Tasuku Honjo

Tasuku Honjo, at Kyoto University, identified programmed cell death protein 1 (PD-1) in 1992 as a gene switched on in dying T cells and, over the following decade, showed with knockout mice that it restrains immune responses and that its blockade lets T cells attack tumours. He worked with Ono Pharmaceutical, later joined by Medarex and Bristol-Myers Squibb, to develop an antibody against it; nivolumab was approved in Japan in July 2014 for melanoma and in the United States in December 2014, and with pembrolizumab established PD-1 blockade as the most widely used cancer immunotherapy, in lung, kidney, bladder, head and neck, Hodgkin lymphoma and many other cancers. He shared the 2018 Nobel Prize in Physiology or Medicine with James Allison for the discovery of cancer therapy by inhibition of negative immune regulation, and his earlier work identified activation-induced cytidine deaminase, central to antibody class switching.