Two scientists who pioneered an entirely new way to treat cancer have won the 2018 Nobel Prize in Physiology or Medicine.
James Allison of the University of Texas MD Anderson Cancer Center in Houston, Texas and Tasuku Honjo from Kyoto University in Japan will share the 9 million Swedish kronor (US$1 million) prize.
The pair showed how proteins on immune cells can be used to manipulate the immune system so that it attacks cancer cells.
In the 1990s, Allison, then at the University of California, Berkeley, was one of several scientists who studied a ‘checkpoint’ protein, CTLA-4, that acts as a brake on immune cells called T cells. Allison and colleagues went on to engineer an antibody that could bind to CTLA-4, removing the brakes on T-cell activity and unleashing them to attack cancer cells. A clinical study in 2010 found that the antibody had a striking effect on people with advanced melanoma skin cancer.
Working independently of Allison, in 1992, Honjo discovered a different T-cell protein, PD-1, which also acts as a brake on the immune system but via a different mechanism. PD-1 went on to become a target in the treatment of cancer. In 2012, research in people revealed that the protein was effective against several different types of cancer. The results were dramatic – some patients with metastatic cancer went into long-term remission, raising the possibility of a cure. Until that point metastatic cancer had been considered by most as incurable.
“Allison’s and Honjo’s discoveries have added a new pillar in cancer therapy. It represents a completely new principle, because unlike previous strategies, it is not based on targeting the cancer cells, but rather the brakes – the checkpoints – of the host immune system”, said Klas Kärre, a member of the Nobel Committee and an immunologist at the Karolinska Institute in Stockholm who described the work of the prizewinners during the Nobel announcement. “The seminal discoveries by the two laureates constitutes a paradigmatic shift and a landmark in the fight against cancer.”
In 2015, Allison won a prestigious Lasker prize for his work on cancer immunotherapy. In 2016, Honjo won the Kyoto Prize in basic sciences, a global prize awarded by the Inamori Foundation.