In trials name-checking some of the world’s highest peaks, longest rivers and most famous seas, Astrazeneca plc has long sought the best use of its CTLA4 inhibitor tremelimumab. Now, after a disappointing cruise along the first-line bladder cancer trial Danube and travails in non-small-cell lung cancer with the trials Mystic, Neptune and Arctic, a trek to the endpoint of its phase III trial Himalaya has yielded top-line success. A single, high priming dose of tremelimumab added to the company's immune checkpoint inhibitor, Imfinzi (durvalumab), led to a statistically significant overall survival (OS) benefit vs. Nexavar (sorafenib, Bayer AG and Amgen Inc.) in the first-line treatment for patients with unresectable hepatocellular carcinoma.