Two researchers from the USA and Japan have won the Nobel Prize in medicine for discoveries that have revolutionised cancer care, turning the body's immune system loose to fight tumours in an approach credited with saving an untold number of lives.
The pioneering work of Allison and Honjo led to the development of several drugs, including ipilimumab (Yervoy), the first immunotherapy drug, and the PD-1 inhibitors nivolumab (Opdivo) and pembrolizumab (Keytruda).
Kim Hyo-sun tells us more. The inhibitors act as a brake on the immune system, and by blocking them it is possible to accelerate the body's ability to kill cancer cells. The resulting treatments, known as immune checkpoint blockade, have "fundamentally changed the outcome" for some advanced cancer patients, the Nobel institute said. "The immune system was neglected because there was no strong evidence it could be effective", said Nadia Guerra, head of a cancer laboratory at Imperial College London.
The pair were honoured "for their discovery of cancer therapy by inhibition of negative immune regulation", the Nobel Assembly said.
T-cells are a type of white blood cell that play a central role in the body's natural immunity to disease. Cancer cells can latch onto these checkpoints, allowing the malignant cells to go unnoticed. It permits them to recognize the cancer cells as foreign and attack them.
Alison discovered another protein that acts as a "checkpoint" against the body's immune system called CTLA-4. "For some patients, we see their tumours shrink or completely disappear and are effectively cured".
Tasuku Honjo discovered PD-1, a protein expressed on the surface of certain immune cells.
"We know that some patients have a very low chance of responding. those with little evidence that these pathways are actively restricting the immune system, or those with cancers that are less heavily mutated", he said.
Allison and Honjo "established an entirely new principle for cancer therapy", according to a press release from the Nobel Assembly. Honjo assembled his team in the lab to enjoy the recognition.
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. "I'd like to continue researching cancer for a while so that this immunotherapy will help save more cancer patients than ever before".
But this platform of studies and drugs will provide us with the foundation to understand how the immune system is structured and could be reactivated in every person with cancer, to try to solve this puzzle in real-time for each individual.
Currently, numerous drugs on the market are expensive and have side effects, reports Karen Weintraub for Scientific American.