Ursula Matulonis, MD of the Dana-Farber Cancer Institute, Boston, MA discusses the poster on the KEYNOTE-100 Phase II trial of pembrolizumab in patients with advanced recurrent ovarian cancer (NCT02674061) presented at the 2016 annual meeting of the European Society of Medical Oncology (ESMO), held in Copenhagen, Denmark. Dr Matulonis explains that it is a trial in progress poster with no actual results yet. Several hundred patients have been enrolled and pembrolizumab, a PD-1 inhibitor, is being used as a single agent. She further explains that they also hope to identify a biomarker around PD-L1 expression or other biomarkers that might help predict, which patients benefit most from a single agent PD-1 strategy.