Panitumumab in Cetuximab Refractory KRAS Wild-Type Colorectal Cancer

- Panitumumab will be given to the participants through a central line. A central line is
a long, thin tube (catheter) that is inserted through the skin into a large vein in the
chest. This is placed by a radiologist or surgeon.

- Panitumumab will be given in 4-week cycles. Panitumumab infusions will be given on days
1 and 15 of each cycle (every 2 weeks).

- The following procedures will be performed on days 1 and 15 of each cycle, before each
infusion: physical exam; questions about any symptoms or side effects; performance
status; routine blood tests and CT or MRI (every 2 cycles).

- Participants can continue to receive panitumumab until their disease gets worse or they
experience unacceptable side effects.

Inclusion Criteria:

- Histologically or cytologically confirmed diagnosis of colorectal adenocarcinoma and
measurable disease by RECIST criteria on CT or MRI

- Treated with cetuximab as part of their last treatment regimen for at least 4 weeks
and must have been taken off cetuximab therapy for disease progression. Patients may
or may not have been treated with 5-FU, oxaliplatin, irinotecan and bevacizumab.
There is no maximal number of pre-existing treatment regimens. At least 2 weeks must
have elapsed between previous anticancer therapy and the start of treatment on
protocol, AND resolution of any skin rash related to prior treatment with epidermal
growth factor receptor inhibitor

- ECOG Performance Status 0, 1 or 2

- Life expectancy of greater than 3 months

- Normal organ, metabolic, and marrow function as defined in the protocol

- A wild-type tumor K-RAS gene as determined by sanger sequencing of exon 2 from tumor
DNA

- 18 years of age or older

Exclusion Criteria:

- History of untreated and or progression central nervous system metastases

- History of another primary cancer except: curatively treated in situ cervical cancer
or breast; curatively resected non-melanoma skin cancer; other primary solid tumor
curatively treated with no known active disease present and no treatment administered
for 3 years or more prior to enrollment

- Intolerance to cetuximab leading to drug discontinuation due to rash, GI toxicity, or
other grade 3 or 4 toxicities

- Radiotherapy < 14 days prior to enrollment

- Systemic chemotherapy, hormonal therapy, immunotherapy, or experimental or approved
proteins/antibodies < 14 days before enrollment

- Subjects requiring chronic use of immunosuppressive agents

- Any investigational agent or therapy 30 days prior to enrollment

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situations that would limit compliance with
any study requirements

- History of interstitial lung disease

- Women who test positive for serum or urine pregnancy test or who are breast feeding