Kai-Keen Shiu, FRCP, PhD, University College London Hospitals NHS Foundation Trust, London, UK, discusses some of the key questions asked during this years American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium regarding the KEYNOTE-177 trial (NCT02563002), a Phase III study investigating first-line pembrolizumab in patients with microsatellite-instability high/mismatch repair deficient metastatic colorectal cancer. This includes whether immunotherapy should be combined with chemotherapy, the role of pseudoprogression in progression-free survival, and biomarkers for response. This interview was recorded via an online conference call with The Video Journal of Oncology (VJOncology).