Ezra Cohen, MD, FRCPC, FASCO, from the University of California, San Diego, CA, discusses the KEYNOTE-040 study (NCT02252042) at the European Society for Medical Oncology (ESMO) 2017 in Madrid, Spain. The KEYNOTE-040 study was a Phase III trial in recurrent or metastatic head and neck cancer. It was based on the fact that anti-PDL1 antibodies have shown single agent activity, and that it might be beneficial for patients who had had failed platinum therapy. Pembrolizumab was used in the experimental arm, compared with methotrexate, cetuximab, or docetaxel. The study found that pembrolizumab was superior to other standards of care, and this treatment is especially effective in patients whose tumors express PDL1.