Panitumumab and Chemotherapy in Patients With Advanced Colorectal Cancer After Prior Therapy With Bevacizumab

Inclusion Criteria

• Patients with advanced adenocarcinoma of the colon or rectum not curable with surgery or radiotherapy and have been previously treated for their disease with FOLFIRI plus bevacizumab in the first line metastatic setting; patients will only be eligible if their last line of therapy prior to enrolling onto the study was FOLFIRI and bevacizumab received no more than 6 months prior to enrolling in this study; they should have been treated with FOLFIRI plus bevacizumab until disease progression is radiographically documented
• Patients' tumors will need to tested for the K-RAS and N-RAS mutation status; only those patients with wild-type or unmutated K-RAS and N-RAS oncogene are eligible to participate in this study
• Provide written informed consent prior to study-specific screening procedures, with the understanding that the patient has the right to withdraw from the study at any time, without prejudice
• Prior cetuximab is allowed in the adjuvant but not in the metastatic setting, but must have been completed at least 6 months before starting this trial
• Eastern Cooperative Oncology Group (ECOG) performance status = = 3000/uL
• Absolute neutrophil count >= 1500/uL
• Platelets >= 100,000/uL
• Hemoglobin >= 9 mg/dL
• Total bilirubin = = 30 ml/min (Cockroft-Gault equation)
• Magnesium >= lower limit of normal
• Measurable disease is required according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria
• The effects of Panitumumab on the developing human fetus are unknown; for this reason and because monoclonal antibodies as well as other therapeutic agents used in this trial are known to be teratogenic, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation and up to 6 months after completing therapy; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately

Exclusion Criteria

• Pregnant or lactating women; women of childbearing potential with either a positive or no pregnancy test at baseline; woman or men of childbearing potential not using a reliable and appropriate contraceptive method; (postmenopausal woman must have been amenorrheic for at least 12 months to be considered of non-childbearing potential)
• Sexually active males unwilling to practice contraception during the study and 6 months beyond
• Uncontrolled intercurrent illness including but not limited to clinically significant cardiac disease not well controlled with medication (e.g. congestive heart failure, symptomatic coronary artery disease and cardiac arrhythmias) or myocardial infarction within the last 12 months, and serious concurrent infections
• History of interstitial lung disease (eg, pneumonitis or pulmonary fibrosis) or evidence of interstitial lung disease on baseline chest computed tomography (CT) scan
• KRAS or NRAS mutant tumors
• Active inflammatory bowel disease or other bowel disease causing chronic diarrhea (defined as >= Common Toxicity Criteria [CTC] grade 2 [Common Terminology Criteria for Adverse Events (CTCAE) version 4.0])
• Clinically significant cardiovascular disease (including myocardial infarction, unstable angina, symptomatic congestive heart failure, serious uncontrolled cardiac arrhythmia) =< 1 year
• Bevacizumab within the last 4 weeks before starting treatment on trial
• Patient is more than 6 months since the last dose of FOLFIRI
• Patients who have required toxicity related dose reductions of no less than 50% of the original dose of infusional 5-FU and/or irinotecan during the administration of FOLFIRI + bevacizumab
• Prior exposure to panitumumab in any setting
• Prior exposure to cetuximab in the metastatic (stage IV) setting
• Radiotherapy =< 14 days prior to enrollment; patients must have recovered from all radiotherapy-related toxicities
• Prior