In the phase II portion, Patients will receive study treatment (E7050 plus Cetuximab or Cetuximab alone) for approximately six 28-day cycles (24 weeks). Beyond 24 weeks, patients who are experiencing clinical benefit may continue E7050 plus cetuximab, cetuximab alone or E7050 alone (Arm 1), or may continue cetuximab alone (Arm 2), depending on the original randomization treatment arm, for as long as clinical benefit is sustained and the treatment is well tolerated.