Inclusion Criteria:

- Diagnosis of metastatic colorectal cancer

- Wild-type (without mutation in codons 12 and 13) KRAS gene in tumor tissue confirmed
by a central laboratory

- ECOG performance status of 0, 1 or 2

- At least 1 measurable or non-measurable lesion per RECIST version 1.1 guidelines.

- Treatment failure (defined as failure due to either disease progression [clinical or
radiological] or toxicity [treatment intolerance]) of a prior regimen containing
irinotecan for metastatic disease and a prior regimen containing oxaliplatin for
metastatic disease. Oxaliplatin and irinotecan may have been administered
sequentially or in combination.

- Disease relapse within 6 months after completing adjuvant chemotherapy (with
either an irinotecan or oxaliplatin containing regimen) will also be considered
as treatment failure of a prior regimen for metastatic disease

- Must have previously received a thymidylate synthase inhibitor (eg, fluorouracil,
capecitabine, raltitrexed, or fluorouracil-uracil) at any point for treatment of CRC

- Man or woman at least 18 years of age

- Adequate hematologic, renal, hepatic and metabolic function

- Negative pregnancy test within 72 hours before randomization (for women of
childbearing potential only)

- Subject or subject's legally acceptable representative has provided informed consent.

- Other protocol-specified criteria may apply

Exclusion Criteria:

- Symptomatic brain metastases requiring treatment

- History of another primary cancer within 5 years of randomization

- Prior anti-EGFR antibody therapy (eg, panitumumab or cetuximab) or treatment with
small molecule EGFR inhibitors (eg, gefitinib, erlotinib, lapatinib)

- Antitumor therapy (eg, chemotherapy, hormonal therapy, immunotherapy, antibody
therapy) within 21 days before randomization

- Radiotherapy within 14 days before randomization.

- Exclusion Criteria for QTc Evaluation Subpart of the Study: Prolongation of QT/QTc
interval > 450 milliseconds at screening

- Other protocol-specified criteria may apply