) - Disappearance of all target lesions; Partial Response (PR) - At least a 30% decrease in the sum of the LD of target lesions, taking as reference the baseline sum LD; Progressive Disease (PD) - At least a 20% increase in the sum of the LD of target lesions, taking as reference the smallest sum LD recorded since the treatment started or the appearance of one or more new lesions; or Stable Disease (SD) - Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum LD since the treatment started.

An AE is any untoward medical occurrence in a participant administered study drug which does not necessarily have a causal relationship with the study drug. AEs may include the onset of new illness and the exacerbation of pre-existing conditions.

Tumor response was assessed by CT or MRI scan using RECIST v1.0 criteria at Screening, at every 8 weeks of robatumumab treatment during Period 2 and at post study. A sum of the LD for all target lesions was calculated and reported as the baseline sum LD. Overall tumor responses were defined as: Complete Response (CR) - Disappearance of all target lesions; Partial Response (PR) - At least a 30% decrease in the sum of the LD of target lesions, taking as reference the baseline sum LD; Progressive Disease (PD) - At least a 20% increase in the sum of the LD of target lesions, taking as reference the smallest sum LD recorded since the treatment started or the appearance of one or more new lesions; or Stable Disease (SD) - Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum LD since the treatment started.

Tumor growth rate was assessed by CT or MRI scans using RECIST criteria at Screening, at every 8 weeks of robatumumab treatment and at post study. For Pre Baseline 1, tumor growth rate=(sum of longest diameter of target lesions at Baseline - the most recent prior to Baseline)/duration between Baseline and Pre Baseline. For all other cycles, tumor growth rate=(sum of longest diameter of target lesions at a cycle - Baseline)/ duration between Baseline and the cycle. The cycles presented below are relative to the first dose of robatumumab in Period 1.