Inclusion Criteria:

- Histologically or cytologically confirmed colorectal cancer

- KRAS wild type metastatic colorectal cancer

- Progression of disease on at least 2 prior therapy to have included 5FU, or
oxaliplatin or bevacizumab or irinotecan

- Prior treatment with cetuximab is allowed (full dose tolerated), provided that the
patient never required a dose reduction due to toxicities

- Must have at least one measurable lesion

- Must be 18 years of age or older

- ECOG performance status 0-1

- Life expectancy must be greater than 12 weeks

- For women of childbearing potential, a negative pregnancy blood test must be obtained
less than 3 days prior to the first AUY922 infusion

Exclusion Criteria:

- Colorectal cancer with a KRAS mutation or in which the KRAS genotype status is
unknown

- Metastasis to the CNS

- Prior treatment with any Hsp90 inhibitor compounds

- Patients who received systemic anti-cancer treatment prior to the first dose of
AUY922 within the following time frames:

- Radiotherapy, conventional chemotherapy: within 2 weeks

- Palliative radiotherapy: within 2 weeks

- Nitrosoureas, monoclonal antibodies, such as trastuzumab and mitomycin: within 6
weeks

- Any continuous-dosing (i.e. daily dosing, every-other-day dosing,
Monday-Wednesday-Friday dosing, weekly etc.) of systemic anti-cancer treatment
for which the recover period is not known, or investigational drugs (i.e.
targeted agents) within a duration of ≤ 5 half lives of the agent and their
active metabolites (if any)

- Treatment of therapeutic doses of coumadin-type anticoagulants. [Maximum daily dose
of 2mg, for line patency permitted]

- Known sensitivity to cetuximab

- Unresolved ≥ grade 1 diarrhea

- Malignant ascites that require invasive treatment

- Concurrent medications that are substrates, inhibitors or inducers of CYP3A4, CYP2C8,
CYP2C9 and CYP2C19 and cannot be switched or discontinued or switched to an
alternative drug prior to commencing AUY922 dosing need special consideration on a
case by case basis

- Major surgery ≤ 2 weeks prior to randomization or who have not recovered from such
therapy

- Impaired cardiac function