James Allison, Tasuku Honjo win Nobel Prize in Medicine

James Allison, Tasuku Honjo win Nobel Prize in Medicine

Dr. James P. Allison, University of Texas MD Anderson Cancer Center, poses for a photo in NY in 2015.

After Allison himself replicated the experiment, "that's when I said, OK, we've got something here". "I didn't set out to study cancer, but to understand the biology of T cells, these incredible cells that travel our bodies and work to protect us", he added.

The American and Japanese researchers worked out what was stopping immune cells from attacking tumors. "The discovery made by the two Medicine Laureates takes advantage of the immune system's ability to attack cancer cells by releasing the brakes on immune cells", the Nobel committee said on Twitter.

Trying everything they could in mice to tweak the immune system, Krummel and Allison soon found that a protein receptor called CTLA-4 seemed to be holding T cells back, like a brake in a auto.

Professor Allison works at the MD Anderson Cancer Center, Houston.

Writing on his cancer centre's website, Allison said he was "honoured and humbled to receive this prestigious recognition".

'Therapies based on his discovery proved to be strikingly effective in the fight against cancer, ' the assembly said in a statement.

The discovery led to a concept called "checkpoint blockade".

More news: #BelieveSurvivors protests erupt in Washington against Brett Kavanaugh; dozens arrested

By the 1970s Allison had developed a strong fascination for T-cells, soldiers of the immune system that help defend the body against foreign invaders. As a result, while attempts to rev up the immune system are like stepping on the gas, they won't be effective unless you also release the brakes.

"Cancer kills millions of people every year and is one of humanity's greatest health challenges".

Despite little initial interest from the pharmaceutical industry, that antibody became ipilimumab, which in 2011 was approved by the Food and Drug Administration to treat metastatic melanoma.

At news conference later Monday in Kyoto, Honjo said what makes him most delighted is when he hears from patients who have recovered from serious illnesses because of his research. Allison then spent more than 15 years convincing other scientists and drug companies that his approach could work.

Their parallel work concerned proteins that act as brakes on the body's immune system. Lower right: Antibodies against PD-1 inhibit the function of the brake leading to activation of T cells and highly efficient attack on cancer cells.

Science magazine named cancer immunotherapy its breakthrough of 2013 because that year, "clinical trials ... cemented its potential in patients and swayed even the skeptics".

Among those to have received such treatment is former USA president Jimmy Carter, who was diagnosed in 2015 with the skin cancer melanoma, which had spread to his brain.

Born on August 7, 1948, Allison's early interest was medicine and was inspired by his father, who was an ENT specialist.