• Number of Participants With a Dose-Limiting Toxicity [ Time Frame: Prior to each 21-day cycle until dose-limiting toxicities ] [ Designated as safety issue: Yes ]
• Maximum Plasma Concentration (Cmax) [ Time Frame: up to 168 hours after the start of the cetuximab infusion during the first 21-day cycle of the study ] [ Designated as safety issue: No ]
• Area Under the Curve, Extrapolated to Infinity (AUC[INF]) [ Time Frame: up to 168 hours after the start of the cetuximab infusion during the first 21-day cycle of the study ] [ Designated as safety issue: No ]
• Terminal Half-Life (T-Half) [ Time Frame: up to 168 hours after the start of the cetuximab infusion during the first 21-day cycle of the study ] [ Designated as safety issue: No ]
• Clearance Corrected for Body Surface Area (CL/BSA) [ Time Frame: up to 168 hours after the start of the cetuximab infusion during the first 21-day cycle of the study ] [ Designated as safety issue: No ]
• Volume of Distribution at Steady State Corrected for Body Surface Area (VSS/BSA) [ Time Frame: up to 168 hours after the start of the cetuximab infusion during the first 21-day cycle of the study ] [ Designated as safety issue: No ]
• Tumor Response [ Time Frame: Every other 21-day cycle ] [ Designated as safety issue: No ]
• Human Anti-cetuximab Antibody (HACA) Response [ Time Frame: Blood was drawn immediately prior to cetuximab infusions, on a 21-day cycle ] [ Designated as safety issue: Yes ]
• Number of Deaths, Serious Adverse Events (SAEs), and Adverse Events (AEs) [ Time Frame: Weekly throughout the study and every 4 weeks thereafter ] [ Designated as safety issue: Yes ]
• Grade 3-4 Laboratory Abnormalities - Leukopenia [ Time Frame: pretreatment visit, prior to each treatment cycle, weekly, and at the end of treatment ] [ Designated as safety issue: Yes ]
• Grade 3-4 Laboratory Abnormalities - Neutropenia [ Time Frame: pretreatment visit, prior to each treatment cycle, weekly, and at the end of treatment ] [ Designated as safety issue: Yes ]
• Grade 3-4 Laboratory Abnormalities - Thrombocytopenia [ Time Frame: pretreatment visit, prior to each treatment cycle, weekly, and at the end of treatment ] [ Designated as safety issue: Yes ]
• Grade 3/4 Laboratory Abnormalities - Hypomagnesemia [ Time Frame: pretreatment visit, prior to each treatment cycle, weekly, and at the end of treatment ] [ Designated as safety issue: Yes ]

• Characterize the serum pharmokinetics of cetuximab in pediatric and adolescent subjects with refractory solid tumors.
• Evaluate the safety profile and determine the dose limiting toxicities of the combination of cetuximab and irinotecan. Evaluate preliminary evidence of anti-tumor activity of the combination of cetuximab and irinotecan in the subject population.
• Evaluate the incidence of human anti-cetuximab antibody formation in subjects receiving cetuximab.

The purpose of this clinical research study is to establish the maximum tolerated dose and recommended Phase II dose of Erbitux™ in combination with Irinotecan in pediatric and adolescent patients with refractory solid tumors.

• Cancer
• Refractory Solid Tumor

• Drug: Cetuximab + Irinotecan
• Drug: Cetuximab + Irinotecan

• Active Comparator: 1-12 years old
• Active Comparator: 13-18 years old

Inclusion Criteria:

• Histologically or cytologically confirmed diagnosis of a solid tumor which has progressed on, or following standard therapy, or for which no standard effective therapy is known.
• Children age 1-18 years.

Exclusion Criteria:

• Presence of active infection.
• Requirement to receive concurrent chemotherapy immunotherapy, radiotherapy, or any other investigational drug while on study.
• Inadequate bone marrow, hepatic, or renal function.