James P Allison, who is Professor and Chair of the Department of Immunology at MD Anderson Cancer Centre at the University of Texas, studied a known protein, CTLA-4, that functions as a brake on the immune system's killer T-cells. Immunotherapy unleashes the body's immune system to target cancerous tumor cells and has fewer devastating side effects compared to chemotherapy.
The institute added that therapies based on Prof Honjo's discovery "proved to be strikingly effective in the fight against cancer". The duo will share the Nobel prize sum of nine million Swedish kronor (about Dollars 1.01 million).
Professor Allison works at the MD Anderson Cancer Center, Houston. Former president Jimmy Carter was successfully treated for the disease through the use of one of the drugs, along with surgery and radiation.
Honjo has said that since his college days the six C's of curiosity, courage, challenge, confidence, concentration and continuation were his driving force in research that led to the development of drugs that opened up new cancer treatments.
Honjo, who is now 76, told a news conference in Tokyo he was honoured to get the Nobel, but that his work was not yet done.
Why did this work win the Nobel prize?Colleagues arrived at his hotel room with champagne at 6:30 a.m.in the morning to celebrate. Allison spent 17 years convincing others that this approach could work, leading to approval in 2011 of the drug Yervoy, which showed near-miraculous results for a fraction of patients with a lethal form of skin cancer. That was a blissful moment.
What's more, he went on to develop a molecule that could release this emergency brake, allowing the T cells to, at last, seek and destroy their quarry.
"They have been able to make evolution many 1000s of times faster and redirect it to create new proteins".
Working separately, Honjo discovered another protein, called PD-1, that also hampers T cells' ability to attack cancer, but in a somewhat different way. Subsequent research has led to agents targeting additional immune checkpoints, often PD-1 and PD-L1, to treat a range of cancers including head and neck, gastric kidney, bladder, gastric, liver, colorectal, and cervical cancers, and Hodgkin lymphoma.
Antoni Ribas, an oncologist and director of the tumor immunology program at the UCLA Jonsson Comprehensive Cancer Center, said the medical community initially doubted drugs could help the body's immune system fight cancer. "They are living proof of the power of basic science", he said in a statement. Expectations are high for further research and development of anti-cancer therapies as the disease continues to be a serious health threat.
Nobel chemistry laureate George Smith, reached at his home in Columbia, Missouri, was quick to credit the work of others in his prize.
Monday, Oct. 8: Nobel Memorial Prize in Economic Sciences will be awarded.
Among the numerous awards and honours that Honjo has received are the Order of Culture, the Robert Koch Prize and the Imperial Prize of the Japan Academy.