A Study of Pembrolizumab (MK-3475) for First Line Treatment of Recurrent or Metastatic Squamous Cell Cancer of the Head and Neck (MK-3475-048/KEYNOTE-048)

Pembrolizumab 200 mg IV on Day 1 of each 3-week cycle for up to 35 cycles (up to \~2 years).

Cisplatin 100 mg/m\^2 IV on Day 1 of each 3-week cycle (6 cycle maximum \[up to \~4 months\]).

Carboplatin at a target AUC 5 IV on Day 1 of each 3-week cycle (6 cycle maximum \[up to \~4 months\]).

5-FU 1000 mg/m\^2/day IV continuous from Day 1-4 of each 3-week cycle (6 cycle maximum \[up to \~4 months\]).

Cetuximab on Day 1 at a dose of 400 mg/m\^2 IV, and then 250 mg/m\^2 IV on Day 1 of each subsequent week until disease progression or unacceptable toxicity