There are numerous ongoing and planned clinical trials investigating immuno-oncology (IO) agents for lung cancer, particularly in combination with other classes of therapy moving forwards. Here, Alastair Greystoke, PhD, of the University of Newcastle & Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle, UK, discusses the key combinations being investigated. Dr Greystoke highlights investigations combining checkpoint inhibitors with an inhibitor of IDO, which may be involved in IO resistance. He also covers the challenges being faced in developing these combination regimens, highlighting the struggle with prioritization and toxicity. This video was recorded at the British Thoracic Oncology Group (BTOG) Annual Conference 2018, held in Dublin, Ireland.