Other anti-PD-1 Phase II/III trials currently underway including NCT03813836 (pembrolizumab in recurrent/metastatic HNSCC with WHO performance status 2), NCT02521870 (pembrolizumab plus intratumoral SD-101 in anti-PD-1/PD-L1 treatment-naïve recurrent/metastatic HNSCC), NCT02741570 (nivolumab plus ipilimumab vs. the EXTREME regimen as first-line treatment in recurrent/metastatic HNSCC), NCT03040999 (pembrolizumab plus cisplatin plus RT vs. cisplatin plus RT alone in locally advanced HNC), and NCT02707588 (pembrolizumab plus RT vs. cetuximab plus RT in locally advanced HNC). Here, PDCD1 is linked to head and neck squamous cell carcinoma.