S1613, Trastuzumab and Pertuzumab or Cetuximab and Irinotecan Hydrochloride in Treating Patients With Locally Advanced or Metastatic HER2/Neu Amplified Colorectal Cancer That Cannot Be Removed by Surgery

Inclusion Criteria

• STEP 1 INITIAL REGISTRATION: HER2 TESTING
• Patients must have histologically or cytologically documented adenocarcinoma of the colon or rectum that is metastatic or locally advanced and unresectable
• Mutation results:
• All patients must have molecular testing performed in a Clinical Laboratory Improvement Act (CLIA) certified lab which includes which includes KRAS and NRAS gene and exon 15 of BRAF gene (BRAF V600E mutation); patients with any known activating mutation in exon 2 [codons 12 and 13], exon 3 [codons 59 and 61] and exon 4 [codons 117 and 146]) of KRAS/NRAS genes and in exon 15 (BRAFV600E mutation) of BRAF gene are not eligible
• Patients must not have been treated with any of the following prior to step 1 initial registration:
• Cetuximab, panitumumab, or any other monoclonal antibody against EGFR or inhibitor of EGFR
• HER-2 targeting for treatment of colorectal cancer; patients who have received prior trastuzumab or pertuzumab for other indications such as prior history of adjuvant or neoadjuvant breast cancer treatment prior to the development of advanced colorectal cancer are eligible
• Patients must not have had history of severe toxicity and intolerance to or hypersensitivity to irinotecan or any other study drug; patients must not have had a severe infusion-related reaction during any prior therapy with pertuzumab or trastuzumab
• Patients must have tumor slides available for submission for HER-2 testing; HER-2 testing must be completed by the central lab prior to step 2 randomization
• Patients must be informed of the investigational nature of this study and must sign and give informed consent in accordance with institutional and federal guidelines; for step 1 initial registration, the appropriate consent form is the step 1 consent form
• As a part of the OPEN registration process the treating institution's identity is provided in order to ensure that the current (within 365 days) date of institutional review board approval for this study has been entered in the system
• STEP 2 RANDOMIZATION
• Patients must have HER-2 amplification as determined by central testing (3+ or 2+ by immunohistochemistry and HER-2 gene amplification by in situ hybridization with a ratio of HER-2 gene signals to centromere 17 signals >= 2.0)
• Patients must have measurable disease that is metastatic or locally advanced and unresectable; imaging used to assess all disease per RECIST 1.1 must have been completed within 28 days prior to step 2 randomization; all disease must be assessed and documented on the Baseline Tumor Assessment Form
• Patients must have had at least one prior regimen of systemic chemotherapy for metastatic or locally advanced, unresectable disease; patients must have progressed following the most recent therapy; prior treatment with irinotecan is allowed; for patients that received adjuvant chemotherapy: prior treatment for metastatic disease is not required for patient who experienced disease recurrence during or within 6 months of completion of adjuvant chemotherapy; if the patient received one line of adjuvant treatment and had disease recurrence after 6 months of completing chemotherapy, patients will only be eligible after failing one additional line of chemotherapy used to treat the metastatic or locally advanced, unresectable disease; patients who have received >= 3 lines of systemic chemotherapy for metastatic or locally advanced, unresectable disease are not eligible
• Patients must have completed prior chemotherapy, immunotherapy, or radiation therapy at least 14 days prior to step 2 randomization and all toxicity must be resolved to Common Terminology Criteria for Adverse Events (CTCAE) version (v)4.0 grade 1 (with the exception of CTCAE v4.0 grade 2 neuropathy) prior to step 2 randomization
• Brain metastases are allowed if they have been adequately treated with radiotherapy or surgery and stable for at least 30 days prior to step 2 randomization; eligible patients must be