|nivolumab versus standard treatment|
|nivolumab (at a dose of 3 mg per kilogram of body weight) every 2 weeks|
standard, single-agent systemic therapy (methotrexate, docetaxel, or cetuximab).
|patients with recurrent squamous-cell carcinoma of the head and neck whose disease had progressed within 6 months after platinum-based chemotherapy||open-label|
|pembrolizumab versus standard treatment|
|pembrolizumab 200 mg intravenous (IV) on Day 1 of each 3-week cycle|
standard treatment (methotrexate, docetaxel or cetuximab)
|patients with recurrent or metastatic head and neck squamous cell cancer||open-design|