Randomised Phase II study of cetuximab alone or in combination with irinotecan in patients with metastatic colorectal cancer (CRC) with either KRAS WT or G13D mutation.

Interventions: Cetuximab & irinotecan combination therapy:
Cetuximab 400mg/m2 Intravenous infusion (IVI) on Day 1, followed by 250mg/m2 Intravenous infusion (IVI) every week;
Irinotecan 180mg/m2 Intravenous infusion (IVI) every 14 days;
Treatment will continue until disease progression, unless there is unacceptable toxicity or either the patient or physician requests cessation of treatment.
Primary outcome(s): To determine the 6 month PFS benefit of cetuximab alone or in combination with irinotecan in patients with KRAS WT or KRAS G13D mutated mCRC (PFS defined from time of randomisation to disease progression as defined by RECIST criteria version 1.1).[Patients will have a CT scan at baseline and every 6 weeks while on treatment. Patients will be followed up for 12 months after they progress on treatment.]
Study Design: Purpose: Treatment; Allocation: Randomised controlled trial; Masking: Open (masking not used);Assignment: Parallel;Type of endpoint: Safety