Dual Epidermal Growth Factor Receptor Inhibition With Erlotinib and Panitumumab With or Without Chemotherapy for Advanced Colorectal Cancer

OBJECTIVES:

Primary

- Determine the response rate in patients with metastatic colorectal cancer treated with
erlotinib hydrochloride and panitumumab with versus without irinotecan hydrochloride as
second-line therapy .

Secondary

- Determine time to disease progression and time to treatment failure in patients treated
with these regimens.

- Determine the safety of these regimens in these patients.

- Determine the effect of these regimens on downstream targets of EGFR in skin rash
associated with pharmacologic EGFR inhibition (exploratory).

- Determine the association between KRAS mutations and response to EGFR inhibition
(exploratory).

OUTLINE: This is a multicenter study. Patients are stratified according to wild-type Kras
tumors ( 6/6 UGT1A1 vs 6/7 UGT1A1), and are randomized to 1 of 2 treatment arms. Patients
with wild-type Kras tumor 7/7 UGT1A1 receive treatment in arm III.

- Arm I: Patients receive oral erlotinib hydrochloride once daily on days 1-14,
panitumumab IV over 30-90 minutes on day 1, and irinotecan hydrochloride IV over 90
minutes on day 1. Treatment repeats every 2 weeks in the absence of disease progression
or unacceptable toxicity.

- Arm II: Patients receive oral erlotinib hydrochloride once daily on days 1-14 and
panitumumab IV over 30-90 minutes on day 1. Treatment repeats every 2 weeks in the
absence of disease progression or unacceptable toxicity. Upon disease progression,
patients receive irinotecan hydrochloride as in arm I.

- Arm III: Patients receive erlotinib hydrochloride and panitumumab as in arm II. Skin
biopsies and blood samples may be collected for further analysis.

After completion of study therapy, patients are followed every 6 weeks.

DISEASE CHARACTERISTICS:

- Histologically confirmed colorectal cancer

- Metastatic disease

- Biopsy of either the primary cancer or metastatic site required

- Tumor expressing wild-type Kras mutations

- Progressive disease within 3 months after treatment with first-line fluorouracil
(5-FU) and oxaliplatin-based chemotherapy OR evidence of metastatic disease within 6
months of completing adjuvant therapy with 5-FU and oxaliplatin

- Measurable disease defined as ≥ 1 lesion that can be accurately measured in ≥ 1
dimension (longest diameter to be recorded) as ≥ 20 mm with conventional techniques OR
as ≥ 10 mm with spiral CT scan

PATIENT CHARACTERISTICS:

- ECOG performance status 0-2

- Life expectancy > 6 months

- ANC > 1,500/mm^3

- Platelet count > 100,000/mm^3

- Hemoglobin ≥ 9 g/dL

- Creatinine < 1.5 times upper limit of normal (ULN)

- Bilirubin < 1.5 times ULN (or < 2 mg/dL)

- AST and/or ALT < 3 times ULN (< 5 times ULN with liver metastases)

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No concurrent malignancy requiring therapy except minor surgery for non-melanoma skin
cancer removal

- No interstitial lung disease with symptoms (e.g., dyspnea or cough) including any of
the following significant conditions:

- Parenchymal lung disease

- Metastatic disease

- Pulmonary infections

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- No prior EGFR inhibitors, irinotecan hydrochloride, or other second-line chemotherapy
regimens

- More than 4 weeks since prior radiotherapy

- No other concurrent investigational agents

- No other concurrent anticancer treatment modalities (e.g., radiotherapy)