Safety and Efficacy Study of MEHD7945A + FOLFIRI Versus Cetuximab + FOLFIRI as Second Line Therapy in Participants With KRAS Wild-Type Metastatic Colorectal Cancer (mCRC)

A Phase II, Multicenter, Open-Label, Randomized Study Evaluating the Efficacy and Safety of MEHD7945A + FOLFIRI Versus Cetuximab + FOLFIRI in Second Line in Patients With KRAS Wildtype Metastatic Colorectal Cancer

This open-label, randomized, multicenter, Phase 2 study will evaluate the safety and efficacy of MEHD7945A when combined with FOLFIRI (folinic acid [leucovorin], 5-fluorouracil [5-FU], and irinotecan) chemotherapy as compared to cetuximab plus FOLFIRI in participants with Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) wild-type mCRC who have progressed after first-line oxaliplatin-containing chemotherapy for metastatic disease. Participants will be randomized to receive FOLFIRI chemotherapy plus either MEHD7945A or cetuximab. Anticipated time on study treatment is until disease progression or unacceptable toxicity occurs.

Inclusion Criteria:

• Histologically or cytologically confirmed adenocarcinoma of the colon and/or rectum, with KRAS wild-type status
• Progressive disease on or after first-line oxaliplatin-containing regimen for mCRC; participants must have received oxaliplatin-containing chemotherapy for greater than or equal to (>/=) 3 months; no more than one prior chemotherapy regimen for metastatic disease is allowed
• Measurable disease per modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1)
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Adequate hematologic and end-organ function

Exclusion Criteria:

• Prior treatment with irinotecan
• Prior treatment with an investigational or approved human epidermal growth factor receptor (HER)-targeted agent
• Last anti-tumor therapy within 4 weeks prior to Cycle 1, Day 1
• Leptomeningeal disease as the only manifestation of the current malignancy
• Active infection requiring intravenous antibiotics
• Active autoimmune disease that is not controlled by nonsteroidal anti-inflammatory drugs
• Current severe, uncontrolled systemic disease
• Known human immunodeficiency virus (HIV) infection
• Untreated/active central nervous system metastases (progressing or requiring anticonvulsants or corticosteroids for symptomatic control)
• Pregnant or lactating women
• Malignancies other than colorectal cancer within 5 years prior to randomization, except for adequately treated basal or squamous cell skin cancer and carcinoma in situ of the cervix