Award-winning cancer treatment at Nobel Prize

While chemotherapy destroys cancer cells with normal cells – often with toxic and debilitating effects on a patient – immunotherapy releases the body's immune system to target tumor cells.

James Allison of the United States and Tasuku Honjo of Japan won the Nobel Prize on Monday 1 October for identifying two different immune system brakes that, when disabled, allow the body's defense system to attack. cancer cells faster and more efficiently.

Allison was one of two scientists to have discovered the blocking effect of a brake molecule – or checkpoint inhibitor – called CTLA-4 in 1995. Honjo discovered another PD- 1 at about the same time.

Once these brakes were identified, the researchers were able to determine how to disable them and get T cells, the white blood cells, to start attacking.

"The goal is to neutralize these molecules, which include CTLA-4 and PD-1, and what the Nobel laureates are working on," said Pierre Golstein, professor emeritus at the Marseilles Immunology Center. Luminy. "We neutralize them and the white blood cells can work on the cancer cells."

Sheena Cruickshank, a lecturer in immunology at the University of Manchester in Britain, said the therapy had "allowed the body's power to help heal itself."

"A lot of conventional cancer treatments involve destroying cells and can be very damaging, but they're much more targeted and more specific because they allow our immune cells to enter and kill the tumor cells directly," he said. she said.

Field in full swing
The therapy has only been used on patients for a few years and is less effective for certain cancers such as pancreatic and brain cancers.
According to the American Cancer Society, 800 clinical trials were underway worldwide and more than 30 drugs under development as of June.
And the pharmaceutical industry has heavily invested in field research.
The US Food and Drug Administration has already approved a number of immunotherapy treatments, including some targeting PD-1.

"The burgeoning field of immunotherapy that these discoveries have precipitated is still in its infancy, so it's exciting to see how this research will progress in the future," said Charles Swanton, Clinician-in-Chief. from Cancer Research UK.

Golstein, whose team identified the CTLA-4 molecule in 1987, said the results were very promising. "Immunotherapy is now probably the most important recent finding for cancer therapy in general, as an alternative to chemotherapy," he said. "For example, immunotherapy can control between 20% and 50% of some advanced melanomas, which is a consideration that this situation would have been a death sentence not too long ago."

But it's not totally harmless either, he added. "Activated immune cells can cause some autoimmune complications in some organs, but we can control them," he said.

A study published in June tested a form of immunotherapy against chemotherapy for non-small cell lung cancer, the most prevalent lung cancer in the world. The drug Keytruda (pembrolizumab), which had helped former US President Jimmy Carter fight the advanced melanoma that had spread to the brain, had allowed lung cancer patients to live four to eight months longer than chemo.

Not for all cancers
However, Karl Peggs of the University College of London said the therapy was not for everyone.

"We know that some patients are very unlikely to respond … those who have little evidence that these pathways are actively limiting the immune system, or those with less mutated cancer," he said.

In theory, it should work for most forms of cancer, but it is particularly effective against the most numerous mutations such as melanoma, lung cancer and smoking, he added.

And the patients sometimes aroused too much enthusiasm. In the United States, some would have asked their doctors to immediately use immunotherapy instead of traditional treatments like chemotherapy, even when they are more effective.

After her big victory Monday, Allison warned that immunotherapy would not replace all other cancer treatments. Instead, this "will be part of the therapy that potentially all cancer patients will receive in five years," he said at a press conference in New York.

Honjo, meanwhile, said he wanted to continue his research "so that this immune treatment saves more cancer patients than ever before."