COURSE 2 AND ALL SUBSEQUENT COURSES (42 days): Patients receive oral sorafenib once or twice daily on days 1-42, cetuximab IV over 1-2 hours on days 1, 8, 15, 22, 29, and 36, and irinotecan IV over 90 minutes on days 1, 8, 15, and 22. Courses repeat every 42 days in the absence of disease progression or unacceptable toxicity.