Pembrolizumab (MK-3475) Versus Standard Treatment for Recurrent or Metastatic Head and Neck Cancer (MK-3475-040/KEYNOTE-040)

200 mg intravenous (IV) on Day 1 of each 3-week cycle.

40 mg/m\^2 IV (may be escalated to 60 mg/m\^2 maximum dose) on Days 1, 8, and 15 of each 3-week cycle

75 mg/m\^2 IV on Day 1 of each 3- week cycle

400 mg/m\^2 IV loading dose on Day 1 and 250 mg/m\^2 IV on Days 8 and 15 of Cycle 1, followed by 250 mg/m\^2 on Days 1, 8, and 15 of each subsequent 3-week cycle.